Updated Important Research Findings from Hong Kong Hereditary Breast Cancer Family Registry
(Analysis of Participants recruited into research study till December 2022):
Analysis of 4720 breast cancer or ovarian cancer patients who are clinically considered high risk based on relatively young age at diagnosis, multiple members with breast/ovarian/prostate and BRCA related cancers in the family.
The average age of women referred for genetic counselling and testing is 49.3 years old, which is at a peri-menopausal age. 31.3% of them were under 40 years old at diagnosis .
BRCA mutation was found in 500 patients (10.6%), of which 242 (48.4%) were BRCA1 mutation while the remaining 258 (51.6%) were BRCA2 mutation. This is noticeably different from patients from the Western world where majority of mutations are BRCA1 mutations.Among these mutations SIX FOUNDER mutations in Chinese have been found. The REGISTRY is the first to report this finding and these 6 founder mutations accounts for 11.96% of all the BRCA mutations.
Among the 500 BRCA mutation carriers we also tested 915 of their family members. 441 (48.2%) of them were tested with positive result which included cancer patients and non-cancer patients.
Besides BRCA mutation, there were 24 (0.5%), 7 (0.15%) and 53 (1.1%)patients carrying TP53, PTEN and PALB2 mutations respectively being identified in the cohort of 4720 patients, since the deployment of the 6-gene testing. The average age of TP53 carriers being referred for genetic counselling and testing was 37.5, much younger than that of BRCA mutation. 17 of them had age of diagnosis younger than 40 years old whereas 9 of them had even younger age of diagnosis – below 30.
Distribution of Gene Mutations Among 584 Patients