
By Carol Guzman
Lynch syndrome (LS) is a
heritable disorder that causes an increased risk of colorectal and many other
types of cancers. People inherit Lynch syndrome in an autosomal dominant manner,
which means that if one parent carries a gene mutation for LS, there is a 50
percent chance LS will pass to each child. When they’re working as they should,
the genes associated with LS protect you from getting certain cancers by
repairing mistakes made in DNA, but mutations in these genes prevent them from
working properly, which can lead to uncontrolled cell growth.
One in 440
Americans are carriers for Lynch syndrome.1 Ashkenazi Jews have specific LS founder mutations and have
among the highest rates of colorectal cancer of any ethnic group.2,3 In honor of Colorectal Cancer Awareness Month and National Lynch
Syndrome Awareness Day, here are three facts you might not have known about
Lynch Syndrome:
- Genes
associated with LS can increase risk of breast and ovarian cancer.4,5
In addition to a higher risk of colorectal cancers, women with specific
variants of LS are twice as likely to develop breast cancer than women without
Lynch syndrome (15%). Women can have up to a 24 percent increased risk of ovarian
cancer with specific variants of LS.
- Lynch
syndrome is the leading cause of hereditary colorectal cancer (CRC).6,7
According to the American Cancer Society (ACS), 5 percent of CRC cases are associated with inherited genetic
mutations. ACS estimates that there will be 145,000 new cases
of colorectal in 2019 and LS will account for approximately 2 – 4
percent of these cancer cases.
- An accurate
family health history is the best identifier of Lynch syndrome.8 Only 1 percent of the estimated 800,000 Americans with LS know they have the disorder. Patients do not typically find out they have LS until after a colorectal cancer
diagnosis. Doctors do not recommend CRC patients get genetic screening for LS because
of the rarity of the syndrome. Accurate family health history records remain the
best strategy for identifying LS.
If you have Lynch Syndrome, talk to your doctor about how
you can reduce your chances of getting cancers in the future. Having Lynch syndrome increases your chances
of getting colorectal, stomach, pancreatic, urinary tract, pancreas, brain,
small bowel, endometrial, breast, ovarian and uterine cancers.
Learn more about
family health history and find tools and worksheets to help
you collect key information
on our family
health history page. If
you have questions about your genetic health, reach out to Sarnoff Center or
your doctor.
- Columbia
University Irving Medical Center: Two New Breast Cancer Genes Emerge from Study
of Lynch Syndrome
- American
Cancer Society: Colorectal Cancer Risk Factors
- OncoLink:
Ashkenazi Jewish Heritage and Genetic Risk
- Columbia
University Irving Medical Center: Two New Breast Cancer Genes Emerge from Study
of Lynch Syndrome
- NCCN:
Genetic/Familial High-Risk Assessment: Breast and Ovarian
- American
Cancer Society: Colorectal Cancer – Facts & Figures 2017-2019
- American
Cancer Society: Key Statistics for Colorectal Cancer
- American
Cancer Society: Colorectal Cancer – Facts & Figures 2017-2019