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Center for Jewish Genetics blog

Gastrointestinal Cancer Genetics: What Practitioners Need to Know

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By: Karen Litwack 

It may surprise you to learn that according to statistics from the American Cancer Society (2014), 136, 830 new cases of colorectal cancer (CRC) were diagnosed and 50,310 deaths were reported.  CRC is the second leading cause of cancer death in men and women in the U.S.  The lifetime risk is about 1 – 17 with the average age of diagnosis at 67 years.

This is in stark contrast to hereditary cancers syndromes such as Lynch syndrome (hereditary non-polyposis colorectal cancer/HNPCC) and familial adenomatous polyposis (FAP) where age of onset can be much lower and specific gene mutations have been found to contribute to these complex cancer syndromes. 

 About 10 – 30% of CRC are considered familial with only about 2 – 5% affected by Lynch syndrome.  The gene mutations involved in Lynch syndrome are autosomal dominant and cause a loss of normal DNA repair which leads to genomic instability.  The cancer spectrum for Lynch syndrome includes CRC, endometrial, ovarian, stomach, urinary tract, small bowel, biliary tract, pancreatic and brain.  Using universal testing, there are about 16,000 new Lynch syndrome patients each year that would benefit from screening and surveillance.

FAP is another autosomal dominant hereditary cancer syndrome.  FAP can affect individuals at a very young age and management with colonoscopies can begin as young as 10 – 12 years of age.  There is no recommended age for surgical intervention.  Children and adolescents usually delay with surveillance until old enough for this procedure.

Given the serious nature of hereditary CRC, when should healthcare providers consider a referral for a cancer risk assessment?   

According to Jessica Stoll, genetic counselor at the University of Chicago Comprehensive Cancer Risk and Prevention Clinic, the following are indications for referral; personal history of an early onset cancer diagnosis, personal history of bilateral or multiple cancers, family history of cancer and for genetic testing for clinical trials. 

How would a patient benefit from a cancer risk assessment?

The patient would receive a comprehensive risk assessment which includes; evaluation of family history and personal risk factors, determination of appropriate genetic testing and management and detailed counseling around genetics, cancer genetics, pre and post test results and psychological issues which may arise with the patient or family members.

What are the benefits of genetic testing for patients?

Genetic testing may provide a patient with a more specific cancer risk; an opportunity for personalized cancer screening and risk reduction options; an answer to patients and families that have experienced multi-generational illness (from cancer) or demise; may decrease cancer anxiety in some patients and/or families; and may provide family members with more information about their own cancer risk.

The Norton & Elaine Sarnoff Center for Jewish Genetics would like to thank Dr. Sonia Kupfer  and  Jessica Stoll, MS, CGC who oversee the Gastrointestinal Cancer Risk and Prevention at the University of Chicago for their excellent presentation on Gastrointestinal Cancer Risk.

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We are proud to announce that our Carrier Screening Program is open with our new medical provider Insight Medical Genetics (IMG). Visit our Get Screened page to learn more about our program and how to register!

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Do You Know What's In Your Genes?

What is the most valuable gift you can give to your family? The gift of good health! There are many health conditions that run in families. Knowing your family health history can alert you to the potential risk for a variety of genetic disorders . Be sure to check with your relatives for warning signs and assess your risk for hereditary cancers!

Did you know: Ashkenazi Jews are 10 TIMES more likely to have BRCA mutations, which significantly increases lifetime risks for hereditary cancers, so what does this heightened risk mean for you? Click here to learn more !