Objective Although R-CHOP (rituximab, cyclophosphamide, vincristine, doxorubicin, and prednisone) is a standard therapy for diffuse large B-cell lymphoma (DLBCL), the optimal dose for elderly patients remains unclear.

Methods and Patients We retrospectively verified our R-CHOP dose-attenuation system implemented from 2005 for DLBCL patients. Among the 115 DLBCL patients treated during 2001-2010, 33 patients treated during 2001-2005 received R-CHOP doses adjusted according to physicians' decisions (PHY group). Eighty-two patients treated after 2005 received adjusted R-CHOP doses according to a unified dose-attenuation system (UNI group). Patients aged <60, 60-69, 70-79, and ≥80 years received the standard R-CHOP, 100% R-CHO+P (50 mg/m²), 100% R+75% CHO+P (40 mg/m²), and 100% R+50% CHO+P (30 mg/m²), respectively. We compared the responses, survival, and treatment cessation between the PHY and UNI groups.

Results The patients' characteristics between both groups were closely comparable. All PHY patients received randomly adjusted R-CHOP doses; 94% of UNI patients received scheduled doses. The complete response rates differed significantly between the UNI (77%) and PHY patients (50%) (p=0.011). The two-year event-free survival rates were 50% and 32% in the UNI and PHY groups, respectively (p=0.0083). The two-year OS rates were 77% and 72% in the UNI and PHY group (p=0.16). Among the patients aged >70 years (n=59) overall survival was shorter in the PHY group (62%) than in the UNI group (72%; p=0.02). The UNI group received higher anti-tumor agent doses than the PHY group. The therapy discontinuation rates were 5% in the UNI group and 24% in the PHY group.

Conclusion Carrying out unified dose reduction may improve the efficacy and prognosis among elderly DLBCL patients.