Consolidative Radiotherapy Underused in Early‑Stage Diffuse Large B-Cell Lymphoma
In a study reported in the Journal of Clinical Oncology, Vargo et al found that use of consolidative radiotherapy, which continues to decline, is associated with a survival benefit compared with multiagent chemotherapy alone in patients with early-stage diffuse large B-cell lymphoma.
Study Details
The study involved data from the National Cancer Data Base on 59,255 patients with stage I (54%) or II (46%) diffuse large B-cell lymphoma treated with multiagent chemotherapy alone (n = 35,915, 61%) or chemotherapy plus consolidative radiotherapy (n = 23,340, 39%) between 1998 and 2012. Propensity-adjusted Cox proportional hazard ratios for survival were used to account for indication bias. Use of a conditional landmark method accounted for immortal time bias, with survival analysis restricted to patients with survival time ≥ 12.0 months. Overall, 42% of patients had extranodal disease, and 58% were > 60 years old.
Factors Associated With Use
The proportion of patients receiving combined-modality therapy decreased from 47% in 2000 to 32% in 2012 (P < .001). A lower likelihood of receiving combined-modality therapy was associated with African American race, higher comorbidity score, being uninsured, lower educational quartile, treatment through an academic/research program, age > 60 years, stage II disease, B symptoms, distance > 30 miles from treatment facility, and more recent year of diagnosis.
Survival
Median follow-up was 60 months. Estimated 5-year and 10-year overall survival rates were 79% and 59% among all patients, 75% and 55% among those receiving chemotherapy alone, and 82% and 64% among those receiving combined-modality therapy (P < .001 vs chemotherapy alone). The overall survival advantage of combined-modality treatment was significant on multivariate analysis without propensity scoring (hazard ratio [HR] = 0.76, P < .001) and with propensity scoring (HR = 0.66, P < .001).
The investigators concluded: “Use of consolidative [radiotherapy] after multiagent chemotherapy in [diffuse large B-cell lymphoma] is decreasing in the modern era. Selection of treatment strategy is affected by both classical prognostic features and socioeconomic factors. Abandonment of combined-modality therapy in favor of chemotherapy alone negatively affects patient survival.”
Sushil Beriwal, MD, of the University of Pittsburgh Medical Center, is the corresponding author of the Journal of Clinical Oncology article.
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