Background: Autologous hematopoietic cell transplantation (HCT) among Multiple myeloma (MM) cases has resulted in greater response rates, higher overall survival (OS) and event-free survival (EFS) over the last two decades compared with the outcome of comparable individuals given conventional treatment. We aimed at this study to determine the prognostic value of the time interval between end of induction chemotherapy and autologous stem cell transplantation among multiple myeloma patients.

Subjects and methods: This observational retrospective cohort study was held at Nasser Institute, Dar El-Salam Hospital and El-Sheikh Zayed Hospital on 211 cases with an initial diagnosis of MM during the study period (2017-2022). We evaluated the influence of the time interval between the end of induction of chemotherapy and Autologous Stem Cell Transplantation on free survival, relapse-free survival and overall survival.

Results: There was a statistically significant relation between relapse-free survival and interval from last chemotherapy date to stem cell infusion among studied patients (significantly lower 26.0 ± 1.67 months in patients with interval>60 days vs. 56.32 ± 2.22 months in patients with interval≤60 days and with increasing interval quartile (with p<0.001 for each).

Conclusion: The present study demonstrated the prognostic value of the time interval between the end of induction of the chemotherapy and autologous stem cell transplantation in multiple myeloma cases, as the overall survival rate was substantially lower in patients whose intervals were greater than 60 days and with increasing interval quartiles.