Occult Breast Cancer in High-Risk Gene-Positive Pakistani Women Undergoing Contralateral Prophylactic Mastectomy/Prophylactic Mastectomy: Implications for Sentinel Lymph Node Biopsy.

INTRODUCTION

Sentinel lymph node biopsy (SLNB) of the axilla is standard in breast cancer (BC) management; however, its role in prophylactic/contralateral prophylactic mastectomy (CPM) is still questioned. To avoid future consequences on surgical morbidity and socioeconomic aspects in low and middle-income countries (LMICs), we intend to determine the prevalence of occult breast cancer (OBC) among CPM cases.

OBJECTIVE

To determine the prevalence of OBC in patients undergoing prophylactic mastectomy (PM).

DESIGN

This is a retrospective cohort study.

MATERIALS AND METHODS

This retrospective cohort study is conducted at a tertiary-care hospital from January 2017 to December 2022. All individuals with the positive genetic test for high-risk breast cancer (HRBC) genes who underwent PMs/CPM at our centre were included. We analysed data using SPSS version 23.0.

RESULTS

Twenty-six mutation-positive females underwent PM/CPM (16.1%). Two (7.69%) of 26 had later post-PM recurrence. Only 8 (30.76%) patients had SLNB and all were negative. No OBC was seen in PM/CPM specimens, whereas 3 (11.5%) had atypical ductal hyperplasia (ADH). Two of the ADH had BI-RADS-1, whereas 1 was BI-RADS-4 (33.3%) on the preoperative assessment. Results also showed that with an increase in the tumour grade of the diseased breast, the BI-RADS score of the asymptomatic breast was subsequently increased ( = .029).

CONCLUSION

Our study shows negative OBCs in PM/CPM cases with persistently negative SLNB results; however, ADH is identified in 11.5% of specimens. Our results suggest that SLNB can be safely omitted in patients undergoing CPM, but, preoperatively, patient and disease factors should be considered.