Safety of radiotherapy in patients undergoing breast reconstruction based on patient-reported outcomes: a multicenter collaborative study.

BACKGROUND

Post-mastectomy radiation therapy (PMRT) improves oncological outcomes of high-risk patients with breast cancer. However, its impact on breast reconstruction remains unclear. This study aimed to evaluate the safety of PMRT in breast reconstruction from the patient's perspective.

METHODS

This multicenter cross-sectional study was conducted in 10 Japanese institutions. Patient-reported outcomes (PROs) were collected using a comprehensive questionnaire incorporating surgical complications and the Japanese version 2.0 of the BREAST-Q "Adverse effect of radiation" module from 830 patients with breast cancer who had undergone reconstruction (214 with PMRT, 616 without). Complication rates were compared between the PMRT and non-PMRT groups. Logistic regression analysis was used to identify independent predictors of complications.

RESULTS

The PMRT group showed a significantly higher overall complication rate (76.2% vs. 45.3%, P < 0.001), including dermatitis (48.1% vs. 9.9%, P < 0.001), cutaneous necrosis (9.8% vs. 2.9%, P < 0.001), capsular contracture (16.4% vs. 4.9%, P = 0.020), breast asymmetry (24.3% vs. 17.0%, P = 0.020), and upper limb lymphedema (7.5% vs. 1.1%, P < 0.001) versus the non-PMRT group. In the multivariate analysis, PMRT was identified as an independent risk factor only for cutaneous necrosis (P < 0.001). Adverse effects of radiation were observed in the PMRT group, including dryness (52.3%), pigmentation (46.4%), irritation (39.8%), soreness (38.7%), telangiectasias (36.4%), and skin thickness changes (33.2%).

CONCLUSION

This is the first large-scale investigation in Japan to evaluate PMRT-related complications in patients who underwent breast reconstruction using PROs. Although PMRT increases complication rates, its direct impact is limited. These findings highlight the importance of incorporating patient-centered data into shared decision-making regarding reconstruction strategies.