Let’s talk about cancer itself. The risk of receiving a diagnosis of different types of cancer varies throughout one’s lifetime. The lifetime risk of ever being diagnosed with cancer is approximately 41%. Now that’s really high! However, different types of cancer are caused by different things. Some cancers can be caused by environmental factors such as asbestos or tobacco. Some cancers like cervical cancer are caused by viruses like HPV. Epstein-Barr virus can cause Burkitt’s lymphoma. Some cancers are caused by circumstances like pregnancy. Choriocarcinoma is a cancer of the placental tissue that occurs usually after or during pregnancy. Some cancers are even caused by chemotherapy drugs- the medications used to cure cancer can actually cause cancer! I guess what I’m trying to say is that all cancer is not genetic. If your grandfather smoked and developed lung cancer, you are not likely going to get lung cancer unless you’re a smoker as well.
However, there are some cancers that are genetic. For a cancer to be genetic, you must inherit a faulty gene that predisposes your normal cells to turning into cancerous cells. So, what’s so great about testing to find out if you have that gene? If we find out if you have a genetic predisposition to certain cancers, there are tests that we can do to catch cancer early or even before it happens. If we catch it early, simply surgery may be curative. In some scenarios, we can offer complete removal of the ovaries or breast tissue to decrease that risk.
So, who qualifies for these genetic tests? With the current technology that is available, we know that certain genes predispose to certain types of cancers. For example, if you have a family history (within two generations) of breast or ovarian cancer, you may be a candidate for genetic testing for the BRCA gene. Talk to your provider and they can do a thorough screen of your family history to determine if you need testing. You need to have certain family members with breast, ovarian or pancreatic to qualify for testing (so that your insurance will cover the cost of the testing). Testing everyone including individuals without a significant family history is not so likely to be beneficial. However, testing people at high risk does increase the chance that we will find the patients that have certain genes. For example, what does it mean if you test positive for the BRCA gene? Your lifetime risk of developing breast cancer can go from 12% to 80% and your lifetime risk of developing ovarian cancer can go from 1.4% to as high as 40% (depending on the mutation). This is a big jump! Simple removal of your ovaries will essentially eliminate the chance of ovarian cancer, and bilateral mastectomy with reconstruction can significantly decrease the chance of breast cancer.
So, while there are a number of cancers with a hereditary component, there are also those unlikely to be passed from one generation to the next. The best way to find out if you have an increased risk is to discuss your family history with your provider. Together you can decide if genetic testing is right for you!