The incidence of pathological findings in contralateral reduction mammoplasty specimens in patients with breast cancer

Abstract

Objectives: Occult invasive contralateral breast carcinoma negatively affects survival in breast cancer patients. The objective of this study is to measure the incidence of abnormal pathological specimens in reduction mammoplasty specimens in patients known to have contralateral breast cancer in a specialist breast unit in South Africa and to interpret the pathological findings and stratify them according to cancer stage and immunohistochemistry. Methods: A retrospective record review of the pathological findings in the contralateral breast of patients known with breast cancer who underwent either oncoplastic bilateral breast reduction or unilateral mastectomy and contralateral reduction between January 2017 and December 2022. Data was obtained from the breast cancer database used at our institution (OncoDB) and histology reports were obtained from the National Health Laboratory Services. The association between cancer stage, axillary findings and immunohistochemistry when compared to contralateral histology findings was done using the Chi-squared test. Results: A total of 112 patients were included with a mean (SD) age of 50.6 (10.8). Within the cohort of patients, 69 underwent mastectomy and contralateral reduction and 43 patients had bilateral oncoplastic breast reductions performed. 91 (81.3%) were 14 found to have no pathology, 12 (10.7%) had benign lesions, 8 (7.1%) were found to have proliferative lesions and 1 patient (0.8%) had a lobular carcinoma in situ (LCIS). Conclusion: There was an increased prevalence of contralateral breast pathology in ER positive patients and as cancer stage increased, however these findings were not statistically significant. Findings were similar with regards to PR, HER2 and nodal status.