Background:

Metformin has antineoplastic and cancer protective effects in vitro, sensitizing leukemia cells to chemotherapeutic agents, inducing apoptosis and cell cycle arrest.

Aim:

To assess the effect of metformin on the induction stage in patients with ALL and its impact on overall survival and relapse. Material and Methods. We included 123 patients treated with metformin and without metformin. The dose used was 850 mg PO at 8 h intervals. The survival analysis was used by Kaplan-Meier method, the difference between the distinct groups was performed using the log Rank test. Results. The overall survival at a median follow up of 700 days of follow-up was 43%, with a disease-free survival of 47%. Regarding the treatment groups, patients with metformin had a lower rate of relapse compared to the group receiving only chemotherapy (6.5% vs 17.1%, p = 0.006). Conclusions. The addition of metformin to the conventional treatment of ALL was associated with an improvement in survival, this association being independent of the type of biological risk at diagnosis.