An evidence-based estimation of local control and survival benefit of radiotherapy for breast cancer.

Abstract

Survival benefits from radiotherapy for breast cancer described in randomised trials represent only those patients eligible for trials. We estimated the benefit of radiotherapy as an adjuvant treatment for the entire population of breast cancer patients if evidence-based treatment guidelines were followed. Evidences on 10-year local control and overall survival gain (radiotherapy vs no radiotherapy) were identified from review of literature. The data were incorporated into the optimal radiotherapy utilization tree that we previously reported for all categories of breast cancer patients and overall local control and survival benefits were estimated. The gains in 10-year local control and overall survival from optimal treatment of all breast cancer patients were 11.1% (95% CI 10.8-11.2%) and 3.1% (95% CI 3.0-3.4%), respectively. The stage-based estimates in local control and survival benefit were: 8% and 0% for Ductal Carcinoma in situ (DCIS), 12% and 2% for stage I-II cancers and 13% and 20% for stage III cancers. Our model was able to estimate the contribution of radiotherapy in breast cancer treatment if all patients were treated according to the recommended guidelines. These estimates could be used to benchmark population-based survival reports and to assess the cost-effectiveness of radiotherapy for breast cancer treatment.