A Single Reference Interval for Interpreting Serum Free Light Chains across Patients with Varying Renal Function.

BACKGROUND: Serum free light chain (sFLC) assays are interpreted using a sFLC-ratio-based reference interval (manufacturer's interval) that was defined using a cohort of healthy patients. However, renal impairment elevates the sFLC-ratio, leading to a high false positive rate when using the manufacturer's interval. Prior studies have developed renal-specific reference intervals; however, this approach has not been widely adopted due to practical limitations. Thus, there remains a critical need for a renally robust sFLC interpretation method. METHODS: Retrospective data mining was used to define patient cohorts that reflect the spectrum of renal function seen in clinical practice. Two new reference intervals, one based on the sFLC-ratio and one based on a novel principal component analysis (PCA)-based metric, were developed for the FREELITE assay (Binding Site) on the Roche Cobas c501 instrument (Roche). RESULTS: Compared to the manufacturer's reference interval, both new methods exhibited significantly lower false positive rates and greater robustness to renal function while maintaining equivalent sensitivity for monoclonal gammopathy (MG) diagnosis. While not significantly different, the point estimate for sensitivity was highest for the PCA-based approach. CONCLUSION: Renally robust sFLC interpretation using a single reference interval is possible given a reference cohort that reflects the variation in renal function observed in practice. Further studies are needed to achieve sufficient power and determine if the novel PCA-based metric offers superior sensitivity for MG diagnosis. These new methods offer the practical advantages of not requiring an estimated glomerular filtration rate result or multiple reference intervals, thereby lowering practical barriers to implementation.

Renal failure among multiple myeloma patients utilizing carfilzomib and associated factors in the "real world".

Carfilzomib, a next-generation proteasome inhibitor, improves outcomes in patients with multiple myeloma (MM); however, a proportion of those treated develop renal failure due to adverse event, comorbidity, or myeloma progression. The rate of renal failure and associated risk factors remains unknown in real-world populations. Adults with relapsed/refractory MM who received carfilzomib between the years 2013 and 2016 were identified in the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked databases. Renal failure was defined using the corresponding International Classification of Diseases, Ninth Revision (ICD-9) and Tenth Revision (ICD-10) diagnostic codes and procedure codes for dialysis. Patients with a pre-existing diagnosis of renal failure were excluded to distinguish an adverse event from comorbidity. Multivariate cox regression analysis was performed to identify the variables independently associated with the development of renal failure among MM patients utilizing carfilzomib. A total of 1950 patients were included in the analysis. Renal failure developed in 22% of patients during the study period. The median time to development of renal failure from first carfilzomib administration was 1.6 months (range < 0.1-23.3). Increasing age (adjusted hazard ratio [aHR] 1.01 per year, p = 0.018), pre-existing heart failure (aHR 1.50, p = 0.005), and pre-existing chronic kidney disease (aHR 2.00, p < 0.001) were associated with a higher risk of developing renal failure. Renal failure occurred in up to 22% of patients on carfilzomib therapy. The exact cause and mechanism of renal failure cannot be determined from our study and may be multifactorial. Future studies are needed to further understand the cause of renal failure among patients on carfilzomib and devise strategies to mitigate the risk.

Utilization of radiation therapy in multiple myeloma: trends and changes in practice.

Plasma cell disorders including plasmacytomas and multiple myeloma (MM) are exquisitely radiosensitive, and thus, radiation therapy (XRT) is used effectively in their management. The role of XRT in the setting of novel MM therapeutics has not been explored. The 2016 National Cancer Database (NCDB) for MM with patients diagnosed between 2004 and 2013 was studied. Association between utilization of XRT as part of initial therapy and patient, disease, or treating facility characteristics was studied. A total of 111,281 cases with 91.6% MM, 7% osseous plasmacytoma (PLA-O), and 1.4% extramedullary plasmacytoma (PLA-E) were identified. XRT was utilized as part of initial therapy in 25.4% cases, including 69.3% of PLA-O, 60% of PLA-E, and 21.5% of MM patients. Patients with PLA-E and MM were significantly less likely to receive XRT as compared to PLA-O (p < 0.001). A significantly decreased use of XRT was noted over time (p < 0.001), and for advancing patient age (p < 0.001), women (p < 0.001), and blacks (p < 0.001), and with increasing income (p = 0.015). Patients with Medicare were less likely to receive XRT (OR 0.86, 95% CI 0.78, 0.94) as compared to uninsured as were those with initial treatment at academic or high-volume facilities and facilities performing stem cell transplant. There was overall decreased utilization of XRT in recent years, possibly due to advent of efficacious systemic agents for MM therapy, with a higher XRT utilization for plasmacytomas. Patterns of XRT use need to be explored prospectively, so that uniform standards of healthcare delivery can be maintained and treatment heterogeneity can be minimized.

A deficit-accumulation frailty index predicts survival outcomes in patients with gynecologic malignancy.

OBJECTIVE: To determine the association between scores from a 25-item patient-reported Rockwood Accumulation of Deficits Frailty Index (DAFI) and survival outcomes in gynecologic cancer patients. METHODS: A frailty index was constructed from the SEER-MHOS database. The DAFI was applied to women age ≥ 65 diagnosed with all types of gynecologic cancers between 1998 and 2015. The impact of frailty status at cancer diagnosis on overall survival (OS) was analyzed using Kaplan-Meier curves and Cox proportional hazards regression. RESULTS: In this cohort (n = 1336) the median age at diagnosis was 74 (range 65-97). Nine hundred sixty-two (72%) women were Caucasian and 132 (10%) were African-American. Overall, 651(49%) of patients were considered frail. On multivariate analysis, frail patients had a 48% increased risk for death (aHR 1.48; 95% CI 1.29-1.69; P < 0.0001). Each 10% increase in frailty index was associated with a 16% increased risk of death (aHR, 1.16; 95% CI, 1.11 to 1.21; P < 0.0001). In subgroup analyses of the varying cancer types, the association of frailty status with prognosis was fairly consistent (aHR 1.15-2.24). The DAFI was more prognostic in endometrial (aHR 1.76; 95% CI 1.41-2.18, P < 0.0001) and vaginal/vulvar (aHR 1.94; 95% CI 1.34-2.81, P = 0.0005) cancers as well as patients with loco-regional disease (aHR 1.94; 95% CI 1.62-2.33, P < 0.0001). CONCLUSIONS: Frailty appears to be a significant predictor of mortality in gynecologic cancer patients regardless of chronological age. This measure of functional age may be of particular utility in women with loco-regional disease only who otherwise would have a favorable prognosis.

Disparities in health care affordability among childhood cancer survivors persist following the Affordable Care Act.

BACKGROUND: The Affordable Care Act (ACA) included many provisions that may have improved access to care for childhood cancer survivors (CCS). In this study, we sought to compare health insurance coverage and the affordability of health care among adult childhood CCS before and after the implementation of the ACA. PROCEDURE: Using data from the National Health Interview Survey (NHIS), two cohorts of CCS age 21-65 years old and matched (1:3) controls without a history of cancer were identified. A difference-in-differences analysis was used to compare insurance coverage and health care affordability pre- (2011-2013) and post-ACA (2015-2017). RESULTS: There were 309 CCS identified in the pre-ACA cohort and 324 in the post-ACA cohort. The two cohorts were similar in demographic composition. Prior to the ACA, CCS were 39% more likely to be uninsured than their peers (p = .046). Post, there was no difference in the odds of being uninsured between CCS and their peers. Following implementation of the ACA, the proportion of CCS who reported having difficulty with the affordability of health care decreased (p = .013) as did the proportion reporting skipping needed care due to cost (p < .001). However, 13% of CCS still reported being uninsured, 36% reported difficulty paying for health care, and 13% reported foregoing needed care due to cost. Relative to their peers, CCS saw improvement in foregoing needed care due to cost, but disparities still remain. CONCLUSIONS: Although improvements were observed, health care affordability, and medical nonadherence remains a problem for CCS. IMPLICATIONS FOR CANCER SURVIVORS: Additional efforts are needed to improve health care affordability among CCS.

Measuring cardiopulmonary complications of carfilzomib treatment and associated risk factors using the SEER-Medicare database.

BACKGROUND: Carfilzomib improves survival in patients with recurrent myeloma. Given the strict eligibility criteria in clinical trials, the actual frequency of cardiac adverse events (CAEs) and pulmonary adverse events (PAEs) and the risk factors associated with these AEs in the general population need to be established. METHODS: The authors extracted myeloma cases in the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database from 2000 through 2013 and corresponding claims through 2014. They then identified patients who received carfilzomib during their disease course. Subsequently, the International Classification of Diseases, Ninth Revision (ICD-9) was used to identify all the codes for CAEs, PAEs, and respiratory infections associated with carfilzomib use. Preexisting diagnoses corresponding to the CAEs and PAEs of interest were excluded to distinguish toxicity from comorbidity. Multivariate Cox regression was performed to determine those variables independently associated with the development of CAEs and PAEs. RESULTS: Of the 635 patients analyzed, the median age was 72 years (range, 36-94 years); 55% of the patients were male and 79% were white. The median duration of carfilzomib treatment was 58 days (range, 1-716 days). Overall, approximately 66% of the patients had codes for either CAEs or PAEs. In terms of CAEs, approximately 22% of patients developed hypertension, 15% developed peripheral edema, and 14% experienced heart failure. With regard to PAEs, approximately 28% of patients developed dyspnea, 15% developed cough, and 15% developed pneumonia. Only chronic obstructive pulmonary disease (COPD) was found to be independently associated with the development of CAEs. Patients with preexisting COPD were found to have a 40% increase in their hazard of developing CAEs (adjusted hazard ratio, 1.40; 95% CI, 1.03-1.90). CONCLUSIONS: In older adults with myeloma who are undergoing treatment with carfilzomib, new cardiac and pulmonary diagnoses were common. Patients with preexisting COPD were found to be at an increased risk of developing CAEs.

DCEP and bendamustine/prednisone as salvage therapy for quad- and penta-refractory multiple myeloma.

Multiple myeloma (MM) almost invariably progresses through novel therapies. Patients with quad-refractory MM (refractory to bortezomib, carfilzomib, lenalidomide, and pomalidomide) and penta-refractory MM (additional refractoriness to daratumumab) have few treatment options. Two chemotherapy regimens, bendamustine/prednisone (BP) and dexamethasone, cyclophosphamide, etoposide, and cisplatin (DCEP), are often used in quad- and penta-refractory MM, but there are limited data on outcomes in this heavily pre-treated population. We conducted a single-center retrospective study to identify all patients who received DCEP and/or BP for quad- or penta-refractory MM. Disease response and refractoriness were defined by International Myeloma Working Group criteria. The primary endpoint was overall response rate (ORR). Secondary endpoints included overall survival (OS), progression-free survival (PFS), and duration of response (DOR). We identified 27 patients who received BP for quad- or penta-refractory MM. The median number of prior lines of therapy was 6. The ORR for BP was 26%. The median PFS for BP was 1.4 months (95% CI 1.1-1.6) and median OS was 8.7 months (95% CI 2.3-15.0). Patients treated with cyclophosphamide had less response to BP. Thirty-one patients received DCEP for quad-refractory or penta-refractory MM. The median number of prior treatment regimens was 8. The ORR to DCEP was 35%. The median PFS was 2.7 months (95% CI 1.5-3.8) and median OS was 6.2 months (95% CI 4.4-7.8). DCEP and BP retain efficacy in quad- and penta-refractory MM. Our analysis supports prospective study of these regimens, possibly in combination or in comparison with other agents in this area of unmet need.

Mobilization of allogeneic peripheral blood stem cell donors with intravenous plerixafor mobilizes a unique graft.

A single subcutaneous (SC) injection of plerixafor results in rapid mobilization of hematopoietic progenitors, but fails to mobilize 33% of normal allogeneic sibling donors in 1 apheresis. We hypothesized that changing the route of administration of plerixafor from SC to IV may overcome the low stem cell yields and allow collection in 1 day. A phase 1 trial followed by a phase 2 efficacy trial was conducted in allogeneic sibling donors. The optimal dose of IV plerixafor was determined to be 0.32 mg/kg. The primary outcome of reducing the failure to collect ≥2 × 106 CD34+/kg recipient weight in 1 apheresis collection to ≤10% was not reached. The failure rate was 34%. Studies evaluating the stem cell phenotype and gene expression revealed a novel plasmacytoid dendritic cell precursor preferentially mobilized by plerixafor with high interferon-α producing ability. The observed cytomegalovirus (CMV) viremia rate for patients at risk was low (15%), as were the rates of acute grade 2-4 graft-versus-host disease (GVHD) (21%). Day 100 treatment related mortality was low (3%). In conclusion, plerixafor results in rapid stem cell mobilization regardless of route of administration and resulted in novel cellular composition of the graft and favorable recipient outcomes. These trials were registered at clinicaltrials.gov as #NCT00241358 and #NCT00914849.

Predicting venous thromboembolism in multiple myeloma: development and validation of the IMPEDE VTE score.

Venous thromboembolism (VTE) is a common cause of morbidity and mortality among patients with multiple myeloma (MM). The International Myeloma Working Group (IMWG) developed guidelines recommending primary thromboprophylaxis, in those identified at high-risk of VTE by the presence of risk factors. The National Comprehensive Cancer Network (NCCN) has adopted these guidelines; however, they lack validation. We sought to develop and validate a risk prediction score for VTE in MM and to evaluate the performance of the current IMWG/NCCN guidelines. Using 4446 patients within the Veterans Administration Central Cancer Registry, we used time-to-event analyses to develop a risk score for VTE in patients with newly diagnosed MM starting chemotherapy. We externally validated the score using the Surveillance, Epidemiology, End Results (SEER)-Medicare database (N = 4256). After identifying independent predictors of VTE, we combined the variables to develop the IMPEDE VTE score (Immunomodulatory agent; Body Mass Index ≥25 kg/m2 ; Pelvic, hip or femur fracture; Erythropoietin stimulating agent; Dexamethasone/Doxorubicin; Asian Ethnicity/Race; VTE history; Tunneled line/central venous catheter; Existing thromboprophylaxis). The score showed satisfactory discrimination in the derivation cohort, c-statistic = 0.66. Risk of VTE significantly increased as score increased (hazard ratio 1.20, P = <.0001). Within the external validation cohort, IMPEDE VTE had a c-statistic of 0.64. For comparison, when evaluating the performance of the IMWG/NCCN guidelines, the c-statistic was 0.55. In summary, the IMPEDE VTE score outperformed the current IMWG/NCCN guidelines and could be considered as the new standard risk stratification for VTE in MM.

Prognostic indicators in primary plasma cell leukaemia: a multicentre retrospective study of 117 patients.

We report a multicentre retrospective study that analysed clinical characteristics and outcomes in 117 patients with primary plasma cell leukaemia (pPCL) treated at the participating institutions between January 2006 and December 2016. The median age at the time of pPCL diagnosis was 61 years. Ninety-eight patients were treated with novel agents, with an overall response rate of 78%. Fifty-five patients (64%) patients underwent upfront autologous stem cell transplantation (ASCT). The median follow-up time was 50 months (95% confidence interval [CI] 33; 76), with a median overall survival (OS) for the entire group of 23 months (95% CI 15; 34). The median OS time in patients who underwent upfront ASCT was 35 months (95% CI 24·3; 46) as compared to 13 months (95% CI 6·3; 35·8) in patients who did not receive ASCT (P = 0·001). Multivariate analyses identified age ≥60 years, platelet count ≤100 × 109 /l and peripheral blood plasma cell count ≥20 × 109 /l as independent predictors of worse survival. The median OS in patients with 0, 1 or 2-3 of these risk factors was 46, 27 and 12 months, respectively (P < 0·001). Our findings support the use of novel agents and ASCT as frontline treatment in patients with pPCL. The constructed prognostic score should be independently validated.

Falls in older adults with multiple myeloma.

OBJECTIVE: To examine the prevalence of falls, factors associated with falls and the relationship between falls and survival in older adults with multiple myeloma. METHODS: In an analysis of the Surveillance, Epidemiology and End Results (SEER)-Medicare Health Outcomes Survey (MHOS)-linked database, we examined 405 older adults with multiple myeloma (MM) and 513 matched non-cancer controls. The primary outcome was self-reported within the past 12 months. Age, race, gender, symptoms, and comorbidities were self-reported in the MHOS. Survival was calculated from SEER data. RESULTS: Of the patients with MM, 171 were within 1 year of diagnosis (cohort 1) and 234 were ≥1 year postdiagnosis (cohort 2). Patients in cohorts 1 and 2 were more likely to have fallen than controls (26% and 33% vs 23%, P = .012). On multivariate analysis, among patients with myeloma (combined cohorts 1 and 2), factors associated with falls included self-report of fatigue (aOR 2.52 [95% CI 1.34-4.93]), depression (aOR 1.90 [95% CI 1.14-3.18]), or poorer general health (aOR 1.86 [95% CI 1.05-3.36]). Falls were not associated with survival. CONCLUSIONS: Older adults with MM have a greater prevalence of falls than matched controls. Self-reported fatigue, depression, and poorer general health are associated with greater odds of falls.

Fresh or Cryopreserved CD34+-Selected Mobilized Peripheral Blood Stem and Progenitor Cells for the Treatment of Poor Graft Function after Allogeneic Hematopoietic Cell Transplantation.

CD34+-selected stem cell boost (SCB) without conditioning has recently been utilized for poor graft function (PGF) after allogeneic hematopoietic stem cell transplantation with promising results. Unfortunately, many patients have been unable to receive the boost infusion as their donors were unwilling or unable to undergo an additional stem cell collection. Therefore, we conducted this study utilizing either fresh or cryopreserved peripheral blood stem cell products to create CD34+-selected boost infusions for the treatment of PGF. Additionally, to explore relationship of CD34+ dose and response, we included a cohort of donors mobilized with plerixafor in addition to the standard granulocyte colony-stimulating factor (G-CSF). Twenty-six patients with PGF were included in this study. Seventeen donor-recipient pairs were enrolled onto the prospective study; an additional 9 patients treated off protocol were reviewed retrospectively. Three different donor products were used for CD34+ selection: (1) fresh mobilized product using G-CSF only, (2) fresh mobilized products using G-CSF and plerixafor, and (3) cryopreserved cells mobilized with G-CSF. CD34+ cell selection was performed using a CliniMACS. The infusion was not preceded by administration of any chemotherapy or conditioning regimen. The primary objective was hematologic response rate and secondary objectives included CD34+ yields, incidence and severity of acute and chronic graft-versus-host disease (GVHD), overall survival (OS), and relapse-free survival (RFS). The median post-selection CD34+ counts per kilogram of recipient weight were 3.1 × 106, 10.9 × 106, and 1 × 106 for G-CSF only, G-CSF plus plerixafor, and cryopreserved products, respectively. The median CD34+ yields (defined as the number of CD34+ cells after selection/CD34+ cells before CD34+ selection) were 69%, 66%, and 28% for G-CSF only, G-CSF plus plerixafor, and cryopreserved products, respectively. After SCB, 16 of the 26 recipients (62%) had a complete response, including 5 of 8 (63%) who received cryopreserved products. Five had a partial response (19%), resulting in an overall response rate of 81%. One-year RFS and OS were 50% and 65%, respectively. There was no treatment-related toxicity reported other than GVHD: 6 (23%) developed acute GVHD (2 grade I and 4 grade II) and 8 (31%) developed chronic GVHD (2 limited and 6 extensive). Cryopreserved products are viable alternatives to create SCB for the treatment of PGF. When collecting fresh products is an option, the addition of plerixafor increases CD34+ yield over G-CSF alone; however, it is currently unclear if the CD34+ cell dose impacts the efficacy of the SCB.

Results of a Prospective Randomized, Open-Label, Noninferiority Study of Tbo-Filgrastim (Granix) versus Filgrastim (Neupogen) in Combination with Plerixafor for Autologous Stem Cell Mobilization in Patients with Multiple Myeloma and Non-Hodgkin Lymphoma.

Autologous hematopoietic stem cell transplantation (auto-HSCT) improves survival in patients with multiple myeloma (MM) and non-Hodgkin lymphoma (NHL). Traditionally, filgrastim (Neupogen; recombinant G-CSF) has been used in as a single agent or in combination with plerixafor for stem cell mobilization for auto-HSCT. In Europe, a biosimilar recombinant G-CSF (Tevagrastim) has been approved for various indications similar to those of reference filgrastim, including stem cell mobilization for auto-HSCT; however, in the United States, tbo-filgrastim (Granix) is registered under the original biological application and is not approved for stem cell mobilization. In retrospective studies, stem cell mobilization with tbo-filgrastim has shown similar efficacy and toxicity as filgrastim, but no prospective studies have been published to date. We have conducted the first prospective randomized trial comparing the safety and efficacy of tbo-filgrastim in combination with plerixafor with that of filgrastim in combination with plerixafor for stem cell mobilization in patients with MM and NHL. This is a phase 2 prospective randomized (1:1) open-label single-institution noninferiority study of tbo-filgrastim and filgrastim with plerixafor in patients with MM or NHL undergoing auto-HSCT. Here 10 µg/kg/day of tbo-filgrastim/filgrastim was administered s.c. for 5 days (days 1 to 5). On day 4 at approximately 1800 hours, 0.24 mg/kg of plerixafor was administered s.c. Apheresis was performed on day 5 with a target cumulative collection goal of at least 5.0 × 106 CD34+ cells/kg. The primary objective was to compare day 5 CD34+ cells/kg collected. Secondary objectives included other mobilization endpoints, safety, engraftment outcomes, and hospital readmission rate. A total of 97 evaluable patients were enrolled (tbo-filgrastim, n = 46; filgrastim, n = 51). Tbo-filgrastim was not inferior to filgrastim in terms of day 5 CD34+ cell collection (mean, 11.6 ± 6.7 CD34+ cells/kg versus 10.0 ± 6.8 CD34+ cells/kg. Multivariate analysis revealed a trend toward increased mobilization in the tbo-filgrastim arm, but this was not statistically significant. The tbo-filgrastim and filgrastim arms were similar in all secondary endpoints. Tbo-filgrastim is not inferior in efficacy and has similar safety compared to reference filgrastim when used for stem cell mobilization in patients with MM and NHL. Granix can be safely used instead of Neupogen for stem cell collection in patients undergoing auto-HSCT for MM or NHL. The study is registered at https://clinicaltrials.gov/ct2/show/NCT02098109.

Racial disparities in treatment use for multiple myeloma.

BACKGROUND: Recent treatment advances have greatly improved the prognosis of patients with multiple myeloma. However, some of these newer, more effective treatments are intensive and expensive and their use remains low, particularly among black patients. METHODS: In the current study, the authors reviewed the use patterns of stem cell transplantation and bortezomib using the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. RESULTS: After controlling for overall health and potential access barriers, black patients were found to be 37% (P<.0001) less likely to undergo stem cell transplantation, and 21% (P<.0001) less likely to be treated with bortezomib. Moreover, the authors found that the underuse of these treatments was associated with a 12% increase in the hazard ratio for death among black patients (P = 0.0007). CONCLUSIONS: Eliminating health disparities, a current focus of US public policy, is highly complex, as illustrated by the results of the current study. In patients with multiple myeloma, treatment disparities are not completely explained by potential access barriers. Additional factors, such as structural barriers in the health care system and individual decision making among black and white patients, must be explored to fully explain the disparity. Cancer 2017;123:1590-1596. © 2017 American Cancer Society.

Similar survival outcomes in patients with biclonal versus monoclonal myeloma: a multi-institutional matched case-control study.

Multiple myeloma is a plasma cell malignancy characterized by clonal proliferation of plasma cells in the bone marrow and associated organ damage. Usually, patients with myeloma present with a single monoclonal protein in serum and/or urine constituted by one heavy chain and one light chain. In less than 5% of the patients, more than one monoclonal protein can be identified. The aim of our retrospective multicenter matched case-control study was to describe the characteristics of cases with biclonal myeloma and compare them against a control group of monoclonal myeloma patients matched by age, sex, and year of diagnosis. A total of 50 previously untreated cases with biclonal myeloma and 50 matched controls with monoclonal myeloma were included in this study. The controls were matched (1:1) for age, sex, year of diagnosis, and participating center. There were no differences in the rates of anemia (52 vs. 59%; p = 0.52), renal dysfunction (36 vs. 34%; p = 0.83), hypercalcemia (9 vs. 16%; p = 0.28), or presence of lytic lesions (23 vs. 16%; p = 0.38) between groups. Similarly, there was no difference in the rates of overall response to therapy (85 vs. 90%; p = 0.88) or survival rates of cases with biclonal myeloma and controls with monoclonal myeloma (4-year survival 72 vs. 76%; p = 0.23). Results of our study suggest that patients with biclonal myeloma have similar response and survival rates than patients with monoclonal myeloma.

IgM myeloma: A multicenter retrospective study of 134 patients.

IgM myeloma is a rare hematologic malignancy for which the clinicopathological features and patient outcomes have not been extensively studied. We carried out a multicenter retrospective study in patients with diagnosis of IgM myeloma defined by >10% marrow involvement by monoclonal plasma cells, presence of an IgM monoclonal paraproteinemia of any size, and anemia, renal dysfunction, hypercalcemia, lytic lesions and/or t(11;14) identified by FISH. A total of 134 patients from 20 centers were included in this analysis. The median age at diagnosis was 65.5 years with a male predominance (68%). Anemia, renal dysfunction, elevated calcium and skeletal lytic lesions were found in 37, 43, 19, and 70%, respectively. The median serum IgM level was 2,895 mg dL-1 with 19% of patients presenting with levels >6,000 mg dL-1 . International Staging System (ISS) stages 1, 2, and 3 were seen in 40 (33%), 54 (44%), and 29 (24%) of patients, respectively. The malignant cells expressed CD20 (58%) and cyclin D1 (67%), and t(11;14) was the most common cytogenetic finding (39%). The median overall survival (OS) was 61 months. Higher ISS score was associated with worse survival (P = 0.02). Patients with IgM myeloma present with similar characteristics and outcomes as patients with more common myeloma subtypes.