Overall survival curves (A: n=1,133) and lymphoma-related survival curves (B: n=984) for patients greater than 80 years old, by treatment regimen. CHOP=cyclophosphamide, doxorubicin, vincristine, prednisone; R-CHOP=rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone; R-CVP=rituximab, cyclophosphamide, vincristine, prednisone; OS=overall survival; LRS=lymphoma-related survival. Patients treated with CVP (cyclophosphamide, vincristine, prednisone) were removed in order to prevent patient identification.