Patients with newly diagnosed diffuse large-B cell non Hodgkin lymphoma, irrespective of cell of origin status will receive metformin in combination to Rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (RCHOP) chemotherapy for 6 cycles, until response evaluation as reported elsewhere:
1.- Rituximab 375 mg/m2 IV, day 1. 2.- Cyclophosphamide 750 mg/m2 IV, day 1. 3.- Doxorubicin 50 mg/m2 IV day 1. 4.- Vincristine 1.4 mg/m2 IV (2 mg maximum dose). 5.- Prednisone 60 mg/m2 PO days 1-5. Six cycles every 21 days.
Metformin will be added and administered in an outpatient basis, starting with 425 mg twice a day for 1 week, followed by 850 mg twice a day for 1 week, and lastly 850 mg every 8 hours maximum dose until re-staging. Laboratory tests will be performed serially.