Gene Testing for Hereditary Cancers in Women
: New On-Site Testing Can Help to Save Lives
Apr 29, 2013 12:15AM
By Russell Turk, MD
A 47-year-old patient I have known for over ten years came to see me for a routine annual exam not long ago. I am sure she was thinking it would be a quick, in and out visit, but after discussing her current medical issues we then reviewed a family cancer history questionnaire she had completed in the waiting room.
It turns out that the patient’s mother recently developed ovarian cancer, and her sister and two maternal aunts were diagnosed with breast cancer – all in the past decade. None of the women had ever been tested to see if they carry a gene that predisposes them to certain types of cancers. What’s more, concerns over the radiation exposure associated with mammography had prevented my patient from having mammograms for the past few years, despite the relatively low risk (about the same you would be exposed to on a round trip cross country flight).
After I discussed the potential benefits of genetic testing, my medical assistant handed the patient a test kit to obtain a quick saliva sample, which was mailed to a laboratory for testing. This scenario is becoming increasingly common because OB/GYN doctors are now able to offer on-the-spot testing to identify patients who carry the BRCA 1 or BRCA 2 gene mutation (the gene abnormalities responsible for the majority of hereditary breast and ovarian cancers). The test screens for something known as hereditary breast and ovarian cancer syndrome (HBOC). Another, somewhat similar test, can also be performed for Lynch Syndrome, an inherited genetic conditions that predispose people to other diseases including cancers of the colon, uterus, ovary, skin and pancreas.
For women with a family history of cancer this type of testing is clearly beneficial because it allows patients to pinpoint their individual risk, ultimately providing the potential to save many lives. Most women have heard the oft-repeated statistic that the average woman faces a one in eight chance of developing breast cancer over her lifetime. But that number jumps to between 15 and 40 percent in women with a family history of breast cancer. And women with HBOC face up to an 87 percent of chance of getting breast cancer. In addition, the average woman has a less than one percent chance of getting ovarian cancer; the risk increases to between 4 and 11 percent in women with a family history of ovarian cancer, and up to 44 percent in women with HBOC.
While BRCA gene testing has been around since the early 1990s, it is only now becoming a common cancer screening tool that a number of medical organizations contend should be utilized more frequently. For example, in April, the U.S. Preventive Task Force (an independent government-backed panel of experts) issued a draft recommendation recommending that women who have family members with breast or ovarian cancer be screened to determine whether their history is associated with an increased risk of carrying a BRCA mutation.
In addition, hereditary cancer screening has traditionally been underutilized because it wasn’t patient-friendly. In the past, when doctors tried to identify women who were candidates, even when we recommended that they see a genetic counselor, the vast majority of patients did not schedule an appointment. One survey found that less than 2 percent of patients referred by their physician, underwent testing.
There are still many, many women who are good candidates but have yet to undergo screening. In fact, just over half (53%) of newly diagnosed breast cancer patients considered high risk of carrying the BRCA 1 or BRCA 2 gene reported that their doctor had urged them to undergo genetic testing, according to a recent study of more than 2,000 Pennsylvania women.
Like most OBGYNs, I have counseled women for two decades to get their breasts checked regularly, perform monthly self-exams and choose a healthy lifestyle to reduce the risk of breast cancer. But for some women, that may not be enough. Doctors, myself included, have been overlooking an effective screening tool: the family history.
When I used to ask patients whether there’s anything new with their family history, most women said, “No.” They still do. It wasn’t until I started delving into the subject and asking pointed questions through a formal questionnaire that patients recall every family member with cancer, and they share details like their age at diagnosis. Myriad Genetics is currently the only company doing this type of testing and their representatives are helping doctors implement screening in their offices. As a result, doctors are now able to identify more candidates and get them tested before they walk out the door. In fact, the company itself provides doctors with resources and support to help clarify which patients are candidates and tries to make the implementation of office screening as smooth as possible.
The test itself costs about $4,000 so careful selection of candidates is important. Fortunately, most insurance plans cover hereditary cancer testing for appropriate candidates, and Myriad takes care of checking with each patient’s insurance carrier in advance of testing. If insurance does not cover the cost, the company offers a payment plan, interest-free over 25 months. Interestingly, Medicare only covers the test if you already have cancer -- even if multiple members of your family have been diagnosed with ovarian or breast cancer.
Keep in mind that HBOC and Lynch Syndrome screening are not appropriate for the majority of patients, even many who might have more than one family member with cancer, and doctors need to evaluate whether a patient is a candidate. Even if you are a candidate, more often than not, the test results will be negative: Only 7 percent of breast cancers and up to 15 percent of ovarian cancers are hereditary, according to Myriad. In real numbers, between one in three hundred and one in five hundred women has a BRCA gene mutation.
But if you happen to have a family history it could be a lifesaver. Women whose test results indicate that they do have a BRCA1 or BRCA2 mutation have several options, including stepped up screening, prophylactic chemotherapy, chemoprevention and/or preventive surgeries such as mastectomy, removal of the ovaries and tubes (salpingo-oophorectomy), and other integrative approaches including lifestyle changes, which can drastically reduce the risks for developing breast and ovarian cancer -- or at the very least, detect it earlier, when it’s still curable. In many cases, referral to a genetic counselor at this point can also prove very helpful. Last but not least, women who learn they carry a BRCA gene and/or have Lynch syndrome typically feel an obligation to share that information with family members, since their parents, children and siblings have a 50 percent chance of having the same aberrant gene.
While no one wants to be a carrier for either of these gene mutations, identifying them in patients is truly a case where knowledge is power. Unlike some diseases for which genetic testing can now be performed such as ALS (Lou Gehrig’s Disease) where there is no cure, BRCA and Lynch syndrome carriers have many options available to combat their risks and help them live a long and healthy life.
Russell Turk, MD is the founder of Riverside Obstetrics & Gynecology in Greenwich, CT. He is the former chief of service for Kaiser Permanente's northern Virginia area, where he supervised 30 physicians and 15 midwives and nurse practitioners. His blog, Housecalls can be found at RiversideOBGYN.com/blog.