We know that genetics and family history play a role in the risk of a woman developing many health problems including heart disease, high cholesterol, various cancers, osteoporosis, and diabetes to name a few.   As the technology, publicity, and access to testing increases, more women are asking themselves if they should consider genetic screening.  There are many factors that should be taken into consideration before a woman makes that decision.  At a minimum she should be aware of the accuracy of the test, how and when the results will be reported, who will have access to that information, the cost of the testing, how the procedure is done, if insurance covers the tests, and what options will be available to her given the specific results.   Though less tangential, issues related to the impact of that information should also be considered.  Who will she share that information with?  Maybe siblings and offspring don’t want to know if they too may have an increased risk.  Would positive or negative results change your lifestyle?  Whereas some may feel motivated to continue healthy habits with a negative screen, others might feel a false sense of security. Would genetic testing affect your choice to have children or not?  What might be the consequences of employers or insurance agencies having access to this information?  Laws and regulations in this area are not always clear.   With so many tough questions to face this obviously is a very personal decision that only a person can make for herself.  I would like to briefly discuss here the two genetic tests that I am most frequently asked about, CA 125 and BRCA genes.  These tests are most commonly associated with breast and ovarian cancer risk.   It is important to realize though that there are several other risk factors, some of which a person can control, for these diseases.

CA 125 is a protein made by certain cells of the body, including the cells of the female reproductive tract.  The CA 125 test is most often done by drawing a blood sample and the result is reported by an actual number value.  Approximately 80% of women diagnosed with ovarian cancer will have high levels of CA 125 in their blood at the time of diagnosis; the other 20 % of women diagnosed with ovarian cancer have normal CA 125 level.  Though abnormal levels are most commonly associated with ovarian cancer, a high value is also correlated with cancer of the fallopian tubes, endometrium, lung, breast, and gastrointestinal tract.  Non-cancer tumors as well as pregnancy, endometriosis, infections, liver problems, and menstruation can also change this number.   An elevated CA 125 value does not alone diagnosis any medical condition.  It is best used, along with other tests and a clinical exam by a health care provider, to help diagnosis a specific condition once an abnormality has been identified and to monitor the effectiveness of treatments.  Currently it is not recommended as a screening tool for woman in the general public though it may be appropriate in specific situations.

BRCA genes that are healthy and functioning help to prevent cancer.  BRCA gene mutations significantly increase a woman’s risk of developing both breast and ovarian cancer.  For example women in the general population have a 1 in 8 chance of developing breast cancer in their lifetime and a 1 in 71 chance of developing ovarian cancer.  Women with the BRCA 1 mutation have a 65% chance of developing breast cancer and a 45% chance of developing ovarian cancer by the age of 70.  A woman’s risk with the BRCA 2 gene is 39% and 11% for these two cancers.  It is important to remember that only 5-10% of female ovarian and breast cancers are hereditary.  That means that only 15% of women diagnosed with breast cancer have a family history.  In the general population approximately 6 in 1000 women will have a BRCA mutation.

The detection of BRCA mutations is also done by a blood test.  This can take weeks and the results are reported as either positive or negative for specific mutations.  The result may also show an abnormality of unknown consequence, meaning the alteration may or may not increase your risk of cancer.  No one testing method can detect all possible mutations on the BRCA gene.   If the specific mutation has been identified in a family member with cancer, other family members can be tested for that specific mutation.  But a woman needs to remember that other possible mutations may still exist.   General testing can be done on women without a family history or if the family member declines testing.  For women who do test positive for a hereditary genetic mutation a more frequent and comprehensive cancer-screening program is often recommended.