Fourteen-year experience of high-risk breast cancer surveillance for female BRCA mutation carriers in Hong Kong

Abstract

Background: Long-term results of high-risk breast cancer surveillance for BRCA mutation carriers are lacking in the literature, especially for Asian population. This study aimed to review our 14-year experience of high-risk surveillance and assess the outcome of cancer detection, breast cancer occurrence and mortality. Methods: BRCA mutation carriers in Hong Kong Hereditary Breast Cancer Family Registry from January 2007 to December 2020 were reviewed. Surveillance program included biannual clinical examination, 6-monthly breast imaging with alternating contrast magnetic resonance imaging and a combination of mammogram and ultrasound. Result: A total of 395 female BRCA mutation carriers who didn’t have bilateral mastectomy were enrolled to our high-risk surveillance protocol with a median follow-up of 39.4 (range, 6~152) months. The uptake of risk-reducing mastectomy was 5%, and was particularly low in breast cancer-free patients, only 2%. The new breast cancer detection rate was 1.7% (34 cancers diagnosed from 1997 screening sessions). Early cancer detection was achieved with 88% diagnosed in stage 0/1 and a node negative rate of 94%, with minimal interval cancer occurrence. Overall breast-cancer specific mortality was 3%. Initially breast-cancer free patients who later developed breast cancer during surveillance, breast-cancer specific mortality was not observed. However, overall mortality of patients was largely dependent on ovarian cancer history. Conclusions: Risk-reducing mastectomy is not popular among Chinese BRCA mutation carriers. High-risk breast cancer surveillance remained the core management and our 6-monthly breast imaging program could achieve early cancer detection with minimal interval cancer occurrence, and a low breast-cancer specific mortality. Further study with cost-effective analysis is warranted.