Accelerated partial irradiation for breast cancer: Systematic review and meta-analysis of 8653 women in eight randomized trials

Background and purpose: Accelerated partial breast irradiation (APBI) is the strategy that allows adjuvant treatment delivery in a shorter period of time in smaller volumes. This study was undertaken to assess the effectiveness and outcomes of APBI in breast cancer compared with whole-breast irradiation (WBI). Material and methods: Systematic review and meta-analysis of randomized controlled trials of WBI versus APBI. Two authors independently selected and assessed the studies regarding eligibility criteria. Results: Eight studies were selected. A total of 8653 patients were randomly assigned for WBI versus APBI. Six studies reported local recurrence outcomes. Two studies were matched in 5years and only one study for different time of follow-up. Meta-analysis of two trials assessing 1407 participants showed significant difference in the WBI versus APBI group regarding the 5-year local recurrence rate (HR=4.54, 95% CI: 1.78–11.61, p=0.002). Significant difference in favor of WBI for different follow-up times was also found. No differences in nodal recurrence, systemic recurrence, overall survival and mortality rates were observed. Conclusions: APBI is associated with higher local recurrence compared to WBI without compromising other clinical outcomes.