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Purpose: Solitary plasmacytoma (SP) is a localized proliferation of monoclonal plasma cells in either bone or soft tissue, without evidence of multiple myeloma (MM), and whose prognosis is marked by a high risk of transformation to MM.Experimental Design: We studied the impact of FDG-PET/CT (2[18F]fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography) on the risk of transformation of SP to overt MM among other markers in a series of 43 patients diagnosed with SP.Results: Median age was 57.5 years; 48% of patients had an abnormal involved serum-free light chain (sFLC) value, and 64% had an abnormal sFLC ratio at diagnosis. Thirty-three percent had two or more hypermetabolic lesions on initial PET/CT, and 20% had two or more focal lesions on initial MRI. With a median follow-up of 50 months, 14 patients transformed to MM with a median time (TTMM) of 71 months. The risk factors that significantly shortened TTMM at diagnosis were two or more hypermetabolic lesions on PET/CT, abnormal sFLC ratio and involved sFLC, and to a lesser extent at completion of treatment, absence of normalized involved sFLC and PET/CT or MRI. In a multivariate analysis, abnormal initial involved sFLC [OR ¼ 10; 95% confidence interval (CI), 1-87; P ¼ 0.008] and PET/CT (OR ¼ 5; 95% CI, 0-9; P ¼ 0.032) independently shortened TTMM.Conclusions: An abnormal involved sFLC value and the presence of at least two hypermetabolic lesions on PET/CT at diagnosis of SP were the two predictors of early evolution to myeloma in our series. This data analysis will need confirmation in a larger study, and the study of these two risk factors may lead to a different management of patients with SP in the future. Clin Cancer Res; 20(12); 3254-60. Ó2014 AACR.

BACKGROUND: Accurate quantification of immunoglobulin A (IgA) monoclonal immunoglobulins by serum protein electrophoresis (SPEP) can be difficult and can impact the assessment of response among patients with multiple myeloma (MM). Therefore, there is a need to identify new assays that better reflect disease burden and response to treatment, and correlate with patient outcome. IgA Hevylite (HLC) measures IgA kappa and IgA lambda separately and provides precise quantitative measurements of the monoclonal IgA expression and polyclonal-isotype matched suppression. In the current study, the authors assessed the usefulness of these assays in the diagnosis of IgA MM and sought to comment on the prognostic value of the assays. METHODS: A study of 157 patients with IgA MM for whom diagnostic samples were available was performed. HLC measurements were performed on a nephelometer and the results were compared with those of electrophoresis. RESULTS: All presentation sera (100 IgA kappa specimens and 57 IgA lambda specimens) were found to have abnormal IgA HLC ratios (IgA kappa median ratio: 336. ). Of the total of 157 patients, 12 patients (8%) presented with oligosecretory myeloma (<10 g/L; including 4 patients with nonquantifiable SPEP bands). HLC uniquely allows for the measurement of isotype paired suppression, which was found to be associated with shortened overall survival in the current study. CONCLUSIONS: In the current study, IgA HLC ratios were found to be abnormal in all patients and the assay was able to produce quantifiable results in more MM sera than either SPEP or total IgA, potentially representing a solution to the issue of comigration and oligosecretory MM. These preliminary data require confirmation in larger prospective trials to validate the usefulness of IgA HLC. Cancer 2014;120:3952-7.

BACKGROUND: Lenalidomide in combination with dexamethasone (Len=Dex) is indicated for patients with recurrent=refractory multiple myeloma (RRMM) who were treated with 1 prior therapy until evidence of disease progression. The objective of the current study was to determine the efficacy and safety profile of long-term exposure to Len=Dex. METHODS: A total of 50 patients with RRMM who were treated with long-term Len for 2 years from 2 Intergroupe Francophone du My elome (IFM) centers (Lille and Nancy) were included in the current study. RESULTS: The median age of the patients was 58 years, with 30% of the patients aged > 65 years, 49% having an International Staging System stage of 2 and 3, 12% having severe renal insufficiency, and 8% demonstrating an adverse result on fluorescence in situ hybridization. Approximately 56% of the patients received treatment with Len=Dex for 3 years. The median duration of treatment with Len=Dex was 3 years (range, 2 years-7 years). The response rates for partial response or better and very good partial response or better for the overall cohort were 96% and 74%, respectively, which is similar to patients exposed to Len for 3 years. With a median follow-up of 4 years, 19 (38%) patients had stopped treatment with Len=Dex. The time to disease progression rate at 37 months was 78% and 91%, respectively, in patients exposed to Len for 2 years to < 3 years and for 3 years (P 5 025). The safety profile was manageable, similar to that of Len when administered for a shorter period of time; 16% of patients had grade 3 to 4 neutropenia, 6% had thrombopenia, 6% had anemia, and 20% experienced thromboembolic events, all of venous type. The annual incidence rate of second primary malignancy was 1.96% in the current series. CONCLUSIONS: The results of the current study confirmed that the Len=Dex combination is feasible for long-term use in patients with RRMM, with a significant benefit noted in terms of time to disease progression for prolonged treatment with Len=Dex. Cancer 2013;119:3680-6.