Abstract P4-05-06: SURGICAL OUTCOMES FOR RECONSTRUCTION AFTER DELAYED CONTRALATERAL PROPHYLACTIC MASTECTOMY
Authors: Soh Chien Lin , Muktar Samantha , Malata Charles M , Benson John R 
Published: March 2023

Abstract
Background: Challenges for breast reconstruction (BR) after delayed CPM relate to previous ipsilateral reconstructive procedures, adjuvant therapies and co-morbidities. The same type of BR for both sides may be impossible and use of an abdominal flap-based reconstruction for the therapeutic side precludes a similar technique for the contralateral side; an implant-based reconstruction may be difficult to size match with autologous tissue reconstruction. Alternative sites for tissue harvest are the latissimus dorsi and gluteal artery perforator flaps but these can be associated with significant donor site morbidity and poorer breast symmetry. Types of reconstruction and complications were evaluated in the context of BR and delayed CPM. Methods: A retrospective analysis examined breast cancer patients undergoing CPM either as an immediate or delayed procedure with or without breast reconstruction (BR) between January 2009 and December 2019. Clinical information was extracted from a prospectively maintained database with collection of data on demographics, timing and type of surgery, previous adjuvant treatments and complications. Patients undergoing delayed CPM were categorized into 4 groups based on BR or no BR and its timing in relation to both CPM and therapeutic mastectomy. Complications were listed according to the Clavien-Dindo system (scale of 1 – 5) with major adverse events being wound infection requiring intravenous antibiotics or drainage and explantation. Despite small numbers, complications were compared for therapeutic and prophylactic mastectomy together with the type and timing of reconstruction. Results: A total of 39 CPM patients were analyzed with 12 (31%) undergoing immediate BR at the time of cognate mastectomy, 22 (56%) choosing bilateral BR simultaneously with delayed CPM, 3(8%) opted for bilateral delayed BR following delayed CPM whilst 2 (5%) had no reconstruction. The mean patient age was 52 years (24–73) and the average interval between initial and delayed mastectomy was 2.67 years (0–22). The majority of reconstructions (28/39) were implant-based (72%) rather than exclusively autologous reconstruction and most patients had a similar type of BR for contralateral and ipsilateral sides. More than half of patients received neoadjuvant therapy and 85% had post-mastectomy radiotherapy prior to CPM. Major complications occurred in 8 patients (67%) with unilateral BR compared with 5 patients (23%) with bilateral immediate BR and 3 patients (100%) undergoing bilateral delayed BR. Small numbers and confounding factors preclude any robust statistical analysis but no statistically significant differences between the immediate and delayed BR groups were found on Fisher’s exact test. Complication rates appeared higher when immediate BR was performed after delayed CPM compared with therapeutic mastectomy. Conclusion: Potential complications and limitations of BR in the context of delayed CPM should be discussed with patients and used to inform decision-making processes for timing of CPM and associated reconstruction. There are no clear differences in rates of complications depending on laterality, type or timing of reconstruction. This study provides reassurance that reconstruction can be successfully performed either at the same time as delayed CPM (with or without BR on therapeutic side) or as a delayed procedure.
Citation Format: Chien Lin Soh, Samantha Muktar, Charles M Malata, John R Benson. SURGICAL OUTCOMES FOR RECONSTRUCTION AFTER DELAYED CONTRALATERAL PROPHYLACTIC MASTECTOMY. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-05-06.