[Application of the Second Revision of the International Staging System (R2-ISS) in the prognostic assessment of newly diagnosed multiple myeloma]

Objective: To investigate the prognostic value of the Second Revision of the International Staging System (R2-ISS) in patients with newly diagnosed multiple myeloma (NDMM) . Methods: The retrospective study was performed in 326 NDMM patients with immunomodulatory drugs and/or proteasome inhibitors as the first-line treatment attending the Department of Hematology, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China, from December 2012 to March 2022. The Kaplan-Meier method was used for the survival analysis, with the Log-rank test comparing the between-group differences and Cox proportional risk regression modeling A multifactorial analysis was performed. Results: ①326 patients were included in the study, 190 of whom were males. The median age was 63 years, and the median followup time was 37 months. R2-ISS can effectively predict prognosis, particularly for R-ISS Ⅱ patients. The median progression-free survival (PFS) time of R2-ISS Ⅰ, R2-ISS Ⅱ, R2-ISS Ⅲ, and R2-ISS Ⅳ was 52, 29, 20, and 15 months (P<0.001), while the median overall survival (OS) time was 91, 60, 44, and 36 months (P<0.001). Multifactor analysis revealed that ISS Ⅱ, ISS Ⅲ, del (17p), t (4;14), 1q+, LDH increased, and age >65 years old were independent negative prognostic factors for OS. ISS Ⅱ, ISS Ⅲ, del (17p), t (4;14), 1q+, and LDH were independent negative prognostic factors for PFS. ②The C-index score of R2-ISS was 0.724, higher than that of R-ISS (0.678), indicating high prediction efficiency. ③The median PFS for 1q+-related double-hit in R2-ISS Ⅲ and Ⅳ were 20, 15 months (P=0.084) and the median OS were 35, 36 months (P=0.786), respectively. In R2-ISS Ⅲ, there were twenty-seven cases of 1q+-related double-hit, sixty-one cases of 1q+ single abnormality, and sixty-eight cases with no 1q+. The median PFS for the three groups were 20, 18, and 21 months (P=0.974), while the median OS was 35, 47, and 56 months (P=0.042), respectively. Adjusting the assignment of 1q+ to 1, the median PFS and OS of different R2-ISS stages differed significantly after regrouping (P<0.001) . Conclusions: The prognostic stratification value of R2-ISS is higher than R-ISS, particularly in the highly heterogeneous R-ISS Ⅱ population. Adjusting the assignment of the 1q+-related double-hit can improve R2-ISS, which should be validated in future studies with multi-center and expanded cases.

Optical Genome Mapping Reveals the Complex Genetic Landscape of Myeloma

Fluorescence in situ hybridization (FISH) on enriched CD138 plasma cells is the standard method for identification of clinically relevant genetic abnormalities in multiple myeloma. However, FISH is a targeted analysis that can be challenging due to the genetic complexity of myeloma. The aim of this study was to evaluate the potential of optical genome mapping (OGM) to detect clinically significant cytogenetic abnormalities in myeloma and to provide larger pangenomic information. OGM and FISH analyses were performed on CD138-purified cells of 20 myeloma patients. OGM successfully detected structural variants (SVs) (IGH and MYC rearrangements), copy number variants (CNVs) (17p/TP53 deletion, 1p deletion and 1q gain/amplification) and aneuploidy (gains of odd-numbered chromosomes, monosomy 13) classically expected with myeloma and led to a 30% increase in prognosis yield at our institution when compared to FISH. Despite challenges in the interpretation of OGM calls for CNV and aneuploidy losses in non-diploid genomes, OGM has the potential to replace FISH as the standard of care analysis in clinical settings and to efficiently change how we identify prognostic and predictive markers for therapies in the future. To our knowledge, this is the first study highlighting the feasibility and clinical utility of OGM in myeloma.

Clinical relevance of high-risk cytogenetic abnormalities and the second revision of the International Staging System (R2-ISS) in patients with multiple myeloma in clinical practice

High-risk cytogenetic abnormalities (HRCAs) are the most critical factor affecting prognosis in multiple myeloma (MM). However, the clinical significance of HRCAs in routine practice has not been fully elucidated. We retrospectively analyzed clinical features and outcome in 60 newly diagnosed MM patients with or without HRCAs including t(4;14), t(14;16), del(17p), and 1q gain/amplification. The median age was 71 years (range, 35-90). Abnormalities with t(4;14), t(14;16), del(17p), and 1q gain/amplification were found in 10, 1, 6, and 21/14 patients, respectively, and 10 patients had ≥ 2 HRCAs. Patients with HRCAs exhibited progressive clinical features such as anemia, high β2-microglobulin, and high LDH. Symptomatic relapse was more common in patients with HRCAs. The median progression-free survival (PFS) by number of HRCAs (0, 1, and ≥ 2) was 51.7, 21.4, and 26.1 months (p = 0.011), and the median overall survival (OS) was not reached, 60.7, and 46.8 months (p = 0.045), respectively. Multivariate analysis revealed that HRCAs were an independent factor for PFS. Accordingly, the second revision of International Staging System (R2-ISS), which incorporates HRCA scores, was more useful for prognostic stratification (p = 0.0023). These results suggest that presence of multiple HRCAs including 1q gain/amplification is associated with advanced stage and poor prognosis in clinical practice as well.

Chromosome 1 instability in multiple myeloma: Aberrant gene expression, pathogenesis, and potential therapeutic target

Multiple myeloma (MM), the terminally differentiated B cells malignancy, is widely considered to be incurable since many patients have either developed drug resistance or experienced an eventual relapse. To develop precise and efficient therapeutic strategies, we must understand the pathogenesis of MM. Thus, unveiling the driver events of MM and its further clonal evolution will help us understand this complicated disease. Chromosome 1 instabilities are the most common genomic alterations that participate in MM pathogenesis, and these aberrations of chromosome 1 mainly include copy number variations and structural changes. The chromosome 1q gains/amplifications and 1p deletions are the most frequent structural changes of chromosomes in MM. In this review, we intend to focus on the genes that are affected by chromosome 1 instability: some tumor suppressors were lost or down regulated in 1p deletions, and others that contributed to tumorigenesis were upregulated in 1q gains/amplifications. We have summarized their biological function as well as their roles in the MM pathogenesis, hoping to uncover potential novel therapeutical targets and promote the development of future therapeutic approaches.