High risk surveillance outcomes in women with breast cancer gene mutations.

Background and Purpose: High risk surveillance is a fundamental management strategy for asymptomatic patients with breast cancer gene mutations. Through dedicated High-Risk Clinics (HRC) patients are screened, counselled and offered risk reduction options. This includes risk reduction mastectomies (RRM) and chemoprophylaxis. The aim of this study is to identify the best risk reduction intervention, whilst evaluating the management and prognosis of women who developed breast cancer during surveillance. Methods: Retrospective cohort review of asymptomatic women with a breast cancer predisposition gene attending HRC at a high-volume tertiary breast unit from 2006 - 2023. Results: A total of 240 women attended 1591 surveillance appointments. Gene mutations included BRCA1 108 (45%), BRCA2 119 (50%) and Others 13 (5%). 56 (23%) women opted for RRM with no subsequent cancer diagnosis during a median follow-up of 60 months, range (2–184). 8 patients (3%) opted for chemoprophylaxis. Surveillance protocol required individualised requirement for MRI or mammogram. Breast cancer was diagnosed in 17 women (7%). The median age of diagnosis was 44, range (31 – 54). These patients had early, node negative, breast cancer with heterogeneous phenotypes. 13 (76%) were recommended for systemic therapy by MDT. Of the 6 patients who received neo-adjuvant chemotherapy, a complete pathological response was achieved in 5 (83%). There was no breast cancer related mortality. Median follow-up; 37 months, range (3-100). Conclusions: Risk reduction mastectomies offer the best protection against developing hereditary breast cancer. High risk surveillance is a good alternative, with early detection of breast cancer possible. Early detection does not obviate the need for systemic therapy in this cohort. Knowledge of HRC outcomes assists in facilitating well-informed discussions and optimises delivery of patient-centered care.