Increasing therapy-related myeloid neoplasms in multiple myeloma.

BACKGROUND: Despite the longer survival achieved in multiple myeloma (MM) patients due to new therapy strategies, a concern is emerging regarding an increased risk of secondary primary malignancies (SPMs) and how to characterize those patients at risk. We performed a retrospective study covering a 28-year follow-up period (1991-2018) in a tertiary single institution. MATERIAL AND METHODS: Data of 403 MM patients were recorded and compared with the epidemiologic register of the population area covered by our centre, calculating the standardize incidence ratio (SIR) for the different types of SPMs diagnosed in the MM cohort. Fine and Gray regression models were used to identify risk factors for SPMs. RESULTS: Out of the 403 MM patients, 23 (5.7%) developed SPMs: 13 therapy-related myeloid (TRM) malignancies (10 of them (77%) myelodysplastic syndrome (MDS), 1 acute lymphoid leukaemia and 9 solid neoplasms. In the MM cohort, the relative risk of MDS was significantly higher than in the general population. Survival of patients with TRM malignancies was poor with a median of 4 months from the diagnosis, and most of them showed complex karyotype. Within the MM subset, multivariable analysis showed a higher risk of TRM malignancies in patients that previously received prolonged treatment with lenalidomide (>18 months). CONCLUSIONS: Though the improvement in MM outcome during the last decades is an unprecedented achievement, it has been accompanied by the rise in TRM malignancies with complex cytogenetic profile and poor prognosis that are in the need of an improved biologic and therapeutic approach.

Transcriptomic rationale for synthetic lethality-targeting ERCC1 and CDKN1A in chronic myelomonocytic leukaemia.

Despite the absence of mutations in the DNA repair machinery in myeloid malignancies, the advent of high-throughput sequencing and discovery of splicing and epigenetics defects in chronic myelomonocytic leukaemia (CMML) prompted us to revisit a pathogenic role for genes involved in DNA damage response. We screened for misregulated DNA repair genes by enhanced RNA-sequencing on bone marrow from a discovery cohort of 27 CMML patients and 9 controls. We validated 4 differentially expressed candidates in CMML CD34+ bone marrow selected cells and in an independent cohort of 74 CMML patients, mutationally contextualized by targeted sequencing, and assessed their transcriptional behavior in 70 myelodysplastic syndrome, 66 acute myeloid leukaemia and 25 chronic myeloid leukaemia cases. We found BAP1 and PARP1 down-regulation to be specific to CMML compared with other related disorders. Chromatin-regulator mutated cases showed decreased BAP1 dosage. We validated a significant over-expression of the double strand break-fidelity genes CDKN1A and ERCC1, independent of promoter methylation and associated with chemorefractoriness. In addition, patients bearing mutations in the splicing component SRSF2 displayed numerous aberrant splicing events in DNA repair genes, with a quantitative predominance in the single strand break pathway. Our results highlight potential targets in this disease, which currently has few therapeutic options.

Persistent cytotoxic T lymphocyte expansions after allogeneic haematopoietic stem cell transplantation: kinetics, clinical impact and absence of STAT3 mutations.

Peripheral expansion of cytotoxic T lymphocytes (CTL) derived from the graft in the initial stages of allogeneic haematopoietic stem cell transplantation (alloHSCT) immune recovery is a well-known physiological event. The description of symptomatic large granular lymphocyte leukaemia in this setting may generate uncertainty, mostly in those cases in which the CTL expansion (CTLe) persists beyond the early transplantation period. We aimed to assess the nature of CTLe during the post-alloHSCT period in 154 adult patients with a long-term surveillance. We studied the longitudinal kinetics of those expansions, their relationship to clinical events, and their phenotypic and molecular features, including recently reported CTL leukaemia-STAT3 mutations. Persistent relative CTLe cases are frequent (49%), related with thymoglobulin prophylaxis (P ≤ 0·001), acute graft-versus-host disease (GVHD, P = 0·02), and reduced intensity conditioning (P = 0·04). Absolute CTLe are scarce (9%) and related to chronic GVHD. T cell receptor rearrangement was reported as clonal and oligoclonal in the majority of patients with CTLe. The absence of STAT3 mutations and the CD8/CD4 declining longitudinal kinetics in the late period supports its benign nature, expressed clinically by the null detrimental impact of these expansions on post-transplant outcome and/or serious infectious events.