Early and late relapses of multiple myeloma after autologous haematopoietic stem cell transplantation

Abstract

Introduction. Autologous haematopoietic stem cell transplantation (auto-HSCT) is a highly effective treatment for multiple myeloma (MM). Auto-HSCT allows a signifi cant improvement of haematological response leading to higher overall survival and quality of life in MM patients. Nonetheless, the majority of patients develop relapse.Aim — a comparison of clinical MM relapses developing at variant terms after auto-HSCT.Patients and methods. A retrospective study enrolled 65 MM patients aged between 39 and 64 years. All patients had auto-HSCT during 2009–2019, all had achieved complete response (CR) or very good partial response (VGPR) and all since developed immunochemical MM relapse in laboratory evidence. Patients were divided in two cohorts by relapse term, the early (within 12 months of auto-HSCT) and late relapse.Results. Early immunochemical relapse was diagnosed in 13 (20 %), late relapse — in 52 (80 %) patients. The dependence between relapse term and depth of post-auto-HSCT antitumour response has been determined. The proportion of CR patients was signifi cantly higher in late than in early relapse (55.8 vs. 23 %). In follow-up, 60 patients (92.3 %) were initiated on antirelapse therapy, all early relapse and 90.3 % late relapse patients. On day +100 of auto-HSCT, CR patients had later relapse vs. VGPR individuals (median 24 vs. 19.9 months, p = 0.08) with signifi cantly weaker paraprotein secretion resembling the clinical course of monoclonal gammopathy of unclear signifi cance (MGUS).Conclusion. Auto-HSCT allows long-term control of the disease. A signifi cant prognostic factor is antitumour response on +100 day of auto-HSCT. Patients attaining CR have later relapse progressing in a MGUS-like manner. Patients with late indolent relapse can be managed long-term without antitumour therapy.