Abstract P4-13-07: Oncoplastic breast conservation surgery for patients with large breast cancers undergoing primary or post-NACT breast conservation surgery is safe and effective

Abstract

Abstract Introduction: Majority of women diagnosed with breast cancers (BC) have self-detected large tumors (mean tumor size >4 cm). There are number of myths and misconceptions regarding safety of breast conservation surgery (BCS), which, coupled with the fear of re-operation for infiltrated margins lead to poor acceptance of BCS by Indian BC patients. Practice of oncoplastic breast surgery (OBS), neo-adjuvant chemotherapy (NACT) and intra-op frozen section (FS) margins assessment have helped us achieve safe, single stage breast conservation even for patients with large tumors. In this retrospective study, we evaluated the OBS techniques used in patients undergoing primary or post-NACT BCS and compared the outcomes in terms of ipsilateral breast tumor recurrence (IBTR) and overall survival (OS) between patient groups that underwent OBS-BCS, non-OBS BCS and mastectomy. Methods: Retrieving data from a prospectively maintained database, all patients treated for stages I-III BC between 2009 & 2018 at a specialty breast surgery unit were reviewed. Patient demographics, TNM stage, pathology, OBS technique, margin re-excision, and outcomes in terms of IBTR and OS, were evaluated; and compared with non-OBS BCS and mastectomy patients. Results: Of 1884 (Median age 50 years, 59% post-menopausal, T3-18%, T4b-7%) who underwent curative breast surgery, 1424 (75%) underwent mastectomy. Rest 460 (24.4%) underwent BCS, of which 43% underwent OBS BCS. Fifty-two patients (26.6%) underwent post-NACT BCS, of which 27.5% had pathological complete response (pCR). OBS techniques used were volume displacement in 169 (86.4%) and volume replacement (mini LD/LD flap) in 29 (13.6%). The OBS techniques used constituted Level-1 OBS in 33% and level-2 OBS in 66%. Procedures performed included round block / modified Benelli-10.6%, batwing mastopexy- 6%, wise pattern reduction mammoplasty+contralateral symmetrization-4%, and other procedures-9.5% (medial mammoplasty, inverted T/vertical scar mastopexy, J or L mammoplasty, parallelogram excision, Z plasty). Intraop FS histology detected infiltrated margins in 11.6% of patients undergoing OBS-BCS, which were re-excised/ converted to mastectomy in the same sitting, thus avoiding a re-operation. In comparison, 17% patients who underwent non-OBS BCS had margin infiltration. Cosmetic outcomes and patient satisfaction were better in OBS BCS patients. Peri-op complications including partial nipple necrosis, skin necrosis, seroma, wound dehiscence and infection occurred in 17%. IBTR occurred in 4% of OBS-BCS patients, compared to 7% patients who underwent non-OBS BCS. Over 36 mo median follow-up, stagewise OS was similar in patient groups undergoing mastectomy, OBS BCS or non-OBS BCS. Conclusion: Employing OBS techniques has enabled us offer BCS for EBC and large or locally advanced BC. These techniques facilitate safe BCS of patients undergoing primary or post-NACT breast surgery, with relatively lower margin infiltration and local recurrence rates, comparable survival and higher patient satisfaction of their cosmetic outcomes, compared to patients undergoing mastectomy or conventional/ non-OBS BCS. Table: Types of oncoplastic procedures used in patients undergoing primary or post-NACT Oncoplastic breast surgical breast conservation surgeryNo.of patientsPercentageLevel I16181.3 %Level II(MiniLD/ LD/ Contralateral Symmetrisation)3718.6%Volume Displacement16985.3%Volume Replacement2913.6%Ipsilateral breast tumor recurrence84.02% Citation Format: Gaurav Agarwal, VC Ramya, Anjali Mishra, Gyan Chand, Sabaretnam Mayilvahanan, Vinita Agrawal, Narendra Krishnani, Namita Mohindra, Punita Lal. Oncoplastic breast conservation surgery for patients with large breast cancers undergoing primary or post-NACT breast conservation surgery is safe and effective [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-13-07.