Prognostic impact of monosomy 13 and deletion of 13q in multiple myeloma patients undergoing upfront autologous transplantation.

Deletion (13q)/monosomy 13 (del[13q]/-13) is common in multiple myeloma (MM), but its independent prognostic value remains unclear, particularly in patients treated with modern therapy and upfront autologous haematopoietic stem cell transplantation (autoHSCT). This study aimed to assess its impact on progression-free survival (PFS) and overall survival (OS), and to evaluate its prognostic impact in the context of established high-risk cytogenetic abnormalities (HRCA). We conducted a retrospective, single-centre study of MM patients undergoing autoHSCT between 2010 and 2021 with available fluorescence in situ hybridization results. Among 1680 patients, del(13q)/-13 was identified in 591 (35.2%). Compared with patients without HRCA or del(13q)/-13, isolated del(13q)/-13 was associated with shorter median PFS (37.3 vs. 64.6 months) and OS (105.4 vs. 131.0 months). Patients with concurrent HRCA and del(13q)/-13 had the poorest outcomes, with median PFS and OS of 33.9 and 81.6 months, respectively. Multivariable Cox regression confirmed that isolated/non-HRCA-associated del(13q)/-13, was independently associated with inferior PFS (hazard ratio [HR] 1.36, 95% confidence interval [CI]: 1.17-1.58, p = 0.0001) and OS (HR 1.49, 95% CI: 1.21-1.84, p = 0.0002). Del(13q)/-13 is independently associated with inferior PFS and OS in MM patients undergoing autoHSCT, with an additive adverse effect when co-occurring with HRCA.