Plasma cell enrichment enhances detection of high-risk cytogenomic abnormalities by fluorescence in situ hybridization and improves risk stratification of patients with plasma cell neoplasms

Enhancing mutation detection in multiple myeloma with an error-corrected ultra-sensitive NGS assay without plasma cell enrichment

BACKGROUND

Risk stratification in multiple myeloma (MM) patients is crucial, and molecular genetic studies play a significant role in achieving this objective. Enrichment of plasma cells for next-generation sequencing (NGS) analysis has been employed to enhance detection sensitivity. However, these methods often come with limitations, such as high costs and low throughput. In this study, we explore the use of an error-corrected ultrasensitive NGS assay called positional indexing sequencing (PiSeq-MM). This assay can detect somatic mutations in MM patients without relying on plasma cell enrichment.

METHOD

Diagnostic bone marrow aspirates (BMAs) and blood samples from 14 MM patients were used for exploratory and validation sets.

RESULTS

PiSeq-MM successfully detected somatic mutations in all BMAs, outperforming conventional NGS using plasma cells. It also identified 38 low-frequency mutations that were missed by conventional NGS, enhancing detection sensitivity below the 5% analytical threshold. When tested in an actual clinical environment, plasma cell enrichment failed in most BMAs (14/16), but the PiSeq-MM enabled mutation detection in all BMAs. There was concordance between PiSeq-MM using BMAs and ctDNA analysis in paired blood samples.

CONCLUSION

This research provides valuable insights into the genetic landscape of MM and highlights the advantages of error-corrected NGS for detecting low-frequency mutations. Although the current standard method for mutation analysis is plasma cell-enriched BMAs, total BMA or ctDNA testing with error correction is a viable alternative when plasma cell enrichment is not feasible.

t(11;14) status is stable between diagnosis and relapse and concordant between detection methodologies based on fluorescence in situ hybridization and next-generation sequencing in patients with multiple myeloma

Multiple myeloma (MM) is associated with a wide variety of recurrent genomic alterations. The most common translocation in MM is t(11;14). In this retrospective, single-center, non-interventional study, patients' bone marrow samples were examined at diagnosis and at relapse(s) following treatment with anti-myeloma regimens to determine whether t(11;14) status was stable over time. This stability cohort consisted of 272 patients, of whom 118 were t(11;14)-positive at diagnosis and 154 were negative. All patients in the stability cohort retained the same t(11;14) status at relapse that they had at diagnosis of MM. Sixteen patients who had t(11;14)-positive MM at diagnosis had multiple longitudinal assessments by fluorescence in situ hybridization (FISH) at relapse events and remained t(11;14)-positive across all timepoints. Patients who had t(11;14)-positive disease at diagnosis of monoclonal gammopathy of unknown significance or smoldering MM also retained t(11;14) positivity through MM diagnosis and relapse. The t(11;14) fusion patterns also remained constant for 90% of patients. For detection of t(11;14), results from FISH and next-generation sequencing (NGS) were compared to determine the rate of concordance between these two methods. This concordance cohort contained 130 patients, of whom 66 had t(11;14)-positive disease and 64 were t(11;14)-negative. In this sample set, the concordance between FISH- and NGS-based detection of t(11;14) was 100%. These results strongly suggest that the t(11;14) rearrangement remains stable during the full disease course in patients with MM and can be detected by FISH- and NGS-based methodologies.

Chromosomal defects in multiple myeloma

Multiple myeloma is a plasma cell neoplasm driven by primary (e.g. hyperdiploidy; IGH translocations) and secondary (e.g. 1q21 gains/amplifications; del(17p); MYC translocations) chromosomal events. These are important to detect as they influence prognosis, therapeutic response and disease survival. Currently, cytogenetic testing is most commonly performed by interphase fluorescence in situ hybridisation (FISH) on aspirated bone marrow samples. A number of variations to FISH methodology are available, including prior plasma cell enrichment and incorporation of immunophenotypic plasma cell identification. Other molecular methods are increasingly being utilised to provide a genome-wide view at high resolution (e.g. single nucleotide polymorphism (SNP) microarray analysis) and these can detect abnormalities in most cases. Despite their wide application at diagnostic assessment, both FISH and SNP-array have relatively low sensitivity, limiting their use for identification of prognostically significant low-level sub-clones or for disease monitoring. Next-generation sequencing is increasingly being used to detect mutations and new FISH techniques such as by flow cytometry are in development and may address some of the current test limitations. Here we review the primary and secondary cytogenetic aberrations in myeloma and discuss the range of techniques available for their assessment.

The landscape of cytogenetic and molecular genetic methods in diagnostics for hematologic neoplasia

Improvements made during the last decades in the management of patients with hematologic neoplasia have resulted in increase of overall survival. These advancements have become possible through progress in our understanding of genetic basis of different hematologic malignancies and their role in the current risk-adapted treatment protocols. In this review, we provide an overview of current cytogenetic and molecular genetic methods, commonly used in the genetic characterization of hematologic malignancies, describe the current developments in the cytogenetic and molecular diagnostics, and give an outlook into their future development. Furthermore, we give a brief overview of the most important public databases and guidelines for sequence variant interpretation.

A Comprehensive Review of the Genomics of Multiple Myeloma: Evolutionary Trajectories, Gene Expression Profiling, and Emerging Therapeutics

Multiple myeloma (MM) is a blood cancer characterized by the accumulation of malignant monoclonal plasma cells in the bone marrow. It develops through a series of premalignant plasma cell dyscrasia stages, most notable of which is the Monoclonal Gammopathy of Undetermined Significance (MGUS). Significant advances have been achieved in uncovering the genomic aberrancies underlying the pathogenesis of MGUS-MM. In this review, we discuss in-depth the genomic evolution of MM and focus on the prognostic implications of the accompanied molecular and cytogenetic aberrations. We also dive into the latest investigatory techniques used for the diagnoses and risk stratification of MM patients.

Multitarget fluorescence in situ hybridization diagnostic applications in solid and hematological tumors

Introduction: Multitarget FISH (mFISH) is a technique allowing for simultaneous detection of multiple targets sequences on the same slide through the choice of spectrally distinct fluorophore labels. The mFISH could represent a useful tool in the field of precision oncology.Areas covered: This review discusses the potential applications of mFISH technology in the molecular diagnosis of different solid and hematological tumors, including non-small cell lung cancers, melanomas, renal cell carcinomas, bladder carcinomas, germ cell tumors, and multiple myeloma, as commonly required in the clinical practice.Expert Opinion: In this emerging era of the tailored therapies and newer histo-molecular classifications, there are increasing numbers of predictive and diagnostic biomarkers required for effective clinical care. The mFISH approach may have several applications in the common clinical practice, improving the molecular diagnosis in terms of time, cost and preservation of biomaterial for tumors with a limited amount of tumor available. The mFISH provides several advantages compared to other high-throughput technologies; however, it requires high level of expertise required to interpret complex results.

The survival impact of CKS1B gains or amplification is dependent on the background karyotype and TP53 deletion status in patients with myeloma

Gains or amplification (amp) of chromosome 1q21/CKS1B are reported to be a high-risk factor in myeloma. In this retrospective study, we analyzed the impact of CKS1B gain/amp on overall survival in the context of other genetic aberrations, such as TP53 deletion, FGFR3-IGH, IGH-MAF, MYEOV/CCND1-IGH, and RB1, as well as karyotype. The cohort included 132 myeloma patients with CKS1B gain/amp detected by fluorescence in-situ hybridization. There were 72 men and 60 women with a median age of 65 years (range 39-88 years). A normal, simple, or complex karyotype was observed in 39.5%, 5.4%, and 55% of patients, respectively. "Double hit," defined as CKS1B gain/amp coexisting with TP53 deletion, or "triple hit," defined as double hit plus t(4;14)FGFR3-IGH or t(14;16)IGH-MAF, were identified in 25 patients (18.9%) and five patients (3.8%), respectively. Double and triple hit were highly associated with a complex karyotype (p = 0.02). Ninety-nine patients (99/128, 77.3%) received stem cell transplantation. The median follow-up time was 48.2 months (range 2-104 months); 68 patients (51.5%) died, with a median overall survival of 58.8 months. Multivariate analysis (Cox model) showed that double hit with TP53 deletion (p = 0.0031), triple hit (p = 0.01), and complex karyotype (p = 0.0009) were each independently associated with poorer overall survival. Stem cell transplantation was associated with better overall survival, mainly in patients with a double or triple hit and complex karyotype (p = 0.003). These findings indicate that the inferior outcome of myeloma patients with CKS1B gain/amp is attributable to the high number of high-risk patients in this group. The prognostic impact of CKS1B gain/amp depends on the background karyotype and TP53 status.

Risk Stratification in Multiple Myeloma in Indian Settings

Multiple myeloma (MM) constitutes 10% of all hematological malignancies. The last one decade has seen a phenomenal progress in the therapeutic options available for the management. Although it still remains incurable, with the advent of newer therapies, the median survival in many risk groups is now around 10 years. Conventional karyotyping of bone marrow samples has a positivity rate of 20-30% at diagnosis in patients of Multiple Myeloma. However, array Comparative Genomic Hybridisation (aCGH) has revealed that almost all MM patients have cytogenetic abnormalities which may affect the pathophysiology, selection of therapy and outcomes of the disease. The progress in the field of exploring the genetic landscape of multiple myeloma with multiple tools like Fluorescent in-situ hybridization, aCGH, Next Generation Sequencing, Flow cytometry, etc., combined with the traditional risk stratification markers like albumin, β2 microglobulin and LDH, is gradually leading towards a risk-adapted therapy. The recent R-ISS risk stratification has combined these two group of information to validate a prognostic score which is an improvement over the past tools like DSS and ISS. In view of the plethora of information available on the multitude of cytogenetic markers there is a tendency to evaluate for all of them at diagnosis, especially in research centers. This leads to a significant increase in the cost of therapy of Multiple Myeloma in day-to-day clinical practice and an increased out-of-pocket spending to the patient, especially in resource-limited settings like India. Also, there is a variable approach to pre-therapy cytogenetic evaluation and risk stratification at different Hematology centres in the country, often dictated by financial constraints and availability of specialized tests. This review discusses the risk stratification markers and tools available in MM in 2019 and how it can be adapted in the resource constraint settings so as to derive the maximum prognostic information from a minimal prognostic panel, as well as lead to standardization of the prognostic protocols in resource limited settings across various Hematology centres in India.

Variability in Cytogenetic Testing for Multiple Myeloma: A Comprehensive Analysis From Across the United States

PURPOSE

Multiple myeloma (MM) treatment has changed tremendously, with significant improvement in patient out-comes. One group with a suboptimal benefit is patients with high-risk cytogenetics, as tested by conventional karyotyping or fluorescence in situ hybridization (FISH). Methodology for these tests has been published, but not necessarily standardized.

METHODS

We address variability in the testing and reporting methodology for MM cytogenetics in the United States using the ongoing African American Multiple Myeloma Study (AAMMS). We evaluated clinical and cytogenetic data from 1,221 patients (1,161 with conventional karyotyping and 976 with FISH) tested between 1998 and 2016 across 58 laboratories nationwide.

RESULTS

Interlab and intralab variability was noted for the number of cells analyzed for karyotyping, with a significantly higher number of cells analyzed in patients in whom cytogenetics were normal (P 5.0025). For FISH testing, CD138-positive cell enrichment was used in 29.7% of patients and no enrichment in 50% of patients, whereas the remainder had unknown status. A significantly smaller number of cells was analyzed for patients in which CD138 cell enrichment was used compared with those without such enrichment (median, 50 v 200; P, .0001). A median of 7 loci probes (range, 1-16) were used for FISH testing across all laboratories, with variability in the loci probed even within a given laboratory. Chromosome 13-related abnormalities were the most frequently tested abnormality (n5956; 97.9%), and t(14;16) was the least frequently tested abnormality (n 5 119; 12.2%).

CONCLUSIONS

We report significant variability in cytogenetic testing across the United States for MM, potentially leading to variability in risk stratification, with possible clinical implications and personalized treatment approaches.

Performance evaluation of detecting circulating tumor cells and tumor cells in bronchoalveolar lavage fluid in diagnosis of peripheral lung cancer

Background

To evaluate the diagnostic performances of detecting circulating tumor cells (CTCs) and tumor cells in bronchoalveolar lavage fluid (BALF) for peripheral lung cancer.

Methods

A total of 247 patients with lung cancer and 70 cases with benign lung disease were recruited in this study. Peripheral blood and BALF samples were collected, in which the tumor cells were enriched by negative immunomagnetic selection and detected by fluorescence in situ hybridization (FISH) of chromosome enumeration probe 8 (CEP8). The levels of tumor-associated markers (e.g., CEA, CA125, and NSE) in peripheral blood plasma were measured by using electrochemiluminescence.

Results

The numbers of CTCs detected in peripheral blood were significantly higher in patients with lung cancer than those with benign lung disease (5.78±0.57 vs. 1.13±0.39, Z=-8.64, P<0.01). Similarly, tumor cells count in BALF of malignancy were higher than that of benign lesions (6.76±0.89 vs. 0.89±0.23, Z=-6.254, P<0.01). However, as for patients with lung cancer and benign lung disease, the numbers of tumor cells in peripheral blood were comparable with those in BALF (both P>0.05). Detecting CTCs and tumor cells in BALF had similar areas under curves (AUC =0.871 and 0.963, respectively; P>0.05) in discriminating benign lesions from lung cancer (sensitivity 83.8% and 92.6%, specificity 86.5% and 99.9%, respectively), both of which were larger than those of NSE, CEA, and CA125 (AUC =0.564, 0.512 and 0.554, respectively; all P<0.05). The diagnostic performances of discriminating benign lesions and lung cancer in BALF and peripheral blood were both in concordance with that of histopathology (kappa values 0.662 and 0.569, respectively; both P<0.001).

Conclusions

Detecting tumor cells in peripheral blood and BALF may sensitive to identify benign and malignant peripheral lung lesions and be of value for early diagnosis of lung cancer.

Clinical implications of cytogenetic heterogeneity in multiple myeloma patients with TP53 deletion

TP53 deletion (ΔTP53) in myeloma is known to be a high-risk finding associated with poorer prognosis. The prognostic impact of underlying cytogenetic heterogeneity in patients with myeloma associated with ΔTP53 is unknown. We studied 90 patients with myeloma associated with ΔTP53 identified by interphase fluorescence in situ hybridization and assessed the impact of karyotype and coexisting alterations of IGH, RB1, and CKS1B. There were 54 men and 36 women with a median age of 59 years (range 38-84); 14 patients had a normal karyotype (NK/ΔTP53), 73 had a complex karyotype (CK/ΔTP53), and 3 had a non-complex abnormal karyotype. Patients with CK/ΔTP53 showed a significantly poorer overall survival compared with patients with NK/ΔTP53 (P=0.0243). Furthermore, in the CK/ΔTP53 group, patients with IGH rearrangement other than t(11;14)(q13;q32)/CCND1-IGH, designated as adverse-IGH, had an even worse outcome (P=0.0045). In contrast, RB1 deletion, CKS1B gain, ploidy, additional chromosome 17 abnormalities, or ΔTP53 clone size did not impact prognosis. Stem cell transplant did not improve overall survival in either the NK/ΔTP53 or CK/ΔTP53 (P=0.8810 and P=0.1006) groups, but tandem stem cell transplant did improve the overall survival of patients with CK/ΔTP53 (P=0.0067). Multivariate analysis confirmed in this cohort that complex karyotype (hazard ratio 1.976, 95% CI 1.022-3.821, P=0.043), adverse-IGH (hazard ratio 3.126, 95% CI 1.192-8.196, P=0.020), and tandem stem cell transplant independently correlate with overall survival (hazard ratio 0.281, 95% CI 0.091-0.866, P=0.027). We conclude that comprehensive genetic assessment adds to TP53 status in the risk stratification of myeloma patients.

Additional-structural-chromosomal aberrations are associated with inferior clinical outcome in patients with hyperdiploid multiple myeloma: a single-institution experience

Multiple myeloma is cytogenetically heterogeneous and a hyperdiploid karyotype is considered currently to have standard risk. In this study, we investigated the clinical impact of additional-structural-chromosomal aberrations assessed by chromosome analysis in 284 patients with a hyperdiploid karyotype that were subdivided into four groups based on the complexity of additional-structural-chromosomal aberrations: group 1, no additional-structural-chromosomal aberrations (n=35); group 2, one additional-structural-chromosomal aberration (n=46); group 3, two additional-structural-chromosomal aberrations (n=39); group 4, ≥three additional-structural-chromosomal aberrations (n=164). Clinicopathological data among these groups showed no differences, except patients in group 1 had higher hemoglobin (P=0.031) and albumin (P=0.045) levels. The median follow-up was 55 months (range, 3-221). The median overall survival of patients in groups 1-4 was negatively correlated with the number of the additional-structural-chromosomal aberrations: 98, 76, 61, and 48 months, respectively (P<0.0001). In group 4, CKS1B gain, RB1, or TP53 deletions had no additional impact on overall survival; however, trisomy 3 or 15 conferred a much better overall survival, and monosomy 13 and 14 predicted a worse outcome. In addition, the overall survival of patients in groups 3 and 4 was similar to a subset of high-risk multiple myeloma cases (n=21) (P=0.387). About 192 (67.6%) patients who received stem cell transplantation did not show improved overall survival compared with non-stem cell transplantation patients (n=92; P=0.142) overall; however, they did show significantly improved overall survival in patients with refractory disease in group 4 (P=0.0084). Multivariate analysis showed that two or more additional-structural-chromosomal aberrations (P<0.0001), stages (P=0.02 and P=0.002) and relapsed disease (P=0.009) negatively impacted the overall survival. We conclude that hyperdiploid karyotypes in multiple myeloma are associated with additional-structural-chromosomal aberrations and a greater number of additional-structural-chromosomal aberrations predicts poorer clinical outcome. A hyperdiploid karyotype with ≥2 additional-structural-chromosomal aberrations at chromosomal level should be considered an independent high-risk factor.

Efficacy and safety of high-dose chemotherapy with autologous stem cell transplantation in senior versus younger adults with newly diagnosed multiple myeloma

We retrospectively studied 340 fit patients with multiple myeloma (MM) who underwent autologous stem cell transplantation (ASCT). We hypothesized that progression-free survival (PFS) of older patients was non-inferior to that of younger patients after ASCT. Our null hypothesis was that the PFS hazard ratio (HR) for a 5-year increase in age was ≥1.05; the alternative (non-inferiority) hypothesis was that the HR was ≤1. The observed HR was 0.94 (95% confidence interval [CI] 0.86-1.03); since the CI upper bound was <1.05, we reject the null hypothesis and conclude that PFS in older patients was at least as good as in younger patients. We cannot reject an analogous null hypothesis for overall survival (HR 1.06 [95% CI 0.94-1.19]), since the CI upper bound >1.05. Toxicity was similar across ages and transplant-related mortality was minimal. 28% of subjects <65 versus 45% of those ≥65 received maintenance therapy. In summary, ASCT prolongs PFS equally well in older vs. younger adults. Although we cannot exclude maintenance as a confounder, these data support ASCT for fit seniors with MM.

Outcome of Patients with Multiple Myeloma and CKS1B Gene Amplification after Autologous Hematopoietic Stem Cell Transplantation

The gain/amplification of the CKS1B gene on chromosome 1q21 region is associated with a poor outcome in patients with multiple myeloma (MM). However, there are limited data on the outcome of patients with CKS1B amplification after a single high-dose chemotherapy and autologous hematopoietic stem cell transplantation (auto-HCT). We retrospectively evaluated the outcome of patients with CKS1B amplification who received an auto-HCT between June 2012 and July 2014 at our institution. We identified 58 patients with MM and CKS1B gene amplification detected by fluorescent in situ hybridization (FISH). We compared their outcomes with a propensity score-matched control group of 58 patients without CKS1B amplification who were treated at approximately the same time. The primary objective was to compare the progression-free (PFS) and overall survival (OS) between the CKS1B and the control groups. Stratified log-rank test with the matched pairs as strata and double robust estimation under the Cox model were used to assess the effect of CKS1B gene amplification on PFS or OS in the matched cohort. Patients in the CKS1B and control groups were well matched for age, gender, disease status, year of auto-HCT, response to pretransplantation therapy, and baseline hemoglobin level. In both groups, 57% patients were in first remission and 43% had relapsed disease at auto-HCT. Twenty-seven (47%) patients with CKS1B amplification had concurrent monosomy 13 or 13q deletion; 6 (10%) by conventional cytogenetics only, 16 (28%) by FISH only, and 5 (9%) by both. Median follow-up after auto-HCT was 25.4 months. The median PFS of the CKS1B and the control groups were 15.0 months and 33.0 months (P = .002), respectively. The median OS have not been reached yet. The 2-year OS rates in the CKS1B and the control groups were 62% and 91% (P = .02), respectively. In conclusion, Patients with CKS1B amplification are more likely to have additional high-risk cytogenetic abnormalities and a shorter PFS and OS after an auto-HCT.

Outcomes in patients with multiple myeloma with TP53 deletion after autologous hematopoietic stem cell transplant

TP53 gene deletion is associated with poor outcomes in multiple myeloma (MM). We report the outcomes of patients with MM with and without TP53 deletion who underwent immunomodulatory drug (IMiD) and/or proteasome inhibitor (PI) induction followed by autologous hematopoietic stem cell transplant (auto-HCT). We identified 34 patients with MM and TP53 deletion who underwent IMiD and/or PI induction followed by auto-HCT at our institution during 2008-2014. We compared their outcomes with those of control patients (n = 111) with MM without TP53 deletion. Median age at auto-HCT was 59 years in the TP53-deletion group and 58 years in the control group (P = 0.4). Twenty-one patients (62%) with TP53 deletion and 69 controls (62%) achieved at least partial remission before auto-HCT (P = 0.97). Twenty-three patients (68%) with TP53 deletion and 47 controls (42%) had relapsed disease at auto-HCT (P = 0.01). Median progression-free survival was 8 months for patients with TP53 deletion and 28 months for controls (P < 0.001). Median overall survival was 21 months for patients with TP53 deletion and 56 months for controls (P < 0.001). On multivariate analysis of both groups, TP53 deletion (hazard ratio 3.4, 95% confidence interval 1.9-5.8, P < 0.001) and relapsed disease at auto-HCT (hazard ratio 2.0, 95% confidence interval 1.2-3.4, P = 0.008) were associated with a higher risk of earlier progression. In MM patients treated with PI and/or IMiD drugs, and auto-HCT, TP53 deletion and relapsed disease at the time of auto-HCT are independent predictors of progression. Novel approaches should be evaluated in this high-risk population. Am. J. Hematol. 91:E442-E447, 2016. © 2016 Wiley Periodicals, Inc.

Optimal strategy for obtaining routine chromosome analysis by using negative fractions of CD138 enriched plasma cells

Fluorescence in situ hybridization (FISH) is superior to routine chromosome analysis (RCA) in detecting important prognostic genetic abnormalities in plasma cell dyscrasia (PCD); however, its sensitivity is hampered due to paucity of plasma cells (PC) in whole bone marrow (BM). Studies showed that the abnormality detection rate in enriched plasma cells (EPC) is greater than unselected plasma cells (UPC), but purification techniques are limiting to only FISH when sample volumes are inadequate. Not performing RCA may compromise patient care since RCA is equally important for detecting non-PC related abnormalities when the diagnosis is undefined. To resolve this critical issue, we designed a study where an immuno-magnetic CD138 enriched positive selection was used for FISH while the negative fraction (NF) was used to retrieve other myeloid elements for RCA. Parallel FISH studies were performed using UPC and CD138 EPC, while karyotyping was achieved using whole BM and discarded myeloid elements from the NF. Results showed that the abnormality rate of EPC was doubled compared to UPC for FISH, and CA displayed 100% success rate using the NF. PCD related chromosome abnormalities were confined to whole BM while non-PCD related abnormalities were found in both whole BM and NF. Our results demonstrate the feasibility of using the NF for RCA.

Genomic and Clinicopathologic Features of Primary Myelofibrosis With Isolated 13q Deletion

BACKGROUND

Primary myelofibrosis (PMF) is a rare myeloproliferative stem cell disorder. The genomic features in PMF are poorly understood. Characterization of genomic alternations in PMF helps to determine their association with clinicopathologic features for further therapeutic implications.

PATIENTS AND METHODS

In this retrospective study, we investigated genomic changes using array-based comparative genomic hybridization (aCGH) in 17 PMF patients with isolated del(13q) and confirmed our aCGH findings with quantitative polymerase chain reaction (PCR) assay. We also compared the clinicopathologic features of patients with del(13q) (n = 17) with those of patients with a normal karyotype (NK) (n = 26).

RESULTS

Clinicopathologically, del(13q) PMF patients had significantly higher blast counts (P = .03) than did NK patients, who had significantly higher marrow cellularity (P = .02). The degree of bone marrow fibrosis of PMF-3 was higher in the del(13q) group than in the NK group. Splenomegaly was present significantly more often in the del(13q) PMF group than in the NK group (P = .03). Genomically, the Janus Kinase 2 V617F mutation was observed less often in del(13q) PMF patients (P = .07). The common deleted region in del(13q) was confined to 13q13-13q14.3 according to G-band karyotyping, demonstrating a minimal deleted region (MDR) of 15.323 Mb, identified using aCGH. The tumor suppressor genes, Retinoblastoma, Forkhead box protein O1, and Succinyl -CoA ligase [ADP-forming] subunit beta in the MDR were deleted, confirmed using real-time PCR to confirm our aCGH findings.

CONCLUSION

Accurate molecular characterization of del(13q) in PMF using aCGH and quantitative PCR provided further insight to define the MDR and analyze the genomic changes in del(13q) PMF patients.

Clinical significance of acquired cytogenetic clones in patients with treated follicular lymphoma

BACKGROUND

Follicular lymphoma (FL) is the second most common B-cell non-Hodgkin lymphoma worldwide. In most patients, the disease is diagnosed at advanced stages and cannot be cured using conventional therapeutic approaches. To assess the role of cytogenetic abnormalities in therapy-related myeloid neoplasms (tMNs), we studied the clinicopathologic and cytogenetic features of treated FL patients who subsequently developed a new acquired cytogenetic clone (ACC).

PATIENTS AND METHODS

Twenty-five treated FL patients developed new cytogenetic abnormalities from 2009 to 2012. Patients were divided into 3 groups based on the presence and absence of tMNs: group 1, ACC without tMNs after a median follow-up of 15 months; group 2, ACC with possible tMN after silent ACC detection; group 3, tMNs present at the first ACC detection.

RESULTS

The most frequent cytogenetic aberrations involved chromosome 7. Compared with group 1, group 3 had significantly greater size of ACC, higher frequency of chromosome 7 aberrations, more likely showed dysplasia, and lower platelet count (P = .03).

CONCLUSION

Our results indicate that the presence of ACC alone is insufficient for diagnosis of tMNs. The proportion of cells with specific aberrations at first ACC, bone marrow dysplasia, and low platelet counts might predict outcome of ACC.

Quantitative analysis of CKS1B mRNA expression and copy number gain in patients with plasma cell disorders

In this study, we have examined CKS1B gene expression and copy number in a total of 114- patients at diagnosis: 83 with multiple myeloma (MM) and 31 with monoclonal gammopathy of undetermined significance (MGUS). Results were correlated with cytogenetics, FISH and clinical characteristic. Significant CKS1B mRNA levels in MM compared to MGUS cases (p<0.048) were detected. In MM, the frequency of 1q21 (CKS1B) copy gain was significantly higher in cases with abnormal karyotype compared to patients with normal karyotype (p=0.021). Global analysis showed a positive correlation between CKS1B expression and 1q21 copy number (p<0.0001). No association between CKS1B mRNA expression and clinical parameters was found. However, a significantly higher level of β2 microglobulin in cases with 1q21 gains than those without (p=0.0094) was observed. Overall survival was shorter in cases with 1q21 gain compared to those with normal 1q21 region (p=0.0082). Our results suggest a role for CKS1B in the multiple step process of progression of MGUS to MM and show that CKS1B copy gain has a more significant prognostic value than its overexpression. This adverse impact on survival probably reflects the genetic instability associated to chromosome 1q alterations resulting in a more aggressive behavior of the disease.