Citations

AbstractWe previously reported an increased risk of monoclonal gammopathy of undetermined significance (MGUS) in first‐degree relatives of MGUS and multiple myeloma patients. Here, we examine whether primary cytogenetic categories of myeloma differ between patients with and without a family history of MGUS or myeloma. We studied 201 myeloma patients with available data on family history and molecular cytogenetic classification. Myeloma with trisomies was more common in probands who had an affected first‐degree relative with MGUS or myeloma compared with those without a family history (46.9% vs. 33.5%, P = 0.125); however, the difference was not statistically significant. Additional studies on the cytogenetic types of myeloma associated with familial tendency are needed.

Disease overviewMultiple myeloma accounts for approximately 10% of hematologic malignancies.DiagnosisThe diagnosis requires 10% or more clonal plasma cells on bone marrow examination or a biopsy proven plasmacytoma plus evidence of associated end‐organ damage. In addition, the presence of 60% or more clonal plasma cells in the marrow is also considered as myeloma regardless of the presence or absence of end‐organ damage.Risk stratificationIn the absence of concurrent trisomies, patients with 17p deletion, t(14;16), and t(14;20) are considered to have high‐risk myeloma. Patients with t(4;14) translocation are considered intermediate‐risk. All others are considered as standard‐risk.Risk‐adapted initial therapyStandard‐risk patients can be treated with lenalidomide plus low‐dose dexamethasone (Rd), or a bortezomib‐containing triplet such as bortezomib, cyclophosphamide, dexamethasone (VCD). Intermediate‐risk and high‐risk patients require a bortezomib‐based triplet regimen. In eligible patients, initial therapy is given for approximately 4 months followed by autologous stem cell transplantation (ASCT). Standard‐risk patients can opt for delayed ASCT if stem cells can be cryopreserved. In patients are not candidates for transplant, initial therapy is given for approximately 12–18 months.Maintenance therapyAfter initial therapy, lenalidomide maintenance is considered for standard‐risk patients who are not in very good partial response or better, while maintenance with a bortezomib‐based regimen should be considered in pateints with intermediate or high‐risk myeloma.Management of refractory diseasePatients with indolent relapse can be treated first with two‐drug or three‐drug combinations. Patients with more aggressive relapse often require therapy with a combination of multiple active agents. Am. J. Hematol. 88:225–235, 2013. © 2013 Wiley Periodicals, Inc.

Key PointsIn this study, African American MM patients have a significantly lower frequency of IgH translocations than European American patients.

To clarify the presentation and course of patients with chronic lymphocytic leukemia (CLL) and amyloidosis. Mayo databases were interrogated for patients who carried a diagnosis of amyloidosis and CLL evaluated at Mayo Clinic, Rochester from January 1974 to October 2012. Charts were abstracted and data analyzed. Of the 33 patients identified, 20 (61%) were diagnosed with AL and 13 (39%) with non‐AL. Only four patients had immunoglobulin light chain amyloidosis (AL) that could be solely attributed to the CLL clone; another six had both a plasma cell clone and a CLL clone that shared the same light chain. Median overall survival was 15.6 months for patients with AL and 58.1 months for patients with non‐AL. For patients with AL management involved chemotherapy targeted toward monoclonal plasma cells, lymphocytes or both, and for patients with non‐AL no specific amyloid treatment was administered. AL is a rare complication of CLL, but in this elderly population of patients non‐AL is nearly as common. Distinguishing between these two groups is essential since patients with non‐AL amyloidosis have better outcomes and they do not require cytotoxic chemotherapy to treat their amyloidosis. Am. J. Hematol. 88:375–378, 2013. © 2013 Wiley Periodicals, Inc.

Abstract Multiple myeloma (MM) is a heterogeneous disease with certain genetic features [eg, t(4;14), del17p] associated with worse outcome. The introduction of thalidomide, lenalidomide, and bortezomib has dramatically improved the outlook for patients with MM, but their relative benefit (or harm) for different genetic patient subgroups remains unclear. Unfortunately, the small number of patients in each subgroup frequently limits the analysis of high-risk patients enrolled in clinical trials. Strategies that result in survival of high-risk genetic subgroups approximating that of patients lacking high-risk features are said to overcome the poor prognostic impact of these high-risk features. This outcome has been difficult to achieve, and studies in this regard have so far been limited by inadequate sample size. In contrast, strategies that compare the survival of high-risk genetic subgroups randomized to different treatment arms can identify approaches that improve survival. This type of analysis is clinically useful, even if the absolute gains do not improve outcomes to levels seen in patients without high-risk cytogenetics. Reviewing available data in high-risk MM from this perspective, it appears that bortezomib has frequently been associated with improved survival, whereas thalidomide maintenance has sometimes been associated with a shorter survival.

Abstract Background: Therapy with proteasome inhibitors (PIs) is an effective strategy against multiple myeloma (MM), but a significant proportion of patients is primarily resistant or eventually becomes refractory. Paradoxical activation of phospho-Akt, induction of HSP27 and excessive proteasome activity in relation to polyubiquitinated protein burden are all mechanisms for bortezomib resistance in MM cells in vitro. Preclinical data showed investigational drug MLN9708, a specific, reversible, orally bioavailable, small molecule PI, to be active in MM cell lines, patient cells and mouse models and is currently under clinical investigation. We compared the signaling pathways induced by MLN2238, the biologically active form of MLN9708, and bortezomib to outline differences that could be employed to design rational combinations to overcome resistance. Results: We performed time course experiments in MM.1S cells with EC50 doses of MLN2238 and bortezomib and analyzed signaling pathways via western blotting. Compared to bortezomib, MLN2238 induced earlier cleavage of caspase 8, 9, 3 and PARP and a significant downregulation of XIAP starting at 12 hours. Early and persistent phosphorylation of Bad, known to protect from mitochondrial apoptosis, was observed in bortezomib-, but not MLN2238-treated cells, in which phospho-Bad was reduced at 24 hours. Similarly, MLN2238 decreased phosphorylated Akt and mTOR at 24 hours, while bortezomib-treated cells only showed subtle changes. Interestingly, both drugs caused downregulation of the mTOR downstream targets phospho-p70 S6 kinase and phospho-4E-BP1, albeit of different intensity. Induction of heat shock proteins was comparable with both PI, opening the possibilities for combination therapy of MLN2238 with HSP90 inhibitors. Importantly, the inhibitory effect on phosphorylation of Akt, mTOR and Bad persisted when MM.1S cells were treated with MLN2238 in the presence of bone marrow stromal cells (BMSC). Conclusion: We observed differences in several crucial signaling pathways upon treatment of MM.1S cells with bortezomib or MLN2238. In particular, treatment with the latter inhibited phosphorylation of Bad, Akt and mTOR, suggesting a broader pro-apoptotic and anti-proliferative profile, compared to bortezomib. MLN2238 retained the capability of targeting these substrates also in the presence of BMSC. Confirmatory data on patient-derived cells are under current investigation in our lab. We believe that these data help understanding the differences in PI pharmacodynamics and bortezomib escape. This will allow us to design new drug combinations in the future that overcome clinical resistance to PIs and improve MM patient survival. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5669. doi:1538-7445.AM2012-5669

Abstract Monoclonal gammopathy of undetermined significance (MGUS) is a precursor to multiple myeloma and related diseases. The majority of MGUS cases are characterized by the expression of immunoglobulin heavy chain (IgH); however, approximately one-fifth of MGUS cases do not present with IgH expression. These individuals have light chain MGUS (LC-MGUS), a precursor to light-chain MM (LC-MM). LC-MGUS is characterized by an absence of IgH and an abnormal free light chain ratio (FLC-R), indicating excessive expression of either κ or ≤ free light chains. LC-MGUS has a prevalence of 0.8% in the general population over the age of 50, as compared with a prevalence of 3.2% for heavy-chain MGUS (HC-MGUS) (Dispenzieri, 2010). There is currently little understanding of the association between family history of HC-MGUS or multiple myeloma (MM) and LC-MGUS. We investigated whether the prevalence of LC-MGUS is elevated in first-degree relatives of patients with either HC-MGUS or MM. HC-MGUS probands expressed IgH and were recruited through a population-based study of Olmsted County residents; MM probands consisted of both HC-MM and LC-MM and were recruited through the Mayo Clinic Hematology practice. Serum samples were collected from first-degree relatives of probands older than 40 years of age and subjected to electrophoresis, immunofixation, and free light chain assay. Prevalence of LC-MGUS was calculated in all first-degree relatives combined, and in relatives from both HC-MGUS and MM families separately. We compared the prevalence in family members to that in a well-defined Olmsted County, MN cohort (Dispenzieri, 2010) of patients aged 50 and over. A total 911 relatives of 232 MM and 97 MGUS patients were studied. LC-MGUS was detected in 17/911 (1.9%) relatives, for an age- and sex-adjusted prevalence of 1.7% (95% CI, 0.9% to 2.6%). Prevalence among relatives of MM probands (age- and sex- adjusted rate 2.1%; 95% CI, 1.0% to 3.2%) was higher than among relatives of MGUS probands (age- and sex- adjusted rate 0.6%; 95% CI, 0.0%-1.6%). There was an increased risk of LC-MGUS in relatives compared to the reference population which was predominantly due to the increased risk among relatives of MM probands (risk ratio=3.4, 95% CI 2.0, 5.51) as opposed to relatives of MGUS probands (risk ratio=1.1, 95% CI, 0.3 to 4.5). Among MM probands, there was no significant difference between the prevalence increase in relatives of the 32 probands with LC-MM and that of the relatives of the 200 probands with HC-MM (3.8 vs 3.3, ratio=1.2, 95% CI: 0.3-5.1, p=0.85). We conclude that the prevalence of LC-MGUS is significantly higher among first degree family members of all MM probands compared to the general population. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5485. doi:1538-7445.AM2012-5485

Abstract Previous epidemiological studies have suggested that African Americans (AA) are twice as likely to be diagnosed with and to die from Multiple Myeloma (MM) as compared to European Americans (EA). In recent years, however, mortality rates have become more comparable between these groups. Although socioeconomic factors could play a major role to this potential disparity, biological factors may also be responsible for influencing these differences in either incidence and/or mortality. Here we examined a multi-ethnic cohort of MM tumors to assess potential differences in the frequency of molecular events in tumors derived from either African American (AA) or European American (EA) patients. First, we compared the frequency of 14q32 translocation breakpoints at the IgH locus among a series of data from 115 AA MM patients from three studies and EA MM from the Eastern Cooperative Oncology Group (ECOG). Furthermore, we analyzed matching genome-wide copy number and transcriptional data among 47 AA MM tumors and 196 EA MM tumors to determine differences in the frequency of molecular events in tumors from these populations. Univariate analyses were conducted using the Fisher's Exact Test and p-values were calculated to measure statistical significance. We observed statistically significant differences in the frequency of IgH translocations and somatic copy number alterations. Although we did not detect differences for specific translocation subtypes, we saw a statistically significant difference in the overall frequency of IgH translocations between the two groups, which occurred more frequently in EA patients (p = 0.032). When assessing genomic copy number events previously shown to be associated with poor outcome in MM, chromosome 13 monosomy was more frequent in hyperdiploid MM from AA patients and significant after correcting for multiple testing using the Bonferoni correction method (p = 0.001). Moreover, when using the Benjamini-Hochberg multiple testing correction method, chromosome 13 monosomy remained significantly different among hyperdiploid AA patients (p = 0.0121). Chromosome 1q amplification was also significant among hyperdiploid tumors from EA patients when using this correction method (p = 0.036). No differences in the frequency of hyperdiploid status or gene expression-based subtypes were detected when comparing tumors from AA and EA patients. Our study represents the first comprehensive assessment of the frequency and distribution of molecular alterations in MM tumors from both AA and EA patients and could help shed light on possible biological features associated with population differences in incidence and outcome in MM. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5064. doi:1538-7445.AM2012-5064