- Email: [email protected]
Novel EGFR Exon 18 (G721R) Mutation in a Patient with Non–Small Cell Lung Carcinoma with Lack of Response to Afatinib
e16 Letters to the Editor
of known fusion patterns for RET rearrangements in lung adenocarcinoma, and it emphasizes the role of comprehensive genomic profiling in identifying clinically actionable genomic alterations in lung cancer and rare and novel fusion variants of potential clinical significance. Vamsidhar Velcheti, MD Department of Hematology and Oncology Cleveland Clinic Cleveland, Ohio Rajat Thawani, MD Department of Oncology Case Western Reserve University Cleveland, Ohio Monica Khunger, MD Department of Internal Medicine Cleveland Clinic Cleveland, Ohio Sanjay Mukhopadhyay, MD, Deborah J. Chute, MD Department of Pathology Cleveland Clinic Cleveland, Ohio
Novel EGFR Exon 18 (G721R) Mutation in a Patient with Non–Small Cell Lung Carcinoma with Lack of Response to Afatinib To the Editor: EGFR alterations are the most frequent clinically actionable genetic events in NSCLC.1–2 Several small molecule EGFR inhibitors such as gefitinib, erlotinib, afatinib, and osimertinib have demonstrated clinical efficacy in patients with EGFR alterations and are now standard treatment options for patients with such alterations.2 The common gain-of-function EGFR alterations are in exons 18 to 21 (Fig. 1A).3 Exon 19 deletions and L858R exon 21 mutations are the most common alterations associated with responsiveness to EGFR tyrosine kinase inhibitors (TKIs), and alterations such as exon 20 insertions (or in-frame duplications) and the gatekeeper Disclosure: The authors declare no conflict of interest. Address for correspondence: Vamsidhar Velcheti, MD, Department of Hematology and Oncology, Cleveland Clinic, 9500 Euclid Avenue/R35, Cleveland, OH 44195. E-mail: [email protected] ª 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved. ISSN: 1556-0864 http://dx.doi.org/10.1016/j.jtho.2016.11.273
Journal of Thoracic Oncology
Vol. 12 No. 2
Alexa B. Schrock, PhD, Siraj M. Ali, MD, PhD Foundation Medicine Boston, Massachusetts
References 1. Mulligan LM. RET revisited: expanding the oncogenic portfolio. Nat Rev Cancer. 2014;14:173–186. 2. Kohno T, Ichikawa H, Totoki Y, et al. KIF5B-RET fusions in lung adenocarcinoma. Nat Med. 2012;18: 375–377. 3. Velcheti V, Hida T, Reckamp K, et al. ESMO 2016: lenvatinib shows promising activity in patients with RET-positive adenocarcinoma of the lung. Paper presented at: European Society of Medical Oncology 2016 Congress. October 7–11, 2016; Copenhagen, Denmark. 4. Lambert J-C, Grenier-Boley B, Harold D, et al. Genomewide haplotype association study identifies the FRMD4A gene as a risk locus for Alzheimer’s disease. Mol Psychiatry. 2013;18:461–470. 5. Goldie SJ, Mulder KW, Tan DW-M, et al. FRMD4A upregulation in human squamous cell carcinoma promotes tumor growth and metastasis and is associated with poor prognosis. Cancer Res. 2012;72: 3424–3436.
mutationT790M are associated with resistance to EGFR TKIs.4 However, the clinical significance of some of the rarer EGFR kinase domain variants are not well defined (Fig. 1B). There have been previous reports of EGFR missense substitutions in the kinase domain with lack of efficacy of EGFR TKIs.5–6 Here we report a novel EGFR exon 18 mutation (G721R, c.2161G>C; p.Gly721Arg) in a patient with metastatic lung adenocarcinoma with a lack of response to the EGFR TKI afatinib.
Case Report Metastatic lung adenocarcinoma was diagnosed in a 57year-old white man in February 2016. He was a current smoker with an approximately 30-pack-year smoking history until the time of diagnosis. He had human immunodeficiency virus/acquired immunodeficiency syndrome that was initially diagnosed in 1988 and had been treated with antiretroviral therapy since 1994. Diffuse large B-cell lymphoma with extensive lymphadenopathy and visceral involvement was diagnosed in the patient in 2009. He had six cycles of R-CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone plus the monoclonal antibody rituximab [Rituxan]) with excellent response and no evidence of disease recurrence on surveillance. On a routine surveillance positron emission tomography/computed tomography (CT) scan in January 2012, he was found to have a left upper lobe nodule measuring 1.3 cm (standardized uptake value [SUV] 7.2). He had a lobectomy, with pathologic examination revealing acinar type lung adenocarcinoma. On pathologic examination, he had a
February 2017
Letters to the Editor
e17
Figure 1. Stacked histogram of genetic alterations demonstrates high (A) and low (B) frequency alterations within the EGFR kinase domain (aa 712-968). Data were obtained from the Catalog of Somatic Mutations in Cancer database.3
2 2 0.7-cm tumor without lymphoascular invasion and clear margins. His pathologic stage was 1A (pT1a, N0). No adjuvant chemotherapy was recommended. During surveillance, a squamous carcinoma of the anus developed and was completely excised with close margins (pT1N0). The patient was treated with 5940 cGy in 33 fractions (completed on June 26, 2012). He did not receive chemotherapy in view of his prior difficulties tolerating chemotherapy. He was followed up with repeat biopsies, which did not show invasive recurrence but did show dysplasia. In January 2016, pain developed in his left chest wall and he had a CT scan of the chest that revealed a 1.5cm left lower lobe (LLL) mass, a left chest wall mass, and mediastinal and hilar adenopathy. Positron emission tomography/CT revealed a fludeoxyglucose F 18–avid chest wall mass (maximum SUV [SUVmax] 14.5), a 1.5-cm LLL lung nodule (SUVmax 4.1), and an additional LLL nodule (SUVmax 2.4). In addition, he had fludeoxyglucose F 18 uptake (SUVmax >5) in the femoral heads bilaterally. The
results of a magnetic resonance imaging brain scan were negative for metastatic disease. The patient had a bronchoscopy, and the sampled mediastinal lymph nodes revealed lung adenocarcinoma with morphologic similarity to the primary tumor resected in 2012, suggesting recurrent disease. Molecular testing of the tumor was requested on the sample. Genomic DNA extracted from the tumor sample (microdissected) was multiplex-amplified using Ion Ampliseq Cancer Hotspot panel v2 (CHPv2) chemistry and a OneTouch2 instrument, followed by sequencing on the semiconductor Ion Torrent PGM platform (Life Technologies, Carlsbad, CA). The sequencing data were analyzed using NextGENe (SoftGenetics, State College, PA), and Torrent-Suite (Life Technologies) bioinformatics tools. Only variants in mutation hotspots of the genes EGFR (NM_005228.3) and KRAS (NM_004985.4) were analyzed and reported. An EGFR exon 18 c.2161G>C; p.Gly721Arg (G721R) variant was identified in the tumor. No other mutations in the EGFR gene were noted. No KRAS
e18 Letters to the Editor
variants were identified. The results of anaplastic lymphoma receptor tyrosine kinase gene (ALK) FISH testing were negative. In view of his history of human immunodeficiency virus/acquired immunodeficiency syndrome and poor performance status (Eastern Cooperative Oncology Group performance status of 2), he was at increased risk for morbidity from cytotoxic chemotherapy. He began taking first-line afatinib, 40 mg daily. After 6 weeks of therapy, clinically and radiographically evident rapid progression of disease in his left chest wall and lung metastases developed. His best response by the Response Evaluation Criteria in Solid Tumors, version 1.1, was progressive disease. Afatinib was held at the time of progression, and he was transitioned to hospice care. He died 4 months from the time treatment was discontinued.
Discussion The EGFR variant reported here has not been previously reported in the Catalog of Somatic Mutations in Cancer database.3 To our knowledge, the G721R mutation in exon 18 of the EGFR gene has not previously been reported. Unlike in the case of the common hotspot alterations in the EGFR gene, the evidence of clinical actionability of rarer EGFR variants have not been fully elucidated. The lack of response to EGFR TKI in our patient highlights the need for additional investigation of the molecular mechanisms underlying clinical response to EGFR TKIs. Further efforts to catalogue clinical experiences with uncommon EGFR variants are essential to understand the relevance of these lowfrequency alterations in routine clinical practice. Vamsidhar Velcheti, MD Department of Hematology and Oncology Cleveland Clinic Cleveland, OH
Cluster Circulating Tumor Cell Is Crucial in Surgically Resected Lung Cancer To the Editor: I have read with interest the article from Crosbie et al. revealing that circulating tumor cells (CTCs) in the blood of the tumor-draining pulmonary vein (PV) was an Disclosure: The author declares no conflict of interest. Address for correspondence: Noriyoshi Sawabata, MD, PhD, Respiratory Center, Department of General Thoracic Surgery, Hoshigaoka Medical Center, Japan Community Healthcare Organization, 4-8-1 Hoshigaoka, Hirakata, Osaka, 873-8511, Japan. E-mail: [email protected] ª 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved. ISSN: 1556-0864 http://dx.doi.org/10.1016/j.jtho.2016.10.006
Journal of Thoracic Oncology
Vol. 12 No. 2
Monica Khunger, MD Department of Internal Medicine Cleveland Clinic Cleveland, OH Mohamed E. Abazeed, MD, PhD Department of Translational Hematology Oncology Research Department of Radiation Oncology Cleveland Clinic Cleveland, OH
References 1. Lynch TJ, Bell DW, Sordella R, 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;350:2129–2139. 2. Pao W, Chmielecki J. Rational, biologically based treatment of EGFR-mutant non-small-cell lung cancer. Nat Rev Cancer. 2010;10:760–774. 3. COSMIC: Catalog of Somatic Mutations in Cancer. BRAF. www.sanger.ac.uk/genetics/CGP/cosmic/. Accessed November 6, 2016. 4. Yu HA, Arcila ME, Rekhtman N, et al. Analysis of tumor specimens at the time of acquired resistance to EGFR-TKI therapy in 155 patients with EGFRmutant lung cancers. Clin Cancer Res. 2013;19: 2240–2247. 5. Sharma A, Tan TH, et al. Rare and novel epidermal growth factor receptor mutations in non-small-cell lung cancer and lack of clinical response to gefitinib in two cases. J Thorac Oncol. 2012;7:941–942. 6. Arcila ME, Nafa K, Chaft JE, et al. EGFR exon 20 insertion mutations in lung adenocarcinomas: prevalence, molecular heterogeneity, and clinicopathologic characteristics. Mol Cancer Ther. 2013;12: 220–229.
indicator of early recurrence.1 They chose the PV because of the low sensitivity of the CellSearch Circulating Tumor Cell Kit for detecting CTCs (Janssen Diagnostics LLC, Raritan, NJ) in the circulating peripheral blood. I found tumor cell dislodgement by surgical manipulation to the peripheral circulating blood using the CellSearch system, but the sensitivity was low.2 As such, we examined isolated tumor cells, surrogates of CTCs extracted from the PV of the resected lung, revealing that detection of isolated tumor cells was an indicator of early recurrence. In particular, detection of cluster CTCs by using the CD45 negative depression gravity method (RosettSep [Stemcell Technologies, Vancouver, Canada]) indicated a poor prognosis.3 Recently, we found CTC dislodgement by detecting CTCs in the peripheral circulating blood, and detecting cluster CTCs using a size selection method (ScreenCell Cyto, ScreenCell, Westford, MA) was an indicator of early recurrence.4
of known fusion patterns for RET rearrangements in lung adenocarcinoma, and it emphasizes the role of comprehensive genomic profiling in identifying clinically actionable genomic alterations in lung cancer and rare and novel fusion variants of potential clinical significance. Vamsidhar Velcheti, MD Department of Hematology and Oncology Cleveland Clinic Cleveland, Ohio Rajat Thawani, MD Department of Oncology Case Western Reserve University Cleveland, Ohio Monica Khunger, MD Department of Internal Medicine Cleveland Clinic Cleveland, Ohio Sanjay Mukhopadhyay, MD, Deborah J. Chute, MD Department of Pathology Cleveland Clinic Cleveland, Ohio
Novel EGFR Exon 18 (G721R) Mutation in a Patient with Non–Small Cell Lung Carcinoma with Lack of Response to Afatinib To the Editor: EGFR alterations are the most frequent clinically actionable genetic events in NSCLC.1–2 Several small molecule EGFR inhibitors such as gefitinib, erlotinib, afatinib, and osimertinib have demonstrated clinical efficacy in patients with EGFR alterations and are now standard treatment options for patients with such alterations.2 The common gain-of-function EGFR alterations are in exons 18 to 21 (Fig. 1A).3 Exon 19 deletions and L858R exon 21 mutations are the most common alterations associated with responsiveness to EGFR tyrosine kinase inhibitors (TKIs), and alterations such as exon 20 insertions (or in-frame duplications) and the gatekeeper Disclosure: The authors declare no conflict of interest. Address for correspondence: Vamsidhar Velcheti, MD, Department of Hematology and Oncology, Cleveland Clinic, 9500 Euclid Avenue/R35, Cleveland, OH 44195. E-mail: [email protected] ª 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved. ISSN: 1556-0864 http://dx.doi.org/10.1016/j.jtho.2016.11.273
Journal of Thoracic Oncology
Vol. 12 No. 2
Alexa B. Schrock, PhD, Siraj M. Ali, MD, PhD Foundation Medicine Boston, Massachusetts
References 1. Mulligan LM. RET revisited: expanding the oncogenic portfolio. Nat Rev Cancer. 2014;14:173–186. 2. Kohno T, Ichikawa H, Totoki Y, et al. KIF5B-RET fusions in lung adenocarcinoma. Nat Med. 2012;18: 375–377. 3. Velcheti V, Hida T, Reckamp K, et al. ESMO 2016: lenvatinib shows promising activity in patients with RET-positive adenocarcinoma of the lung. Paper presented at: European Society of Medical Oncology 2016 Congress. October 7–11, 2016; Copenhagen, Denmark. 4. Lambert J-C, Grenier-Boley B, Harold D, et al. Genomewide haplotype association study identifies the FRMD4A gene as a risk locus for Alzheimer’s disease. Mol Psychiatry. 2013;18:461–470. 5. Goldie SJ, Mulder KW, Tan DW-M, et al. FRMD4A upregulation in human squamous cell carcinoma promotes tumor growth and metastasis and is associated with poor prognosis. Cancer Res. 2012;72: 3424–3436.
mutationT790M are associated with resistance to EGFR TKIs.4 However, the clinical significance of some of the rarer EGFR kinase domain variants are not well defined (Fig. 1B). There have been previous reports of EGFR missense substitutions in the kinase domain with lack of efficacy of EGFR TKIs.5–6 Here we report a novel EGFR exon 18 mutation (G721R, c.2161G>C; p.Gly721Arg) in a patient with metastatic lung adenocarcinoma with a lack of response to the EGFR TKI afatinib.
Case Report Metastatic lung adenocarcinoma was diagnosed in a 57year-old white man in February 2016. He was a current smoker with an approximately 30-pack-year smoking history until the time of diagnosis. He had human immunodeficiency virus/acquired immunodeficiency syndrome that was initially diagnosed in 1988 and had been treated with antiretroviral therapy since 1994. Diffuse large B-cell lymphoma with extensive lymphadenopathy and visceral involvement was diagnosed in the patient in 2009. He had six cycles of R-CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone plus the monoclonal antibody rituximab [Rituxan]) with excellent response and no evidence of disease recurrence on surveillance. On a routine surveillance positron emission tomography/computed tomography (CT) scan in January 2012, he was found to have a left upper lobe nodule measuring 1.3 cm (standardized uptake value [SUV] 7.2). He had a lobectomy, with pathologic examination revealing acinar type lung adenocarcinoma. On pathologic examination, he had a
February 2017
Letters to the Editor
e17
Figure 1. Stacked histogram of genetic alterations demonstrates high (A) and low (B) frequency alterations within the EGFR kinase domain (aa 712-968). Data were obtained from the Catalog of Somatic Mutations in Cancer database.3
2 2 0.7-cm tumor without lymphoascular invasion and clear margins. His pathologic stage was 1A (pT1a, N0). No adjuvant chemotherapy was recommended. During surveillance, a squamous carcinoma of the anus developed and was completely excised with close margins (pT1N0). The patient was treated with 5940 cGy in 33 fractions (completed on June 26, 2012). He did not receive chemotherapy in view of his prior difficulties tolerating chemotherapy. He was followed up with repeat biopsies, which did not show invasive recurrence but did show dysplasia. In January 2016, pain developed in his left chest wall and he had a CT scan of the chest that revealed a 1.5cm left lower lobe (LLL) mass, a left chest wall mass, and mediastinal and hilar adenopathy. Positron emission tomography/CT revealed a fludeoxyglucose F 18–avid chest wall mass (maximum SUV [SUVmax] 14.5), a 1.5-cm LLL lung nodule (SUVmax 4.1), and an additional LLL nodule (SUVmax 2.4). In addition, he had fludeoxyglucose F 18 uptake (SUVmax >5) in the femoral heads bilaterally. The
results of a magnetic resonance imaging brain scan were negative for metastatic disease. The patient had a bronchoscopy, and the sampled mediastinal lymph nodes revealed lung adenocarcinoma with morphologic similarity to the primary tumor resected in 2012, suggesting recurrent disease. Molecular testing of the tumor was requested on the sample. Genomic DNA extracted from the tumor sample (microdissected) was multiplex-amplified using Ion Ampliseq Cancer Hotspot panel v2 (CHPv2) chemistry and a OneTouch2 instrument, followed by sequencing on the semiconductor Ion Torrent PGM platform (Life Technologies, Carlsbad, CA). The sequencing data were analyzed using NextGENe (SoftGenetics, State College, PA), and Torrent-Suite (Life Technologies) bioinformatics tools. Only variants in mutation hotspots of the genes EGFR (NM_005228.3) and KRAS (NM_004985.4) were analyzed and reported. An EGFR exon 18 c.2161G>C; p.Gly721Arg (G721R) variant was identified in the tumor. No other mutations in the EGFR gene were noted. No KRAS
e18 Letters to the Editor
variants were identified. The results of anaplastic lymphoma receptor tyrosine kinase gene (ALK) FISH testing were negative. In view of his history of human immunodeficiency virus/acquired immunodeficiency syndrome and poor performance status (Eastern Cooperative Oncology Group performance status of 2), he was at increased risk for morbidity from cytotoxic chemotherapy. He began taking first-line afatinib, 40 mg daily. After 6 weeks of therapy, clinically and radiographically evident rapid progression of disease in his left chest wall and lung metastases developed. His best response by the Response Evaluation Criteria in Solid Tumors, version 1.1, was progressive disease. Afatinib was held at the time of progression, and he was transitioned to hospice care. He died 4 months from the time treatment was discontinued.
Discussion The EGFR variant reported here has not been previously reported in the Catalog of Somatic Mutations in Cancer database.3 To our knowledge, the G721R mutation in exon 18 of the EGFR gene has not previously been reported. Unlike in the case of the common hotspot alterations in the EGFR gene, the evidence of clinical actionability of rarer EGFR variants have not been fully elucidated. The lack of response to EGFR TKI in our patient highlights the need for additional investigation of the molecular mechanisms underlying clinical response to EGFR TKIs. Further efforts to catalogue clinical experiences with uncommon EGFR variants are essential to understand the relevance of these lowfrequency alterations in routine clinical practice. Vamsidhar Velcheti, MD Department of Hematology and Oncology Cleveland Clinic Cleveland, OH
Cluster Circulating Tumor Cell Is Crucial in Surgically Resected Lung Cancer To the Editor: I have read with interest the article from Crosbie et al. revealing that circulating tumor cells (CTCs) in the blood of the tumor-draining pulmonary vein (PV) was an Disclosure: The author declares no conflict of interest. Address for correspondence: Noriyoshi Sawabata, MD, PhD, Respiratory Center, Department of General Thoracic Surgery, Hoshigaoka Medical Center, Japan Community Healthcare Organization, 4-8-1 Hoshigaoka, Hirakata, Osaka, 873-8511, Japan. E-mail: [email protected] ª 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved. ISSN: 1556-0864 http://dx.doi.org/10.1016/j.jtho.2016.10.006
Journal of Thoracic Oncology
Vol. 12 No. 2
Monica Khunger, MD Department of Internal Medicine Cleveland Clinic Cleveland, OH Mohamed E. Abazeed, MD, PhD Department of Translational Hematology Oncology Research Department of Radiation Oncology Cleveland Clinic Cleveland, OH
References 1. Lynch TJ, Bell DW, Sordella R, 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;350:2129–2139. 2. Pao W, Chmielecki J. Rational, biologically based treatment of EGFR-mutant non-small-cell lung cancer. Nat Rev Cancer. 2010;10:760–774. 3. COSMIC: Catalog of Somatic Mutations in Cancer. BRAF. www.sanger.ac.uk/genetics/CGP/cosmic/. Accessed November 6, 2016. 4. Yu HA, Arcila ME, Rekhtman N, et al. Analysis of tumor specimens at the time of acquired resistance to EGFR-TKI therapy in 155 patients with EGFRmutant lung cancers. Clin Cancer Res. 2013;19: 2240–2247. 5. Sharma A, Tan TH, et al. Rare and novel epidermal growth factor receptor mutations in non-small-cell lung cancer and lack of clinical response to gefitinib in two cases. J Thorac Oncol. 2012;7:941–942. 6. Arcila ME, Nafa K, Chaft JE, et al. EGFR exon 20 insertion mutations in lung adenocarcinomas: prevalence, molecular heterogeneity, and clinicopathologic characteristics. Mol Cancer Ther. 2013;12: 220–229.
indicator of early recurrence.1 They chose the PV because of the low sensitivity of the CellSearch Circulating Tumor Cell Kit for detecting CTCs (Janssen Diagnostics LLC, Raritan, NJ) in the circulating peripheral blood. I found tumor cell dislodgement by surgical manipulation to the peripheral circulating blood using the CellSearch system, but the sensitivity was low.2 As such, we examined isolated tumor cells, surrogates of CTCs extracted from the PV of the resected lung, revealing that detection of isolated tumor cells was an indicator of early recurrence. In particular, detection of cluster CTCs by using the CD45 negative depression gravity method (RosettSep [Stemcell Technologies, Vancouver, Canada]) indicated a poor prognosis.3 Recently, we found CTC dislodgement by detecting CTCs in the peripheral circulating blood, and detecting cluster CTCs using a size selection method (ScreenCell Cyto, ScreenCell, Westford, MA) was an indicator of early recurrence.4