Abstract PS1-49: The effect of oncoplastic reduction on the incidence of post-operative breast lymphedema in breast cancer patients undergoing lumpectomy

Abstract

Abstract Purpose / Objectives: In patients with macromastia, breast conservation surgery (BCS) followed by radiation therapy (RT) for the treatment of breast cancer may be associated with a different complication profile than those without macromastia. General complications of BCS followed by RT includes seroma, infection, wound complications, cosmetic deformity, asymmetry, acute versus long term arm and/or breast lymphedema. Oncoplastic reduction mammoplasty (ORM) aims to reduce breast volume while excising the tumor bed and its margins. Since breast volume was found to be a risk factor for chronic breast lymphedema, this study was performed to determine the impact of ORM on chronic breast lymphedema as well as other complications compared to BCS without ORM. Materials / Methods: We performed a retrospective chart review on patients who underwent lumpectomy with RT from 2014 to 2018. Chronic breast lymphedema (CBL) was defined as swelling that persisted >1 year post-RT. Breast volumes (BV) were determined by contoured breast volumes or, if unavailable, estimated by the 95% isodose volumes from the RT treatment planning system. Univariate analysis was used to evaluate various patient factors and treatment outcomes in women with BV ≥1300 cc compared to <1300 cc. These same factors were compared in women who underwent ORM vs. BCS alone. Multivariate regression analysis was used to evaluate factors associated with ≥1 complication. Logistic regression was performed to identify factors associated with the development of CBL. Results: The total population included 1173 patients, of which 51 (4.3%) underwent ORM and 1122 (95.7%) underwent BCS. 440 (37.5%) patients had BV ≥1300 cc and 733 (62.5%) patients had a BV <1300 cc. Multivariate regression analysis demonstrated that patients with BV ≥1300 cc had a higher BMI (OR=1.200, P<0.001), decreased risk of grade 2 radiation dermatitis (OR=0.457, P=0.002), and increased risk of CBL (OR=2.127, P=0.024) compared to patients with BV <1300 cc. However, oncoplastic reduction was associated with an increased risk of hematoma (OR=5.934, P<0.001), increased risk of wound dehiscence (OR=12.433, P<0.001), and decreased risk of seroma (OR=0.201, P<0.001) compared to BCS patients. Conclusions: Our data demonstrates that patients with breast volume > 1300 cc are at increased risk for developing several complications regardless of the presence of ORM. Those who had ORM experienced an increase in wound complications but having undergone ORM appeared to eliminate the increased risk of CBL associated with macromastia. This suggests that ORM should be considered at the time of BCS to reduce their future risk of CBL as there is no cure for this disease. Citation Format: Jenna Nicole Luker, Cara Canella, Sanjay Rama, Kelley Park, Renee Barry, Saheli Ghosh, Simeng Zhu, Yalei Chen, Jessica Bensenhaver, Eleanor Walker, Kenneth Levin, Maristella Evangelista, Dunya Atisha. The effect of oncoplastic reduction on the incidence of post-operative breast lymphedema in breast cancer patients undergoing lumpectomy [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-49.