Clinical benefit loss in myeloma patients declining autologous stem cell transplantation: a real-world study

Autologous hematopoietic stem cell transplantation (ASCT) is a recommended treatment for multiple myeloma (MM). Currently, with multiple treatment alternatives, patients' prognosis has improved significantly compared to the pre-proteasome inhibitor period. However, this has raised deliberations on the value and timing of ASCT. Compared with Western countries, the proportion of Chinese patients undergoing ASCT is relatively low. Nevertheless, this situation allows us to observe the treatment outcomes of transplant-eligible (TE) patients who haven't received ASCT and explore the role of ASCT in patients with distinct clinicopathological features. This real-world analysis encompassed 1059 newly diagnosed MM patients from 2012 to 2022, among whom 480 were TE. These patients were categorized into the TE-ASCT group (158 received ASCT) and the TE-no-ASCT group (322 did not receive ASCT). Disease progression and treatment response are evaluated based on the definition of IMWG. We found that the progression-free survival (PFS) was significantly prolonged in TE-ASCT group compared to TE-no-ASCT group, but there was no significant difference in overall survival (OS). Further exploratory analyses revealed that ASCT conspicuously augmented the PFS of patients aged ≤ 60 years, featuring ISS stage II/III, 1q gain/amplification, and positive minimal residual disease (MRD). Nevertheless, for patients aged > 60 years, presenting with ISS stage I, high-risk cytogenetics, renal insufficiency, and negative MRD, ASCT did not confer PFS benefits. Our investigation furnishes evidence of the clinical superiority of ASCT for MM patients with disparate clinicopathological characteristics in the contemporary treatment era, laying a groundwork for individualized ASCT selection.