Some Cancers are Hereditary - How to know if You Need Genetic Testing

The majority of cancers that develop are considered to be sporadic, due to environmental exposures and/or lifestyle choices. These account for about 70% of all cancers. Twenty percent of cancers develop due to similar lifestyles and exposures within a family. About 5-10% of all cancers are considered to be hereditary and develop due to a genetic mutation that is passed down through the generations.

Are You at Risk for Developing Hereditary Cancer?

You should consider looking into genetic counseling and testing if the following apply to you or members of your family:

• Breast, colorectal, or uterine cancer diagnosed before age 50
• More than one type of cancer in an individual
• Certain types of cancer, including ovarian, pancreatic, prostate cancer that has spread, medullary thyroid, triple-negative breast or male breast cancer
• Cancer in both of a set of paired organs (for example, both kidneys or both breasts)
• 10+ gastrointestinal (colon) polyps
• Ashkenazi Jewish ancestry

What are the Most Common Types of Hereditary Cancer?

The most common types of hereditary cancer syndrome are:

1. Hereditary breast or ovarian cancer. These cancers develop due to a genetic mutation; usually in the BRCA1 and BRCA2 genes, but there are many more such as PALB2, ATM, CHEK2.
2. Lynch Syndrome: a common hereditary colon cancer syndrome due to a mutation in one of five genes: MLH1, MSH2, MSH6, PMS2 and EPCAM.
3. Familial Adenomatous Polyposis (FAP) or Attenuated FAP: a common hereditary colon cancer syndrome due to mutations in the APC or MUYTH genes. In this syndrome an individual who carries a mutation on one of these genes has a higher risk of developing multiple colon polyps and then have a higher risk of developing colon cancer. There are two types of FAP:
   1. FAP an individual develops hundreds of colon polyps, usually by the time they are in their 20s
   2. AFAP an individual develops 10-50 colon polyps, usually later in life, in their 40-50s.

There are many other types of hereditary cancer syndromes.

How Can Genetic Testing Help?

If you or your family members have hereditary cancer syndrome present and a genetic mutation is identified upon testing, there are ways to manage that risk:

• More frequent screenings can identify cancer at its earliest, most treatable stage.
• Start cancer screenings at a younger age, sometimes 10-20 years earlier than the general population.
• Preventative surgery, like mastectomy, is an option that can significantly reduce the risk for breast cancer.
• Targeted therapies have been developed based on the presence of certain gene mutations.
• Identifying a genetic mutation in a family can help all other bloodline relatives and they can benefit from being tested to define their own cancer risk and guide their own cancer screening and prevention.

How Much Does Genetic Testing Cost?

Many of the commercial genetic laboratories in the United States offer genetic testing for a hereditary cancer syndrome for approximately $250 out of pocket. Most insurance companies cover the genetic testing if certain criteria are met. If the insurance company covers the genetic testing then the individual will owe approximately $100 or less out of pocket. The cost of genetic testing for hereditary cancer has come down quite a bit over the past 7-8 years as new, more efficient techniques for sequencing and analyzing DNA has improved.

More Information About Genetic Testing and Counseling

If you would like to learn more about your own cancer risk based on your personal risk factors as well as your family history you can schedule an appointment with a genetics professional. CHI Health has a Cancer Genetics Program. You are welcome to call the clinic and schedule an appointment.