Risk factors for complications among breast cancer patients treated with post-mastectomy radiotherapy and immediate tissue-expander/permanent implant reconstruction: a retrospective cohort study

Background The use of post-mastectomy radiotherapy (PMRT) following immediate breast reconstruction has increased recently, and its safety is becoming a major concern. We aimed to evaluate the complication rates of PMRT to immediate tissue-expander/permanent implant (TE/PI)-based reconstructions for breast cancer and its association with radiotherapy timing (irradiation to TE or PI). Methods We retrospectively reviewed the cases of breast cancer patients who underwent mastectomy, immediate TE/PI reconstruction, and PMRT between January 2003 and December 2014. The rates of complications including reconstruction failure, re-operation, and infection were estimated by Kaplan–Meier analysis. The risk factors including radiotherapy timing were analyzed by log-rank test and multivariate Cox proportional hazard model. Results A total of 81 patients were included. Median follow-up was 32 months (range 2–120 months). Radiotherapy consisted of 50 Gy to the reconstructed breast and supraclavicular region in most cases. Total reconstruction failure, re-operation, and infection rates were 12.3, 13.6, and 11.1%, and 5-year cumulative reconstruction failure, re-operation, and infection rates were 16.7, 16.6, and 12.2%, respectively. No significant differences were observed in complication rates with respect to radiotherapy timing. In multivariate analysis, age 55 years and older was a significant risk factor for complications ( P < 0.05). Conclusion There were no significant differences in rates of reconstruction failure, re-operation, or infection with regard to radiotherapy timing. PMRT to reconstructed breasts of older patients aged 55 years or over can be expected to result in more complications than in younger patients.