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

Abstract

PURPOSE: Hormone therapy is a mainstay in the treatment of receptor positive breast cancers. There have been conflicting reports regarding the effects of pre-operative hormonal therapy on outcomes after autogenous breast reconstruction (ABR). Here, we present a matched cohort analysis to determine if hormonal therapy truly affects outcomes following ABR. Method: A review was conducted of patients undergoing bilateral deep inferior epigastric perforator flaps (DIEP) between 2016-2020. Patients were split into two cohorts: hormonal therapy (HT) (tamoxifen or aromatase inhibitor), and not on hormonal therapy (NH). A 1:1 propensity match was conducted based on risk factors for complications following DIEP, including BMI, smoking, history of radiation and diabetes. RESULTS: A total of 356 patients were entered in the analysis. From this, 108 patients were matched into the HT and NH cohorts. Overall, patients in the HT cohort were significantly more likely to develop a complication (HT: 44 (41%) vs NH: 25 patients (23%); p=0.006). Incidence of intraoperative thrombosis was similar between the cohorts as was incidence of post-operative total flap loss (HT: 3 patients (2.8%) vs NH: 2 patients (1.9%); p=0.65). HT patients were at a significantly increased risk of venous thromboembolism (VTE) when compared to NH patients (HT: 3.7 % vs NH 0%; p=0.04). CONCLUSION: This is the first study examining the effect of pre-operative hormonal therapy on DIEP breast reconstruction, 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.