- Email: [email protected]
Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer
G Model LUNG-4173; No. of Pages 6
ARTICLE IN PRESS Lung Cancer xxx (2012) xxx–xxx
Contents lists available at SciVerse ScienceDirect
Lung Cancer journal homepage: www.elsevier.com/locate/lungcan
Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer Ha Yeon Lee a,b,1 , Hee Kyung Ahn a,1 , Ji Yun Jeong c , Mi Jung Kwon d , Jung-Ho Han c , Jong-Mu Sun a , Jin Seok Ahn a , Keunchil Park a , Yoon-La Choi c,∗∗ , Myung-Ju Ahn a,∗ a
Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea Division of Hematology-Oncology, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea c Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea d Department of Pathology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Republic of Korea b
a r t i c l e
i n f o
Article history: Received 21 May 2012 Received in revised form 11 September 2012 Accepted 4 October 2012 Keywords: Non-small cell lung cancer Pemetrexed Anaplastic lymphoma kinase Adenocarcinoma
a b s t r a c t Introduction: The development of anaplastic lymphoma kinase (ALK) inhibitor has just followed the recent discovery of ALK rearrangement in lung cancer, therefore not much is yet known about the clinical course and treatment outcomes to chemotherapy in ALK-positive patients. The purpose of this study was to investigate the clinical characteristics and treatment outcomes in patients with ALK-positive NSCLC treated with conventional chemotherapy during pre-ALK inhibitor period. Patients and Methods: We retrospectively screened 381 consecutive NSCLC patients without known epidermal growth factor receptor (EGFR) or KRAS mutation who were diagnosed between 2007 and 2008 at a single center, and identified ALK rearrangements by fluorescence in situ hybridization. Additional 44 ALK-positive patients who were identified since 2009 by central lab for participation on clinical trial were included for the analysis of clinical outcomes. Results: Of the 381 tumors screened, 21 (5.6%) showed ALK rearrangements, with twenty adenocarcinomas and one pleomorphic carcinoma. Of 65 ALK-positive patients including additional 44 ALK-positive patients, 32 patients received pemetrexed as a second- or further-line therapy, in whom the response rate was 34.4% (11/32), median progression-free survival (PFS) was 4.0 months (range: 0–22.0 months) and median overall survival (OS) was 50.8 months (95% confidence interval [CI]: 38.7–62.8). Conclusions: The prevalence of ALK rearrangement was 5.6% among EGFR and/or KRAS wildtype/unknown NSCLC population. Pemetrexed, given as a second- or further-line therapy, showed favorable clinical outcomes in ALK-positive NSCLC patients. © 2012 Elsevier Ireland Ltd. All rights reserved.
1. Introduction The treatment for non-small-cell lung cancer (NSCLC) has changed dramatically over the last 8 years. In 2004, erlotinib was approved as a second- and third-line therapy. Subsequently, gefitinib has recently shown superior efficacy compared to cytotoxic chemotherapy in epidermal growth factor receptor (EGFR)-mutation-positive patients with previously untreated,
∗ Corresponding author at: Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, Republic of Korea. Tel.: +82 2 3410 3438; fax: +82 2 3410 1754. ∗∗ Corresponding author at: Department of Pathology, Samsung Medical Center Sungkyunkwan University School of Medicine, Seoul 135-710, Republic of Korea. Tel.: +82 2 3410 2797. E-mail addresses: [email protected] (Y.-L. Choi), [email protected] (M.-J. Ahn). 1 These first two authors contributed to this work equally.
advanced NSCLC [1–3]. The remarkable success of EGFR tyrosine kinase inhibitors (TKIs) signifies the importance of identifying specific genetic lesions to appropriately select targeted therapies. The EML4–ALK fusion oncogene is a recently identified molecular target in the treatment of NSCLC. First described in 2007, the fusion results from a small inversion within chromosome 2p, in which the sequence encoding the N-terminal half of echinoderm microtubule associated protein like 4 (EML4) is fused to the encoding of the intracellular kinase domain of anaplastic lymphoma kinase (ALK) [4–6]. EML4–ALK has shown potent oncogenic drive in cell lines and animal models [4,7], and several studies have reported patients with ALK-positive NSCLC. EML4–ALK is uncommon, occurring in ∼5% of NSCLC patients, and is associated with younger age, never or light smoking and adenocarcinoma histology [8–12]. This fusion gene rarely overlaps with EGFR or KRAS mutations [12]. Although patients with ALK-positive tumors have shown a dramatic clinical response to crizotinib, even in a phase I study of previously heavily treated patients [13], leading
0169-5002/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.lungcan.2012.10.002
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002
G Model LUNG-4173; No. of Pages 6
ARTICLE IN PRESS H.Y. Lee et al. / Lung Cancer xxx (2012) xxx–xxx
2
to accelerated FDA approval, information on the clinical course and treatment outcomes to chemotherapy in ALK-positive NSCLC patients is still limited. Therefore, we investigated the clinical characteristics and treatment outcomes in ALK-positive NSCLC patients who were treated with conventional chemotherapy during pre-ALK inhibitor period. 2. Patients and methods 2.1. Patients We evaluated the prevalence of ALK-positive tumors by retrospectively screening consecutive patients who had been diagnosed with NSCLC between January 2007 and December 2008, at Samsung Medical Center, Seoul, Korea. Patients with known EGFR and/or KRAS mutations were excluded. Because the frequency of ALK positive is just 1.0–5.0% in nonselected NSCLC patient, another cohort of 44 ALK-positive patients who were previously enrolled in a study involving crizotinib, identified at Samsung Medical Center since 2009, was included in the analysis of treatment outcome. The patient demographics and clinical characteristics, including smoking history, histological type, response rate (RR), progressionfree survival (PFS) and overall survival (OS) after previous chemotherapy were obtained from the patients’ medical records. Patients who had smoked <100 cigarettes in their lifetimes were defined as “never smokers”. Smokers were classified either as “light smokers” if they had smoked fewer than 10 pack-years or as “smokers” if they had smoked ≥10 pack-years in their lifetimes. Tumor histology and subtype were classified according to the World Health Organization criteria [14]. Responses were classified as complete response, partial response, stable disease, or progressive disease, according to RECIST version 1.0. The study protocol was reviewed and approved by the institutional review board of Samsung Medical Center (SMC 2011-01-079-001) and adhered to the recommendations for biomedical research involving human subjects of the Declaration of Helsinki (1975). 2.2. ALK test All 381 NSCLC patients with wild-type or unknown EGFR/KRAS were initially screened with immunohistochemistry (IHC) to determine their ALK status. EGFR/KRAS mutational status had been determined by DNA directed sequencing test at the time of diagnosis. IHC for ALK (NCL-ALK [clone 5A4], 1:40, Novocastra, UK) was performed using a biotin–avidin peroxidase complex method on a BOND-MAX autostainer (Leica, Wetzlar, Germany) after retrieval with ER2 solution. Samples showing strong diffuse ALK positivity in the cytoplasm were regarded as positive. An IHC score was assigned to each case according to the following criteria: 3+, intense, granular cytoplasmic staining; 2+, moderate, smooth cytoplasmic staining; 1+, faint cytoplasmic staining in >10% of tumor cells; and 0, no staining. The IHC score was estimated independently by two pathologists (J.Y.J. and Y.L.C.) before fluorescent in situ hybridization (FISH) testing and were in agreement for the interpretation. Although FISH with dual-color break-apart probes has been considered the gold standard method to detect ALK rearrangements, it is not readily available as a routine method in pathology practice [15]. Therefore, based on recently reported studies, FISH was performed on samples with ALK IHC scores of 1, 2, or 3 [15,16]. Interphase molecular cytogenetic studies using a commercially available ALK probe (Vysis LSI ALK Dual Color, Break Apart Rearrangement Probe; Abbott Molecular, Abbott Park, IL) were performed according to the manufacturer’s protocol. One hundred cells were analyzed in each sample. All FISH was interpreted without knowledge of the IHC results for ALK. ALK FISH was considered positive when more than
15% of the tumor cells showed split red and green signals and/or single red (residual 3 ) signals; otherwise the specimen was classified as ALK FISH negative, as described previously [17,18]. A sample was defined as “ALK positive” only when the FISH result was positive. Given the low prevalence of EML4–ALK in NSCLC, additional cohort of patients who were enrolled in global clinical trials of crizotinib was added for clinical outcome analysis. These patients include 44 ALK-positive patients with stage IV NSCLC, in whom ALK rearrangements were confirmed by FISH from central lab. 2.3. Statistical analysis PFS was calculated from the date of the first cycle of chemotherapy to the date of disease progression or death from any cause. OS was calculated from the date of diagnosis to the date of death or to the date of the last follow-up. The objective tumor response rates and disease control rates were calculated from each patient’s data. Survival curves were generated using the Kaplan–Meier method, and the log-rank test was used to compare survival curves according to ALK status. All statistical tests were two sided, with significance defined as P < 0.05. All analyses were performed with the SPSS statistics version 17.0. 3. Results 3.1. ALK positivity and clinical characteristics Of the 381 NSCLC tissue samples screened, 39 (10.2%) demonstrated ALK IHC scores of 1, 2, or 3 (12, 19, and 8 tumors, respectively) and 342 (89.8%) had an ALK IHC score of 0. Ten tumors with an ALK IHC score of 0 were tested with ALK FISH and all were ALK negative. Therefore, based on previous reports, we considered an ALK IHC score of 0 to be ALK negative and 332 tumors were not subjected to FISH analysis. Of the 39 tumors evaluated for ALK rearrangement using FISH, four were excluded because the sample was unevaluable, after which 21 tumors (5.6%, 21/377) showed ALK rearrangements. The four unevaluable samples were all IHC 2+. All eight IHC 3+ tumors were ALK positive on FISH analysis, whereas 12 of 15 (80.0%) IHC 2+ tumors and 1 of 12 (8.3%) IHC 1+ tumors were ALK positive on FISH analysis. Representative data are shown in Fig. 1. We analyzed the baseline clinicopathological characteristics of the two (ALK-positive and ALK-negative) groups. Compared with the 356 ALK-negative patients, 21 ALKpositive patients were significantly younger (median age, 62 vs. 50 years, respectively; P < 0.001), with a higher proportion of never or light smokers (32.9% vs. 71.4%, respectively; P = 0.002). Of the 21 ALK-positive tumors, 20 were adenocarcinomas and one was a pleomorphic carcinoma. Gender difference (P = 0.013) was also observed in our study where male was dominant in ALK-negative patients but not in ALK-positive group. These results are summarized in Table 1. Another cohort of 44 patients with stage IV NSCLC, who were screened for a clinical trial of crizotinib and were ALK positive on FISH, was included for the analysis of clinical outcomes. Therefore, a total of 65 ALK-positive NSCLC patients were analyzed for their RRs and PFS after conventional chemotherapy before administration of ALK inhibitor. The median age was 50 years (range 25–73 years); the proportion of never or light smokers was 73.9% (48/65); 64 tumors (64/65, 98.5%) were adenocarcinomas and one was a pleomorphic carcinoma. These results are summarized in Table 2. 3.2. Response to conventional chemotherapy and PFS in ALK-positive patients Among the 65 ALK-positive patients, 56 had received palliative chemotherapies. Platinum-based (either cisplatin or carboplatin,
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002
G Model LUNG-4173; No. of Pages 6
ARTICLE IN PRESS H.Y. Lee et al. / Lung Cancer xxx (2012) xxx–xxx
3
Fig. 1. Diffuse ALK immunohistochemical staining in lung adenocarcinoma (A). ALK break-apart FISH showing split green 5 and orange 3 signals, indicating an ALK rearrangement (B).
Table 1 Clinical and demographic features of an enriched sample of NSCLC patients who were diagnosed between January 2007 and December 2008. Characteristic Age (year) Sex (n) Smoking history (n) (%)
Histology (n) (%)
Stage at diagnosis (n) (%)
Median Range M/F Never smoker <10 pack-years ≥10 pack-years Adenocarcinoma Squamous cell carcinoma Othersa I II III IV
ALK positive N = 21
ALK negative N = 356
P value
50 35–72 11/10 13 (61.9%) 2 (9.5%) 6 (28.6%) 20 (95.2%) 0 1 (4.8%) 1 (4.8%) 3 (14.3%) 6 (28.6%) 10 (47.6%)
62 35–83 272/84 101 (28.4%) 16 (4.5%) 239 (67.1%) 181 (50.8%) 127 (35.7%) 48 (13.5%) 39 (11.0%) 36 (10.1%) 127 (35.7%) 152 (42.7%)
<0.001 0.013 0.002
0.001
0.639
Othera types of histologies were pleomorphic carcinomas and poorly differentiated non-small-cell carcinomas. Abbreviations: yr = years; n = number; M = male; F = female.
Fig. 2. Waterfall plots of tumor shrinkage after (A) platinum-based chemotherapy (29 patients received platinum-based chemotherapy. Among 28 patients evaluated, 27 patients had measurable lesions) and (B) pemetrexed monotherapy (among 29 patients evaluated, 25 patients had measurable lesions).
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002
ARTICLE IN PRESS
G Model LUNG-4173; No. of Pages 6
H.Y. Lee et al. / Lung Cancer xxx (2012) xxx–xxx
4
Table 2 Clinical and demographic features of 65 ALK-positive NSCLC patients. Characteristic Age (year) Sex (n) Smoking history (n) (%)
Histology (n) (%)
No. of patients (%) N = 65 Median Range M/F Never smoker <10 pack-years ≥10 pack-years Adenocarcinoma Pleomorphic carcinoma
50 25–73 27/38 41 (63.1%) 7 (10.8%) 17 (26.1%) 64 (98.5%) 1 (1.5%)
Abbreviations: n = number; M = male; F = female.
Dose of platinum-based combination chemotherapy was reduced only five patients of them. The pemetrexed monotherapy response evaluation after platinum-based chemotherapy was performed in 26 patients. Eight patients (30.8%) had PD, 8 patients (30.8%) had SD, and the other 10 patients (38.4%) had PR after platinum-based chemotherapy. The waterfall plots of response to platinum-based chemotherapy and pemetrexed monotherapy are displayed in Fig. 2. However, in ALK-positive NSCLC patients, the RR and PFS when EGFR TKIs were given as the second- or further-line therapy were only 3.4% (range, 0–4.3%) and 1.3 months (95% CI, 0.8–1.9), respectively. These results are summarized in Table 3 and Fig. 3. 4. Discussion
not the pemetrexed combination) combination chemotherapy was administered to 69.6% of patients as the first-line therapy. The RR and median PFS were 33.3% and 5.2 months (95% CI, 3.6–6.9), respectively. Thirty-two ALK-positive patients were treated with pemetrexed monotherapy as the second- or further-line therapy. The objective RR and median PFS after pemetrexed monotherapy were 34.4% (11/32) and 4.0 months (95% CI, 2.2–5.8), respectively. The median overall survival (OS) was 50.8 months (95% CI, 38.7–62.8). Among them, 29 patients received platinum-based (not the pemetrexed combination) combination chemotherapy as the first- or second-line therapy. The other three patients were not received front-line platinum-based combination chemotherapy. Platinum-based combination chemotherapies were as followed; gemcitabine-cisplatin (15 patients), gemcitabine-carboplatin (7 patients), paclitaxel-carboplatin (5 patients) and docetaxelcisplatin (2 patients). Of the 29 patients, 25 (86.2%) patients were received 4–6 cycles of platinum-based combination chemotherapy.
In this large cohort study, the proportion of ALK positivity in the NSCLC patients with wild-type or unknown EGFR/KRAS was 5.6%. This prevalence is quite consistent with previous data [13]. We used ALK IHC first to screen the samples and then confirmed these results with ALK FISH. Previous reports have shown that all those patients with ALK IHC scores of 3 were ALK positive on FISH, whereas those with scores of 0 or 1 were ALK negative on FISH [15,16]. These data confirm that ALK IHC scores of 0, 1, 2 or 3 were highly consistent with the FISH results. Our findings also demonstrate that the negative predictive value of ALK IHC is very high, therefore ALK IHC can be considered for screening purpose. We also found that ALKpositive tumors occurred in younger patients and in never or light smokers compared with ALK-negative tumors, which is consistent with previous results [8,9,12]. Considering the high incidence of EGFR gene mutations in patients of Asian ethnicity and never smokers, it is important to identify those patients who can benefit from
Table 3 Best overall responses and progression free survival to previous conventional chemotherapy in crizotinib-naïve ALK-positive NSCLC patients.
No. of patients Partial response Stable disease Progressive disease No response assessed Response rate Progression free survival (95% CI)
1st line platinum-based
2nd or further-line pemetrexed
2nd or further-line EGFR TKIs
39 13 18 2 6 13/39 (33.3%) 5.2 months (3.6–6.9)
32 11 10 8 3 11/32 (34.4%) 4.0 months (2.2–5.8)
29 1 10 18 0 1/29 (3.4%) 1.3 months (0.8–1.9)
Abbreviations: no = number; CI = confidence interval.
Fig. 3. Progression free survival on second- or further-line (A) pemetrexed and (B) EGFR TKIs between ALK-positive and -negative NSCLC patients. Solid line is ALK-positive cases and dashed line is ALK-negative cases. There was a statistically significant difference in median PFS to second- or further-line EGFR TKIs between the two groups. Abbreviations: EGFR TKIs = epidermal growth factor receptor tyrosine kinase inhibitors and PFS = progression free survival.
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002
G Model LUNG-4173; No. of Pages 6
ARTICLE IN PRESS H.Y. Lee et al. / Lung Cancer xxx (2012) xxx–xxx
specific target agents, such as EGFR TKIs or ALK inhibitor, in this era of targeted molecular therapies [2,17]. Furthermore, because it is not always possible to obtain sufficient tissue samples to establish the molecular profiles of many different genes in patients with NSCLC, detailed recommendations for screening guidelines should be established. In this study, the treatment outcomes including RR and PFS after platinum-based combination chemotherapies as a first-line in ALK-positive patients were similar to those of the historical controls [19–21]. However, it is noteworthy that RR of 34.4% and median PFS of 4.0 months after pemetrexed given as a secondor further-line therapy in ALK-positive population in our study seemed to be higher compared with those of the historical controls with RR of 11.5% and median PFS 3.1 months [22]. In contrast, RR and PFS to pemetrexed as a second- or further-line therapy were 9.7% and 1.6 months (95% CI, 1.0–2.2), respectively, in ALKnegative patients. The difference should be interpreted cautiously and should not be compared directly between ALK-positive and -negative groups because the ALK-positive group included two different cohorts. Although the number of ALK-positive patients treated with pemetrexed was quite small in this study, longer PFS and higher RR in this population have also been observed in other studies [23,24]. Recently, Camidge et al. reported that ALKpositive patients had a significantly longer PFS on pemetrexed than triple-negative patients [24]. The median PFS for ALK-positive patients was nine months (95% CI, 3–12), whereas that of triplenegative patients was four months (95% CI, 3–5). In a multivariate analysis that adjusted for line of therapy, mono- vs. platinum and non-platinum combination therapy, age, sex, histology, and smoking status, the only significant predictor for prolonged PFS after pemetrexed treatment was ALK positivity (hazard ratio = 0.36, 95% CI, 0.17–0.73; P = 0.0051) [24]. Although it is unclear why ALK-positive patients demonstrate greater clinical benefit from pemetrexed, potential biological plausibility based on the TS level of ALK-positive NSCLC can be considered [25]. We have previously demonstrated that low TS was significantly associated with better clinical outcomes in nonsquamous NSCLC patients who were treated with pemetrexed-based chemotherapy [26]. Therefore, we speculated that ALK-positive tumor specimens expressed low-level TS than ALK-negative ones and were highly sensitive to pemetrexed. Recent in vitro data demonstrating TS mRNA levels in ALK-positive cells had significantly lower levels compared with control cells [23]. However, the direct association between low TS expression and ALK-positive tumors remains to be explained. A limitation of our study is that we did not perform TS expression analysis in ALK-positive and -negative patients because of unavailable tumor specimens and therefore we cannot assess the prevalence of TS positivity in both groups. Analysis of different cohorts and retrospective study were another limitation of this study. Further research involving a large cohort study is required to investigate the association between TS levels and ALK-positive tumors and its clinical significance. In this study, ALK-positive patients treated with EGFR TKIs achieved very poor objective responses and had shorter median PFS. These results emphasize the importance of identifying ALKpositive patients, especially before treatment with EGFR TKIs is considered for never or light smokers, and for adenocarcinoma patients with an unknown EGFR mutation status. Given the mutual exclusiveness of EGFR mutations and ALK fusion genes, every effort should be made to screen patients with a simple and quick method such as IHC to avoid poor outcomes that arise when ALK-positive patients are treated with EGFR TKIs. In conclusion, we found that 5.6% of EGFR and/or KRAS wild-type/unknown NSCLC patients had ALK-positive tumors. Pemetrexed, given as a second- or further-line therapy, showed high RR and PFS in ALK-positive NSCLC patients. Further research
5
is required to clarify the underlying mechanism associated with favorable clinical outcomes of pemetrexed treatment in ALKpositive NSCLC patients. Conflict of interest statement None declared. References [1] Paez JG, Janne PA, Lee JC, Tracy S, Greulich H, Gabriel S, et al. EGFR mutations in lung cancer: correlation with clinical response to gefitinib therapy. Science 2004;304:1497–500. [2] Mok TS, Wu YL, Thongprasert S, Yang CH, Chu DT, Saijo N, et al. Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma. N Engl J Med 2009;361:947–57. [3] Lynch TJ, Bell DW, Sordella R, Gurubhagavatula S, Okimoto RA, Brannigan BW, et al. Activating mutations in the epidermal growth factor receptor underlying responsiveness of non-small-cell lung cancer to gefitinib. N Engl J Med 2004;350:2129–39. [4] Soda M, Choi YL, Enomoto M, Takada S, Yamashita Y, Ishikawa S, et al. Identification of the transforming EML4–ALK fusion gene in non-small-cell lung cancer. Nature 2007;448:561–6. [5] Rikova K, Guo A, Zeng Q, Possemato A, Yu J, Haack H, et al. Global survey of phosphotyrosine signaling identifies oncogenic kinases in lung cancer. Cell 2007;131:1190–203. [6] Chiarle R, Voena C, Ambrogio C, Piva R, Inghirami G. The anaplastic lymphoma kinase in the pathogenesis of cancer. Nat Rev Cancer 2008;8:11–23. [7] Soda M, Takada S, Takeuchi K, Choi YL, Enomoto M, Ueno T, et al. A mouse model for EML4–ALK-positive lung cancer. Proc Natl Acad Sci USA 2008;105: 19893–7. [8] Takeuchi K, Choi YL, Soda M, Inamura K, Togashi Y, Hatano S, et al. Multiplex reverse transcription-PCR screening for EML4–ALK fusion transcripts. Clin Cancer Res 2008;14:6618–24. [9] Koivunen JP, Mermel C, Zejnullahu K, Murphy C, Lifshits E, Holmes AJ, et al. EML4–ALK fusion gene and efficacy of an ALK kinase inhibitor in lung cancer. Clin Cancer Res 2008;14:4275–83. [10] Mano H. Non-solid oncogenes in solid tumors: EML4–ALK fusion genes in lung cancer. Cancer Sci 2008;99:2349–55. [11] Perner S, Wagner PL, Demichelis F, Mehra R, Lafargue CJ, Moss BJ, et al. EML4–ALK fusion lung cancer: a rare acquired event. Neoplasia 2008;10:298–302. [12] Wong DW, Leung EL, So KK, Tam IY, Sihoe AD, Cheng LC, et al. The EML4–ALK fusion gene is involved in various histologic types of lung cancers from nonsmokers with wild-type EGFR and KRAS. Cancer 2009;115:1723–33. [13] Kwak EL, Bang YJ, Camidge DR, Shaw AT, Solomon B, Maki RG, et al. Anaplastic lymphoma kinase inhibition in non-small-cell lung cancer. N Engl J Med 2010;363:1693–703. [14] Beasley MB, Brambilla E, Travis WD. The 2004 World Health Organization classification of lung tumors. Semin Roentgenol 2005;40:90–7. [15] Paik JH, Choe G, Kim H, Choe JY, Lee HJ, Lee CT, et al. Screening of anaplastic lymphoma kinase rearrangement by immunohistochemistry in non-small cell lung cancer: correlation with fluorescence in situ hybridization. J Thorac Oncol 2011;6:466–72. [16] Yi ES, Boland JM, Maleszewski JJ, Roden AC, Oliveira AM, Aubry MC, et al. Correlation of IHC and FISH for ALK gene rearrangement in non-small cell lung carcinoma: IHC score algorithm for FISH. J Thorac Oncol 2011;6: 459–65. [17] Shaw AT, Yeap BY, Mino-Kenudson M, Digumarthy SR, Costa DB, Heist RS, et al. Clinical features and outcome of patients with non-small-cell lung cancer who harbor EML4–ALK. J Clin Oncol 2009;27:4247–53. [18] Martelli MP, Sozzi G, Hernandez L, Pettirossi V, Navarro A, Conte D, et al. EML4–ALK rearrangement in non-small cell lung cancer and non-tumor lung tissues. Am J Pathol 2009;174:661–70. [19] Schiller JH, Harrington D, Belani CP, Langer C, Sandler A, Krook J, et al. Comparison of four chemotherapy regimens for advanced non-small-cell lung cancer. N Engl J Med 2002;346:92–8. [20] Ardizzoni A, Boni L, Tiseo M, Fossella FV, Schiller JH, Paesmans M, et al. Cisplatinversus carboplatin-based chemotherapy in first-line treatment of advanced non-small-cell lung cancer: an individual patient data meta-analysis. J Natl Cancer Inst 2007;99:847–57. [21] Koh Y, Kim DW, Kim TM, Lee SH, Jeon YK, Chung DH, et al. Clinicopathologic characteristics and outcomes of patients with anaplastic lymphoma kinase-positive advanced pulmonary adenocarcinoma: suggestion for an effective screening strategy for these tumors. J Thorac Oncol 2011;6: 905–12. [22] Scagliotti G, Hanna N, Fossella F, Sugarman K, Blatter J, Peterson P, et al. The differential efficacy of pemetrexed according to NSCLC histology: a review of two Phase III studies. Oncologist 2009;14:253–63. [23] Lee JO, Kim TM, Lee SH, Kim DW, Kim S, Jeon YK, et al. Anaplastic lymphoma kinase translocation: a predictive biomarker of pemetrexed in patients with non-small cell lung cancer. J Thorac Oncol 2011;6:1474–80.
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002
G Model LUNG-4173; No. of Pages 6 6
ARTICLE IN PRESS H.Y. Lee et al. / Lung Cancer xxx (2012) xxx–xxx
[24] Camidge DR, Kono SA, Lu X, Okuyama S, Baron AE, Oton AB, et al. Anaplastic lymphoma kinase gene rearrangements in non-small cell lung cancer are associated with prolonged progression-free survival on pemetrexed. J Thorac Oncol 2011;6:774–80. [25] Assaraf YG. Molecular basis of antifolate resistance. Cancer Metastasis Rev 2007;26:153–81.
[26] Sun JM, Han J, Ahn JS, Park K, Ahn MJ. Significance of thymidylate synthase and thyroid transcription factor 1 expression in patients with nonsquamous nonsmall cell lung cancer treated with pemetrexed-based chemotherapy. J Thorac Oncol 2011;6:1392–9.
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002
ARTICLE IN PRESS Lung Cancer xxx (2012) xxx–xxx
Contents lists available at SciVerse ScienceDirect
Lung Cancer journal homepage: www.elsevier.com/locate/lungcan
Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer Ha Yeon Lee a,b,1 , Hee Kyung Ahn a,1 , Ji Yun Jeong c , Mi Jung Kwon d , Jung-Ho Han c , Jong-Mu Sun a , Jin Seok Ahn a , Keunchil Park a , Yoon-La Choi c,∗∗ , Myung-Ju Ahn a,∗ a
Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea Division of Hematology-Oncology, Kyung Hee University Hospital at Gangdong, Seoul, Republic of Korea c Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea d Department of Pathology, Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang, Republic of Korea b
a r t i c l e
i n f o
Article history: Received 21 May 2012 Received in revised form 11 September 2012 Accepted 4 October 2012 Keywords: Non-small cell lung cancer Pemetrexed Anaplastic lymphoma kinase Adenocarcinoma
a b s t r a c t Introduction: The development of anaplastic lymphoma kinase (ALK) inhibitor has just followed the recent discovery of ALK rearrangement in lung cancer, therefore not much is yet known about the clinical course and treatment outcomes to chemotherapy in ALK-positive patients. The purpose of this study was to investigate the clinical characteristics and treatment outcomes in patients with ALK-positive NSCLC treated with conventional chemotherapy during pre-ALK inhibitor period. Patients and Methods: We retrospectively screened 381 consecutive NSCLC patients without known epidermal growth factor receptor (EGFR) or KRAS mutation who were diagnosed between 2007 and 2008 at a single center, and identified ALK rearrangements by fluorescence in situ hybridization. Additional 44 ALK-positive patients who were identified since 2009 by central lab for participation on clinical trial were included for the analysis of clinical outcomes. Results: Of the 381 tumors screened, 21 (5.6%) showed ALK rearrangements, with twenty adenocarcinomas and one pleomorphic carcinoma. Of 65 ALK-positive patients including additional 44 ALK-positive patients, 32 patients received pemetrexed as a second- or further-line therapy, in whom the response rate was 34.4% (11/32), median progression-free survival (PFS) was 4.0 months (range: 0–22.0 months) and median overall survival (OS) was 50.8 months (95% confidence interval [CI]: 38.7–62.8). Conclusions: The prevalence of ALK rearrangement was 5.6% among EGFR and/or KRAS wildtype/unknown NSCLC population. Pemetrexed, given as a second- or further-line therapy, showed favorable clinical outcomes in ALK-positive NSCLC patients. © 2012 Elsevier Ireland Ltd. All rights reserved.
1. Introduction The treatment for non-small-cell lung cancer (NSCLC) has changed dramatically over the last 8 years. In 2004, erlotinib was approved as a second- and third-line therapy. Subsequently, gefitinib has recently shown superior efficacy compared to cytotoxic chemotherapy in epidermal growth factor receptor (EGFR)-mutation-positive patients with previously untreated,
∗ Corresponding author at: Division of Hematology-Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, Republic of Korea. Tel.: +82 2 3410 3438; fax: +82 2 3410 1754. ∗∗ Corresponding author at: Department of Pathology, Samsung Medical Center Sungkyunkwan University School of Medicine, Seoul 135-710, Republic of Korea. Tel.: +82 2 3410 2797. E-mail addresses: [email protected] (Y.-L. Choi), [email protected] (M.-J. Ahn). 1 These first two authors contributed to this work equally.
advanced NSCLC [1–3]. The remarkable success of EGFR tyrosine kinase inhibitors (TKIs) signifies the importance of identifying specific genetic lesions to appropriately select targeted therapies. The EML4–ALK fusion oncogene is a recently identified molecular target in the treatment of NSCLC. First described in 2007, the fusion results from a small inversion within chromosome 2p, in which the sequence encoding the N-terminal half of echinoderm microtubule associated protein like 4 (EML4) is fused to the encoding of the intracellular kinase domain of anaplastic lymphoma kinase (ALK) [4–6]. EML4–ALK has shown potent oncogenic drive in cell lines and animal models [4,7], and several studies have reported patients with ALK-positive NSCLC. EML4–ALK is uncommon, occurring in ∼5% of NSCLC patients, and is associated with younger age, never or light smoking and adenocarcinoma histology [8–12]. This fusion gene rarely overlaps with EGFR or KRAS mutations [12]. Although patients with ALK-positive tumors have shown a dramatic clinical response to crizotinib, even in a phase I study of previously heavily treated patients [13], leading
0169-5002/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.lungcan.2012.10.002
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002
G Model LUNG-4173; No. of Pages 6
ARTICLE IN PRESS H.Y. Lee et al. / Lung Cancer xxx (2012) xxx–xxx
2
to accelerated FDA approval, information on the clinical course and treatment outcomes to chemotherapy in ALK-positive NSCLC patients is still limited. Therefore, we investigated the clinical characteristics and treatment outcomes in ALK-positive NSCLC patients who were treated with conventional chemotherapy during pre-ALK inhibitor period. 2. Patients and methods 2.1. Patients We evaluated the prevalence of ALK-positive tumors by retrospectively screening consecutive patients who had been diagnosed with NSCLC between January 2007 and December 2008, at Samsung Medical Center, Seoul, Korea. Patients with known EGFR and/or KRAS mutations were excluded. Because the frequency of ALK positive is just 1.0–5.0% in nonselected NSCLC patient, another cohort of 44 ALK-positive patients who were previously enrolled in a study involving crizotinib, identified at Samsung Medical Center since 2009, was included in the analysis of treatment outcome. The patient demographics and clinical characteristics, including smoking history, histological type, response rate (RR), progressionfree survival (PFS) and overall survival (OS) after previous chemotherapy were obtained from the patients’ medical records. Patients who had smoked <100 cigarettes in their lifetimes were defined as “never smokers”. Smokers were classified either as “light smokers” if they had smoked fewer than 10 pack-years or as “smokers” if they had smoked ≥10 pack-years in their lifetimes. Tumor histology and subtype were classified according to the World Health Organization criteria [14]. Responses were classified as complete response, partial response, stable disease, or progressive disease, according to RECIST version 1.0. The study protocol was reviewed and approved by the institutional review board of Samsung Medical Center (SMC 2011-01-079-001) and adhered to the recommendations for biomedical research involving human subjects of the Declaration of Helsinki (1975). 2.2. ALK test All 381 NSCLC patients with wild-type or unknown EGFR/KRAS were initially screened with immunohistochemistry (IHC) to determine their ALK status. EGFR/KRAS mutational status had been determined by DNA directed sequencing test at the time of diagnosis. IHC for ALK (NCL-ALK [clone 5A4], 1:40, Novocastra, UK) was performed using a biotin–avidin peroxidase complex method on a BOND-MAX autostainer (Leica, Wetzlar, Germany) after retrieval with ER2 solution. Samples showing strong diffuse ALK positivity in the cytoplasm were regarded as positive. An IHC score was assigned to each case according to the following criteria: 3+, intense, granular cytoplasmic staining; 2+, moderate, smooth cytoplasmic staining; 1+, faint cytoplasmic staining in >10% of tumor cells; and 0, no staining. The IHC score was estimated independently by two pathologists (J.Y.J. and Y.L.C.) before fluorescent in situ hybridization (FISH) testing and were in agreement for the interpretation. Although FISH with dual-color break-apart probes has been considered the gold standard method to detect ALK rearrangements, it is not readily available as a routine method in pathology practice [15]. Therefore, based on recently reported studies, FISH was performed on samples with ALK IHC scores of 1, 2, or 3 [15,16]. Interphase molecular cytogenetic studies using a commercially available ALK probe (Vysis LSI ALK Dual Color, Break Apart Rearrangement Probe; Abbott Molecular, Abbott Park, IL) were performed according to the manufacturer’s protocol. One hundred cells were analyzed in each sample. All FISH was interpreted without knowledge of the IHC results for ALK. ALK FISH was considered positive when more than
15% of the tumor cells showed split red and green signals and/or single red (residual 3 ) signals; otherwise the specimen was classified as ALK FISH negative, as described previously [17,18]. A sample was defined as “ALK positive” only when the FISH result was positive. Given the low prevalence of EML4–ALK in NSCLC, additional cohort of patients who were enrolled in global clinical trials of crizotinib was added for clinical outcome analysis. These patients include 44 ALK-positive patients with stage IV NSCLC, in whom ALK rearrangements were confirmed by FISH from central lab. 2.3. Statistical analysis PFS was calculated from the date of the first cycle of chemotherapy to the date of disease progression or death from any cause. OS was calculated from the date of diagnosis to the date of death or to the date of the last follow-up. The objective tumor response rates and disease control rates were calculated from each patient’s data. Survival curves were generated using the Kaplan–Meier method, and the log-rank test was used to compare survival curves according to ALK status. All statistical tests were two sided, with significance defined as P < 0.05. All analyses were performed with the SPSS statistics version 17.0. 3. Results 3.1. ALK positivity and clinical characteristics Of the 381 NSCLC tissue samples screened, 39 (10.2%) demonstrated ALK IHC scores of 1, 2, or 3 (12, 19, and 8 tumors, respectively) and 342 (89.8%) had an ALK IHC score of 0. Ten tumors with an ALK IHC score of 0 were tested with ALK FISH and all were ALK negative. Therefore, based on previous reports, we considered an ALK IHC score of 0 to be ALK negative and 332 tumors were not subjected to FISH analysis. Of the 39 tumors evaluated for ALK rearrangement using FISH, four were excluded because the sample was unevaluable, after which 21 tumors (5.6%, 21/377) showed ALK rearrangements. The four unevaluable samples were all IHC 2+. All eight IHC 3+ tumors were ALK positive on FISH analysis, whereas 12 of 15 (80.0%) IHC 2+ tumors and 1 of 12 (8.3%) IHC 1+ tumors were ALK positive on FISH analysis. Representative data are shown in Fig. 1. We analyzed the baseline clinicopathological characteristics of the two (ALK-positive and ALK-negative) groups. Compared with the 356 ALK-negative patients, 21 ALKpositive patients were significantly younger (median age, 62 vs. 50 years, respectively; P < 0.001), with a higher proportion of never or light smokers (32.9% vs. 71.4%, respectively; P = 0.002). Of the 21 ALK-positive tumors, 20 were adenocarcinomas and one was a pleomorphic carcinoma. Gender difference (P = 0.013) was also observed in our study where male was dominant in ALK-negative patients but not in ALK-positive group. These results are summarized in Table 1. Another cohort of 44 patients with stage IV NSCLC, who were screened for a clinical trial of crizotinib and were ALK positive on FISH, was included for the analysis of clinical outcomes. Therefore, a total of 65 ALK-positive NSCLC patients were analyzed for their RRs and PFS after conventional chemotherapy before administration of ALK inhibitor. The median age was 50 years (range 25–73 years); the proportion of never or light smokers was 73.9% (48/65); 64 tumors (64/65, 98.5%) were adenocarcinomas and one was a pleomorphic carcinoma. These results are summarized in Table 2. 3.2. Response to conventional chemotherapy and PFS in ALK-positive patients Among the 65 ALK-positive patients, 56 had received palliative chemotherapies. Platinum-based (either cisplatin or carboplatin,
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002
G Model LUNG-4173; No. of Pages 6
ARTICLE IN PRESS H.Y. Lee et al. / Lung Cancer xxx (2012) xxx–xxx
3
Fig. 1. Diffuse ALK immunohistochemical staining in lung adenocarcinoma (A). ALK break-apart FISH showing split green 5 and orange 3 signals, indicating an ALK rearrangement (B).
Table 1 Clinical and demographic features of an enriched sample of NSCLC patients who were diagnosed between January 2007 and December 2008. Characteristic Age (year) Sex (n) Smoking history (n) (%)
Histology (n) (%)
Stage at diagnosis (n) (%)
Median Range M/F Never smoker <10 pack-years ≥10 pack-years Adenocarcinoma Squamous cell carcinoma Othersa I II III IV
ALK positive N = 21
ALK negative N = 356
P value
50 35–72 11/10 13 (61.9%) 2 (9.5%) 6 (28.6%) 20 (95.2%) 0 1 (4.8%) 1 (4.8%) 3 (14.3%) 6 (28.6%) 10 (47.6%)
62 35–83 272/84 101 (28.4%) 16 (4.5%) 239 (67.1%) 181 (50.8%) 127 (35.7%) 48 (13.5%) 39 (11.0%) 36 (10.1%) 127 (35.7%) 152 (42.7%)
<0.001 0.013 0.002
0.001
0.639
Othera types of histologies were pleomorphic carcinomas and poorly differentiated non-small-cell carcinomas. Abbreviations: yr = years; n = number; M = male; F = female.
Fig. 2. Waterfall plots of tumor shrinkage after (A) platinum-based chemotherapy (29 patients received platinum-based chemotherapy. Among 28 patients evaluated, 27 patients had measurable lesions) and (B) pemetrexed monotherapy (among 29 patients evaluated, 25 patients had measurable lesions).
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002
ARTICLE IN PRESS
G Model LUNG-4173; No. of Pages 6
H.Y. Lee et al. / Lung Cancer xxx (2012) xxx–xxx
4
Table 2 Clinical and demographic features of 65 ALK-positive NSCLC patients. Characteristic Age (year) Sex (n) Smoking history (n) (%)
Histology (n) (%)
No. of patients (%) N = 65 Median Range M/F Never smoker <10 pack-years ≥10 pack-years Adenocarcinoma Pleomorphic carcinoma
50 25–73 27/38 41 (63.1%) 7 (10.8%) 17 (26.1%) 64 (98.5%) 1 (1.5%)
Abbreviations: n = number; M = male; F = female.
Dose of platinum-based combination chemotherapy was reduced only five patients of them. The pemetrexed monotherapy response evaluation after platinum-based chemotherapy was performed in 26 patients. Eight patients (30.8%) had PD, 8 patients (30.8%) had SD, and the other 10 patients (38.4%) had PR after platinum-based chemotherapy. The waterfall plots of response to platinum-based chemotherapy and pemetrexed monotherapy are displayed in Fig. 2. However, in ALK-positive NSCLC patients, the RR and PFS when EGFR TKIs were given as the second- or further-line therapy were only 3.4% (range, 0–4.3%) and 1.3 months (95% CI, 0.8–1.9), respectively. These results are summarized in Table 3 and Fig. 3. 4. Discussion
not the pemetrexed combination) combination chemotherapy was administered to 69.6% of patients as the first-line therapy. The RR and median PFS were 33.3% and 5.2 months (95% CI, 3.6–6.9), respectively. Thirty-two ALK-positive patients were treated with pemetrexed monotherapy as the second- or further-line therapy. The objective RR and median PFS after pemetrexed monotherapy were 34.4% (11/32) and 4.0 months (95% CI, 2.2–5.8), respectively. The median overall survival (OS) was 50.8 months (95% CI, 38.7–62.8). Among them, 29 patients received platinum-based (not the pemetrexed combination) combination chemotherapy as the first- or second-line therapy. The other three patients were not received front-line platinum-based combination chemotherapy. Platinum-based combination chemotherapies were as followed; gemcitabine-cisplatin (15 patients), gemcitabine-carboplatin (7 patients), paclitaxel-carboplatin (5 patients) and docetaxelcisplatin (2 patients). Of the 29 patients, 25 (86.2%) patients were received 4–6 cycles of platinum-based combination chemotherapy.
In this large cohort study, the proportion of ALK positivity in the NSCLC patients with wild-type or unknown EGFR/KRAS was 5.6%. This prevalence is quite consistent with previous data [13]. We used ALK IHC first to screen the samples and then confirmed these results with ALK FISH. Previous reports have shown that all those patients with ALK IHC scores of 3 were ALK positive on FISH, whereas those with scores of 0 or 1 were ALK negative on FISH [15,16]. These data confirm that ALK IHC scores of 0, 1, 2 or 3 were highly consistent with the FISH results. Our findings also demonstrate that the negative predictive value of ALK IHC is very high, therefore ALK IHC can be considered for screening purpose. We also found that ALKpositive tumors occurred in younger patients and in never or light smokers compared with ALK-negative tumors, which is consistent with previous results [8,9,12]. Considering the high incidence of EGFR gene mutations in patients of Asian ethnicity and never smokers, it is important to identify those patients who can benefit from
Table 3 Best overall responses and progression free survival to previous conventional chemotherapy in crizotinib-naïve ALK-positive NSCLC patients.
No. of patients Partial response Stable disease Progressive disease No response assessed Response rate Progression free survival (95% CI)
1st line platinum-based
2nd or further-line pemetrexed
2nd or further-line EGFR TKIs
39 13 18 2 6 13/39 (33.3%) 5.2 months (3.6–6.9)
32 11 10 8 3 11/32 (34.4%) 4.0 months (2.2–5.8)
29 1 10 18 0 1/29 (3.4%) 1.3 months (0.8–1.9)
Abbreviations: no = number; CI = confidence interval.
Fig. 3. Progression free survival on second- or further-line (A) pemetrexed and (B) EGFR TKIs between ALK-positive and -negative NSCLC patients. Solid line is ALK-positive cases and dashed line is ALK-negative cases. There was a statistically significant difference in median PFS to second- or further-line EGFR TKIs between the two groups. Abbreviations: EGFR TKIs = epidermal growth factor receptor tyrosine kinase inhibitors and PFS = progression free survival.
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002
G Model LUNG-4173; No. of Pages 6
ARTICLE IN PRESS H.Y. Lee et al. / Lung Cancer xxx (2012) xxx–xxx
specific target agents, such as EGFR TKIs or ALK inhibitor, in this era of targeted molecular therapies [2,17]. Furthermore, because it is not always possible to obtain sufficient tissue samples to establish the molecular profiles of many different genes in patients with NSCLC, detailed recommendations for screening guidelines should be established. In this study, the treatment outcomes including RR and PFS after platinum-based combination chemotherapies as a first-line in ALK-positive patients were similar to those of the historical controls [19–21]. However, it is noteworthy that RR of 34.4% and median PFS of 4.0 months after pemetrexed given as a secondor further-line therapy in ALK-positive population in our study seemed to be higher compared with those of the historical controls with RR of 11.5% and median PFS 3.1 months [22]. In contrast, RR and PFS to pemetrexed as a second- or further-line therapy were 9.7% and 1.6 months (95% CI, 1.0–2.2), respectively, in ALKnegative patients. The difference should be interpreted cautiously and should not be compared directly between ALK-positive and -negative groups because the ALK-positive group included two different cohorts. Although the number of ALK-positive patients treated with pemetrexed was quite small in this study, longer PFS and higher RR in this population have also been observed in other studies [23,24]. Recently, Camidge et al. reported that ALKpositive patients had a significantly longer PFS on pemetrexed than triple-negative patients [24]. The median PFS for ALK-positive patients was nine months (95% CI, 3–12), whereas that of triplenegative patients was four months (95% CI, 3–5). In a multivariate analysis that adjusted for line of therapy, mono- vs. platinum and non-platinum combination therapy, age, sex, histology, and smoking status, the only significant predictor for prolonged PFS after pemetrexed treatment was ALK positivity (hazard ratio = 0.36, 95% CI, 0.17–0.73; P = 0.0051) [24]. Although it is unclear why ALK-positive patients demonstrate greater clinical benefit from pemetrexed, potential biological plausibility based on the TS level of ALK-positive NSCLC can be considered [25]. We have previously demonstrated that low TS was significantly associated with better clinical outcomes in nonsquamous NSCLC patients who were treated with pemetrexed-based chemotherapy [26]. Therefore, we speculated that ALK-positive tumor specimens expressed low-level TS than ALK-negative ones and were highly sensitive to pemetrexed. Recent in vitro data demonstrating TS mRNA levels in ALK-positive cells had significantly lower levels compared with control cells [23]. However, the direct association between low TS expression and ALK-positive tumors remains to be explained. A limitation of our study is that we did not perform TS expression analysis in ALK-positive and -negative patients because of unavailable tumor specimens and therefore we cannot assess the prevalence of TS positivity in both groups. Analysis of different cohorts and retrospective study were another limitation of this study. Further research involving a large cohort study is required to investigate the association between TS levels and ALK-positive tumors and its clinical significance. In this study, ALK-positive patients treated with EGFR TKIs achieved very poor objective responses and had shorter median PFS. These results emphasize the importance of identifying ALKpositive patients, especially before treatment with EGFR TKIs is considered for never or light smokers, and for adenocarcinoma patients with an unknown EGFR mutation status. Given the mutual exclusiveness of EGFR mutations and ALK fusion genes, every effort should be made to screen patients with a simple and quick method such as IHC to avoid poor outcomes that arise when ALK-positive patients are treated with EGFR TKIs. In conclusion, we found that 5.6% of EGFR and/or KRAS wild-type/unknown NSCLC patients had ALK-positive tumors. Pemetrexed, given as a second- or further-line therapy, showed high RR and PFS in ALK-positive NSCLC patients. Further research
5
is required to clarify the underlying mechanism associated with favorable clinical outcomes of pemetrexed treatment in ALKpositive NSCLC patients. Conflict of interest statement None declared. References [1] Paez JG, Janne PA, Lee JC, Tracy S, Greulich H, Gabriel S, et al. EGFR mutations in lung cancer: correlation with clinical response to gefitinib therapy. Science 2004;304:1497–500. [2] Mok TS, Wu YL, Thongprasert S, Yang CH, Chu DT, Saijo N, et al. Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma. N Engl J Med 2009;361:947–57. [3] Lynch TJ, Bell DW, Sordella R, Gurubhagavatula S, Okimoto RA, Brannigan BW, et al. Activating mutations in the epidermal growth factor receptor underlying responsiveness of non-small-cell lung cancer to gefitinib. N Engl J Med 2004;350:2129–39. [4] Soda M, Choi YL, Enomoto M, Takada S, Yamashita Y, Ishikawa S, et al. Identification of the transforming EML4–ALK fusion gene in non-small-cell lung cancer. Nature 2007;448:561–6. [5] Rikova K, Guo A, Zeng Q, Possemato A, Yu J, Haack H, et al. Global survey of phosphotyrosine signaling identifies oncogenic kinases in lung cancer. Cell 2007;131:1190–203. [6] Chiarle R, Voena C, Ambrogio C, Piva R, Inghirami G. The anaplastic lymphoma kinase in the pathogenesis of cancer. Nat Rev Cancer 2008;8:11–23. [7] Soda M, Takada S, Takeuchi K, Choi YL, Enomoto M, Ueno T, et al. A mouse model for EML4–ALK-positive lung cancer. Proc Natl Acad Sci USA 2008;105: 19893–7. [8] Takeuchi K, Choi YL, Soda M, Inamura K, Togashi Y, Hatano S, et al. Multiplex reverse transcription-PCR screening for EML4–ALK fusion transcripts. Clin Cancer Res 2008;14:6618–24. [9] Koivunen JP, Mermel C, Zejnullahu K, Murphy C, Lifshits E, Holmes AJ, et al. EML4–ALK fusion gene and efficacy of an ALK kinase inhibitor in lung cancer. Clin Cancer Res 2008;14:4275–83. [10] Mano H. Non-solid oncogenes in solid tumors: EML4–ALK fusion genes in lung cancer. Cancer Sci 2008;99:2349–55. [11] Perner S, Wagner PL, Demichelis F, Mehra R, Lafargue CJ, Moss BJ, et al. EML4–ALK fusion lung cancer: a rare acquired event. Neoplasia 2008;10:298–302. [12] Wong DW, Leung EL, So KK, Tam IY, Sihoe AD, Cheng LC, et al. The EML4–ALK fusion gene is involved in various histologic types of lung cancers from nonsmokers with wild-type EGFR and KRAS. Cancer 2009;115:1723–33. [13] Kwak EL, Bang YJ, Camidge DR, Shaw AT, Solomon B, Maki RG, et al. Anaplastic lymphoma kinase inhibition in non-small-cell lung cancer. N Engl J Med 2010;363:1693–703. [14] Beasley MB, Brambilla E, Travis WD. The 2004 World Health Organization classification of lung tumors. Semin Roentgenol 2005;40:90–7. [15] Paik JH, Choe G, Kim H, Choe JY, Lee HJ, Lee CT, et al. Screening of anaplastic lymphoma kinase rearrangement by immunohistochemistry in non-small cell lung cancer: correlation with fluorescence in situ hybridization. J Thorac Oncol 2011;6:466–72. [16] Yi ES, Boland JM, Maleszewski JJ, Roden AC, Oliveira AM, Aubry MC, et al. Correlation of IHC and FISH for ALK gene rearrangement in non-small cell lung carcinoma: IHC score algorithm for FISH. J Thorac Oncol 2011;6: 459–65. [17] Shaw AT, Yeap BY, Mino-Kenudson M, Digumarthy SR, Costa DB, Heist RS, et al. Clinical features and outcome of patients with non-small-cell lung cancer who harbor EML4–ALK. J Clin Oncol 2009;27:4247–53. [18] Martelli MP, Sozzi G, Hernandez L, Pettirossi V, Navarro A, Conte D, et al. EML4–ALK rearrangement in non-small cell lung cancer and non-tumor lung tissues. Am J Pathol 2009;174:661–70. [19] Schiller JH, Harrington D, Belani CP, Langer C, Sandler A, Krook J, et al. Comparison of four chemotherapy regimens for advanced non-small-cell lung cancer. N Engl J Med 2002;346:92–8. [20] Ardizzoni A, Boni L, Tiseo M, Fossella FV, Schiller JH, Paesmans M, et al. Cisplatinversus carboplatin-based chemotherapy in first-line treatment of advanced non-small-cell lung cancer: an individual patient data meta-analysis. J Natl Cancer Inst 2007;99:847–57. [21] Koh Y, Kim DW, Kim TM, Lee SH, Jeon YK, Chung DH, et al. Clinicopathologic characteristics and outcomes of patients with anaplastic lymphoma kinase-positive advanced pulmonary adenocarcinoma: suggestion for an effective screening strategy for these tumors. J Thorac Oncol 2011;6: 905–12. [22] Scagliotti G, Hanna N, Fossella F, Sugarman K, Blatter J, Peterson P, et al. The differential efficacy of pemetrexed according to NSCLC histology: a review of two Phase III studies. Oncologist 2009;14:253–63. [23] Lee JO, Kim TM, Lee SH, Kim DW, Kim S, Jeon YK, et al. Anaplastic lymphoma kinase translocation: a predictive biomarker of pemetrexed in patients with non-small cell lung cancer. J Thorac Oncol 2011;6:1474–80.
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002
G Model LUNG-4173; No. of Pages 6 6
ARTICLE IN PRESS H.Y. Lee et al. / Lung Cancer xxx (2012) xxx–xxx
[24] Camidge DR, Kono SA, Lu X, Okuyama S, Baron AE, Oton AB, et al. Anaplastic lymphoma kinase gene rearrangements in non-small cell lung cancer are associated with prolonged progression-free survival on pemetrexed. J Thorac Oncol 2011;6:774–80. [25] Assaraf YG. Molecular basis of antifolate resistance. Cancer Metastasis Rev 2007;26:153–81.
[26] Sun JM, Han J, Ahn JS, Park K, Ahn MJ. Significance of thymidylate synthase and thyroid transcription factor 1 expression in patients with nonsquamous nonsmall cell lung cancer treated with pemetrexed-based chemotherapy. J Thorac Oncol 2011;6:1392–9.
Please cite this article in press as: Lee HY, et al. Favorable clinical outcomes of pemetrexed treatment in anaplastic lymphoma kinase positive non-small-cell lung cancer. Lung Cancer (2012), http://dx.doi.org/10.1016/j.lungcan.2012.10.002