Purpose: Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype. The purpose of this study was to evaluate the clinical features, prognostic factors, and results of DLBCL that was treated in the cancer centers of the public health system in Chile and compare cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) with rituximab with cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP).
Patients and methods: Patients age > 15 years who were treated in 18 cancer centers in the country between 2001 and 2017 were included. The Kaplan-Meier method was used to calculate overall survival (OS), and Cox proportional hazard regression modeling was used to evaluate the effect of the addition of rituximab to CHOP on OS.
Results: A total of 1,807 patients were evaluated. The median age at diagnosis was 62 (range, 15-95) years, with a female predominance (53%). Half of the patients were age ≥ 60 years. Serology for HIV infection was positive in 5% of cases (96 cases). International Prognostic Index scores were available for 90% of patients, of which 45% had low-risk, 25% low-intermediate-risk, 18% high-intermediate-risk, and 11% high-risk scores. CHOP was administered to 986 patients (55%; median follow-up, 13.2 years) and R-CHOP to 821 patients (45%; median follow-up, 8.4 years). R-CHOP was associated with superior OS compared with CHOP (5-year 66% v 48%, and 10-year 53% v 35%; P < .001).
Conclusion: Rituximab improved the survival of patients with DLBCL diagnosed and treated in Chile. The benefit was sustained over time, with curative rates of > 50%. This intervention shows that the inclusion of this biological drug justified the expenses incurred by the Ministry of Health in the National Lymphoma Protocols in Chile.