Safety of Hormonal Therapy prior to DIEP Reconstruction: A Matched Cohort Analysis.

Abstract

Hormone therapy (HT) has become a mainstay in the treatment of receptor positive breast cancers. There have been conflicting reports regarding the effects of HT after autologous breast reconstruction (ABR), with some reports suggesting patients on HT have a higher risk of complication and flap failure, while other studies bolstering the peri-operative safety of HT. Here, we present a matched cohort analysis to determine if HT affects outcomes following ABR. A retrospective review was conducted of patients undergoing ABR between 2016-2020. Patients were split into two cohorts: those on HT and those not on hormonal therapy (NH), based on a 1:1 propensity match using variables known to be risk factors for complications following DIEP, including BMI, smoking, timing of reconstruction, mastectomy indication, history of radiation and diabetes. 85 patients were matched into the HT and NH cohorts. Overall, patients in the HT cohort were significantly more likely to develop a complication (HT: 28% vs NH: 15%; p=0.04). Incidence of intraoperative thrombosis was similar between the cohorts as was incidence of post-operative total flap loss. HT did have a significantly increased risk of venous thromboembolism (VTE) when compared to NH patients (HT: 7.0 % vs NH 0%; p=0.03). This is the first study examining the effect of pre-operative hormonal therapy on ABR, with matched cohorts to control for comorbidities. HT patients had a significantly higher risk of complication and VTE, suggesting patients should discontinue hormonal therapy prior to surgery.