- Email: [email protected]
Clinical Characteristics and Prognosis of MAF Deletion in Chinese Patients With Multiple Myeloma
Original Study
Clinical Characteristics and Prognosis of MAF Deletion in Chinese Patients With Multiple Myeloma Ying Wang, Qinlu Li, Shugang Xing, Heng Zhang, Dengju Li Abstract We analyzed the frequency, clinical characteristics, and prognosis of MAF deletion in Chinese patients with multiple myeloma (MM). The incidence rate of MAF deletion was 15.0% (30/200) in newly diagnosed patients and all of them had monoallelic of MAF deletion. Among all factors, we found that sex and lactate dehydrogenase were associated with MAF deletion. In an analysis of the overall survival rates of patients with MAF deletion who received bortezomib-based treatment, MAF deletion did not influence prognosis in patients with MM who were given a bortezomib-based chemotherapy regimen. Background: In this study, we analyzed the frequency, clinical characteristics, and prognosis of MAF deletion in Chinese patients with multiple myeloma (MM). Patients and Methods: Two hundred consecutive patients with newly diagnosed MM were analyzed. Patient samples were evaluated using a fluorescence in situ hybridization probe set, including 13q deletion, 17p deletion, and 1q21 gain, as well as immunoglobulin heavy chain gene (IgH ) rearrangement, IgH/cyclin D1, IgH/fibroblast growth factor receptor 3 (FGFR3), and IgH/MAF. The frequency of MAF deletion and the clinical characteristics and overall survival of patients with MAF deletion were analyzed. Results: The incidence rate of MAF deletion was 15.0% (30/200) in newly diagnosed patients and all of them were monoallelic of MAF deletion. MAF deletion was associated with sex (P ¼ .008), lactate dehydrogenase level (P ¼ .026), 13q deletion (P ¼ .028), FGFR3 deletion (P ¼ .006), and IgH deletion (P ¼ .018). Additionally, in an analysis of the overall survival rates of patients with MAF deletion who received a bortezomib-based regimen treatment, no significant differences were found in overall survival between positive and negative groups (P ¼ .365). Conclusion: MAF deletion was more frequent than MAF translocation with IgH in patients with MM and was more commonly observed in women. Moreover, MAF deletion was often combined with 13q, FGFR3, and IgH deletion. MAF deletion did not influence prognosis in patients with MM who were given a bortezomib-based chemotherapy regimen. Clinical Lymphoma, Myeloma & Leukemia, Vol. -, No. -, --- ª 2019 Elsevier Inc. All rights reserved. Keywords: Bortezomib-based chemotherapy, FISH, MAF deletion, Multiple myeloma, Prognosis
Introduction Multiple myeloma (MM) is a heterogeneous plasma cell (PC) disorder characterized by complex numerical and structural chromosome aberrations.1,2 In recent years, identification of chromosomal aberrations using interphase fluorescence in situ hybridization (iFISH) has become
Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China Submitted: Feb 25, 2019; Revised: May 3, 2019; Accepted: May 26, 2019 Address for correspondence:Dengju Li, MD, PhD, Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China Fax: 86-27-83662680; E-mail contact: [email protected]
2152-2650/$ - see frontmatter ª 2019 Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.clml.2019.05.016
an important clinical strategy for disease stratification and management.1,3 Recent studies have evaluated the potential prognostic roles of cytogenetic events, namely del(13q), del(17p), add(1q21), and translocations involving the immunoglobulin (Ig) heavy chain gene (IgH) located on 14q32, including t(4;14), t(14;16), t(11;14), and their combinations.4-6 Translocations involving the IgH locus are present in at least half of the patients with MM.7 The IgH translocation t(14;16), which juxtaposes the oncogene MAF into the IgH locus, leading to MAF overexpression, is associated with poor prognosis and has a very low incidence rate.7-10 However, some studies have not confirmed the poor prognostic value of t(14;16) and do not support the use of t(14;16)specific probes in diagnostic panels for patients with MM.11 In our clinical practice, we found that the deletion of MAF was more common than its translocation. However, reports of the
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MAF Deletion in Multiple Myeloma clinical characteristics and prognosis of patients with MAF deletion have been rare, particularly for Chinese individuals. Deletion of MAF had been reported in 19.5% of newly diagnosed myeloma cases from the United Kingdom and was associated with a worse overall survival using conventional induction chemotherapy.12 Additionally, it is unclear whether the effects of bortezomib are altered for patients with this cytogenetic abnormality. Accordingly, in this study, the frequency of MAF deletion and the clinical characteristics and prognosis of patients with MAF deletion identified using iFISH were investigated in Chinese patients with MM.
Patients and Methods Patients During the period between January 2014 and November 2016, 200 newly diagnosed patients with MM with available iFISH results and clinical factors from Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology (Wuhan, China) were recruited. The diagnostic criteria for symptomatic myeloma used in this study were defined according to the International Myeloma Working Group.13 The International Staging System14 and Durie-Salmon15 staging systems were used to assess patients.
Interphase Fluorescence in Situ Hybridization Analysis The PCs were isolated using CD138 immunomagnetic bead selection, and CD38/CD45 flow cytometry was used to determine
that the PC purity was routinely >85%. iFISH was carried out according to the manufacturer’s instructions. Seven commercially available probes (Vysis, Downers, Grove, IL) were used in iFISH examinations. A D13S319 probe, 17p13.1 (P53), and 1q21 (CKS1B) probes were used to detect 13q deletion, 17p deletion, and 1q21 gain, respectively. The LSI IGH dual-color, break-apart rearrangement probe was used to determine the translocation involving IgH, and the probes LSI IgH/cyclin D1, LSI IgH/fibroblast growth factor receptor 3 (FGFR3), and LSI IgH/MAF were used to detect the patterns of IGH translocation, including t(11;14)(q13;q32), t(4;14)(p16;q32), and t(14;16)(q32;q23). Fluorescence images were captured with an epifluorescence microscope equipped with a charge coupled device camera and appropriate filters. Two hundred nuclei were scored for each probe. The cutoff levels for positive values for each probe in iFISH were as follows: 10% for fusion and 20% for numerical abnormalities according to the recommendations of the European Myeloma Network FISH workshops.16
Statistical Analysis We used SPSS version 16.0 (SPSS Inc) was used for all analyses. Comparisons among groups and comparisons between 2 groups were performed using 1-way analysis of variance and c2 tests; the survival carves were plotted using the KaplaneMeier method, with differences assessed using log rank tests. Differences were considered significant when the P value was <.05.
Table 1 Clinical Features of the Study Cohort Clinical Feature Male Sex Age, Years
MAF Deletion 11/30 (36.7) 60 (41-80)
No MAF Deletion 106/170 (62.4) 58 (32-82)
ISS Stage I
32/170 (18.8)
8/30 (26.7)
61/170 (35.9)
III
18/30 (60.0)
77/170 (45.3)
2/30 (6.7)
27/170 (15.9)
DS Stage II
.363 9/30 (30.0)
40/170 (23.5)
IIIA
12/30 (40.0)
51/170 (30.0)
IIIB
7/30 (23.3)
52/170 (30.6)
M Component
2
-
.428 .33
4/30 (13.3)
II
I
P .008
.666
IgG
15/30 (50.0)
84/170 (49.4)
IgA
4/30 (13.3)
38/170 (22.4)
IgD
1/30 (3.3)
6/170 (3.5)
k
2/30 (6.7)
12/170 (7.1)
l
8/30 (26.7)
27/170 (15.9)
Nonsecretory
0/30 (0)
3/170 (1.8)
Albumin, g/L
33.2 (13.3-45.7)
33.0 (18.1-50.9)
.525
Serum Calcium, mmol/L
2.54 (2.32-3.06)
2.64 (2.15-4.58)
.629
Lactate Dehydrogenase, U/L
232 (109-442)
190 (72-481)
.026
Hemoglobin, g/L
88.1 (53.9-127.0)
93.8 (55.0-150.0)
.783
b2-Microglobin, mg/L
7.16 (1.99-16.86)
9.51 (1.36-100)
.391
Abbreviations: DS ¼ Durie-Salmon staging; ISS ¼ International Staging System.
Clinical Lymphoma, Myeloma & Leukemia Month 2019
Ying Wang et al Compliance With Ethical Standards Appropriate informed consent was obtained from all donors before specimen collection in accordance with the Declaration of Helsinki and the research protocol approved by the ethics committees of Tongji Hospital.
Results Clinical Characteristics of the Patients and Correlation of MAF Deletion With Clinical Characteristics Two hundred newly diagnosed patients with MM were studied. The median age was 58.5 (range 32-82) years, and the male/female ratio was 1.41 (117/83). Of the 200 patients, the types of M protein were IgG in 99, IgA in 42, IgD in 7, k light chain in 14, l light chain in 35, and nonsecretory in 3. According to Durie and Salmon staging, 29 were stage I, 49 were stage II, and 122 were stage III. According to the International Staging System, 36 were stage I, 69 were stage II, and 95 were stage III. A variety of clinical factors were observed (Table 1). The correlation between MAF deletion and clinical characteristics was investigated. Among all factors, we found that sex and lactate dehydrogenase (LDH) were associated with MAF deletion. The percentage of male patients in MAF deletionpositive cases was 36.7% (11/30), which was significantly lower than that in MAF deletion-negative cases (62.4% [106/170]; P < .05). The median LDH of MAF deletion-positive cases was 232, which was significantly higher than that in MAF-negative cases (n ¼ 190; P < .05).
Frequencies and Patterns of Alterations in iFISH Among the 200 patients, all were analyzed for del(17p), t(14;16), t(4;14), t(11;14), rearrangement of IgH, gain of 1q21, and deletion of 13q. In total, 188 patients (94.0%) exhibited at least 1 abnormality in the regions analyzed. Thirty-nine (19.5%) had 1 abnormality, 62 (31.0%) had 2 abnormalities, and 87 (43.5%) had 3 or more abnormalities. These abnormalities were present in del(17p) in 17
(8.5%) of patients, IgH translocation in 94 (47.0%) patients, t(14;16) in 3 (1.6%) patients, t(4;14) in 31 (15.5%) patients, t(11;14) in 29 (14.5%) patients, gain of 1q21 in 108 (54.0%) of patients, and deletion of 13q in 103 (51.5%) of patients.
The Prevalence of MAF Deletion and Correlation of MAF Deletion With Frequent Fluorescence In Situ Hybridization Aberrations in Patients With MM MAF deletion was found in 30 (15.0%) of newly diagnosed patients and all 30 patients with MAF deletion had monoallelic deletion. Thus, the signal of MAF deletion was 2G1R when we observed the IgH/MAF probe and the normal signal is 2G2R (Figure 1). MAF deletion was shown to be associated with 13q deletion, FGFR3 deletion, and IgH deletion. Moreover, 13q deletion was also found to be correlated with MAF deletion, and the incidence rate of 13q deletion in MAF deletionpositive cases was significantly higher than that in MAF deletionnegative cases (70.0% vs. 48.2%, respectively, P ¼ .028). Similarly, the frequency of FGFR3 deletion in patients with MAF deletion was 23.3% (7/30), whereas that in patients without MAF deletion was 1.8% (3/170); this difference was significant (P ¼ .006). In addition, we also found that the IgH deletion was associated with MAF deletion, and the incidence rate of IgH deletion in MAF deletion-positive cases was significantly higher than that in MAF deletion-negative cases (33.3% vs. 11.7%, respectively; P ¼ .018). Notably, IgH deletion is known to be heterogeneous in MM; however, in our study, we defined IgH deletion as a monoallelic deletion of the whole IgH locus. Thus, the patterns of IgH deletion included 1F, 1R1G, 1R, and 1G. In addition, there were no obvious differences in other frequent fluorescence in situ hybridization (FISH) aberration groups, including deletion of P53, rearrangement of IgH, and gain of 1q21. Among 30 patients with MAF deletion, there were 7 patients who also had concurrent 13q deletion, FGFR3 deletion, and monoallelic deletion of the whole locus of IgH. Detailed data are shown in Table 2.
Figure 1 Fluorescence in Situ Hybridization Pattern of Normal and MAF Deletion Signals. (A) The Cell Shows 2 Green Signals and 2 Red Signals, Indicating There Is No MAF Deletion. (B) The Cell Shows 3 Green Signals and a Red Signal, Indicating It Is a Monoallelic Deletion of MAF.
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MAF Deletion in Multiple Myeloma Table 2 Correlation of MAF Deletion With Frequent FISH Aberrations in MM All Cases IgH translocation IgH deletion 17p deletion 13q deletion FGFR3 deletion 1q21 gain t(11;14) t(4;14) t(14;16)
47.0% 15.0% 8.5% 51.5% 5.0% 54.0% 14.5% 15.5% 1.5%
(94/200) (30/200) (17/200) (103/200) (10/200) (108/200) (29/200) (31/200) (3/200)
MAF Deletion 33.3% 33.3% 3.3% 70.0% 23.3% 70.0% 6.7% 6.7% 0%
Prognostic Value of MAF Deletion in Patients With Newly Diagnosed MM Follow-up data from 200 patients were analyzed to ascertain the prognostic value of MAF deletion in patients with newly diagnosed MM. The patients were treated with bortezomib-based chemotherapy regimens, including a 2-drug regimen: BD (bortezomib with dexamethasone) and 3-drug regimen: BAD (bortezomib, doxorubicin, and dexamethasone). In total, 34 patients did not complete the follow-up examination because of lack of appropriate contact information. The median follow-up time was 27 (range, 260) months. There were no significant differences in overall survival between MAF deletion-positive and MAF deletion-negative patients (Figure 2A). When we compared other FISH abnormalities, including 17p deletion, t(4;14), t(11;14), and 1q21 gain, we found that 17p deletion was still an independent prognostic factor, and the prognostic influence of MAF deletion in patients with MM was similar to that of t(4;14) and 1q21 gains (Figure 2B).
Discussion Cytogenetic abnormalities have important prognostic value in patients with MM, particularly in distinguishing high-risk patients. Conventional karyotype analysis is often hindered by the low mitotic index of MM cells in vitro and the low ratio of PCs in bone marrow samples. In contrast, FISH analysis has substantially
(10/30) (10/30) (1/30) (21/30) (7/30) (21/30) (2/30) (2/30) (0/30)
No MAF Deletion 49.4% 11.7% 9.4% 48.2% 1.8% 51.2% 15.9% 17.1% 1.8%
(84/170) (20/170) (16/170) (82/170) (3/170) (87/170) (27/170) (29/170) (3/170)
P .104 .018 .271 .028 .006 .056 .186 .147 .463
enhanced the sensitivity of cytogenetic analysis because it is applicable not only to dividing cells but also to interphase nuclei.17 Thus, the identification of specific cytogenetic abnormalities using iFISH has become a routine procedure for MM prognostic stratification. The most common commercial FISH probe set was used for the detection of del(17p), del(13q), add(1q21), t(4;14), t(11;14), and t(14;16). The prognostic significance of different FISH abnormalities, including the aforementioned probe sets, has been widely reported; however, the clinical characteristics and value of the MAF deletion have not been extensively studied, particularly in Chinese patients. In our study, we examined MAF deletion (16q-) rather than translocation between IgH and MAF (t(14;16)) because the incidence rate of t(14;16) was considerably lower than that of MAF deletion. As reported in other studies, the cytogenetic abnormality of t(14;16) was quite rare, and the incidence rates of t(14;16) were 3% and 1.9%; thus, the poor prognostic value of t(14;16) was not confirmed.11,18 In a report by Avet-Loiseau et al, the data did not support the use of t(14;16)-specific probes in the diagnostic panels of MM because the poor prognostic value of t(14;16) was not confirmed.11 The frequency of MAF deletion was 15%, which was obviously higher than that of t(14;16), which was only observed in 1.6% of individuals in our study. Because of the limited number of cases, we did not perform statistical analysis of the clinical characteristic and overall survival of these patients.
Figure 2 KaplaneMeier Plots of Overall Survival Related to Fluorescence in Situ Hybridization Abnormalities. (A) Overall Survival According to the Presence of MAF Deletion. (B) Overall Survival According to the Presence of t(11;14), 17p Deletion, 13q Deletion, 1q21 Gains, and MAF Deletion.
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Ying Wang et al Of the 200 patients enrolled in our study, the ratio of men to women was 1.41:1 (117:83), which was consistent with populationbased statistics, with incidence rates of 4.4 per 100,000 in men and 2.9 per 100,000 in women (eg, a 60:40 split).19 However, we found that MAF deletion was more common in women (22.9% of female patients vs. 9.4% of male patients; P < .05), which had not been reported in previous studies. Similarly, in a report by Boyd et al, sexdependent differences in the prevalence of IgH translocations and hyperdiploidy were observed in patients with newly presenting myeloma.12 In our study, the LDH level in patients with MAF deletion was higher than that in patients without MAF deletion. High serum LDH levels are generally associated with a worse median overall survival and worse progression-free survival in hematologic malignancies. Many studies have defined elevated serum LDH as a risk factor for MM. In survival analysis, we did not find a significant difference in overall survival between patients with MAF deletion and patients without MAF deletion. In a study by Jenner et al, del(16q) was found to be an independent prognostic marker and was associated with worse overall survival, in contrast to our results.20 This difference between studies might be the result of the small number of patients (168 patients in the report by Jenner et al, 30 patients in this series), but also to treatment and ethnic differences. The patients from the United Kingdom were treated with conventional chemotherapy, whereas all of ours received a bortezomib-based chemotherapy regimen. When we compared groups with different cytogenetic abnormalities, we found that deletion of 17p13 involving the p53 gene, which was observed in 17 (8.5%) of all patients with newly diagnosed MM in our cohort, was also considered an important adverse prognostic factor in MM. Our results were consistent with those from other studies, supporting the independent, poor prognostic significance for the presence of del(17p) on the basis of the use of bortezomib.6,21,22 Patients with MAF deletion did not show a significant difference in median overall survival time. This was likely to be a result of the use of bortezomib, which can also abrogate the adverse prognostic effects of t(4;14).21 Interestingly, we found that MAF deletion was easily combined with 13q deletion, FGFR3 deletion, and IgH deletion, which seemed to illustrate that the likelihood of hypodiploidy was increased in these patients. This result was also consistent with a report by Van Wier et al, in which 16q24 deletions were significantly enriched in hypodiploid MM compared with that in nonhyperdiploid MM.23 Hypodiploidy was associated with poor outcomes and disease progression; however, the number of patients with MAF deletion combined with 13q deletion, FGFR3 deletion, and IgH deletion was rather small, limiting the analysis of overall survival. There were certain limitations of this study because of its retrospective nature. First, the number of patients was low, particularly for positive patients, limiting the power of statistical analysis. Second, the follow-up time should be prolonged to further increase the accuracy of overall survival analysis.
Conclusion MAF deletion was much more frequent than t(14;16) in Chinese patients with MM. We found that MAF deletion was significantly
related to female sex, high levels of LDH, 13q deletion, FGFR3 deletion, and IgH deletion. With the use of bortezomib, patients with MAF deletion did not show significant differences in median overall survival time compared with patients without MAF deletion. Future studies with larger samples are needed to detect the overall survival of patients with MAF deletion combined with FGFR3, IgH, and Rb1 deletion as well as the effect of MAF deletion on de novo standard-risk or high-risk patients. Therefore, we also need to further explore the value of t(14;16)-specific probes in diagnostic panels for MM.
Clinical Practice Points Reports of the clinical characteristics and prognosis of patients
with MAF deletion have been rare, particularly for Chinese individuals. We analyzed the frequency, clinical characteristics, and prognosis of MAF deletion in Chinese patients with MM. The incidence rate of MAF deletion was 15.0% (30/200) in newly diagnosed patients and all of them had monoallelic MAF deletion. Among all factors, we found that sex and LDH were associated with MAF deletion. No differences were found in the overall survival rates of patients with MAF deletion and without MAF deletion who received bortezomib-based treatment. Future studies with larger samples are needed to detect the overall survival of patients with MAF deletion combined with FGFR3, IgH, and Rb1 deletion as well as the effect of MAF deletion on de novo standard-risk or high-risk patients.
Acknowledgments This work was supported by a grant from the National Science Foundation of China (NSFC 81770168).
Disclosure The authors have stated that they have no conflicts of interest.
References 1. Sawyer JR. The prognostic significance of cytogenetics and molecular profiling in multiple myeloma. Cancer Genet 2011; 204:3-12. 2. Chng WJ, Dispenzieri A, Chim CS, et al. IMWG consensus on risk stratification in multiple myeloma. Leukemia 2014; 28:269-77. 3. Nahi H, Sutlu T, Jansson M, Alici E, Gahrton G. Clinical impact of chromosomal aberrations in multiple myeloma. J Intern Med 2011; 269:137-47. 4. Dimopoulos M, Kyle R, Fermand JP, et al. Consensus recommendations for standard investigative workup: report of the International Myeloma Workshop Consensus Panel 3. Blood 2011; 117:4701-5. 5. Avet-Loiseau H. Role of genetics in prognostication in myeloma. Best Pract Res Clin Haematol 2007; 20:625-35. 6. Avet-Loiseau H, Attal M, Moreau P, et al. Genetic abnormalities and survival in multiple myeloma: the experience of the Intergroupe Francophone du Myelome. Blood 2007; 109:3489-95. 7. Yuregir OO, Sahin FI, Yilmaz Z, Kizilkilic E, Karakus S, Ozdogu H. Fluorescent in situ hybridization studies in multiple myeloma. Hematology 2009; 14:90-4. 8. Munshi NC, Anderson KC, Bergsagel PL, et al. Consensus recommendations for risk stratification in multiple myeloma: report of the International Myeloma Workshop Consensus Panel 2. Blood 2011; 117:4696-700. 9. Boyd KD, Ross FM, Chiecchio L, et al. A novel prognostic model in myeloma based on co-segregating adverse FISH lesions and the ISS: analysis of patients treated in the MRC Myeloma IX trial. Leukemia 2012; 26:349-55. 10. Chesi M, Bergsagel PL, Shonukan OO, et al. Frequent dysregulation of the c-maf proto-oncogene at 16q23 by translocation to an Ig locus in multiple myeloma. Blood 1998; 91:4457-63. 11. Avet-Loiseau H, Malard F, Campion L, et al. Translocation t(14;16) and multiple myeloma: is it really an independent prognostic factor? Blood 2011; 117: 2009-11.
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MAF Deletion in Multiple Myeloma 12. Boyd KD, Ross FM, Chiecchio L, et al. Gender disparities in the tumor genetics and clinical outcome of multiple myeloma. Cancer Epidemiol Biomarkers Prev 2011; 20:1703-7. 13. International Myeloma Working Group. Criteria for the classification of monoclonal gammopathies, multiple myeloma and related disorders: a report of the International Myeloma Working Group. Br J Haematol 2003; 121:749-57. 14. Greipp PR, San MJ, Durie BG, et al. International staging system for multiple myeloma. J Clin Oncol 2005; 23:3412-20. 15. Durie BG, Salmon SE. A clinical staging system for multiple myeloma. Correlation of measured myeloma cell mass with presenting clinical features, response to treatment, and survival. Cancer 1975; 36: 842-54. 16. Ross FM, Avet-Loiseau H, Ameye G, et al. Report from the European Myeloma Network on interphase FISH in multiple myeloma and related disorders. Haematologica 2012; 97:1272-7. 17. Gao X, Li C, Zhang R, et al. (2012) Fluorescence in situ hybridization analysis of chromosome aberrations in 60 Chinese patients with multiple myeloma. Med Oncol 2012; 29:2200-6.
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18. Sergentanis TN, Kastritis E, Terpos E, Dimopoulos MA, Psaltopoulou T. Cytogenetics and survival of multiple myeloma: isolated and combined effects. Clin Lymphoma Myeloma Leuk 2016; 16:335-40. 19. Howlader N, Noone AM, Krapcho M, et al, eds. SEER Cancer Statistics Review. Bethesda, MD: National Cancer Institute; 1975-2010. 20. Jenner MW, Leone PE, Walker BA, et al. Gene mapping and expression analysis of 16q loss of heterozygosity identifies WWOX and CYLD as being important in determining clinical outcome in multiple myeloma. Blood 2007; 110:3291-300. 21. Avet-Loiseau H, Leleu X, Roussel M, et al. Bortezomib plus dexamethasone induction improves outcome of patients with t(4;14) myeloma but not outcome of patients with del(17p). J Clin Oncol 2010; 28:4630-4. 22. Jian Y, Chen X, Zhou H, et al. (2016) Prognostic impact of cytogenetic abnormalities in multiple myeloma: a retrospective analysis of 229 patients. Medicine (Baltimore) 2016; 95:e3521. 23. Van Wier S, Braggio E, Baker A, et al. Hypodiploid multiple myeloma is characterized by more aggressive molecular markers than non-hyperdiploid multiple myeloma. Haematologica 2013; 98:1586-92.
Clinical Characteristics and Prognosis of MAF Deletion in Chinese Patients With Multiple Myeloma Ying Wang, Qinlu Li, Shugang Xing, Heng Zhang, Dengju Li Abstract We analyzed the frequency, clinical characteristics, and prognosis of MAF deletion in Chinese patients with multiple myeloma (MM). The incidence rate of MAF deletion was 15.0% (30/200) in newly diagnosed patients and all of them had monoallelic of MAF deletion. Among all factors, we found that sex and lactate dehydrogenase were associated with MAF deletion. In an analysis of the overall survival rates of patients with MAF deletion who received bortezomib-based treatment, MAF deletion did not influence prognosis in patients with MM who were given a bortezomib-based chemotherapy regimen. Background: In this study, we analyzed the frequency, clinical characteristics, and prognosis of MAF deletion in Chinese patients with multiple myeloma (MM). Patients and Methods: Two hundred consecutive patients with newly diagnosed MM were analyzed. Patient samples were evaluated using a fluorescence in situ hybridization probe set, including 13q deletion, 17p deletion, and 1q21 gain, as well as immunoglobulin heavy chain gene (IgH ) rearrangement, IgH/cyclin D1, IgH/fibroblast growth factor receptor 3 (FGFR3), and IgH/MAF. The frequency of MAF deletion and the clinical characteristics and overall survival of patients with MAF deletion were analyzed. Results: The incidence rate of MAF deletion was 15.0% (30/200) in newly diagnosed patients and all of them were monoallelic of MAF deletion. MAF deletion was associated with sex (P ¼ .008), lactate dehydrogenase level (P ¼ .026), 13q deletion (P ¼ .028), FGFR3 deletion (P ¼ .006), and IgH deletion (P ¼ .018). Additionally, in an analysis of the overall survival rates of patients with MAF deletion who received a bortezomib-based regimen treatment, no significant differences were found in overall survival between positive and negative groups (P ¼ .365). Conclusion: MAF deletion was more frequent than MAF translocation with IgH in patients with MM and was more commonly observed in women. Moreover, MAF deletion was often combined with 13q, FGFR3, and IgH deletion. MAF deletion did not influence prognosis in patients with MM who were given a bortezomib-based chemotherapy regimen. Clinical Lymphoma, Myeloma & Leukemia, Vol. -, No. -, --- ª 2019 Elsevier Inc. All rights reserved. Keywords: Bortezomib-based chemotherapy, FISH, MAF deletion, Multiple myeloma, Prognosis
Introduction Multiple myeloma (MM) is a heterogeneous plasma cell (PC) disorder characterized by complex numerical and structural chromosome aberrations.1,2 In recent years, identification of chromosomal aberrations using interphase fluorescence in situ hybridization (iFISH) has become
Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China Submitted: Feb 25, 2019; Revised: May 3, 2019; Accepted: May 26, 2019 Address for correspondence:Dengju Li, MD, PhD, Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China Fax: 86-27-83662680; E-mail contact: [email protected]
2152-2650/$ - see frontmatter ª 2019 Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.clml.2019.05.016
an important clinical strategy for disease stratification and management.1,3 Recent studies have evaluated the potential prognostic roles of cytogenetic events, namely del(13q), del(17p), add(1q21), and translocations involving the immunoglobulin (Ig) heavy chain gene (IgH) located on 14q32, including t(4;14), t(14;16), t(11;14), and their combinations.4-6 Translocations involving the IgH locus are present in at least half of the patients with MM.7 The IgH translocation t(14;16), which juxtaposes the oncogene MAF into the IgH locus, leading to MAF overexpression, is associated with poor prognosis and has a very low incidence rate.7-10 However, some studies have not confirmed the poor prognostic value of t(14;16) and do not support the use of t(14;16)specific probes in diagnostic panels for patients with MM.11 In our clinical practice, we found that the deletion of MAF was more common than its translocation. However, reports of the
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MAF Deletion in Multiple Myeloma clinical characteristics and prognosis of patients with MAF deletion have been rare, particularly for Chinese individuals. Deletion of MAF had been reported in 19.5% of newly diagnosed myeloma cases from the United Kingdom and was associated with a worse overall survival using conventional induction chemotherapy.12 Additionally, it is unclear whether the effects of bortezomib are altered for patients with this cytogenetic abnormality. Accordingly, in this study, the frequency of MAF deletion and the clinical characteristics and prognosis of patients with MAF deletion identified using iFISH were investigated in Chinese patients with MM.
Patients and Methods Patients During the period between January 2014 and November 2016, 200 newly diagnosed patients with MM with available iFISH results and clinical factors from Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology (Wuhan, China) were recruited. The diagnostic criteria for symptomatic myeloma used in this study were defined according to the International Myeloma Working Group.13 The International Staging System14 and Durie-Salmon15 staging systems were used to assess patients.
Interphase Fluorescence in Situ Hybridization Analysis The PCs were isolated using CD138 immunomagnetic bead selection, and CD38/CD45 flow cytometry was used to determine
that the PC purity was routinely >85%. iFISH was carried out according to the manufacturer’s instructions. Seven commercially available probes (Vysis, Downers, Grove, IL) were used in iFISH examinations. A D13S319 probe, 17p13.1 (P53), and 1q21 (CKS1B) probes were used to detect 13q deletion, 17p deletion, and 1q21 gain, respectively. The LSI IGH dual-color, break-apart rearrangement probe was used to determine the translocation involving IgH, and the probes LSI IgH/cyclin D1, LSI IgH/fibroblast growth factor receptor 3 (FGFR3), and LSI IgH/MAF were used to detect the patterns of IGH translocation, including t(11;14)(q13;q32), t(4;14)(p16;q32), and t(14;16)(q32;q23). Fluorescence images were captured with an epifluorescence microscope equipped with a charge coupled device camera and appropriate filters. Two hundred nuclei were scored for each probe. The cutoff levels for positive values for each probe in iFISH were as follows: 10% for fusion and 20% for numerical abnormalities according to the recommendations of the European Myeloma Network FISH workshops.16
Statistical Analysis We used SPSS version 16.0 (SPSS Inc) was used for all analyses. Comparisons among groups and comparisons between 2 groups were performed using 1-way analysis of variance and c2 tests; the survival carves were plotted using the KaplaneMeier method, with differences assessed using log rank tests. Differences were considered significant when the P value was <.05.
Table 1 Clinical Features of the Study Cohort Clinical Feature Male Sex Age, Years
MAF Deletion 11/30 (36.7) 60 (41-80)
No MAF Deletion 106/170 (62.4) 58 (32-82)
ISS Stage I
32/170 (18.8)
8/30 (26.7)
61/170 (35.9)
III
18/30 (60.0)
77/170 (45.3)
2/30 (6.7)
27/170 (15.9)
DS Stage II
.363 9/30 (30.0)
40/170 (23.5)
IIIA
12/30 (40.0)
51/170 (30.0)
IIIB
7/30 (23.3)
52/170 (30.6)
M Component
2
-
.428 .33
4/30 (13.3)
II
I
P .008
.666
IgG
15/30 (50.0)
84/170 (49.4)
IgA
4/30 (13.3)
38/170 (22.4)
IgD
1/30 (3.3)
6/170 (3.5)
k
2/30 (6.7)
12/170 (7.1)
l
8/30 (26.7)
27/170 (15.9)
Nonsecretory
0/30 (0)
3/170 (1.8)
Albumin, g/L
33.2 (13.3-45.7)
33.0 (18.1-50.9)
.525
Serum Calcium, mmol/L
2.54 (2.32-3.06)
2.64 (2.15-4.58)
.629
Lactate Dehydrogenase, U/L
232 (109-442)
190 (72-481)
.026
Hemoglobin, g/L
88.1 (53.9-127.0)
93.8 (55.0-150.0)
.783
b2-Microglobin, mg/L
7.16 (1.99-16.86)
9.51 (1.36-100)
.391
Abbreviations: DS ¼ Durie-Salmon staging; ISS ¼ International Staging System.
Clinical Lymphoma, Myeloma & Leukemia Month 2019
Ying Wang et al Compliance With Ethical Standards Appropriate informed consent was obtained from all donors before specimen collection in accordance with the Declaration of Helsinki and the research protocol approved by the ethics committees of Tongji Hospital.
Results Clinical Characteristics of the Patients and Correlation of MAF Deletion With Clinical Characteristics Two hundred newly diagnosed patients with MM were studied. The median age was 58.5 (range 32-82) years, and the male/female ratio was 1.41 (117/83). Of the 200 patients, the types of M protein were IgG in 99, IgA in 42, IgD in 7, k light chain in 14, l light chain in 35, and nonsecretory in 3. According to Durie and Salmon staging, 29 were stage I, 49 were stage II, and 122 were stage III. According to the International Staging System, 36 were stage I, 69 were stage II, and 95 were stage III. A variety of clinical factors were observed (Table 1). The correlation between MAF deletion and clinical characteristics was investigated. Among all factors, we found that sex and lactate dehydrogenase (LDH) were associated with MAF deletion. The percentage of male patients in MAF deletionpositive cases was 36.7% (11/30), which was significantly lower than that in MAF deletion-negative cases (62.4% [106/170]; P < .05). The median LDH of MAF deletion-positive cases was 232, which was significantly higher than that in MAF-negative cases (n ¼ 190; P < .05).
Frequencies and Patterns of Alterations in iFISH Among the 200 patients, all were analyzed for del(17p), t(14;16), t(4;14), t(11;14), rearrangement of IgH, gain of 1q21, and deletion of 13q. In total, 188 patients (94.0%) exhibited at least 1 abnormality in the regions analyzed. Thirty-nine (19.5%) had 1 abnormality, 62 (31.0%) had 2 abnormalities, and 87 (43.5%) had 3 or more abnormalities. These abnormalities were present in del(17p) in 17
(8.5%) of patients, IgH translocation in 94 (47.0%) patients, t(14;16) in 3 (1.6%) patients, t(4;14) in 31 (15.5%) patients, t(11;14) in 29 (14.5%) patients, gain of 1q21 in 108 (54.0%) of patients, and deletion of 13q in 103 (51.5%) of patients.
The Prevalence of MAF Deletion and Correlation of MAF Deletion With Frequent Fluorescence In Situ Hybridization Aberrations in Patients With MM MAF deletion was found in 30 (15.0%) of newly diagnosed patients and all 30 patients with MAF deletion had monoallelic deletion. Thus, the signal of MAF deletion was 2G1R when we observed the IgH/MAF probe and the normal signal is 2G2R (Figure 1). MAF deletion was shown to be associated with 13q deletion, FGFR3 deletion, and IgH deletion. Moreover, 13q deletion was also found to be correlated with MAF deletion, and the incidence rate of 13q deletion in MAF deletionpositive cases was significantly higher than that in MAF deletionnegative cases (70.0% vs. 48.2%, respectively, P ¼ .028). Similarly, the frequency of FGFR3 deletion in patients with MAF deletion was 23.3% (7/30), whereas that in patients without MAF deletion was 1.8% (3/170); this difference was significant (P ¼ .006). In addition, we also found that the IgH deletion was associated with MAF deletion, and the incidence rate of IgH deletion in MAF deletion-positive cases was significantly higher than that in MAF deletion-negative cases (33.3% vs. 11.7%, respectively; P ¼ .018). Notably, IgH deletion is known to be heterogeneous in MM; however, in our study, we defined IgH deletion as a monoallelic deletion of the whole IgH locus. Thus, the patterns of IgH deletion included 1F, 1R1G, 1R, and 1G. In addition, there were no obvious differences in other frequent fluorescence in situ hybridization (FISH) aberration groups, including deletion of P53, rearrangement of IgH, and gain of 1q21. Among 30 patients with MAF deletion, there were 7 patients who also had concurrent 13q deletion, FGFR3 deletion, and monoallelic deletion of the whole locus of IgH. Detailed data are shown in Table 2.
Figure 1 Fluorescence in Situ Hybridization Pattern of Normal and MAF Deletion Signals. (A) The Cell Shows 2 Green Signals and 2 Red Signals, Indicating There Is No MAF Deletion. (B) The Cell Shows 3 Green Signals and a Red Signal, Indicating It Is a Monoallelic Deletion of MAF.
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MAF Deletion in Multiple Myeloma Table 2 Correlation of MAF Deletion With Frequent FISH Aberrations in MM All Cases IgH translocation IgH deletion 17p deletion 13q deletion FGFR3 deletion 1q21 gain t(11;14) t(4;14) t(14;16)
47.0% 15.0% 8.5% 51.5% 5.0% 54.0% 14.5% 15.5% 1.5%
(94/200) (30/200) (17/200) (103/200) (10/200) (108/200) (29/200) (31/200) (3/200)
MAF Deletion 33.3% 33.3% 3.3% 70.0% 23.3% 70.0% 6.7% 6.7% 0%
Prognostic Value of MAF Deletion in Patients With Newly Diagnosed MM Follow-up data from 200 patients were analyzed to ascertain the prognostic value of MAF deletion in patients with newly diagnosed MM. The patients were treated with bortezomib-based chemotherapy regimens, including a 2-drug regimen: BD (bortezomib with dexamethasone) and 3-drug regimen: BAD (bortezomib, doxorubicin, and dexamethasone). In total, 34 patients did not complete the follow-up examination because of lack of appropriate contact information. The median follow-up time was 27 (range, 260) months. There were no significant differences in overall survival between MAF deletion-positive and MAF deletion-negative patients (Figure 2A). When we compared other FISH abnormalities, including 17p deletion, t(4;14), t(11;14), and 1q21 gain, we found that 17p deletion was still an independent prognostic factor, and the prognostic influence of MAF deletion in patients with MM was similar to that of t(4;14) and 1q21 gains (Figure 2B).
Discussion Cytogenetic abnormalities have important prognostic value in patients with MM, particularly in distinguishing high-risk patients. Conventional karyotype analysis is often hindered by the low mitotic index of MM cells in vitro and the low ratio of PCs in bone marrow samples. In contrast, FISH analysis has substantially
(10/30) (10/30) (1/30) (21/30) (7/30) (21/30) (2/30) (2/30) (0/30)
No MAF Deletion 49.4% 11.7% 9.4% 48.2% 1.8% 51.2% 15.9% 17.1% 1.8%
(84/170) (20/170) (16/170) (82/170) (3/170) (87/170) (27/170) (29/170) (3/170)
P .104 .018 .271 .028 .006 .056 .186 .147 .463
enhanced the sensitivity of cytogenetic analysis because it is applicable not only to dividing cells but also to interphase nuclei.17 Thus, the identification of specific cytogenetic abnormalities using iFISH has become a routine procedure for MM prognostic stratification. The most common commercial FISH probe set was used for the detection of del(17p), del(13q), add(1q21), t(4;14), t(11;14), and t(14;16). The prognostic significance of different FISH abnormalities, including the aforementioned probe sets, has been widely reported; however, the clinical characteristics and value of the MAF deletion have not been extensively studied, particularly in Chinese patients. In our study, we examined MAF deletion (16q-) rather than translocation between IgH and MAF (t(14;16)) because the incidence rate of t(14;16) was considerably lower than that of MAF deletion. As reported in other studies, the cytogenetic abnormality of t(14;16) was quite rare, and the incidence rates of t(14;16) were 3% and 1.9%; thus, the poor prognostic value of t(14;16) was not confirmed.11,18 In a report by Avet-Loiseau et al, the data did not support the use of t(14;16)-specific probes in the diagnostic panels of MM because the poor prognostic value of t(14;16) was not confirmed.11 The frequency of MAF deletion was 15%, which was obviously higher than that of t(14;16), which was only observed in 1.6% of individuals in our study. Because of the limited number of cases, we did not perform statistical analysis of the clinical characteristic and overall survival of these patients.
Figure 2 KaplaneMeier Plots of Overall Survival Related to Fluorescence in Situ Hybridization Abnormalities. (A) Overall Survival According to the Presence of MAF Deletion. (B) Overall Survival According to the Presence of t(11;14), 17p Deletion, 13q Deletion, 1q21 Gains, and MAF Deletion.
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Clinical Lymphoma, Myeloma & Leukemia Month 2019
Ying Wang et al Of the 200 patients enrolled in our study, the ratio of men to women was 1.41:1 (117:83), which was consistent with populationbased statistics, with incidence rates of 4.4 per 100,000 in men and 2.9 per 100,000 in women (eg, a 60:40 split).19 However, we found that MAF deletion was more common in women (22.9% of female patients vs. 9.4% of male patients; P < .05), which had not been reported in previous studies. Similarly, in a report by Boyd et al, sexdependent differences in the prevalence of IgH translocations and hyperdiploidy were observed in patients with newly presenting myeloma.12 In our study, the LDH level in patients with MAF deletion was higher than that in patients without MAF deletion. High serum LDH levels are generally associated with a worse median overall survival and worse progression-free survival in hematologic malignancies. Many studies have defined elevated serum LDH as a risk factor for MM. In survival analysis, we did not find a significant difference in overall survival between patients with MAF deletion and patients without MAF deletion. In a study by Jenner et al, del(16q) was found to be an independent prognostic marker and was associated with worse overall survival, in contrast to our results.20 This difference between studies might be the result of the small number of patients (168 patients in the report by Jenner et al, 30 patients in this series), but also to treatment and ethnic differences. The patients from the United Kingdom were treated with conventional chemotherapy, whereas all of ours received a bortezomib-based chemotherapy regimen. When we compared groups with different cytogenetic abnormalities, we found that deletion of 17p13 involving the p53 gene, which was observed in 17 (8.5%) of all patients with newly diagnosed MM in our cohort, was also considered an important adverse prognostic factor in MM. Our results were consistent with those from other studies, supporting the independent, poor prognostic significance for the presence of del(17p) on the basis of the use of bortezomib.6,21,22 Patients with MAF deletion did not show a significant difference in median overall survival time. This was likely to be a result of the use of bortezomib, which can also abrogate the adverse prognostic effects of t(4;14).21 Interestingly, we found that MAF deletion was easily combined with 13q deletion, FGFR3 deletion, and IgH deletion, which seemed to illustrate that the likelihood of hypodiploidy was increased in these patients. This result was also consistent with a report by Van Wier et al, in which 16q24 deletions were significantly enriched in hypodiploid MM compared with that in nonhyperdiploid MM.23 Hypodiploidy was associated with poor outcomes and disease progression; however, the number of patients with MAF deletion combined with 13q deletion, FGFR3 deletion, and IgH deletion was rather small, limiting the analysis of overall survival. There were certain limitations of this study because of its retrospective nature. First, the number of patients was low, particularly for positive patients, limiting the power of statistical analysis. Second, the follow-up time should be prolonged to further increase the accuracy of overall survival analysis.
Conclusion MAF deletion was much more frequent than t(14;16) in Chinese patients with MM. We found that MAF deletion was significantly
related to female sex, high levels of LDH, 13q deletion, FGFR3 deletion, and IgH deletion. With the use of bortezomib, patients with MAF deletion did not show significant differences in median overall survival time compared with patients without MAF deletion. Future studies with larger samples are needed to detect the overall survival of patients with MAF deletion combined with FGFR3, IgH, and Rb1 deletion as well as the effect of MAF deletion on de novo standard-risk or high-risk patients. Therefore, we also need to further explore the value of t(14;16)-specific probes in diagnostic panels for MM.
Clinical Practice Points Reports of the clinical characteristics and prognosis of patients
with MAF deletion have been rare, particularly for Chinese individuals. We analyzed the frequency, clinical characteristics, and prognosis of MAF deletion in Chinese patients with MM. The incidence rate of MAF deletion was 15.0% (30/200) in newly diagnosed patients and all of them had monoallelic MAF deletion. Among all factors, we found that sex and LDH were associated with MAF deletion. No differences were found in the overall survival rates of patients with MAF deletion and without MAF deletion who received bortezomib-based treatment. Future studies with larger samples are needed to detect the overall survival of patients with MAF deletion combined with FGFR3, IgH, and Rb1 deletion as well as the effect of MAF deletion on de novo standard-risk or high-risk patients.
Acknowledgments This work was supported by a grant from the National Science Foundation of China (NSFC 81770168).
Disclosure The authors have stated that they have no conflicts of interest.
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