By Kelli Conlan, MS CGC | Genomic Services

March 19, 2019 Better Health

March is upon us. With March comes the excitement of March Madness, the chance for everyone to be a little Irish on St. Patrick’s Day, and the promise of spring. March is also a time to think about cancer prevention. That’s right, cancer prevention – not just treating cancer or beating cancer but PREVENTING cancer! March is Colon Cancer Awareness Month – a reminder to all of us that colon cancer screening can save lives.

Colon cancer is one of the most preventable cancers, yet it is still one of the most common cancers.

While everyone has some risk to develop colon cancer, for some people the risk can be even higher because of an inherited risk. In 2%-5% of colon cancers, the cancers are caused by an inherited change in a gene, called a mutation.1 Mutations may also be referred to as pathogenic/likely pathogenic variants and can be passed down in families from one generation to the next. Lynch syndrome, also known as Hereditary Non-Polyposis Colorectal Cancer (HNPCC), is the most common cause of inherited colon cancer.2

What do you need to know about Lynch Syndrome?

Lynch syndrome is hereditary2
Lynch syndrome is caused by inheriting a mutation in one of five genes, MLH1, MSH2, MSH6, PMS2 and EPCAM. Having a mutation in one of these genes causes a significantly increased risk for colon and other cancers. In addition, these cancers tend to develop at younger-than-expected ages before routine screening would normally begin.

Lynch syndrome is more common than you might think
It is estimated that approximately 1 in 300 Americans have Lynch Syndrome.2

Lynch syndrome isn’t only associated with colon cancer
Not only is Lynch syndrome the most common cause of hereditary colon cancer, but it is also the most common cause of hereditary uterine or endometrial cancers. Individuals with Lynch syndrome can have as much as an 82% chance of colon cancer and 60% chance of endometrial cancer by age 70.2,3 There is also an increased risk for ovarian, stomach, prostate and some other rare cancers with Lynch syndrome.2,3

Who should consider genetic testing for Lynch syndrome?
Genetic testing is available for Lynch syndrome. Families with Lynch syndrome often have multiple relatives with a history of cancer, but not always. Frequently, these cancers occur before age 50.

Consider talking with your healthcare provider about getting tested if you3:
▭ Have had colon or uterine cancer before age 50
▭ Have had two or more cancers such as colon, uterine, ovarian, stomach, or other cancers
▭ Have a strong family history of colon, uterine, ovarian, stomach, or other cancers
▭ Have a relative with positive genetic testing for Lynch syndrome

Not everyone with Lynch syndrome will develop cancer
Having Lynch syndrome means the risk for colon, uterine, and other associated cancers is significantly increased compared to the general population. This does not mean someone will definitely develop cancer; there are options that can lower the risk of getting cancer or help detect cancer earlier when it is more treatable. These include2

● Increased screening
● Risk-reducing medications
● Preventive surgery

Knowing your risk is important for everyone
For people without a family history or inherited risk of colon cancer (average risk), screening with colonoscopy or a stool-based test such as a highly sensitive FIT test is usually recommended to begin at age 45. The age to begin and frequency can vary depending on one’s medical and family history.

With Lynch syndrome, cancer can develop at a much younger age so screening needs to start earlier. Screening also needs to be performed more frequently because cancer can develop faster.

Screening guidelines for Lynch Syndrome4

  • Colonoscopy beginning age 20-25, every 1-2 years (unless otherwise indicated based on family history)
  • Screening of the upper gastrointestinal tract with endoscopy
  • Urine cytology
  • Transvaginal ultrasound annually to check uterus/ovaries
  • Physical Exam – yearly
  • Medications/Aspirin to reduce polyp risk

What can you do?

  • Talk to your healthcare provider about colon cancer screening.
  • Visit QuestVantage.com and take the Know Your Risk quiz to see if genetic testing might be right for you.
  • Join us in supporting Lynch Syndrome Awareness Day on March 22 by visiting AliveAndKickn, an advocacy organization dedicated to Lynch syndrome and hereditary cancer.

To learn more about colon cancer guidelines and prevention, please check out the National Colorectal Cancer Roundtable and Fight Colorectal Cancer.

 

References

1. Jasperson KW, et al. Hereditary and familial colon cancer. Gastroenterology. 2010;138(6):2044-58.

2. Cancer.net. ASCO website. https://www.cancer.net/cancer-types/lynch-syndrome. Updated August 2018. Accessed March 7, 2019.

3. Colorectal Cancer Alliance website. https://www.ccalliance.org/screening-prevention/family-history/lynch-syndrome. Accessed March 7, 2019.

4. American Society of Clinical Oncology (ASCO) website. Management of individuals at increased hereditary risk. https://www.asco.org/practice-guidelines/cancer-care-initiatives/genetics-toolkit/management-individuals-increased. Updated December 2018. Accessed March 7, 2019.