Survey on high risk female breast/ ovarian cancer patients
A total of 202 high risk female breast cancer patients or ovarian cancer patients with family history of breast cancer have been recruited with their BRCA1 and BRCA 2 genes analysed to date.
* High risk is based on age, family history, type of cancers
Research Findings:
The demographic information and medical records of the 202 patients were assessed. The mean age of first diagnosis of breast cancer is 43 year old. Within this group of patient seen, 8.5% were aged < 30, 33% patients aged 30-39, 39.5% patients aged 40-49, 10.5% patients aged 50-59 and 8.5% patients aged ≥ 60.
BRCA mutation was found in 12.4% of patients (25 patients), of which 44% were BRCA1 mutation while the remaining 56% were BRCA2 mutation. This is noticeably different from patients from the Western world where majority of mutations are BRCA1 mutations.
Among the 25 BRCA mutation carriers we also tested 50 other family members. 22 of them were tested with positive result.
For BRCA mutation carriers, the mean age first diagnosed to have breast cancer is 40 year old, for which BRCA 1 mutation carriers tend to be diagnosed at a younger mean age of 36.5 year old compared to BRCA 2 mutation carriers where the mean age of diagnosis is 43 years old.
BRCA mutation carriers are associated with the following type of cancers in our Hong Kong study cohort:
74.2% of the patients had local relapse, in which 75% were opposite side and 25% were same side / axilla;
70% of the patients had invasive cancer and 30% had DCIS;
64% of the patients had a family history of breast cancer, in which 12.5% had ≥ 3 family members had breast cancer;
62.5% of the patients were aged 40 or below;
36.7% of the patients had overall stage 2 cancer;
33.3% of the patients had bilateral breast cancer;
25.9% of the patients had triple negative breast cancer;
24% of the patients had a family history of ovarian cancer;
16% of the patients had ovarian cancer;
88% of the patients had a family history of any cancer and the type of cancer these family members had as below:
Breast cancer: 31.4%;
Ovarian cancer: 11.8%;
Lung cancer: 11.8%;
Gastric cancer: 9.8%;
Colon cancer: 7.8%;
Liver cancer: 5.9%;
Nasopharyngeal cancer (NPC): 5.9%;
Other cancer: 15.9%
A Founder mutation in BRCA2 is also found of which the ancestors have all been traced back to Guangdong province. This may explain the higher BRCA2 mutation rate in Hong Kong Chinese population.
Figure 1: Distribution of 202 female patients
Figure 2: Distribution of 25 BRCA mutation carriers
Important finding between BRCA 1 and BRCA 2 carriers
BRCA 1 carriers were more likely to have invasive cancer than BRCA 2 carriers (p=0.042);
BRCA 1 carriers were more likely to have ER negative than BRCA 2 carriers (p=0.009).
