Risk for Lynch Syndrome Related Cancers in MSH6 Mutations

People with a mutation in the MSH6 gene, part of the Lynch syndrome, have a greatly increased risk of colorectal, endometrial, and other related cancers. The cancers can occur in old age, with an increasing risk from age 70 to 80.

About 4 in every 1000 colorectal cancers are due to an inherited mutation in the MSH6 gene. It accounts for about 10 to 20 percent of Lynch syndrome mutations.

By the time they are 80 years old, men have eight times the risk of getting colorectal cancer and women have 26 times the risk of endometrial cancer — cancer that begins in the lining of the uterus.

A research team identified 113 families with inherited MSH6 mutations in five countries, including 3,104 relatives. They estimated the risk that they would have been diagnosed with a Lynch-related cancer by the time they were 70 and by the age of 80. They also compared the risk of a cancer diagnosis in Lynch carriers to the general population.

Men had a 22 percent risk of colorectal cancer by age 70 which rose to 44 percent by age 80.
Women had a 10 percent risk of colorectal cancer by 70 which was 20 percent by 80.
Women had a 26 percent risk of endometrial cancer by 70, 44 percent by 80.

For any Lynch-related cancer

Men had a 24 percent risk by 70 with a 47 percent risk by 80.
Women had a 40 percent risk by 70 and a 65 percent risk by 80.

Compared to other people without the Lynch-related MSH6 gene:

Men had 8 times the risk of getting colorectal cancer in their lifetime.
Women had 26 times the risk of endometrial cancer and 6 times the risk of any Lynch-related cancer.

Lynch syndrome, also known as hereditary nonpolyposis colon cancer (HNPCC), is an increased cancer risk, inherited directly from parent to child. Changes in the genes that repair damaged DNA increase the chances that cells can grow out of control and develop into cancer.

SOURCE: Baglietto et al., Journal of the National Cancer Institute, Advance Access, December 22, 2009.

This news article was originally posted on December 23rd, 2009 and was accurate at the time of publication. Since then, information may have changed or links may now be outdated. Please call our Answer Line 1-877-427-2111 for the latest information, or talk to your doctor before making any medical decisions.

Posted by Kate Murphy on December 23rd, 2009
Tags: inherited cancer, Lynch syndrome, MSH6