Surgical Outcomes of Mastectomy with Immediate Autologous Reconstruction Followed by Radiation

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.

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.

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.

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.