There are currently two known genes associated with hereditary breast and ovarian cancer: BRCA1 and BRCA2. Approximately 1:1000 to 1:500 people in the general population are born with an inherited mutation in the BRCA1 or BRCA2 gene, however people of Ashkenazi Jewish ancestry the mutation frequency of one of these genes is about 1:40. Genetic counselling for hereditary breast and ovarian cancer should be made available to all individuals and families who meet the following criteria:
• three cases of in 1st degree relatives (or 2nd degree if in the father’s side) of the same family, one of them diagnosed before the age of 50;
• two cases of breast cancer at any age, provided that there is a case of ovarian carcinoma in the same family;
• one case of breast cancer before age 45 and ovarian cancer at any age;
• bilateral before age 50 and a family member with breast or ovarian cancer;
• two family members with breast cancer before the age of 40 or one of them with ovarian cancer before the age of 50;
• breast or ovarian cancer before age 30;
• breast cancer before the age of 40 with a histological diagnosis of poorly differentiated, medullary or hormone receptor and HER2 negative breast cancer;
• breast cancer in men;
• individual belonging to a family with an identified pathogenic mutation.
Following the genetic counselling consultation, the probability of having a mutation in the BRCA1 and BRCA2 genes is calculated, taking into account family history (including that of healthy individuals). Genetic testing of the BRCA1 and BRCA2 genes will be advised if the mutation probability is equal to or greater than 10%.
For people with a BRCA1 or BRCA2 gene mutation (or who have a 50% chance of having inherited the known mutation in the family), the current recommendations for screening are for women: Annual Mammogram and Breast MRI beginning at age 25 or 5 to10 years before the youngest breast cancer age diagnosed in the family (MRI scheduled to alternate with mammography every 6 months); careful clinical examination of the breasts and regional lymph nodes every six months, along with imaging studies. In men: regular physical examination; special attention to any changes in the breasts; screening for prostate cancer following general population recommendations, unless family history suggests high risk.
Women who carry a pathogenic mutation in the BRCA1 or BRCA2 gene may also consider options of prophylactic surgery.
For more information contact HPA Grupo Saude on +351 282 420 400