Surgical Outcomes of Mastectomy with Immediate Autologous Reconstruction Followed by Radiation.

ABSTRACT

INTRODUCTION: Timing of autologous reconstruction relative to postmastectomy radiation therapy (PMRT) is debated. Benefits of immediate reconstruction must be weighed against a possibly heightened risk of complications from flap irradiation. We reviewed flap outcomes after single operation plus PMRT in a large institutional cohort. METHODS: Medical records were reviewed for women who underwent simultaneous mastectomy-autologous reconstruction with PMRT from 2007 to 2016. Primary endpoints were rates and types of radiation-related flap complications and reoperations, whose predictors were assessed by multivariable analysis. A p value < 0.10 was deemed significant to avoid type II error. Non-parametric logistic regression generated a model of PMRT timing associated with probabilities of complications and reoperations. RESULTS: One-hundred and thirty women underwent 208 mastectomy reconstruction operations, with a median follow up of 35.1 months (interquartile range 23.6-56.5). Forty-seven (36.2%) women experienced radiation-related complications, commonly fat necrosis (44.1%) and chest wall asymmetry (28.8%). Complications were higher among women who received PMRT < 3 months after surgery (46.8% for < 3 months vs. 29.3% for ≥ 3 months; p = 0.06), most of whom received neoadjuvant chemotherapy, and among women treated with internal mammary nodal (IMN) radiation (65.2% vs. 26.4%; p < 0.01); IMN radiation remained strongly associated in multivariable analysis (odds ratio [OR] 5.24; p < 0.01). Thirty-two (24.6%) women underwent 70 reoperations, commonly fat grafting (51.9%) and fat necrosis excision (17.1%). Reoperations were higher among women who received PMRT < 3 months after surgery (48.9 for < 3 months vs. 36.6 for ≥ 3 months; p = 0.19), which was significantly associated in multivariable analysis (OR 0.42; p = 0.08 for ≥ 3 months). The probabilities of complications and reoperations were lowest when PMRT was administered ≥ 3 months after surgery. CONCLUSIONS: Among a large institutional cohort, immediate autologous reconstruction was associated with similar rates of adverse flap outcomes as historically reported alternatively sequenced protocols. IMN radiation increased risk, while PMRT ≥ 3 months after surgery decreased risk. Additional studies are needed to elaborate the impact of IMN radiation and early PMRT in immediate versus delayed autologous reconstruction.