Abstract PO4-12-05: Immediate breast reconstruction is associated with reduced incidence of ipsilateral lymphedema in breast cancer patients undergoing mastectomy

Abstract Purpose: The number of patients undergoing immediate breast reconstruction after mastectomy is increasing. A study of ipsilateral lymphedema after immediate breast reconstruction is also needed.This retrospective study aimed to identify the risk factors associated with lymphedema incidence after mastectomy in breast cancer patients, particularly focusing on the impact of the immediate breast reconstruction. Methods: A retrospective analysis was conducted on 6,105 patients who underwent mastectomy for breast cancer with or without immediate breast reconstruction from Jan 2012 to Dec 2022 at Seoul National University Hospital to identify the potential risk factors for developing ipsilateral lymphedema. Results: A total of 6,105 breast cancer patients with a mean age of 50.1 years were included in this study, with a median follow-up period of 52.0 months. In univariate analysis, the incidence of lymphedema was significantly lower in the immediate breast reconstruction group (4.47%) compared to the no reconstruction group (9.15%) (p 0.001). Other significant risk factors included the number of dissected axillary lymph nodes, number of metastatic lymph nodes, body mass index (BMI) over 25 kg/m2, the use of neo-adjuvant chemotherapy or adjuvant radiation therapy, and older age at the time of operation. In multivariate analysis, the immediate breast reconstruction remained to be an independent predictor of developing lymphedema (OR: 0.71, 95% CI: 0.55-0.91, p = 0.008), along with the number of dissected lymph nodes (OR: 1.06, 95% CI: 1.05-1.08, p 0.001), neoadjuvant chemotherapy (OR: 1.83, 95% CI: 1.44-2.33; p 0.001), adjuvant radiation therapy (OR: 6.77, 95% CI: 5.16-8.96, p 0.001), BMI 25 kg./m2 (OR: 1.58, 95% CI: 1.26–1.97, p 0.001) and older age at surgery (OR: 1.01, 95% CI: 1.00-1.02, p = 0.007). Conclusion: Our data demonstrates significantly lower rates of ipsilateral lymphedema for the patients undergoing immediate reconstruction after mastectomy when compared to that of the mastectomy alone. While these observations require further validation, our study provides useful information for the surgical decision making in patients who are considering the option of immediate reconstruction after mastectomy. Citation Format: Jin Young Byeon, Ik Beom Shin, Hawjeong Lee, Eunhye Kang, Ji-Jung Jung, Changjin Lim, Wonshik Han, Hong-Kyu Kim, Han-Byoel Lee, Hyeong-Gon Moon. Immediate breast reconstruction is associated with reduced incidence of ipsilateral lymphedema in breast cancer patients undergoing mastectomy abstract. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-12-05.