Does cancer run in your family? Genetic testing will tell you your odds of getting cancer in Kingston, New York
Some scary facts about a a cancer-causing gene mutation
Hereditary nonpolyposis colorectal cancer ("HNPCC") is the most common hereditary cause of colon cancer, uterine and ovarian cancer, stomach cancer and small intestinal cancer. Mutations in the genes that cause HNPCC dramatically increases the risk of developing colon cancer, uterine and ovarian cancer, and stomach cancer.
Here are some scary statistics: People with HNPCC have an 80% likelihood of getting colon cancer compared to 4% for the general population. That's not all. The average age that colon cancer is diagnosed in persons with HNPCC is 44 years of age compared to 65 years old for the general population. Nearly all colon cancer begin as non-cancerous polyps or mushroom-like growths inside the colon. People with HNPCC are much more likely to develop these polyps and tend to develop them at a younger age.
HNPCC also puts you at high risk of other forms of cancer, including uterine and ovarian cancer for females, stomach cancer, small intestinal cancer, cancer of the urinary tract, cancer of the gallbladder and bile ducts and brain cancer. Persons with HNPCC have a 40% likelihood of getting uterine cancer compared with 3% for the general female population. Wait, there's more. People with HNPCC have a 20% risk of getting stomach cancer compared to less than 1% for the general population and a lifetime risk of 10% of getting ovarian cancer compared to 1.5% for the general female population. Pretty scary stuff, right? It gets worse.
If either of your parents has HNPCC, you have a 50% chance of inheriting the altered gene and thus inheriting the increased risk of cancer.
How you get find out if cancer "runs in the family"
The genetic test is a simple blood test that involves drawing blood from your arm for analysis by a testing lab. The test is usually performed on DNA taken from the white blood cells in your blood. If a harmful gene mutation is identified in one of your family members, your other family members can be tested for the same gene mutation.
If you have a family member who has been stricken by cancer, you may not even need to have your blood tested. The likelihood that a cancer victim in your family will have a mutation is much higher than it is for an unaffected family member.
The genetic testing can begin with molecular tests on tumor samples from the family member affected by cancer. Because tumor samples are routinely collected during cancer surgery, testing can be done on the stored tumor samples, even after a cancer patient has died. If the tests on the tumor samples reveal a genetic mutation, i.e., HNPCC, you are more likely to have a genetic abnormality and you can go on to have blood testing to look for a genetic mutation.
With this sort of genetic testing, families can sort out who has inherited the mutation. If no mutation can be found in the testing of the tumor sample, it means that the mutation responsible for that family's high incidence of cancer has not yet been discovered and it is unnecessary for other family members to undergo genetic testing.
The results of genetic testing can indicate which family members have inherited a mutated gene and thus have an increased risk of cancer. This will affect your screening and prevention options, and indicate whether your children or siblings are at risk. Those family members who have the mutation will need to undergo more intensive screening and prevention efforts. Those who are free of the mutation will be able to follow the simpler cancer screening for the general population.
Should everyone rush out for genetic testing for gene mutations that can cause cancer? No. But if you have an unusually high rate of cancer in your family, there's a decent chance that cancer "runs in the family". Genetic testing will reveal whether you are at increased risk for various forms of cancer. In that case, you will need to be much more vigilant about screening for cancer than the general population.
What you can do if you have questions
If you have questions or want more information, send me an e-mail at [email protected] or better yet, you can call me on my toll-free cell at 866-889-6882. You are welcome to join my e-mail newletter list, where you will get FREE e-mail alerts about patient rights.