Before undergoing genetic tests for breast cancer, the patient will take an intensive genitive counseling during which the doctor will fully explain the benefits and risks of genetic testing and answer any questions patient may have.
Also, the patient will sign a consent form which is an agreement between patient and doctor, showing that patient has discussed the test and how its results might affect patient’s family.
The patient must keep in mind that the vast majority of breast cancer cases are not associated with a breast cancer gene and scientists do not know all of the genes that can cause breast cancer so the test is only done for the known genes.
Patient can discuss genetic testing with her doctor if:
- Two or more blood relatives (mother, sister, aunt, cousin, or daughter) are having premenopausal breast cancer or ovarian cancer diagnosed at any age
- The patient has been diagnosed with breast cancer, especially if it was diagnosed before patient reached menopause, if patient is having a blood relative with breast or ovarian cancer, or if patient’s cancer is in both breasts
- The patient has been diagnosed with ovarian cancer and patient is having blood relatives who have had ovarian or breast cancer
- The patient is related to someone (male or female) who has a BRCA1 or BRCA2 mutation
- Patiently is of Ashkenazi Jewish descent and it is having blood relatives who have had breast or ovarian cancer, or the patient has had breast or ovarian cancer.
During testing, the patient will first obtain a family pedigree to determine if there is a cancer development pattern within the patient’s family.
Then a blood test it is given. If a patient with a cancer diagnosis and a family history of the disease has been tested and found to have an altered BRCA1 or BRCA2 gene, the family is having a "known mutation".
If an association between the development of breast cancer and a breast cancer gene is made, then all family members willing to participate in genetic testing are asked to give a sample of blood. The results of the genetic test will be available after few weeks and the length depends on the test performed and under what circumstances they are done.
If there was a mutation identified in patient’s family and the test is negative, that means that patient is not caring the specific mutation that was identified in patient’s family.
When a genetic test is negative, it must be interpreted cautiously because is some cases, there is still a chance patient is at an increased risk to develop breast cancer due to potential mutations in genes other than those doctors currently can test for.
A positive test result means that a mutation known to increase the risk of breast and ovarian cancer was identified and knowing this, patient can be guided to important health care decisions for patient and her family, for example, starting regular breast cancer screening at age 25 or 10 years earlier than the age of the youngest person with breast cancer at the time of their diagnosis and start using the anti-estrogen drug used to treat osteoporosis, to help prevent development of breast cancer.
Some women choose preventive (prophylactic) mastectomy to decrease the chances of developing breast cancer, although this doesn't offer complete protection.
The benefits of genetic testing are the ability to make informed medical and lifestyle decisions while reducing the anxiety of not knowing their genetic background and ability to make a proactive decision regarding prophylactic surgery. Also, many women are able to participate in medical research that may, in the long run, decrease their risk of death from breast cancer.
Genetic testing is costly, ranging from about $200 to more than $2,000, depending on the type of test. Insurance policies vary in providing coverage for genetic testing.
