Are You At Risk For Cancer? The Answer Is In Your Genes

Nov 26, 2018

Credit cancer dot gov

Your genetic make-up could shed some light on the likelihood that you or members of your family are at risk for certain types of cancer. And some different cancers can be closely related.

Every October we commemorate Breast Cancer Awareness Month. In November, it’s Prostate Cancer’s turn in the spotlight. While these two diseases may sound like night and day, they have some things in common including a genetic component. "Genetics is used to identify patients who are at increased risk of having a specific subtype or group of cancers" said Dr. Lonnie Miller, a hematologist/oncologist at Sacred Heart Medical Oncology Group in Pensacola.

Dr. Miller says patients who have certain types of cancer could have a genetic marker that would make it more likely for them, or members of their family, to be at higher risk for other cancers, what’s called a cancer syndrome. The most common of these markers are the BRCA 1 and BRCA 2 genes. "Patients who are diagnosed, especially young patients who are diagnosed with, say, metastatic prostate cancer, those patients should be considered for genetic testing for a cancer syndrome. And prostate cancer can fall under the breast and ovarian cancer syndromes which are, most commonly, the BRCA 1 & 2. Now, there are other cancer syndromes, but those don't usually involve prostate (cancer), those are more for sarcomas and leukemias."

Of course women with breast cancer are not at risk for prostate cancer and men with prostate cancer are at a very low risk for breast cancer. But it’s the genetic component of these syndromes that make testing for BRCA genes a tool that families can use. Dr. Miller says there are certain types of patients that he believes should be tested. That includes young people with breast cancer under the age of 45, a person who has more multiple breast cancers that are not a recurrence of the original disease, patients with a unique type of breast cancer called "triple negative breast cancer", patients who have first or second degree relatives with multiple cancers and patients who have a family history of a known genetic mutation. He also points out that, while it is rare, men do get breast cancer and should be tested because of the connection to prostate cancer.

Dr. Lonnie Miller
Credit Sacred Heart Hospital

But the testing is not for everyone. Dr. Miller says that while he and his team can order the tests for their patients, he prefers to refer them to a genetics counselor, where they can talk about the ramifications of testing, including not only the likelihood of a positive test, but if having a positive result would change anything. "If it's not going to change anything, then I'm not sure we really need to do the testing."

And that’s key, because if a patient is not ready to take action after a positive test, it may be best that they don’t know. Those genetic counselors can walk patients through some pretty intense options if they test positive for the BRCA genes. "Let's say a family member got diagnosed with breast cancer at age 25 or 30 and they had testing and they were BRCA positive, and then you had testing and were positive, then the recommendation would be to, if you were done child bearing, the recommendation would be to get a bilateral mastectomy and have your ovaries removed. If you were not done child bearing and actually wanted to have more children, then we would do enhanced surveillance. So we would do imaging every 6 months, and we would consider putting you on a medicine to try to prevent a breast cancer."

Current recommendations are that average risk women get a screening mammogram every one or two years beginning between age 40 and 45. As for prostate cancer, the PSA blood test is still the gold standard although it has come under fire in recent years. "There are other reasons that your PSA could be elevated (such as) inflammation or an infection in your prostate, recent sexual intercourse, things like that. So there are other reason (your PSA) could be elevated. It has to be interpreted appropriately."

The latest recommendations from the US Preventive Services Task force say for men aged 55 to 69, the decision to undergo periodic PSA screening for prostate cancer should be an individual one. They recommend testing end at age 70.