Cancer genetics and BRCA 1 and BRCA 2 gene mutations
With the recent announcement from actress and director Angelina Jolie in the New York Times Op-Ed section about her choice to have a double mastectomy in order to drastically reduce her chances of getting breast cancer, many women are wondering whether they should be screened to determine their genetic risk of getting breast cancer.
At UNC Lineberger Comprehensive Cancer Center, we help patients determine their risk of developing cancer and provide genetic testing through our Cancer Genetics Program. UNC Lineberger members James P. Evans, MD, PhD, Director of Clinical Cancer Genetics and the Bryson Program in Human Genetics; David Ollila, MD, surgical oncologist with the Melanoma Program & UNC Breast Center; Paola Gehrig, MD, Director, UNC Gynecologic Oncology; and Keith D. Amos, MD, FACS, surgical oncologist at UNC Breast Center help answer questions about genetic testing.
To which of your patients would you recommend genetic testing for BRCA 1 and BRCA 2 mutations?
Evans: It is now recommended for women who have a strong family history of breast cancer or ovarian cancer, or who are diagnosed with breast cancer at a young age (typically under 45, but this precise age cut-off is not hard and fast). Other things that can prompt consideration of testing would be bilateral disease diagnosed in an individual. Finally, women of Ashkenazi Jewish ancestry have an increased risk of carrying certain BRCA1/2 mutations.
Who should a patient consult if they want to know if they carry a BRCA 1 or BRCA 2 mutation?
Evans: A geneticist and/or genetic counselor who specializes in assessing cancer risk. The interpretation of genetic testing is sometimes not straight-forward. Thus, it is imperative that women have expert advice so that their genetic situation and their risk is properly calculated. There are also important considerations for other family members and a genetics specialist will help determine the impact of the mutation on other family members who may share it.
It is important for a patient to also consult with a surgeon with experience in risk-reducing mastectomy if the BRCA 1 or BRCA 2 mutations are present. The surgery has to be done right and this kind of context demands a careful approach to ensure that maximal risk reduction is achieved.
Ollila: Risk-reduction in gene carriers is maximized by removing all of the breast tissue on both sides.
Evans: A patient will also want to consult with a plastic surgeon since most women desire reconstructive surgery and there are many options with different advantages and disadvantages, as well as a gynecologist since women who carry such mutations are at a high risk of ovarian cancer and specific strategies (such as removal of the ovaries to prevent ovarian cancer) are important at the appropriate time in a woman’s life.
To what extent is a prophylactic mastectomy a recommended procedure after discovering that a patient carries either a BRCA 1 or BRCA 2 mutation?
Evans: This is a standard strategy recommended to and chosen by many women who are found to have such mutations. Some women opt for increased surveillance instead but certainly prophylactic mastectomy is the most effective means of reducing breast cancer risk in this setting.
Ollila: It is important for each individual to understand their lifetime risk of developing breast cancer and make informed choices based upon that risk assessment.
Is a prophylactic mastectomy typically covered by insurance?
Evans: Yes, as is subsequent reconstruction.
To what extent is a prophylactic oophorectomy (removal of the ovaries) a recommended procedure after discovering that a patient carries either a BRCA 1 or BRCA 2 mutation?
Amos: It is challenging to screen for ovarian cancer. For breast disease, physicians use mammograms for screening. For the ovaries, ultrasound of the ovaries and blood tests for tumor markers are used for screening, which have not been as effective as mammograms have been for catching a breast cancer at early stages.
The benefit is that preventive surgery can significantly reduce a woman's chance of getting ovarian cancer which is very difficult to treat. Ovarian Cancer usually is found at advanced stages where patients need radical pelvic surgery and chemotherapy. The downsides are removing the ovaries which affect a woman's ability to have children.
Gehrig: I agree with Dr. Amos that we do not have a good screening test for ovarian cancer. In women who have not completed their families or are less than 40 year of age, we can screen them with ultrasound and CA-125 every 6 months. In addition, these women can be offered birth control pills that have been shown to decrease the risk of ovarian cancer by as much as 50%. Removal of the ovaries can also help decrease the risk of breast cancer.
What would be your advice to a patient who was considering a prophylactic oopherectomy after a BRCA mutation finding?
Amos: I would ask the patient whether they are interested in getting pregnant again. If the patient is not interested in getting pregnant again and having more children, I would recommend proceeding with prophylactic removal of the ovaries and fallopian tubes.
Gehrig: I agree with Dr. Amos. In addition, recent studies have shown that a rare but aggressive type of endometrial cancer (uterine papillary serous carcinoma) is also in the BRCA spectrum, so a hysterectomy should also be included in the discussion of prophylactic surgery.
Any final comments?
Evans: The most important thing is that a woman who may be carrying a mutation in BRCA 1 or BRCA 2 have a team of experts to help her make the decisions that are right for her. A mutation in one of these genes confers a very high risk of both breast and ovarian cancer. The strategy that Ms. Jolie used is perfectly appropriate. Indeed, it is the most effective means of reducing risk. That said, these decisions hinge upon many factors and are very personal in nature and it is not necessarily the decision that other women might take in the same situation. Thus, it is important that women in her position consult with the right team of experts.
Finally, it should be pointed out that Ms. Jolie’s situation is not typical. She was at an especially elevated risk of breast cancer due to the mutation which she carries. Most women do not have such mutations and are therefore not at the very high risk for breast cancer that existed in Ms. Jolie.
Date: May 15, 2013