Comparing hypofractionated to conventional fractionated radiotherapy in postmastectomy breast cancer: a meta-analysis and systematic review

PURPOSE: To compare the efficacy and toxicity of hypofractionated radiotherapy versus conventional fractionated radiotherapy in postmastectomy breast cancer using meta-analysis. METHODS: The PubMed, EMbase, Cochrane Library, Google Scholar, Wan Fang and CNKI databases were searched to identify controlled clinical trials comparing hypofractionated radiotherapy versus conventional fractionated radiotherapy in postmastectomy breast cancer. Overall survival (OS) was the primary endpoint, and disease-free survival (DFS), locoregional recurrence (LRR), distant metastasis (DM), acute skin toxicity, acute lung toxicity, late skin toxicity, lymphedema,, shoulder restriction, and late cardiac related toxicity were the secondary endpoints. RESULTS: Twenty-five controlled clinical trials involving 3871 postmastectomy breast cancer patients were included in this meta-analysis according to the selection criteria. The meta-analysis revealed that there were no significant differences in OS (OR = 1.08, 95% CI = 0.87~1.33, P = 0.49), DFS (OR = 1.13, 95% CI = 0.91~1.40, P = 0.28), LRR (OR = 1.01, 95% CI = 0.76~1.33, P = 0.96), DM (OR = 1.16, 95% CI = 0.85~1.58, P = 0.34), acute skin toxicity (OR = 0.94, 95% CI = 0.67~1.32, P = 0.72), acute lung toxicity (OR = 0.94, 95% CI = 0.74~1.20, P = 0.62), late skin toxicity (OR = 0.98, 95% CI = 0.75~1.27, P = 0.88), lymphedema (OR = 0.99, 95% CI = 0.77~1.28, P = 0.94), shoulder restriction (OR = 0.75, 95% CI = 0.43~1.31, P = 0.31), or late cardiac related toxicity (OR = 1.17, 95% CI = 0.82~1.65, P = 0.39) between the two groups. CONCLUSIONS: The results of this study show that compared to conventional fractionated radiotherapy, hypofractionated radiotherapy is not significantly different with respect to efficacy or toxicity in postmastectomy breast cancer. Additional large randomized clinical trials are needed to further confirm this conclusion.