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.

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.