Impact of radiation on immediate breast reconstruction: a retrospective single institution cohort study

Background: While the trend towards immediate breast reconstruction is growing, data on the long-term outcomes of patients receiving irradiation afterwards are scarce. We retrospectively reviewed the long-term complication rates in patients who received adjuvant radiation therapy after immediate breast reconstruction in our institution. Methods: We included 134 patients with breast cancer who underwent single-stage immediate breast reconstruction between January 2008 and December 2018. Sixty-eight patients received adjuvant irradiation and 66 patients did not. Autologous tissue, implant-based, and combined (implant and flap) reconstruction were performed in 40, 55, and 39 patients, respectively. Flap and implant complications data were collected. Baker's classification was used to assess capsular contracture. Results: The average follow-up was 47 months. Both groups had similar baseline clinical characteristics and treatments received. The irradiated-group had a higher incidence of adjuvant chemotherapy (P<0.01) and a significantly higher rate of grade III/IV capsular contracture (42.1% vs. 26.9%; P=0.004) than that of the non-irradiated group. The median time to the development of capsular contracture was 37 vs. 41 months in the irradiated vs. the non-irradiated group, respectively. There were no differences in the incidence of flap complications between both groups. The only significant risk factor associated with grade III/IV capsular contracture was adjuvant post-mastectomy irradiation. The irradiated group had a higher risk of developing grade III/IV capsular contracture [odds ratio (OR), 4.35; 95% confidence interval (CI): 1.55-12.27]. Conclusions: Postmastectomy radiotherapy adversely affects implant-based immediate one-stage reconstruction by increasing the rate of moderate to severe capsular contracture but is not associated with flap complications.