External Beam Partial Breast Irradiation Versus Whole Breast Irradiation for in Early Breast Cancer：A Systematic Review and Meta-Analysis

Abstract

\n PurposePostoperative radiotherapy can reduce the recurrence of breast cancer. Postoperative radiotherapy is divided into whole breast irradiation (WBI) and partial breast irradiation (PBI) for early breast cancers. Due to the characters of saving time, money, and easy to deliver, external beams PBI (EB PBI) is brought into focus. However, the researches on outcomes, safety, and efficacy between EB PBI and WBI are still insufficient. We concluded a meta-analysis for LRR, regional node recurrence, contralateral breast cancer, distant recurrence, mortality, less acute skin toxicity (˃ 1 grade), late skin toxicity and the cosmetic score of external beam partial breast irradiation (EB PBI) and whole breast irradiation(WBI) to develop a radiotherapy plan for early low recurrence risk breast cancer patients. MethodWe searched Pubmed、Embase、Cochrane Library、Clinicaltrals. Study eligibility criteria are as below: (1) RCTs for EB PBI vs WBI; (2) Histologically confirmed breast cancer; (3) AJCC staged Tis-2N0-1M0; (4)\u2009≥\u200940 years old; (5) Tumor size\u2009≤\u20093 cm;(6) microscopically clear margins\u2009≤\u20095 cm; (7) Mean follow-up time༞5 years. All data is used by Cochrane’s Review Manager 5.3 (RevMan) to process.ResultsThere were 4 RCT studies included in our study with 1999 patients in EB PBI group and 1999 patients in EB PBI. There was no statistic difference between PBI and WBI groups in local recurrence rates (RR\u2009=\u20091.15; 95% CI, 0.76 to 1.74; p\u2009=\u20090.52; I2\u2009=\u20090%), regional node recurrence(RR\u2009=\u20091.00; 95% CI, 0.49 to 2.04, p\u2009=\u20090.99, I2\u2009=\u20090%), contralateral breast cancer (RR\u2009=\u20090.79; 95% CI, 0.54 to 1.16; p\u2009=\u20090.23; I2\u2009=\u20090%), distant recurrence(RR\u2009=\u20091.00; 95% CI, 0.63 to 1.59; p\u2009=\u20091.00; I2\u2009=\u20090%), non-breast second cancer (RR\u2009=\u20091.03; 95% CI, 0.50 to 2.16; p\u2009=\u20090.93; I2\u2009=\u200983%), mortality(RR\u2009=\u20090.96; 95% CI, 0.60 to 1.55; p\u2009=\u20090.88, I2\u2009=\u200954%). EB PBI had worse cosmetic score (RR\u2009=\u20091.56; 95% CI, 1.04 to 2.34; p\u2009=\u20090.003, I2\u2009=\u200984%), less acute skin toxicity (˃ 1 grade) (RR\u2009=\u20090.17; 95% CI, 0.07 to 0.42; p༜ 0.0001, I2\u2009=\u200987%) and late skin toxicity(RR\u2009=\u20090.65; 95% CI, 0.48 to 0.88; p\u2009=\u20090.005; I2\u2009=\u200927%) than WBI.ConclusionEB PBI has similar LRR, regional node recurrence, contralateral breast cancer, distant recurrence, non-breast second cancer and mortality with WBI. But EB PBI has worse cosmetic score, less acute skin toxicity (˃ 1 grade) and late skin toxicity than WBI.