Genetic Testing for Hereditary Breast Cancer
BRCA Testing at Pune Breast Care
At Pune Breast Care, we offer Genetic Testing for BRCA and other genes responsible for inherited risk of breast cancer. Genetic Testing has now become affordable and accessible to most women and families who can benefit from it. These include
Hereditary Breast Cancer
About 5-10 percent of all breast cancers are said to be hereditary and caused by known inherited mutations in specific genes. 80-90% of these are caused by mutations in BRCA1 or BRCA2 gene. TP53, PTEN,CDH1, ATM, CHEK2 and PALB2 are other genes responsible for hereditary cancers.
Suspicion of Genetic causes
The possibility of a genetic mutation is suspected in scenarios such as
Young Breast cancer: Breast Cancer is diagnosed at or before age 50 years
Bilateral Breast Cancer: Breast Cancer is present in Both Breasts
Ovarian cancer: of epithelial origin.
Multiple breast cancers: either developing at one time or sequentially
Male breast cancer: At any age
Triple-negative breast cancer: in women diagnosed at age < 60 years.
Breast cancer in a patient who has a close relative having breast, ovarian, pancreatic, or high grade prostate cancer.
A previously identified BRCA1 or BRCA2 gene mutation in the family
Breast cancer in ethnicities where the mutation is common (e.g.Ashkenazi Jewish ancestry)
The Genetic Testing Process
We follow a 3-step process for genetic testing
A)Pre-test Genetic Counselling: Here we assess your need for testing. We ask you about your history, the composition of your family tree and known cancers in the family. We may verify some pathology reports and do a physical exam. We explain to you the benefits of testing and any possible downside. We discuss options available in the scenarios of obtaining a positive, negative or inconclusive result. We outline how to best proceed with testing.
B)Genetic Testing: A simple blood draw provides a good sample for the test.We usually collect 3 ml of blood for the test. A saliva sample can also be used. No biopsy or other procedure needs to be done. The sample is sent to a genetics lab. A genetic test report is generated, which describes any gene mutations which may be found. The entire process can take 4-6 weeks.
C) Post Test Counselling: During this session we help you understand and interpret your test reports. We also guide you on how to use this information to make positive health decisions. We also guide you on how to disclose your reports to close blood relatives for their benefit when needed.
Have Questions About Genetic Testing?
Genetic Testing FAQs
Who is a close blood relative when considering family history?
What about men who are BRCA positive?
Men who are BRCA mutation carriers have increased risk of breast cancer and prostate cancer. They are instructed on self breast exams and advised annual breast exams after the age of 35 year and annual prostate cancer screening after age 40 years. Men can pass on the mutation to their biological children- both their sons and daughters.
How does a BRCA mutation impact my breast cancer treatment?
If you have a known harmful gene mutation, the surgical plan for your breast cancer treatment may change. We may give you the option to consider removal and reconstruction of both breasts instead of undergoing a lumpectomy. The reason for this is that even after successful treatment of your known cancer, you may have a significant risk of developing a new cancer in the remaining breast tissue on the same side, or a new tumor on the opposite side in future.
I am afraid to undergo genetic testing- what if I get a bad report?
If you have a significant family history and have seen other family members struggle with cancers, it is natural to be apprehensive of your own risk. Knowledge of this risk however should be used as a tool to make positive health decisions.
If I am BRCA positive, will my children be tested?
If you carry the gene, a biological child has a 50% probability of inheriting the genetic mutation. Genetic testing for BRCA and similar mutations is only done after the child is18 years of age when he or she can understand the testing process, its implications, and give consent for testing. The children who do not inherit the gene have the same cancer risk as the average population, which can be a source of great relief in the background of strong family history. If they do test positive they will be offered options similar to those mentioned before.
Is breast cancer hereditary?
Around 5-10 percent of breast cancers can be attributed to known genetic mutations. Upto 20 percent cases may be familial even if no mutations are known or found. The vast majority of patients who have breast cancer, have no family history and are called 'sporadic'.
What genetic defects can cause breast cancer?
80-90% of hereditary breast cancer is caused by mutations in BRCA1 or BRCA2 gene. TP53, PTEN,CDH1, ATM, CHEK2 and PALB2 are other genes responsible for familial cancers.
What is the cancer risk in women with BRCA gene defects?
A patient with a harmful mutation in BRCA may have a 60-80% lifetime risk of developing breast and 40-60 % risk of developing ovarian or fallopian tube cancer. In a patient who has already developed breast cancer, the lifetime risk of developing a breast cancer in the opposite breast may be 40%-60%. These are rough estimates and individial risk may vary with the mutation and the pattern of family history.
Can a BRCA mutation be inherited from the father?
Yes ,risk of breast cancer risk can be inherited with equal probability from the mother or father. Paternal uncles, aunts, cousins and grandparents also contribute to your family hisotry.
What sample will be collected for the test?
As we are testing for inherited gene mutations that are present in all cells of the body, a blood sample or saliva swab can be used for the test. We usually collect 3ml of blood and send it to the genetics lab for testing.
How long does the genetic testing report take?
The genetics lab isolates DNA from the blood, then processes the DNA in several complex steps using specialized gene sequencing equipment. A large amount of data is generated in the process which needs detailed analysis, referencing and then interpretation. A genetic test report is generated, which describes any gene mutations which may be found. The entire process can take 4-8 weeks of time.
How much does genetic testing cost?
With use of Next Generation Sequencing, and availablity of the test locally, the cost of testing has decreased considerably, compared to what it was a few years ago. The initial cost can vary based on whether we are testing for specific gene mutations or a comprehensive panel. Once a familial mutation is known, other family members can be tested at much lower cost. Discuss what test that is right for you, with your breast specailist or genetic counsellor.
Management BRCA positive patients
Management of a BRCA positive patient, i.e. a patient with a suspected harmful genetic mutation involves shared decision making between the breast surgeon and the patient. This decision may be influenced by the patients age, details of her family history, whether the patient has completed her family, whether she has already been diagnosed with cancer or other high-risk pathology. The options of management include
Risk Reducing Surgery
As BRCA gene increase a woman’s risk of ovarian and fallopian tube cancer. This risk is dramatically reduced by surgical removal of the tubes and ovaries. This procedure is usually advised after a woman has completed her family. This procedure also reduces her risk of future breast cancer. The most effective way to reduce the high risk of breast cancer however is removal of the breast gland with a bilateral mastectomy. Bilateral prophylactic mastectomy when performed using nipple-skin sparing technique and immediate reconstruction can be done with excellent cosmetic results
Women who are not yet ready for surgery, can choose to undergo more frequent breast cancer screening. We usually advise 6 monthly visits and typically alternate digital mammography with breast MRI for 6 monthly evaluations. For ovarian cancer screening, a yearly transvaginal /pelvic ultrasound and a blood test for CA-125 levels are typically used. Aggressive surveillance does not decrease risk, but allows early detection of potential cancers that are likely to develop.
Some patients may be prescribed chemoprevention such as tamoxifen. These medications can potentially lower risk but do not prevent all cancers in these patients. As they have certain side effects, they should only be used under guidance from your breast surgeon or oncologist.