Value of radiotherapy for early-stage Waldeyer's ring diffuse large B-cell lymphoma in the rituximab era

Objective: To evaluate the value of radiotherapy following rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP)-based chemotherapy for patients with early-stage Waldeyer's ring diffuse large B-cell lymphoma (WR-DLBCL). Methods: Eighty-three patients diagnosed with early-stage WR-DLBCL who were admitted to our hospital from 2000 to 2013 were enrolled in the study. In these patients,twenty-five had stage I disease and fifty-eight had stage n disease. All patients received R-CHOP-based chemotherapy with (n = 62) or without (n = 21) involved-field radiotherapy (Waldeyer's ring plus cervical lymph nodes). The overall survival (OS), progression-free survival (PFS), and local-regional control (LRC) rates were calculated using the Kaplan-Meier method. The univariate analysis was performed using the log-rank method. The multivariate analysis was performed using the Cox regression model. Results: In all patients, the 5-year sample size was 18; the 5-year OS, PFS, and LRC rates were 89%, 84%, and 90%, respectively. According to the univariate analysis, patient age greater than 60 years, an increased lactate dehydrogenase level, Eastern Cooperative Oncology Group (ECOG) performance status no less than 2, and International Prognostic Index (IPI) no less than 2 were poor prognostic factors. Patient age greater than 60 years, a tumor size no less than 5 cm, ECOG performance status no less than 2, and IPI no less than 2 were influencing factors for PFS and LRC rates. In addition to the treatment with rituximab, patients treated with consolidative radiotherapy had significantly higher PFS and LRC rates (94% vs. 58%, P = 0.003; 100% vs. 61%, P = 0.000) as well as slightly higher OS rate (94% vs. 71%, P = 0.063) than those treated with out radiotherapy. Conclusions: Consolidative radiotherapy following R-CHOP-based chemotherapy significantly improves PFS, LRC, and probably OS rates for early-stage WR-DLBCL. This conclusion still needs to be confirmed by prospective studies with a large sample size. (authors)