Contralateral Prophylactic Mastectomy in Unilateral Breast Cancer: Histopathological Yield and Patient Reported Outcomes from a Single Institution Experience

Objective: Despite advances in early detection and treatment, patients with unilateral breast cancer remain at risk for developing contralateral breast malignancy. Contralateral Prophylactic Mastectomy (CPM) is often pursued as a risk-reducing option in high-risk individuals. This study presents a single-institution experience with CPM by evaluating clinical profiles, histopathological findings and Patient Reported Outcome Measures (PROMs). Methods: This retrospective-prospective study was conducted at the Breast Surgery Department, Liaquat National Hospital, from January 2018 to December 2024. Clinical and pathological data were reviewed for patients who underwent CPM. PROMs, including the Decision Regret Scale (DRS), Personal Well-being Index (PWI) and Body Image Scale (BIS), were assessed via structured phone interviews. A DRS ≤25 indicated mild regret, PWI ≥70 denoted normal well-being and BIS ≤14 indicated a positive body image. Results: Among 22 patients (mean age: 43.9 ± 11.2 years), 13 (59.1%) had a positive family history and 19 (86.3%) underwent genetic testing. BRCA1, BRCA2 and TP53 mutations were detected in 13 (59.1%), 3 (13.6%) and 2 (9.1%) cases, respectively and 1 (4.5%) patient was BRCA1/2 negative. Histopathology of CPM specimens revealed stromal fibrosis in 13 (59.1%), adenosis in 5 (22.7%), dilated ducts in 3 (13.6%) and benign tissue without abnormality in 6 (27.3%) cases. PROMs from 19 patients showed mild or no regret in 16 (84.2%), normal well-being in 15 (78.9%) and a positive body image in 17 (89.5%) patients. Moderate fear of recurrence was reported by 13 (40.9%) patients. Conclusion: CPM in this cohort was largely associated with benign histological findings. PROMs indicate overall psychological acceptance, though recurrence anxiety remains. These findings highlight the importance of individualized counseling in decision-making for CPM.