When should you consider undergoing genetic testing for breast cancer?

There are two known breast cancer genes (BRCA): BRCA1 and BRCA2. When a BRCA gene is mutated, this can significantly increase the risk of developing breast cancer and ovarian cancer.

My mother had breast cancer before and is now in remission. Should I undergo genetic testing? Why didn’t the doctor recommend for me to receive genetic testing?

Most breast cancer patients and their family members do not need to receive genetic testing. This is because genetic testing only detects the genetic causes of breast cancer. Hereditary breast cancers typically account for up to 10% of all breast cancers, so genetic testing won’t be appropriate for most breast cancers.

Who should receive genetic testing for breast cancer? Generally speaking, breast cancer patients are the first to be considered. Therefore, if genetic testing is necessary, the doctor will consider your mother to first receive genetic testing. Factors that determine the need for genetic testing include the age of the person when diagnosed with breast cancer,  type of breast cancer, number of family members with breast cancer and any family history of other types of cancer, such as ovarian cancer.

Once we have the above information and if we find that your mother is likely to have an inherited gene mutation for breast cancer, then she may be recommended to undergo genetic testing. She will also be advised to consult a genetic counsellor, who can provide advice on the types of genetic testing that would be appropriate and what it means to test positively for an inherited breast cancer mutation.

If your mother is found to have an inherited gene mutation for breast cancer such as BRCA1 or BRCA2, the doctor will discuss the increased risk of breast cancer and other cancers such as ovarian cancer and pancreatic cancer. The doctor may also suggest surgery to reduce the risk of cancer in the future, such as prophylactic mastectomy or salpingo-oophorectomy (removal of the ovaries).

Meanwhile, as a member of her immediate family, you will also be advised to receive genetic counselling and possibly undergo genetic testing.

If I test positively for an inherited breast cancer gene mutation, does this mean I will definitely get breast cancer?

Even if you test positively for an inherited breast cancer gene mutation, this does not mean that you will definitely get breast cancer.

However, your risk of developing some types of cancer is much higher, such as breast, ovarian and pancreatic cancers. It is recommended you should consult with a doctor and receive counselling to learn about screening for these cancers and may need to undergo surgery to reduce the risk of these cancers and help prevent their development.