Clinical significance of the translocation (11;14)(q13;q32) in multiple myeloma

The Role of t(11;14) in Tailoring Treatment Decisions in Multiple Myeloma

Multiple myeloma (MM) represents a hematological neoplasia with an uncontrolled proliferation of malignant plasma cells and complex cytogenetic abnormalities. t(11;14) has emerged as a crucial genetic aberration and is one of the most common primary translocations in MM. Patients harboring t(11;14) represent a distinctive subgroup with a clinical profile that differs from t(11;14)-negative MM risk categories. One of the key features linked with t(11;14) is the BCL2 dependency, indicating vulnerability to BCL2 inhibition. BCL2 inhibitors, such as venetoclax, demonstrated impressive efficacy alone or in combination with other anti-myeloma drugs in patients with RRMM accompanied by t(11;14) and BCL2 overexpression. Therefore, t(11;14) plays a key role in both risk stratification and informed decision making towards a tailored therapy. In this review, we highlight the biology of t(11;14) in MM cells, summarize the current evolving role of t(11;14) in the era of novel agents and novel targeted therapies, illuminate current efficacy and safety data of BCL2-based treatment options and explore the future prospects of individualized precision medicine for this special subgroup of patients with MM.

Effect of t (11;14) Abnormality on Outcomes of Patients With Newly Diagnosed Multiple Myeloma in the Connect MM Registry

BACKGROUND

The t (11;14) (q13;32) translocation [t (11;14)] is present in ∼20% of patients with newly diagnosed multiple myeloma (NDMM), but studies examining its prognostic ability have yielded divergent results, and data are lacking on outcomes from first-line therapy.

PATIENTS AND METHODS

Data from the Connect MM Registry, a large US, multicenter, prospective observational cohort study of patients with NDMM were used to examine the effect of t (11;14) status on first-line therapy outcomes in the Overall population (n = 1574) and race groups (African American [AA] vs. non-African American [NAA]).

RESULTS

Baseline characteristics were generally similar between patients with (n = 378) and without (n = 1196) t (11;14). Prevalence of t (11;14) was similar by race (AA, 27%; NAA, 24%). In the overall population, regardless of first-line therapy, t (11;14) status did not affect progression-free survival (hazard ratio, 1.02; P = 0.7675) or overall survival (hazard ratio, 0.99; P = .9417). AA patients with t (11;14) had higher likelihood of death (Nominal Cox regression P = .0298) vs. patients without t (11;14).

CONCLUSIONS

Acknowledging observational study and inferential limitations, this exploratory analysis of a predominantly community-based population suggests that t (11;14) is a neutral prognostic factor in the general MM population but may be a negative factor for overall survival in AA patients.

Impact of Autologous Transplantation in Patients with Multiple Myeloma with t(11;14): A Propensity-Score Matched Analysis

PURPOSE

Patients with multiple myeloma with t(11;14) have been considered to have standard-risk disease. However, several recent reports have shown contradictory results. We identified 95 patients with multiple myeloma with t(11;14) on FISH studies, who underwent upfront autologous hematopoietic stem cell transplant (auto-HCT) at our center. We compared their outcome with a group of standard-risk patients with multiple myeloma who had diploid cytogenetics by both conventional cytogenetics (CC) and FISH (n = 287).

EXPERIMENTAL DESIGN

To reduce the bias between the groups, we performed a 1:1 propensity score matching technique for analysis. A total of 160 patients, 80 in each group, were identified. Patients in the 2 groups were matched for age, International staging system stage at diagnosis, serum creatinine at presentation, disease status at auto-HCT, type of preparative regimens, dose of melphalan used for conditioning, and induction and maintenance regimens.

RESULTS

Patients in t(11;14) group had a post auto-HCT overall response rate (ORR) of 97.5% (78/80), compared with 100% (80/80) in the standard-risk control group (P = 0.50). Complete response rate in the t(11;14) group was 35% (28/80), compared with 45% (36/80) in the standard-risk control group (P = 0.26). The 4-year PFS rates were 40.8% (95% CI, 29.6%-56.1%) and 51.1% (95% CI, 39.4%-66.3%) in the t(11;14) and standard-risk control groups, respectively (P = 0.14). The 4-year OS rates were 74.9% (95% CI, 63.3%-88.7%) and 88.3% (95% CI, 80.4%-97.0%) in the t(11;14) and standard-risk control groups, respectively (P = 0.17). Also, patients with t(11;14) with concurrent cytogenetics had significantly poor PFS and OS compared with a propensity matched standard-risk control group.

CONCLUSIONS

Our study confirms that t(11;14) multiple myeloma undergoing upfront autologous transplantation had similar outcomes as patients with multiple myeloma with normal cytogenetic and FISH studies. Existence of additional genomic aberrations by CC or FISH was associated with a worse outcome.

Precision Medicine in Myeloma: Challenges in Defining an Actionable Approach

Recently, large sequencing studies have provided insights into the mutational landscape of multiple myeloma (MM), identifying actionable mutations and giving a precious opportunity for exploring new targeted therapies. The main goal of precision medicine, matching patients with the right drug, seems to be closer than ever. However, no targeted therapies in MM are approved yet. Several clinical trials testing targeted drugs and enrolling patients with MM are currently ongoing and will provide predictive biomarkers that might support clinical decision making. In this review, we evaluate the evidence supporting the implementation of precision medicine in MM and we discuss the challenges that should be dealt with in this imminent and promising new era.

Review of molecular diagnostics in multiple myeloma

Multiple myeloma evolves clinically from monoclonal gammopathy of undetermined significance through smoldering disease, active myeloma with end organ damage to a preterminal phase of extramedullary disease and marrow collapse. The molecular equivalents of such clinical observation can now be defined as genetically dormant, genetic crisis and genetic chaos (popularly termed malignant myeloma). Patients may present for the first time in any one of these stages. Not surprisingly, clinical outcomes for multiple myeloma are variable and the prospects for therapeutic responsiveness are defined by the stage at presentation. We describe here a genetically driven definition of high- and low-risk myeloma and offer guidelines for the adoption of routine diagnostic testing. We define high-risk disease as the presence of t(4;14), t(14;16), deletion 17p13 by FISH or the presence of hypodiploidy or deletion of chromosome 13 by conventional cytogenetics. By default, other patients are not considered high risk. Thus, as a minimum, we recommend routine testing for t(4;14) and 17p13 deletion by FISH and conventional cytogenetics. This classification will identify multiple myeloma patients at high genetic risk for early progression after conventional therapies.

Plasma cell leukemia: consensus statement on diagnostic requirements, response criteria and treatment recommendations by the International Myeloma Working Group

Plasma cell leukemia (PCL) is a rare and aggressive variant of myeloma characterized by the presence of circulating plasma cells. It is classified as either primary PCL occurring at diagnosis or as secondary PCL in patients with relapsed/refractory myeloma. Primary PCL is a distinct clinic-pathological entity with different cytogenetic and molecular findings. The clinical course is aggressive with short remissions and survival duration. The diagnosis is based upon the percentage (≥ 20%) and absolute number (≥ 2 × 10(9)/l) of plasma cells in the peripheral blood. It is proposed that the thresholds for diagnosis be re-examined and consensus recommendations are made for diagnosis, as well as, response and progression criteria. Induction therapy needs to begin promptly and have high clinical activity leading to rapid disease control in an effort to minimize the risk of early death. Intensive chemotherapy regimens and bortezomib-based regimens are recommended followed by high-dose therapy with autologous stem cell transplantation if feasible. Allogeneic transplantation can be considered in younger patients. Prospective multicenter studies are required to provide revised definitions and better understanding of the pathogenesis of PCL.

Gene expression profiling for molecular classification of multiple myeloma in newly diagnosed patients

To identify molecularly defined subgroups in multiple myeloma, gene expression profiling was performed on purified CD138+ plasma cells of 320 newly diagnosed myeloma patients included in the Dutch-Belgian/German HOVON-65/GMMG-HD4 trial. Hierarchical clustering identified 10 subgroups; 6 corresponded to clusters described in the University of Arkansas for Medical Science (UAMS) classification, CD-1 (n = 13, 4.1%), CD-2 (n = 34, 1.6%), MF (n = 32, 1.0%), MS (n = 33, 1.3%), proliferation-associated genes (n = 15, 4.7%), and hyperdiploid (n = 77, 24.1%). Moreover, the UAMS low percentage of bone disease cluster was identified as a subcluster of the MF cluster (n = 15, 4.7%). One subgroup (n = 39, 12.2%) showed a myeloid signature. Three novel subgroups were defined, including a subgroup of 37 patients (11.6%) characterized by high expression of genes involved in the nuclear factor kappa light-chain-enhancer of activated B cells pathway, which include TNFAIP3 and CD40. Another subgroup of 22 patients (6.9%) was characterized by distinct overexpression of cancer testis antigens without overexpression of proliferation genes. The third novel cluster of 9 patients (2.8%) showed up-regulation of protein tyrosine phosphatases PRL-3 and PTPRZ1 as well as SOCS3. To conclude, in addition to 7 clusters described in the UAMS classification, we identified 3 novel subsets of multiple myeloma that may represent unique diagnostic entities.

Genetic aberrations and survival in plasma cell leukemia

Plasma cell leukemia (PCL) is an aggressive and rare hematological malignancy that originates either as primary disease (pPCL) or as a secondary leukemic transformation (sPCL) of multiple myeloma (MM). We report here the genetic aberrations and survival of 80 patients with pPCL or sPCL and make comparisons with 439 cases of MM. pPCL presents a decade earlier than sPCL (54.7 vs 65.3 years) and is associated with longer median overall survival (11.1 vs 1.3 months; P<0.001). 14q32 (IgH) translocations are highly prevalent in both sPCL and pPCL (82-87%); in pPCL IgH translocations almost exclusively involve 11q13 (CCND1), supporting a central etiological role, while in sPCL multiple partner oncogenes are involved, including 11q13, 4p16 (FGFR3/MMSET) and 16q23 (MAF), recapitulating MM. Both show ubiquitous inactivation of TP53 (pPCL 56%; sPCL 83%) by coding mutation or 17p13 deletion; complemented by p14ARF epigenetic silencing in sPCL (29%). Both show frequent N-RAS or K-RAS mutation. Poor survival in pPCL was predicted by MYC translocation (P=0.006). Survival in sPCL was consistently short. Overall pPCL and sPCL are different disorders with distinct natural histories, genetics and survival.

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.

A practical guide to defining high-risk myeloma for clinical trials, patient counseling and choice of therapy

Clinical outcomes for multiple myeloma (MM) are highly heterogeneous and it is now clear that pivotal genetic events are the primary harbingers of such variation. These findings have broad implications for counseling, choice of therapy and the design and interpretation of clinical investigation. Indeed, as in acute leukemias and non-hodgkins lymphoma, we believe it is no longer acceptable to consider MM a single disease entity. As such, the accurate diagnosis of MM subtypes and the adoption of common criteria for the identification and stratification of MM patients has become critical. Herein, we provide a consensus high-risk definition and offer practical guidelines for the adoption of routine diagnostic testing. Although acknowledging that more refined classifications will continue to be developed, we propose that the definition of high-risk disease (any of the t(4;14), t(14;16), t(14;20), deletion 17q13, aneuploidy or deletion chromosome 13 by metaphase cytogenetics, or plasma cell labeling index >3.0) be adopted. This classification will identify most of the 25% of MM patients for whom current therapies are inadequate and for whom investigational regimens should be vigorously pursued. Conversely, the 75% of patients remaining have more favorable outcomes using existing - albeit non-curative - therapeutic options.

Prognostic and biological implications of genetic abnormalities in multiple myeloma undergoing autologous stem cell transplantation: t(4;14) is the most relevant adverse prognostic factor, whereas RB deletion as a unique abnormality is not associated with adverse prognosis

Fluorescence in situ hybridization (FISH) has become a powerful technique for prognostic assessment in multiple myeloma (MM). However, the existence of associations between cytogenetic abnormalities compels us to re-assess the value of each abnormality. A total of 260 patients with MM at the time of diagnosis, enrolled in the GEM-2000 Spanish transplant protocol, have been analyzed by FISH in order to ascertain the independent influence on myeloma prognosis of IGH translocations, as well as RB and P53 deletions. Survival analyses showed that patients with t(4;14), RB or P53 deletions had a significantly shorter survival than patients without these abnormalities. However, patients with RB deletions without other abnormalities in FISH analysis, displayed a similar outcome to those patients without genetic changes by FISH (46 vs 54 months, P=0.3). In the multivariate analysis the presence of t(4;14), RB deletion associated with other abnormalities, age >60 years, high proportion of S-phase cells and advanced stage of the disease according to the International Staging System retained their independent prognostic influence. In summary, RB deletion as a sole abnormality does not lead to a shortening in the survival of MM patients, whereas t(4;14) confers the worst prognosis in MM patients treated with high-dose chemotherapy.

Cytogenetic and fluorescence in situ hybridization studies in 60 patients with multiple myeloma and plasma cell leukemia

We report cytogenetic results in a series of 60 patients affected with multiple myeloma (MM) and plasma cell leukemia (PCL) and compare the results with those previously reported. In our series, a total of 41% of MM patients and 71% of PCL patients displayed chromosome abnormalities. To evaluate the clinical value of monosomy 18, we obtained fluorescence in situ hybridization results (using centromeric probe for chromosome 18) of 22 MM patients who displayed a normal karyotype. Monosomy 18 was present in 3 of 22 patients (14%). Using conventional cytogenetics, we detected monosomy 18 in one patient affected with PCL. Two of four cases with monosomy 18 followed an aggressive course, with overall survival of 1 and 9 months. The remaining two are in follow-up and remain stable. The association of monosomy 18 with IgA subtype predominance and poor prognosis was not observed in this series of MMs and PCLs. Although these results do not confirm our previous hypothesis, further observations of this group of patients (with monosomy 18) regarding malignant transformation is warranted.

Thalidomide paradoxical effect on concomitant multiple myeloma and myelodysplasia

We present five cases of concomitant relapsed multiple myeloma and therapy related myelodysplasia (t-MDS). After treatment with thalidomide marked anti-myeloma activity was observed, but it was associated with rapid progression of the MDS clone to acute myeloid leukemia (AML). This paradoxical effect of thalidomide is concerning because there is increasing use of thalidomide in relapsed, heavily treated multiple myeloma patients who already have a higher propensity to develop MDS. The leukemic transformation in our cases most probably reflects the natural progression of MDS, though it clearly demonstrates that thalidomide is ineffective in controlling blast proliferation in t-MDS. More concerning, however, is the possibility that thalidomide, while suppressing the myeloma clone, eliminates inhibitory signals and subsequently stimulates the proliferation of the leukemic clone. The use of thalidomide should be carefully assessed in relapsed multiple myeloma patients with clinical and cytogenetic evidence of t-MDS.

Myeloma and the t(11;14)(q13;q32); evidence for a biologically defined unique subset of patients

The t(11;14)(q13;q32) results in up-regulation of cyclin D1 and is the most common translocation detected in multiple myeloma, where it is also associated with a lymphoplasmacytic morphology. We performed an interphase fluorescent in situ hybridization (FISH) study to determine the clinical and biologic significance of the abnormality when testing a large cohort of myeloma patients. Bone marrow slides from multiple myeloma patients entered into the Eastern Cooperative Oncology Group phase III clinical trial E9486 and associated laboratory correlative study E9487 were analyzed using interphase FISH combined with immune-fluorescent (cytoplasmic immunoglobulin-FISH) detection of clonal plasma cells. We used FISH probes that hybridize to the 14q32 and 11q13 chromosomal loci. The t(11;14)(q13;q32) was correlated with known biologic and prognostic factors. Of 336 evaluable patients, 53 (16%) had abnormal FISH patterns compatible with the t(11;14)(q13;q32). These patients appeared to be more likely to have a serum monoclonal protein of less than 10 g/L (1 g/dL) (28% vs 15%, P =.029) and a lower plasma cell labeling index (P =.09). More strikingly, patients were less likely to be hyperdiploid by DNA content analysis (n = 251, 14% vs 62%, P <.001). Patients with the t(11;14)(q13;q32) appeared to have better survival and response to treatment, although this did not reach statistical significance. Multiple myeloma with the t(11;14)(q13;q32) is a unique subset of patients, not only characterized by cyclin D1 up-regulation and a lymphoplasmacytic morphology, but is also more frequently associated with small serum monoclonal proteins and is much less likely to be hyperdiploid. These patients do not have a worsened prognosis as previously thought.

Frequency and prognostic relevance of cyclin D1 dysregulation in multiple myeloma

OBJECTIVE

Cyclin D1 dysregulation has been found with varying frequencies in multiple myeloma (MM) and has been suggested to be associated with a poor prognosis. The aim of this study was to investigate the frequency of cyclin D1 dysregulation in patients being treated for MM and to test whether cyclin D1 dysregulation is a prognostic factor for MM patients.

METHODS

To achieve the above aims we designed a highly sensitive and reproducible real-time reverse-transcription polymerase chain reaction (RT-PCR) assay for quantitation of cyclin D1 mRNA. Using this assay, 110 diagnostic bone marrow (BM) samples from patients with MM were screened for cyclin D1 dysfunction.

RESULTS

The real-time assay was able to detect the presence of 0.01% cyclin D1 positive cells allowing a safe detection in MM BM samples. In 42% (46/110) of MM BM samples a greater-than-or-equals 3-fold increase in cyclin D1 mRNA was observed compared to the cyclin D1 level in normal BM. In the remaining group of MM patients the cyclin D1 mRNA levels were comparable to normal donors. Follow-up of 76 MM patients showed no significant (P = 0.35) difference in survival between cyclin D1 positive and negative MM patients. In addition, cyclin D1 dysregulation did not correlate with known prognostic factors.

CONCLUSION

The developed real-time RT-PCR assay for detection of cyclin D1 mRNA levels offers a fast and safe screening for cyclin D1 dysfunction. When a large cohort of MM patients was screened, the cyclin D1 gene was found to be frequently dysregulated, but there was no significant correlation to survival or known prognostic parameters.

Plasma cell leukemia

Plasma cell leukemia (PCL) is a rare aggressive variant of multiple myeloma (MM) characterized by a fulminant course and poor prognosis. The median survival is measured in months. Therapy and prognosis partially depend on whether the disease presents de novo or as a secondary process involving the leukemic transformation of a previously diagnosed MM. Secondary PCL represents a terminal event for refractory/relapsed MM and is usually not responsive to any treatment modality. The optimal regimens for the treatment of primary PCL have not been firmly established. Induction with combination chemotherapy, followed by high-dose chemotherapy (preferably within the setting of a clinical trial), is the current recommended approach for eligible patients.

Cyclin D1 and E2F-1 immunoreactivity in bone marrow biopsy specimens of multiple myeloma: relationship to proliferative activity, cytogenetic abnormalities and DNA ploidy

Cyclin D1, encoded by the CCND1 gene, is immunohistochemically detectable in up to one-third of cases of multiple myeloma (MM). To examine the mechanism of cyclin D1 overexpression, we compared cyclin D1 immunoreactivity with the results of conventional cytogenetics to determine if the t(11;14)(q13;q32) or other abnormalities of 11q11-14 explained cyclin D1 overexpression. Karyotypic abnormalities were found in 45 out of 67 (67%) MM cases; the t(11;14) was present in seven cases (10%). Additional 11q11-14 abnormalities were not identified. The t(11;14) correlated with cyclin D1 upregulation in low to intermediately proliferative MM, but was not present in highly proliferative tumours (assessed using bromodeoxyuridine labelling index). Cyclin D1 indirectly activates the transcription factor E2F-1. In the bone marrow biopsy specimens of MM cases, E2F-1 was concurrently expressed with cyclin D1 (P = 0.001), indicating that cyclin D1 is functional. However, as neither E2F-1 nor cyclin D1 expression correlated with proliferative activity, the speculation that t(11;14) upregulates the CCND1 gene to induce higher proliferation and possibly more aggressive disease is not supported. We conclude that in low to intermediately proliferative MM cases, cyclin D1 is probably upregulated by t(11;14), but an alternative mechanism is more probable in highly proliferative MM.

Immunophenotypic Aberrations, DNA Content, and Cell Cycle Analysis of Plasma Cells in Patients with Myeloma and Monoclonal Gammopathies

We describe the immunophenotypic and gross DNA defects in 55 patients with myeloma and 50 patients with monoclonal gammopathy and review the literature on this subject (MedLine, 1994-2000). Our data confirmed previous reports indicating that in myeloma nearly all marrow plasma cells are abnormal (98.7 +/- 8.1%). In monoclonal gammopathy the fraction of abnormal plasma cells was 35.0 +/- 32.8%. In both myeloma and monoclonal gammopathy, the most frequent aberrant phenotypic features consisted of absence of expression of CD19, strong expression of CD56, and decreased intensity of expression of CD38; aberrant expression of CD10, CD20, CD22, or CD28 was observed in less than one-third of myeloma cases. The vast majority of cases had two or more phenotypic aberrations. In the DNA studies, 7% of myeloma cases were biclonal and 93% of cases were monoclonal. In those studies with only one plasma cell mitotic cycle, 37% had normal DNA content and 63% were aneuploid (hyperploid, 61%; hypoploid, 2%). The mean percentages of plasma cells in S- and G2M phases were 4.9 +/- 8.5 and 4.4 +/- 6.9%, respectively. Thirty-eight percent of cases had more than 3% of plasma cells in S phase. In monoclonal gammopathy, the DNA index of abnormal plasma cells ranged from 0.89 to 1.30 and the percentage of diploid (31%) and aneuploid (69%) cases was not different from the results found in myeloma. The differences in percentage of abnormal plasma cells in S- (7.4 +/- 8.6%) and G2M-phases (2.4 +/- 1.7%) in patients with monoclonal gammopathy were not statistically significant.