Efficacy and Safety of Adjuvant Breast Radiation Therapy for Patients With Early-Stage Breast Cancer: A Systematic Review and Network Meta-Analysis.

Abstract

PURPOSE/OBJECTIVE(S)\nTo compare the efficacy and safety of various adjuvant breast radiation therapy treatment approaches for patients with early-stage breast cancer treated with breast conservation surgery.\n\n\nMATERIALS/METHODS\nWe searched PubMed, EMBASE, CENTRAL for randomized trials comparing two or more adjuvant breast RT treatment approaches for patients with early-stage breast cancer treated with breast conservation surgery. Eligible trials reported at least one of the outcomes including time to ipsilateral breast recurrence, overall survival and breast tissue related adverse events. We performed frequentist and Bayesian meta-analyses for time to ipsilateral breast recurrence and overall survival outcomes. We used the synthesis without meta-analysis (SWiM) approach to evaluate the breast tissue related adverse events outcome.\n\n\nRESULTS\nWe identified nine eligible trials involving 14799 patients and five treatments: conventional or moderately hypofractionated whole breast irradiation (CF/MFWBI), ultra hypofractionated whole breast irradiation (UFWBI), accelerated ultra hypofractionated whole breast irradiation (AUFWBI), moderately hypofractionated partial breast irradiation (MFPBI) and accelerated partial breast irradiation (APBI). MFPBI was ranked the most favorable for delay in time to ipsilateral breast recurrence (P score: 78%) and overall survival (P score: 70%) compared to other treatment approaches, although there were no statistically significant differences. APBI was ranked the least favorable for both time to ipsilateral breast recurrence (P score: 17%) and overall survival (P score 35%) and was associated with statistically significant higher hazards for ipsilateral breast recurrence compared to CF/MFWBI (Hazard ratio 1.28, 95% confidence interval 1.01 - 1.63). Sensitivity analysis using Bayesian analyses showed similar results. SWiM approach demonstrated that the overall direction of effect favors MFPBI when compared to MFWBI for breast tissue related adverse events. The overall direction of effect favors CF/MFWBI when compared to UFWBI, AUFWBI and APBI for breast tissue related adverse events.\n\n\nCONCLUSION\nAmongst the alternatives to CF/MFWBI, adjuvant MFPBI was associated with the best time to ipsilateral breast recurrence and overall survival benefits. MFPBI also reduced breast tissue related adverse events for patients with early-stage breast cancer treated with breast conservation surgery, compared with CF/MFWBI.