Abstract ES3-3: Post-mastectomy breast reconstruction: defining the effects of adjuvant treatment modalities on surgical outcomes

Abstract

Abstract Post-mastectomy breast reconstruction is routinely offered immediately at the time of mastectomy, and can be performed using prosthetic or autologous techniques. Successful surgical outcomes are routine with these procedures, but can be complicated when adjuvant treatment modalities for breast cancer are employed. The most common adjuvant treatments effecting outcomes in post-mastectomy breast reconstruction are radiation, chemotherapy/hormonal therapy, and axillary lymph node dissection. Adjuvant radiation therapy has been shown to increase the complication rate in prosthetic breast reconstruction, specifically with increased rates of implant infection (22%, p=0.0), full-thickness mastectomy skin necrosis (11.5%, p=.001), and expander/implant removal (17.7%, p=0.0). Such complication rates are improvements over earlier reports, likely due to altered incision placement in nipple sparing mastectomy to the periareolar area, waiting at least 6 months following radiation completion prior to implant exchange, and the use of acellular dermal matrices (shown on multivariate analysis to reduce explantation rates in setting of radiation). With autologous breast reconstruction, adjuvant radiation has been shown to increase rates of volume flap volume loss (19.75%, p=.0001), but not flap loss rates (1.23%, p=1). The use of adjuvant chemotherapy and hormonal therapy has not been shown to negatively impact outcomes in prosthetic breast reconstruction, to any statistically significant amount. This includes tamoxifen and herceptin therapy. Similarly, the use of hormonal therapy does not significantly effect overall outcomes in autologous breast reconstruction. The use of axillary lymph node dissection has been shown to have a significant negative impact on outcomes in prosthetic breast reconstruction, compared to sentinel lymph node biopsy. On multivariate analysis, axillary lymph node dissection increased rates of breast implant loss (RR 2.0, p=.021), relative to sentinel lymph node biopsy. This is due to the decreased lymphatic drainage of remaining breast tissue, and resultant increase in infection and implant loss. Citation Format: Sbitany H. Post-mastectomy breast reconstruction: defining the effects of adjuvant treatment modalities on surgical outcomes. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr ES3-3.