Predictive role of interphase cytogenetics for survival of patients with multiple myeloma

Precision medicine for multiple myeloma: The case for translocation (11;14)

The t(11;14) translocation is among the most prevalent cytogenetic abnormalities in multiple myeloma (MM), distinguished by its unique features and biology that have been thoroughly explored for decades. What further sets this MM subtype apart is its oscillating prognostic significance, from initially being considered a favorable alteration to intermediate risk and potential future reclassification as favorable risk. Despite not being inherently a high-risk alteration indicative of an aggressive phenotype, it appears that t(11;14)-MM is less responsive to novel agents like proteasome inhibitors and immunomodulatory drugs which have otherwise transformed the disease's treatment landscape, perhaps partially explained by its reduced propensity for immunoglobulin production and oligosecretory nature. However, its distinct reliance on Bcl-2 has heightened its sensitivity to venetoclax. Further subclassification based on morphological and genomic characteristics could enhance our prediction models of treatment responses and enable more tailored therapeutic strategies for patients. This review aims to encapsulate the existing research evidence in this area.

Bone marrow microenvironment- induced regulation of Bcl-2 family members in multiple myeloma (MM): Therapeutic implications

In Multiple Myeloma (MM) the finely tuned homeostasis of the bone marrow (BM) microenvironment is disrupted. Evasion of programmed cell death (apoptosis) represents a hallmark of cancer. Besides genetic aberrations, the supportive and protective MM BM milieu, which is constituted by cytokines and growth factors, intercellular and cell: extracellular matrix (ECM) interactions and exosomes, in particular, plays a key role in the abundance of pro-survival members of the Bcl-2 family (i.e., Mcl-1, Bcl-2, and Bcl-xL) in tumor cells. Moreover, microenvironmental cues have also an impact on stability- regulating post-translational modifications of anti-apoptotic proteins including de/phosphorylation, polyubiquitination; on their intracellular binding affinities, and localization. Advances of our molecular knowledge on the escape of cancer cells from apoptosis have informed the development of a new class of small molecules that mimic the action of BH3-only proteins. Indeed, approaches to directly target anti-apoptotic Bcl-2 family members are among today's most promising therapeutic strategies and BH3-mimetics (i.e., venetoclax) are currently revolutionizing not only the treatment of CLL and AML, but also hold great therapeutic promise in MM. Furthermore, approaches that activate apoptotic pathways indirectly via modification of the tumor microenvironment have already entered clinical practice. The present review article will summarize our up-to-date knowledge on molecular mechanisms by which the MM BM microenvironment, cytokines, and growth factors in particular, mediates tumor cell evasion from apoptosis. Moreover, it will discuss some of the most promising science- derived therapeutic strategies to overcome Bcl-2- mediated tumor cell survival in order to further improve MM patient outcome.

Comparison of laboratory methods for the detection of neoplastic plasma cells in plasma cell dyscrasias

Aims

To compare the ability of immunohistochemistry (IHC), multiparameter flow cytometry (MFC) and fluorescence in situ hybridisation (FISH) to detect clonal plasma cells. We also attempted to outline a testing strategy for monitoring multiple myeloma patients.

Methods

A retrospective review was performed on 278 CD138+sorted FISH studies from November 2019 to December 2020 along with their concurrent IHC and MFC results. A p value was computed using McNemar’s test for paired data. Association was calculated using the non-parametric Spearman correlation coefficient.

Results

Using the Mc Nemar’s test for paired data, CD138+sorted FISH studies achieved the highest proportion of positive results and was significantly greater than MFC (63% vs 53%, p=0.01). FISH had more positive results than IHC, although this did not reach statistical significance (60% vs 57%, p=0.34). IHC and MFC had high correlation and high agreement (90.3% agreement, kappa=0.805, p<0.0001). CD138+sorted FISH studies achieved the highest proportion of positive results relative to IHC and MFC, indicating that it may be a reliable marker for clonal plasma cell detection.

Conclusions

While CD138+sorted FISH is primarily used for prognostication, it may be employed as a single test for detection and monitoring clonality in certain scenarios. Further studies are needed to monitor the outcomes of patients with positive FISH and negative IHC and MFC. Additionally, there was high agreement between IHC and MFC, suggesting that performing both tests may not be necessary.

Low dose venetoclax in combination with bortezomib, daratumumab, and dexamethasone for the treatment of relapsed/refractory multiple myeloma patients-a single-center retrospective study

Venetoclax is a BCL-2 inhibitor currently indicated for use in treating hematologic malignancies with recommended doses ranging from 400 to 600 mg/day. Although currently not FDA-approved to treat multiple myeloma (MM) patients, there is a growing number of reports indicating its efficacy as a salvage therapy for these patients, especially for those with the t(11;14) chromosomal marker. These studies, however, have also indicated that venetoclax given at doses ≥ 400 mg/day can cause serious adverse events (SAEs) especially when administered with bortezomib, commonly related to infections. The purpose of this single-center retrospective study was to determine the efficacy of low dose venetoclax (defined as ≤ 250 mg/day) in combination with low dose bortezomib (defined as 1.0 mg/m² per dose), daratumumab, and dexamethasone (Dvvd) as a salvage therapy for relapsed/refractory myeloma (RRMM) patients. Twenty-two RRMM patients were given venetoclax orally at doses ranging from 100 to 250 mg daily using this four-drug regimen. While the low doses resulted in reduced venetoclax efficacy among those lacking t(11;14) (overall response rate [ORR] = 31%), those harboring the t(11;14) marker exhibited an ORR of 80%. Notably, this response was without frequent infection-related SAEs as reported in previous studies. Together, the results of this study demonstrate that treatment of t(11;14) positive RRMM patients with Dvvd is both effective and well-tolerated.

Chromosome 1q21 abnormalities in multiple myeloma

Gain of chromosome 1q (+1q) is one of the most common recurrent cytogenetic abnormalities in multiple myeloma (MM), occurring in approximately 40% of newly diagnosed cases. Although it is often considered a poor prognostic marker in MM, +1q has not been uniformly adopted as a high-risk cytogenetic abnormality in guidelines. Controversy exists regarding the importance of copy number, as well as whether +1q is itself a driver of poor outcomes or merely a common passenger genetic abnormality in biologically unstable disease. Although the identification of a clear pathogenic mechanism from +1q remains elusive, many genes at the 1q21 locus have been proposed to cause early progression and resistance to anti-myeloma therapy. The plethora of potential drivers suggests that +1q is not only a causative factor or poor outcomes in MM but may be targetable and/or predictive of response to novel therapies. This review will summarize our current understanding of the pathogenesis of +1q in plasma cell neoplasms, the impact of 1q copy number, identify potential genetic drivers of poor outcomes within this subset, and attempt to clarify its clinical significance and implications for the management of patients with multiple myeloma.

Targeting BCL-2 with venetoclax and dexamethasone in patients with relapsed/refractory t(11;14) multiple myeloma

Venetoclax (Ven) is a selective small-molecule inhibitor of BCL-2 that exhibits antitumoral activity against MM cells with t(11;14) translocation. We evaluated the safety and efficacy of Ven and dexamethasone (VenDex) combination in patients with t(11;14) positive relapsed/refractory (R/R) multiple myeloma (MM). This open-label, multicenter study had two distinct phases (phase one [P1], phase two [P2]). Patients in both phases received VenDex (oral Ven 800 mg/day + oral Dex 40 mg [20 mg for patients ≥75 years] on days 1, 8, and 15, per 21-day cycle). The primary objective of the P1 VenDex cohort was to assess safety and pharmacokinetics. Phase two further evaluated efficacy with objective response rate (ORR) and very good partial response or better. Correlative studies explored baseline BCL2 (BCL-2) and BCL2L1 (BCL-X_L ) gene expression, cytogenetics, and recurrent somatic mutations in MM. Twenty and 31 patients in P1 and P2 with t(11;14) positive translocation received VenDex. P1/P2 patients had received a median of 3/5 lines of prior therapy, and 20%/87% were refractory to daratumumab. Predominant grade 3/4 hematological adverse events (AEs) with ≥10% occurrence included lymphopenia (20%/19%), neutropenia (15%/7%), thrombocytopenia (10%/10%), and anemia (5%/16%). At a median follow-up of 12.3/9.2 months, ORR was 60%/48%. The duration of response estimate at 12 months was 50%/61%, and the median time to progression was 12.4/10.8 months. In biomarker evaluable patients, response to VenDex was independent of concurrent del(17p) or gain(1q) and mutations in key oncogenic signaling pathways, including MAPK and NF-kB. VenDex demonstrated efficacy and manageable safety in heavily-pre-treated patients with t(11;14) R/R MM.

Venetoclax in combination with carfilzomib and dexamethasone in relapsed/refractory multiple myeloma harboring t(11,14)(q13;q32): two case reports and a review of the literature

Background

Multiple myeloma has witnessed significant advances due to the approval of many novel agents. However, in spite of all these new developments, multiple myeloma remains an incurable disease with inevitable relapse in the majority of patients. Venetoclax is a selective antiapoptotic protein B-cell lymphoma 2 inhibitor that induces cell death in multiple myeloma cells, particularly in those harboring t(11,14)(q13;q32). We report two cases of patients with multiple myeloma with t(11,14)(q13;q32) who were treated with venetoclax/carfilzomib/dexamethasone with rapid initial response; however, the response was short-lived.

Cases presentation

Patient 1 was a 50-year-old Saudi man with International Staging System stage III kappa light chain multiple myeloma with normal karyotype diagnosed in May 2013. He received bortezomib/thalidomide/dexamethasone treatment and underwent autologous hematopoietic stem cell transplant. Three years later, he presented with disease progression and received multiple lines of chemotherapy, including carfilzomib/lenalidomide/dexamethasone. Venetoclax/carfilzomib/dexamethasone was started after acquiring t(11,14)(q13;q32) 5 years into his disease course. He achieved complete remission, with disease progression after cycle 6. Patient 2 was a 48-year-old Saudi man with International Staging System stage III immunoglobulin G kappa multiple myeloma with t(11,14)(q13;q32) diagnosed in May 2017. He received bortezomib/thalidomide/dexamethasone treatment and underwent autologous hematopoietic stem cell transplant. Eighteen months later, he had disease progression, and he received multiple lines of chemotherapy, including carfilzomib/dexamethasone. He was shifted to venetoclax/carfilzomib/dexamethasone in April 2019 and had an initial clinical response; two months later, he progressed to plasma cell leukemia with rapid deterioration to multiorgan failure.

Conclusions

Acquired t(11;14)(q13;q32) is unreported in the multiple myeloma literature. In the era of targeted therapy, it is essential to repeat the cytogenetic and multiple myeloma fluorescence in situ hybridization panel with each disease progression. Multiple myeloma remains a challenging hematological malignancy despite advances in personalized/precision medicine.

Translocation (11;14) in newly diagnosed multiple myeloma, time to reclassify this standard risk chromosomal aberration?

OBJECTIVES

The most common translocation in multiple myeloma (MM) is t(11;14)(q13;q32), and its importance as prognostic factor has been controversial. The aim was to analyze its prognostic value.

METHOD

In this retrospective study of 469 newly diagnosed myeloma patients, outcomes in patients with (11;14) and standard risk (t(11;14)SR) or high risk (t(11;14)HR) cytogenetics were compared to outcomes of patients without t(11;14) and SR (non-t(11;14)SR) or HR (non-t(11;14)HR), respectively.

RESULTS

Overall progression-free survival (PFS) was shorter in t(11;14)SR than non-t(11;14)SR (median 28.9 vs 35.3 months); however, the difference was not significant (P = .2). Overall survival (OS) did not differ significantly between the groups. In the subgroup of patients that did not receive high-dose treatment, PFS was shorter for t(11;14)SR compared to non-t(11;14)SR, 10.6 vs 24.6 months (P = .01). Although OS were shorter for t(11,14)SR compared to non-t(11;14)SR (5-year OS 41.7% vs 63.8%), the difference was not significant (P = .1). In HDT patients, no significant difference was observed for OS or PFS between those with or without t(11;14).

CONCLUSION

This study shows that t(11;14) is associated with poorer outcome in MM, particularly in non-high-dose-treated SR patients. It should be considered an intermediate or high-risk marker in these patients.

Natural history of multiple myeloma with de novo del(17p)

We compared the outcomes of 310 patients with newly diagnosed multiple myeloma with del(17p) detected by FISH to patients with high-risk translocations (HRT) (n = 79) and standard-risk (SR) cytogenetics (n = 541). The median progression-free survival (PFS) following initial therapy for the three groups was 21.1, 22, and 30.1 months, respectively (P = 0.437- del(17p) vs. HRT); the median overall survival (OS) was 47.3, 79.1, and 109.8 months, respectively, (P = 0.007- del(17p) vs. HRT). PFS and OS for patients with relative loss of 17p (n = 21) were comparable to other patients with del(17p). The PFS was similar between the del(17p) and HRT groups when stratified for age, ISS stage or treatment. The OS of del(17p) and HRT groups were similar in presence of advanced age, ISS III stage or if patients did not receive a proteasome-inhibitor containing induction. ISS III stage, high LDH and HRT, but not the percentage of cells with del(17p) predicted shorter OS in patients with del(17p). The median OS for low (ISS I, normal LDH and no HRT), intermediate (neither low nor high-risk) and high-risk (ISS III and either elevated LDH or coexistent HRT) groups among del(17p) patients were 96.2, 45.4, and 22.8 months, respectively, allowing further risk stratification.

Combined Selection System to Lower the Cutoff for Plasma Cell Enrichment Applied to iFISH Analysis in Multiple Myeloma

Multiple myeloma (MM) is a very heterogeneous disease, characterized by multiple cytogenetic aberrations on plasma cells (PC) that have been traditionally used to predict the outcome of the disease. A mayor issue on the analysis of PC is the sometimes low infiltration of these cells in the bone marrow that hampers cytogenetic studies. To solve this problem we have optimized a selection strategy based on PC immunomagnetic isolation that has allowed us to lower to 1% the minimal PC infiltration requirement without loss of purity, enabling to perform genetic analysis. In this study, we have analyzed 153 bone marrow samples of patients suspected of MM, collected from February 2015 to May 2017 by the Genetics service of the Complejo Hospitalario de Navarra. Clinical characteristics of the patients and PC immunophenotyping, conventional cytogenetics and interphase fluorescence in situ hybridization (iFISH) analyses have been assessed on these samples. In our cohort 90% of the samples had cytogenetic abnormalities, among them 50% presented immunoglobulin rearrangements, 41.9% showed 1q gains, 29.7% showed 1p deletions and 33% presented TP53 deletion.

The combination of a sphingosine kinase 2 inhibitor (ABC294640) and a Bcl-2 inhibitor (ABT-199) displays synergistic anti-myeloma effects in myeloma cells without a t(11;14) translocation

Multiple myeloma (MM) remains an incurable disease in need of the development of novel therapeutic agents and drug combinations. ABT‐199 is a specific Bcl‐2 inhibitor in clinical trials for MM; however, its activity as a single agent was limited to myeloma patients with the t(11;14) translocation who acquire resistance due to co‐expression of Mcl‐1 and Bcl‐xL. These limitations preclude its use in a broader patient population. We have recently found that a sphingosine kinase 2‐specific inhibitor (ABC294640) induces apoptosis in primary human CD138⁺ cells and MM cell lines. ABC294640 is currently in phase I/II clinical trials for myeloma (clinicaltrials.gov: #NCT01410981). Interestingly, ABC294640 down‐regulates c‐Myc and Mcl‐1, but does not have any effects on Bcl‐2. We first evaluated the combinatorial anti‐myeloma effect of ABC294640 and ABT‐199 in vitro in 7 MM cell lines, all of which harbor no t(11;14) translocation. Combination index calculation demonstrated a synergistic anti‐myeloma effect of the combination of ABC294640 and ABT‐199. This synergistic anti‐myeloma effect was maintained even in the presence of bone marrow (BM) stromal cells. The combination of ABC294640 and ABT‐199 led to enhanced cleavage of PARP and caspase‐3/9 and increased Annexin‐V expression, consistent with the induction of apoptosis by the combination treatment. In addition, the combination of ABC294640 and ABT‐199 resulted in the down‐regulation of the anti‐apoptotic proteins Mcl‐1, Bcl‐2, and Bcl‐xL and the cleavage of Bax and Bid. The combination induced both the mitochondrial mediated‐ and caspase‐mediated apoptosis pathways. Finally, the combination of ABC294640 and ABT‐199 resulted in augmented anti‐myeloma effect in vivo in a mouse xenograft model. These findings demonstrate that the co‐administration of ABC294640 and ABT‐199 exhibits synergistic anti‐myeloma activity in vitro and in vivo, providing justification for a clinical study of this novel combination in patients with relapsed/refractory multiple myeloma.

Evaluation of in vitro effects of various targeted drugs on plasma cells and putative neoplastic stem cells in patients with multiple myeloma

Multiple myeloma (MM) is a malignancy characterized by monoclonal paraproteinemia and tissue plasmocytosis. In advanced MM cytopenia and osteopathy may occur. Although several effective treatment strategies have been developed in recent years, there is still a need to identify new drug targets and to develop more effective therapies for patients with advanced MM. We examined the effects of 15 targeted drugs on growth and survival of primary MM cells and 5 MM cell lines (MM.1S, NCI-H929, OPM-2, RPMI-8226, U-266). The PI3-kinase blocker BEZ235, the pan-BCL-2 inhibitor obatoclax, the Hsp90-targeting drug 17AAG, and the Polo-like kinase-1 inhibitor BI2536, were found to exert major growth-inhibitory effects in all 5 MM cell lines tested. Moreover, these drugs suppressed the in vitro proliferation of primary bone marrow-derived MM cells and induced apoptosis at pharmacologic drug concentrations. Apoptosis-inducing effects were not only seen in the bulk of MM cells but also in MM stem cell-containing CD138⁻/CD20⁺/CD27⁺ memory B-cell fractions. Synergistic growth-inhibitory effects were observed in MM cell lines using various drug combinations, including 17AAG+BI2536 in MM.1S, OPM-2, RPMI-8226, and U-266 cells, 17AAG+BEZ235 in MM.1S, OPM-2, RPMI-8226, and U-266 cells, 17AAG+obatoclax in MM.1S, NCI-H929, OPM-2, and RPMI-8226 cells, BI2536+BEZ235 in MM.1S, NCI-H929, OPM-2, and RPMI-8226 cells, BI2536+obatoclax in MM.1S, OPM-2 and RPMI-8226 cells, and BEZ235+obatoclax in MM.1S and RPMI-8226 cells. Together, our data show that various targeted drugs induce profound and often synergistic anti-neoplastic effects in MM cells which may have clinical implications and may contribute to the development of novel treatment strategies in advanced MM.

Distinct predictive impact of FISH abnormality in proteasome inhibitors and immunomodulatory agents response: redefining high-risk multiple myeloma in Asian patients

For risk-adaptive therapeutic approaches in multiple myeloma (MM) treatment, we analyzed treatment outcome according to in situ hybridization (FISH) profiles to investigate the prognostic and predictive values of structural variations in a large series of Asian population. A total of 565 newly diagnosed patients with multiple myeloma between January 2005 and June 2015 were evaluated. FISH results showed del(17p13) in 8.8% (29/331), del(13q14) in 35.5% (184/519), t(14;16) in 2.5% (8/326), t(4;14) in 27.9% (109/390), IgH rearrangement in 47.7% (248/520), and +1q21 in 40.8% (211/517). The presence of del(17p13), IgH rearrangement, and t(14;16) was associated with worse overall survival. Interestingly, however, the presence of t(4;14) conferred little prognostic impact. Treatment-specific analysis revealed the presence of del(17p13), t(14;16), IgH rearrangement, and trisomy 1q21 was predictive of unsatisfactory response to bortezomib. On the other hand, patients with del(13q14) and del(9p21) were less likely to benefit from lenalidomide. Autologous stem cell transplantation (autoSCT) was less effective in patients with del(17p13), t(14;16), and trisomy 1q21. Predictive values of del(17p13) and t(14;16) to bortezomib and autoSCT are seemingly universal, but predictive marker del(13q14) and del(9p21) for lenalidomide response appears ethnicity-specific. Thus, FISH profiles in MM treatment should be interpreted with regards to patient's ethnicity.

Identification and expression of MMSA-8, and its clinical significance in multiple myeloma

In our previous studies, we identified 12 multiple myeloma (MM)-associated antigens by serological analysis of tumor-associated antigens with a recombinant cDNA expression library (SEREX) on MM. MM-associated antigen-8 (MMSA-8) was one of the new antigens identified. We determined the 3′- and 5′-ends of MMSA-8 using SMART-rapid amplification of cDNA ends (RACE) and then cloned its full-length cDNA in the U266 cell line. The full cDNA sequence revealed that MMSA-8 is RPS27A-related transcript variant 1 that is specifically associated with MM. We examined its prognostic significance for the first time, by investigating the correlations between MMSA-8 expression and definite clinicopathological features. We quantitatively assessed MMSA-8 expression using qRT-PCR and western blot analysis in healthy donors and MM patients. The expression levels of MMSA-8 were upregulated with statistical significance in MM patients in contrast to those in healthy donors. The expression of MMSA-8 was also upregulated in relapsed patients compared with that in the complete remission (CR) group. Contrasting MMSA-8 expression levels in different patients with definite clinicopathological features suggested an association between MMSA-8 with unfavorable clinicopathological characteristics, such as international staging system (ISS) stage III, higher lactate dehydrogenase (LDH) levels and higher C-reactive protein (CRP) levels. The expression of MMSA-8 was also increased in patients with unfavorable cytogenetic and genetic abnormalities, including the presence of t(11;14), t(4;14), t(14;16), del(17p), del(13q) and p53 deletion, which was statistically significant. The expression of MMSA-8 exhibited significant variance in the treatment responses of the CR, PR, progression and relapse groups. Univariate and multivariate analyses revealed that high MMSA-8 values were associated with poorer progression-free survival (PFS) and overall survival (OS) in MM patients independently. In conclusion, our data indicated that MMSA-8 is an independent and unfavorable prognostic risk factor in MM; MMSA-8 is also a promising diagnostic and therapeutic target in MM patients, but further validation is needed.

Patient population with multiple myeloma and transitions across different lines of therapy in the USA: an epidemiologic model

PURPOSE

Multiple myeloma (MM) is a progressive, malignant neoplasia with a worldwide, age-standardized annual incidence of 1.5 per 100 000 individuals and 5-year prevalence around 230 000 patients. Main favorable prognostic factors are younger age, low/standard cytogenetic risk, and undergoing stem cell transplantation. Our aim was to estimate the size of the patient population with MM eligible to receive a new MM therapy at different lines of therapy in the USA.

METHODS

We constructed a compartmental, differential equation model representing the flow of MM patients from diagnosis to death, via two possible treatment pathways and distinguished in four groups based on prognostic factors. Parameters were obtained from published references, available statistics, and assumptions. The model was used to estimate number of diagnosed MM patients and number of patient transitions from one line of therapy to the next over 1 year. Model output included 95% credible intervals from probabilistic sensitivity analyses.

RESULTS

The base-case estimates were 80 219 patients living with MM, including 70 375 on treatment, 780 symptomatic untreated patients, and 9064 asymptomatic untreated patients. Over a 1-year period, the number of MM patients on treatment line 1 was estimated at 23 629 (credible intervals 22 236-25 029), and the number of transitions from treatment line 1 to treatment line 2 was estimated at 14 423.

CONCLUSIONS

The size of the patient population with MM on different lines of therapy and in patient subgroups of interest estimated from this epidemiologic model can be used to assess the number of patients who could benefit from new MM therapies and their corresponding budgetary impact. Copyright © 2016 John Wiley & Sons, Ltd.

Impact of t(11;14)(q13;q32) on the outcome of autologous hematopoietic cell transplantation in multiple myeloma

The t(11;14)(q13;q32) translocation is seen in 15%-20% patients with multiple myeloma (MM). It generally is not associated with worse outcomes. We studied the impact of t(11;14)(q13;q32) on outcome in patients with MM who received high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (auto-HCT). Eligible patients underwent high-dose chemotherapy followed by auto-HCT at the M.D. Anderson Cancer Center between February 2000 and August 2010, and had conventional cytogenetic (CC) or fluorescence in situ hybridization (FISH) results available before auto-HCT (n = 993). The cohort was divided into 3 groups of patients: (1) normal (diploid by CC and negative by FISH; n = 869); (2) t(11;14)(q13;q32) by CC or FISH (n = 27); and (3) high-risk (HR) abnormalities by CC or FISH (n = 97). Of the 27 patients with t(11;14)(q13;q32), 18 had isolated t(11;14)(q13;q32) and 9 had concurrent HR abnormalities. The primary objective was to compare outcomes in patients with t(11;14)(q13;q32) and patients with diploid or HR markers detected by CC or FISH studies. The median duration of follow-up in surviving patients was 37 months. The 3-year progression-free survival (PFS) was 47% for the normal group, 27% for the t(11;14)(q13;q32) group, and 13% for the HR group (P < .00001). The 3-year OS was 83% for the normal group, 63% for the t(11;14)(q13;q32) group, and 34% for the HR group (P < .00001). On multivariate analysis, t(11;14)(q13;q32) and HR abnormalities by CC or FISH and relapsed disease at auto-HCT were associated with shorter PFS, whereas t(11;14)(q13;q32) and HR abnormalities by CC or FISH, β2 microglobulin of >3.5, and relapsed disease at the time of auto-HCT were associated with shorter OS. In conclusion, patients with t(11;14)(q13;q32) had worse outcomes than patients with normal CC or FISH studies, but better outcomes than patients with HR markers detected by CC or FISH studies.

Cell death via DR5, but not DR4, is regulated by p53 in myeloma cells

Myeloma cells are sensitive to TRAIL through the two death receptors DR4 and DR5. Because p53 directly modulates expression of death receptors, we investigated here whether p53 can modulate myeloma sensitivity to TRAIL. We found that p53 affects the sensitivity of myeloma cells to the DR5 agonistic human antibody lexatumumab but not the DR4 antibody mapatumumab. TP53 wild-type myeloma cells overexpressed DR5 in correlation with sensitivity to lexatumumab. Both nongenotoxic (nutlin-3a) and genotoxic (melphalan) p53-inducing stresses increased DR5 expression only in TP53 wild-type cells and synergistically increased lexatumumab efficiency yet did not increase DR4 expression, nor sensitivity to mapatumumab. Silencing of p53 strongly decreased DR5 expression and induced resistance to nutlin-3a and lexatumumab but did not modulate DR4 expression or sensitivity to mapatumumab. Increase of lexatumumab efficiency induced by nutlin-3a was related to a p53-dependent increase of DR5 expression. In primary myeloma cells, nutlin-3a increased DR5 expression and lexatumumab efficiency but did not increase mapatumumab efficiency. Taken together, our findings indicate that p53 controls the sensitivity of myeloma through DR5 but not DR4 and suggest that a subset of patients with multiple myeloma may benefit from DR5 therapy.

Conventional and molecular cytogenetic analyses in Turkish patients with multiple myeloma

OBJECTIVE

Multiple myeloma (MM) is characterized by the accumulation and proliferation of malignant plasma cells, secreting monoclonal immunoglobulins and genetic abnormalities in MM have implications for disease progression and survival. In the present study, we investigated the frequency of chromosomal abnormalities (CA) in Turkish patients with MM, using interphase FISH and CC and evaluated the relationship between the rearrangements detected, prognosis and stage of disease.

MATERIAL AND METHODS

We performed conventional cytogenetic and FISH studies in 50 patients to detect chromosome anomalies associated with MM. FISH probes were used to detect 13q14, 13q34, 17p13 deletions, IGH rearrangements, and monosomy and/or trisomy of chromosomes 5, 9, and 15.

RESULTS

CC studies could be performed in 32 of 50 cases and five patients (15.6%) showed chromosomal aberrations while 27 (84.3%) had normal karyotypes. By FISH, eighteen percent (9/50) of cases were found to be normal for all parameters evaluated. Eighty-two percent (41/50) of the patients were positive for at least one abnormality. Chromosome 13 anomalies were detected in 54% (27/50) of cases. The second most common aberration observed is chromosome 15 aberrations (50%).

CONCLUSION

Median survival rate was shorter in patients with one of the abnormalities including chromosome 13 aberrations, IGH rearrangements or P53 deletions. Chromosome 15 aberrations were significantly higher in patients with stage III disease (p=0.02). We conclude that FISH studies should be performed in conjunction with conventional cytogenetic analysis for prognosis in multiple myeloma patients.

Application of an immune-magnetic cell sorting method for CD138-positive plasma cells in FISH analysis of multiple myeloma

INTRODUCTION

Interphase fluorescence in situ hybridization (FISH) analysis of multiple myeloma (MM) may indiscriminately count signals of nonplasma cells, thus decreasing specificity and sensitivity. We aimed to evaluate the usefulness of an immune-magnetic sorting method for plasma cells in FISH analysis of MM and define optimal sample preparation conditions.

METHODS

Plasma cells were purified using EasySep(®) CD138 Positive Selection Cocktail and Magnetic Nanoparticles (Invitrogen). We compared FISH results with and without plasma cell purification for three sample preparation methods: direct harvest, 24-h culture, and 96-h culture with interleukin-4 in five newly diagnosed MM patients. Archived fixed bone marrow cells of 17 MM patients were also studied.

RESULTS

The percentage of abnormal cells identified was significantly higher with plasma cell purification than without purification (median, 88.0%; range, 84.0-100.0%vs. 15.0%, 12.5-29.5%, respectively). The three sample preparation methods showed comparable results. Immune-magnetic sorting also significantly increased the percentage of abnormal cells identified in FISH analysis of archived fixed bone marrow cells (P < 0.001).

CONCLUSIONS

Immune-magnetic CD138-positive cell sorting significantly increased the percentage of abnormal cells identified in FISH analysis of MM samples for all sample preparation methods. This method could also be applied for retrospective FISH analysis of archived fixed bone marrow cells.

Monosomy 13 in metaphase spreads is a predictor of poor long-term outcome after bortezomib plus dexamethasone treatment for relapsed/refractory multiple myeloma

We retrospectively investigated the prognostic impact of high-risk cytogenetic abnormalities (CAs) on the outcome of treatment with bortezomib plus dexamethasone (BD) in 43 relapsed/refractory (Rel/Ref) multiple myeloma patients. Fluorescence in situ hybridization (FISH) analysis identified del(13q) in 25 patients, t(4;14) in 14, t(14;16) in 4, 1q21 abnormality in 12 and del(17p) in 2, while G-banding also detected chromosome 13 monosomy (-13) in metaphase spreads from 7 patients. Eighteen of 25 patients with FISH-detected chromosome 13 abnormalities also exhibited other abnormalities. Median observation period was 510 days, and median overall survival (OS) and progression-free survival (PFS) were 912 days and 162 days, respectively. Detection of del(13q), t(4;14), t(14;16) or 1q21 abnormalities by FISH and co-occurrence of chromosome 13 abnormality with other abnormalities were not associated with poorer outcomes. In contrast, detection of -13 by G-banding in metaphase spreads showed significant association with shorter OS, although the overall response rate and PFS were not inferior to those for patients without -13 detected by G-banding. BD therapy may be a potent weapon for overcoming most classical high-risk CAs, while the detection of -13 in metaphase spreads may serve as a predictor of highly progressive disease, even when treated with BD.

Extramedullary plasmacytoma of the small intestine: clinical features, diagnosis and treatment

Extramedullary plasmacytoma (EMP) of the small intestine is an unusual plasma cell neoplasm in this anatomic region with only 61 cases described so far. Clinical suspicion is infrequent owing to its location and nonspecific manifestations such as abdominal pain, obstructive symptoms or even bleeding. Diagnosis is reached through histopathological examination coupled with immunohistochemistry of the endoscopic biopsy or surgical resection specimens. Nevertheless, the differential diagnosis between EMP, lymphoma and other kinds of tumors can sometimes be troublesome. The managements include surgery, radiotherapy or chemotherapy. Generally, the prognosis of EMP is favorable, but occasionally it may relapse, or progress to a plasma cell myeloma. EMP should therefore be followed-up for a long period after treatment. In this comprehensive review of the current literature, the patients' characteristics, clinical manifestations, diagnosis, differential diagnosis, treatment and outcome were discussed.

Multiple myeloma: biology of the disease

Multiple myeloma (MM) is a clonal B-cell malignancy characterized by the aberrant expansion of plasma cells within the bone marrow, as well as at extramedullary sites. Decades of scientific research are now beginning to unravel the intricate biology that underlies the pathophysiology of MM. In particular, the roles of cellular differentiation, molecular pathogenesis, and oncogenes involved in the natural history of MM are becoming clearer. This has enabled the identification of specific cytokines, adhesion molecules, and stromal cells that affect MM cell development, disease progression, and treatment responses. This review describes our current understanding regarding the biology of MM, and how this has led to a robust pipeline of novel therapeutic agents with the potential to overcome resistance to existing MM therapies and, therefore, further improve outcomes in patients with MM.

Should Chemotherapy Be Administered for Essential Thrombocythemia (ET) Patients with Leukemic Transformation?

Introduction:

Essential Thrombocythemia (ET) is a clonal myeloproliferative disease presenting predominantly with thrombocytosis. One of its rare complications is leukemic transformation (LT). Once leukemic transformation occurs, prognosis is dismal. We aim to determine the disease profile of LT in our ET patients and evaluate if chemotherapy can alter prognosis.

Methods:

Clinical data of all patients diagnosed and treated with ET from 1999 to 2008 in the Department of Hematology, Singapore General Hospital, were captured in the Myeloproliferative Disease(MPD) Registry. ET patients with LT were selected. Patient characteristics, disease profile, including ET treatment, duration from ET diagnosis to LT, prior myelofibrosis (MF) history, type of chemotherapy, response and eventual survival were recorded.

Results:

Two hundred and thirty ET patients were diagnosed and treated from 1999 to 2008. Six patients had LT (2.6%). All were Chinese. Four were females. Age range was 47–70 years (mean 61.2 years). Transformation to acute myeloid leukemia (AML) was seen in 5 patients, after a latency period of 3–28 years. Acute biphenotypic leukemia was diagnosed in 1 patient 4 years after ET diagnosis. All patients had received hydroxyurea. There was no prior evolution to MF. Complex cytogenetics were seen in all cases. Three patients treated conservatively died within 1 month. The other 3 patients did not go into durable complete remission despite chemotherapy and succumbed within 9 months.

Conclusions:

Leukemic transformation in ET, though rare, is associated with grave prognosis. Outcome with chemotherapy is dismal. More studies are needed to evaluate if alternative treatment can improve survival.

BSc2118 is a novel proteasome inhibitor with activity against multiple myeloma

OBJECTIVES

The ubiquitin-proteasome system emerged as a new therapeutic target in cancer treatment. The purpose of this study was to elucidate the effects of the novel proteasome inhibitor BSc2118 on t(4;14) positive and negative multiple myeloma (MM) cells and normal peripheral blood mononuclear cells (PBMNC).

METHODS

Human MM cell lines OPM-2, RPMI-8226, and U266 and primary MM cells from bone marrow aspirates were exposed to BSc2118. Cytotoxicity levels were evaluated using the MTT-test. BSc2118-induced apoptosis was analyzed by annexin-V assay. Further methods used included proteasomal activity determination, cell cycle analysis, western blot, and transcription factor assays.

RESULTS

In OPM-2, RPMI-8226, U266 cell lines and primary MM cells, BSc2118 caused dose-dependent growth inhibitory effects. After 48 h, dose-dependent apoptosis occurred both in cell lines and primary myeloma cells irrespective of t(4;14). A significant G2-M cell cycle arrest occurred after 24 h. Furthermore, we observed a marked inhibition of intracellular proteasome activity, an increase in intracellular p21 levels, and an inhibition of NF-kappaB activation. The toxicity against PBMNC remained low, suggesting a broad therapeutic range of this agent.

CONCLUSION

Taken together, BSc2118 shows significant antimyeloma activity and may be considered as a promising agent in cancer drug development.

Expression of WT1 gene in multiple myeloma patients at diagnosis: is WT1 gene expression a useful marker in multiple myeloma?

Monitoring patients with multiple myeloma during and after treatment for the presence of residual myeloma cells (minimal residual disease - MRD) has been shown to give a major insight into the effectiveness of treatment. It has been reported that Wilms' tumor gene (WT1) expression levels measured by real-time quantitative polymerase chain reaction was useful as an indicator of minimal residual disease in leukemia and myelodysplastic syndrome. The aim of this study was to measure levels of WT1 expression, in order to find a possible association between the expression of this gene and multiple myeloma at diagnosis. If an association was found, the WT1 gene could be evaluated as an MRD marker by comparison with other prognostic factors. We investigated peripheral blood WT1 expression level measured by real-time light cycler quantitative polymerase chain reaction in 50 newly diagnosed multiple myeloma patients. The normal WT1 gene copy number was found to be <23/microl cDNA and all patients with myeloma were found to have normal WT1-mRNA levels. On this basis WT1 expression analyses is unlikely to be a useful genetic marker for routine clinical use in multiple myeloma patients at diagnosis.

Management of newly diagnosed symptomatic multiple myeloma: updated Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) consensus guidelines

Multiple myeloma is a malignant plasma cell neoplasm that affects more than 20,000 people each year and is the second most common hematologic malignancy. It is part of a spectrum of monoclonal plasma cell disorders, many of which do not require active therapy. During the past decade, considerable progress has been made in our understanding of the disease process and factors that influence outcome, along with development of new drugs that are highly effective in controlling the disease and prolonging survival without compromising quality of life. Identification of well-defined and reproducible prognostic factors and introduction of new therapies with unique modes of action and impact on disease outcome have for the first time opened up the opportunity to develop risk-adapted strategies for managing this disease. Although these risk-adapted strategies have not been prospectively validated, enough evidence can be gathered from existing randomized trials, subgroup analyses, and retrospective studies to develop a working framework. This set of recommendations represents such an effort-the development of a set of consensus guidelines by a group of experts to manage patients with newly diagnosed disease based on an interpretation of the best available evidence.

Dynamic model for predicting death within 12 months in patients with primary or post-polycythemia vera/essential thrombocythemia myelofibrosis

PURPOSE

Current prognostic tools in myelofibrosis (MF) fail to identify patients at the highest risk of death and are limited by their applicability only to the time of diagnosis. We aimed to define an accelerated phase (AP) in MF by characterizing disease features that can identify patients with median overall survival of <or= 12 months at any time in the disease course.

PATIENTS AND METHODS

Baseline characteristics of 370 consecutive patients with MF from a single center were analyzed to identify features associated with a median overall survival of <or= 12 months. These putative AP features were then validated by following the course of chronic-phase patients (no AP features at baseline) until the development of one or more AP features and determining their subsequent survival.

RESULTS

The following three characteristics were associated with poor survival at baseline and were selected as putative AP features: blasts in blood or bone marrow >or= 10%, platelets less than 50 x 10(9)/L, and chromosome 17 aberrations (median overall survival, 10, 12, and 5 months, respectively). In the validation phase, chronic-phase patients who developed AP features during follow-up were found to have short subsequent survival times (median overall survival, 12, 15, and 6 months, respectively). AP was a necessary step in the progression to blast phase, with leukemic transformation being exceedingly rare (3% risk at 10 years) in patients who remained persistently in chronic phase.

CONCLUSION

Blood or bone marrow blasts >or= 10%, platelets less than 50 x 10(9)/L, and chromosome 17 aberrations defined AP in patients with MF. Patients in AP should be candidates for intensive therapeutic interventions.

Clinical and immunohistochemical features associated with a response to bortezomib in patients with multiple myeloma

PURPOSE

Multiple myeloma is an incurable disease with heterogeneous clinical behavior. Bortezomib has offered some patients with relapsed and refractory disease an opportunity for prolonged survival. However, there remains a paucity of data in patients treated with bortezomib that accurately delineates and identifies such patients. This information is crucial to guide management.

EXPERIMENTAL DESIGN

In this study, we aimed to identify the patients most likely to respond to bortezomib salvage therapy. We analyzed the baseline clinical variables and profiled the baseline expression of a broad range of immunohistochemical markers of cell cycle activity, apoptosis, and angiogenesis in a large cohort of multiply relapsed myeloma patients recruited to one of two prospective multicentre trials assessing the efficacy of bortezomib salvage therapy.

RESULTS

Using the European Group for Bone Marrow Transplantation criteria, response (complete or partial) to bortezomib salvage therapy was associated with a previous history of complete response to alternative antimyeloma treatment. Patients who expressed cyclin D1 were more likely to achieve a response. In contrast, patients who expressed p16(INK4A), cytoplasmic p53, and the highest intensity of Bcl-2 staining had a poor response. Patients who achieved a response to bortezomib and those patients who expressed cyclin D1 at baseline showed a significant survival advantage. Patients who expressed FGFR3, a poor prognostic marker, responded equally well and had similar outcomes with bortezomib compared with FGFR3-negative patients.

CONCLUSIONS

Baseline clinical variables and selective immunohistochemical markers expressed by patients may be used effectively to identify patients that are most likely to achieve a meaningful clinical response to bortezomib salvage therapy.

Staging systems and prognostic factors as a guide to therapeutic decisions in multiple myeloma

Multiple myeloma (MM) patients have a highly variable disease course and survival varies from a few months to more than 10 years. Numerous prognostic factors have been identified, including age, performance status (PS), serum albumin, beta2-microglobulin (beta2M), lactate dehydrogenase (LDH), renal function, genetic factors, and serum free light chains (sFLCs) or their ratio (sFLCR). Several models have been built to separate patients into various risk groups with different outcomes. Staging systems need to be simple, accurate, and readily available in order to effectively guide treatment decisions now that effective treatments exist that prolong survival. The International Staging System (ISS) is currently in use; it is highly prognostic but presents some limitations. We suggest that the ISS prognostic potential could be improved with the addition of sFLCR and eventually LDH.

Relevant prognostic features of multiple myeloma and the new International Staging System

The new International Staging System should be reported in all future studies of multiple myeloma. However, the system fails to account for recent research findings pertaining to mechanisms of disease progression. This review describes development of the International Staging System and details prognostic factors that may further our understanding of the biology of multiple myeloma.

Multiple myeloma--an update on diagnosis and treatment

Multiple myeloma is a plasma cell (PC) malignancy characterized by the accumulation of monoclonal PCs in the bone marrow and the production of large amounts of a monoclonal immunoglobulin or paraprotein. In the past years, new approaches in the diagnosis and treatment were introduced aiming to identify high-risk patients who need proper anti-myeloma treatment. Intensive therapy including autologous hematopoietic stem cell transplantation and the new agents bortezomib, thalidomide, and lenalidomide have improved patients' responses. Further optimalization of the different treatment schedules in well-defined patient groups may prolong their survival. Patient stratification is currently based on patient characteristics, extent of myeloma disease, and associated cytogenetic and laboratory anomalies. More and more gene expression studies are introduced to stratify patients and to individualize therapy.

The natural history and treatment outcome of blast phase BCR-ABL- myeloproliferative neoplasms

We analyzed the outcomes of 74 patients diagnosed with BCR-ABL(-) myeloproliferative neoplasms in blast phase receiving induction chemotherapy (55%), low-intensity therapy (16%), stem cell transplantation (SCT; 3%), or supportive care (26%). Median survival from the date of blastic transformation was 5 months. Patients receiving supportive therapy had a median survival of 6 weeks. Complete remission with or without blood recovery was achieved in 46% of patients receiving induction chemotherapy, but remissions were not durable with a median progression-free survival of only 5 months. Eight patients received SCT either as first therapy or after responding to antileukemia therapy. These patients had a markedly superior survival, with 73% alive at a median follow-up of 31 months. JAK2V617F kinetics were assessed in 16 patients: 0 of 4 negative patients became positive at transformation, and among 12 positive patients, 1 had an increase in JAK2V617F% at transformation, 7 had a substantial decrease, and 4 had stable levels. Myeloproliferative neoplasm blast phase is associated with a dismal prognosis. Responses to chemotherapy can be achieved but are not durable. Long-term survivors had all received SCT either as first therapy or in first remission.

Chromosome 13q deletion and IgH abnormalities may be both masked by near-tetraploidy in a high proportion of multiple myeloma patients: A combined morphology and I-FISH analysis

Ploidy status and chromosomal aberrations involving chromosome 13q and the immunoglobulin heavy chain locus (IgH) are important prognostic features in multiple myeloma (MM). However, conventional cytogenetic studies are often not reveling and determination of plasma cells (PC) ploidy status in MM is technically difficult. We have used a combined cell morphology and interphase FISH (I-FISH) analysis in 184 consecutive BM samples from 136 MM patients for the diagnosis of chromosome 13q deletion [del (13q)] and IgH abnormalities. We have found a high prevalence (37%) of near-tetraploid (NT) PC in the BM samples studied. NT status of PC was verified with DNA index (DI) measurements. del (13q) was found in 69% and a total absence of one IgH copy (loss of IgH) in 20% of NT samples. We have shown that the presence of del (13q) and loss of IgH can be masked in NT cases: in 12 NT samples originally identified as normal for del (13q) the abnormality was obscured in the majority of plasma cells due to the presence of NT. Similarly, loss of IgH was masked in four samples with a large population of NT cells. Moreover, in one case the appearance of a 100% tetraploidy during disease progression masked the presence of del (13q), originally present, and could therefore falsely appear as disappearance of this prognostic marker. In conclusion, we have shown that a combination of three abnormalities, i.e., del (13q), loss of IgH and NT, all of potential prognostic significance, can be overlooked unless NT is specifically searched for and ruled out. Therefore, we suggest that a search for NT should be added to the routine BM assessment in MM patients.

Abnormalities of chromosome 1p/q are highly associated with chromosome 13/13q deletions and are an adverse prognostic factor for the outcome of high-dose chemotherapy in patients with multiple myeloma

The prognostic value of chromosomal abnormalities was studied in untreated multiple myeloma patients who were registered into a prospective randomised multicentre phase 3 study for intensified treatment (HOVON24). A total of 453 patients aged less than 66 years with stage II and III A/B disease were registered in the clinical study. Cytogenetic analysis was introduced as a standard diagnostic assay in 1998. It was performed at diagnosis in 160 patients and was successful in 137/160 patients (86%). An abnormal karyotype was observed in 53/137 (39%) of the patients. Abnormalities of chromosome 1p and 1q were found in 19 (36% of patients with an abnormal karyotype) and 21 patients (40%). There was a strong association between chromosome 1p and/or 1q abnormalities and deletion of chromosome 13 or 13q (n = 27, P < 0.001). Patients with karyotypic abnormalities had a significantly shorter overall survival (OS) than patients with normal karyotypes. Complex abnormalities, hypodiploidy, chromosome 1p abnormalities, chromosome 1q abnormalities, and chromosome 13 abnormalities were associated with inferior OS on univariate analysis, as well as after adjustment for other prognostic factors. In conclusion, chromosome 13 abnormalities and chromosome 1p and/or 1q abnormalities were highly associated, and are risk factors for poor outcome after intensive therapy in multiple myeloma.

Interphase fluorescence in situ hybridization in multiple myeloma and monoclonal gammopathy of undetermined significance without and with positive plasma cell identification: analysis of 192 cases from the Region of Southern Denmark

Interphase fluorescence in-situ hybridization (i-FISH) was used to investigate 192 patients with multiple myeloma (MM; n = 182) and benign monoclonal gammopathy of undetermined significance (MGUS; n = 10). Of the 182 MM cases, 132 were investigated without and 50 with positive plasma cell identification (PC-ID+); 134 were investigated at diagnosis, 32 at time of progression, 7 at time of relapse, and 9 were investigated with partial remission or no response. The FISH analysis detected 11q23 (n = 61), 13q13 approximately q14 (n = 181), 14q32 (n = 121), 17p13.1 (n = 181), t(4;14) (n = 76), and t(11;14) (n = 73). Of the 132 patients investigated without PC-ID+, 61 (46%) showed chromosomal abnormalities, compared with 45 of 49 of evaluable cases (92%) with PC-ID+. The increase in abnormal cases identified was due mainly to the detection of more cases with 13q-, 17p-, and der(14)(q32). G-banding cytogenetics was performed in 72 patients; abnormalities were revealed in 19 cases (26%). Concordance between G-banding and i-FISH for one or more aberrations was found in 14 patients. Translocation (11;14) was detected by both methods in four of five cases. In four out of seven cases with either near-tetraploidy/triploidy or hypoploidy in the G-banded karyotypes, the modal number in the G-banded karyotypes could not be elucidated with certainty with i-FISH. Three of the 10 MGUS patients showed abnormalities. In conclusion, PC-ID+ is important for the detection of structural aberrations and disclosing translocations involving 14q32. Of these, translocations t(4;14) constituted 9% and t(11;14), 20%. Finally, based on the small number of cytogenetically abnormal cases, it is recommended to include cytogenetics (and, for example, the DNA index) in the prognostic armamentarium.

Treatment of newly diagnosed multiple myeloma based on Mayo Stratification of Myeloma and Risk-adapted Therapy (mSMART): consensus statement

Multiple myeloma is a neoplastic plasma cell dyscrasia that on a yearly basis affects nearly 17,000 individuals and kills more than 11,000. Although no cure exists, many effective treatments are available that prolong survival and improve the quality of life of patients with this disease. The purpose of this consensus is to offer a simplified, evidence-based algorithm of decision making for patients with newly diagnosed myeloma. In cases in which evidence is lacking, our team of 18 Mayo Clinic myeloma experts reached a consensus on what therapy could generally be recommended. The focal point of our strategy revolves around risk stratification. Although a multitude of risk factors have been identified throughout the years, including age, tumor burden, renal function, lactate dehydrogenase, beta2-microglobulin, and serum albumin, our group has now recognized and endorsed a genetic stratification and patient functional status for treatment.

6q deletion in Waldenström macroglobulinemia is associated with features of adverse prognosis

Fluorescence in situ hybridisation (FISH) is an effective technique for the cytogenetic analysis of Waldenström macroglobulinemia (WM), but the potential impact of molecular cytogenetics on disease evolution and as a prognostic marker is still unknown. Deletion of the long arm of chromosome 6 (6q-) is the most frequent cytogenetic abnormality in WM. This study analysed the prevalence of this aberration in 102 WM patients, and correlated it with disease characteristics. The incidence of 6q21 deletion was 7% by conventional cytogenetics and 34% when analysed by FISH (54% when cytoplasmic immunoglobulin M-FISH was used). Patients with deletion of 6q displayed features of adverse prognosis, such as higher levels of beta2-microglobulin and monoclonal paraprotein and a greater tendency to display anaemia and hypoalbuminemia. Interestingly, there was a correlation between the presence of 6q deletion and the International Staging System prognostic index (incidence of 6q- among patients stratified in stages 1, 2 and 3 was 24%, 42% and 67% respectively). Those patients diagnosed with smouldering WM who displayed the abnormality showed a trend to an earlier requirement of treatment. Finally, the survival analysis did not show differences between the two groups of patients, probably due to the short follow up of our series.