Hypofractionated whole breast radiotherapy in breast conservation for early-stage breast cancer: a systematic review and meta-analysis of randomized trials

Abstract

Purpose: Breast conservation therapy (BCT) for early-stage breast cancer involves lumpectomy followed by whole breast radiotherapy, which can involve either standard fractionation (SRT) or accelerated fractionation (ART). This systematic review and meta-analysis was performed to determine whether any benefit exists for ART or SRT. Materials and methods: We searched MEDLINE (1966–2014), all seven databases of the Cochrane Library (1968–2014), EMBASE (1974–2014), clinicaltrials.gov, ISRCTN, WHO ICTRP, and meeting abstracts in the Web of Science Core Collection (1900–2014). RCTs comparing SRT to ART among women undergoing BCT with stage T1–T2 and/or N1 breast cancer or carcinoma in situ were included. Follow-up was 30 days for acute toxicity, or three years for disease control and late toxicity. Results: 13 trials with 8189 participants were included. No differences were observed in local failure (n = 7 trials; RR 0.97; 95% CI 0.78–1.19, I2 = 0%), locoregional failure, (n = 8 trials; RR 0.86; 95% CI 0.63–1.16, I2 = 0%), or survival (n = 4 trials; RR 1.00; 95% CI 0.85–1.17, I2 = 0%). ART was associated with significantly less acute toxicity (n = 5 trials; RR 0.36; 95% CI 0.21–0.62, I2 = 20%), but no difference in late cosmesis (RR 0.95; 95% CI 0.81–1.12, I2 = 54%). Conclusions: ART use does not reduce disease control or worsen long-term cosmetic outcome, and may decrease the risk of acute radiation toxicity as compared to SRT.