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Genetic Screening for Inherited Cancer

Posted on Jun 16, 2015 in Cancer

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What if you knew you would get cancer and the exact type of cancer you would get? For some people, that knowledge can be gained through genetic testing for cancer, allowing them to take steps to prevent the cancer, or at least catch it early.

This type of testing looks for mutations in the genes a person was born with – mutations that researchers now know put a person at high risk of developing certain types of cancer. Often people with these mutated genes have relatives who have developed cancer younger than expected.

“We can do a risk assessment of the entire family. Then, if someone tests positive, we can recommend high-risk screening aimed at catching cancer at the earliest stages and possibly surgical options to prevent someone from developing cancer altogether,” says Lauren Schenck, a genetic counselor at Mills-Peninsula’s Dorothy E. Schneider Cancer Center.

How Common Are Hereditary Cancers?

Most cancers are caused by genetic mutations that occur gradually over the course of our lives. Environmental hazards such as smoking or asbestos can trigger those mutations, but many factors are involved. There’s no way to predict if a person will get one of those cancers.

About 5 to 10 percent of cancers are caused by mutated genes we inherit from our parents. If you carry a genetic mutation linked to a specific cancer, your odds of getting that cancer rise to at least 20 percent and as much as nearly 100 percent, depending on the mutation.

Today, genetic testing can spot mutations that put you at risk for many types of cancer, including breast, colon, endometrial, pancreatic, prostate and ovarian cancers, as well as melanoma, diffuse gastric and kidney cancers.

Who Benefits Most From Testing?

Not everyone should be tested, Schenck says. Genetic counseling for cancer most benefits people who have a strong personal or family history of cancer. Signs that you may have a hereditary cancer syndrome include:

  • Early onset of cancer in yourself or a relative, before age 45 or 50
  • Same or related types of cancer in several relatives (such as breast and ovarian)
  • Multiple cancers in yourself or a relative
  • Cancer in several generations of your family

If you test positive for a genetic mutation, you may opt for careful screening, such as a yearly mammogram and breast MRI, or a colonoscopy every year or two. There aren’t good screening options for every type of cancer, but awareness raises the odds that you will detect cancer in its early stages, when treatment works best, Schenck says.