A family history of colorectal cancer and uterine cancer may put you at increased risk for uterine cancer. This pattern of cancer in family members, especially if the cancer occurred at relatively young ages, could indicate a genetic condition called Lynch syndrome.
"Many doctors aren't as aware of [Lynch syndrome] as they should be," says Karen Lu, MD, a professor of gynecologic oncology at the University of Texas M. D. Anderson Cancer Center in Houston. She adds that women with Lynch syndrome who develop uterine cancer "develop it at a younger age, and they tend not to be obese. That's where knowing your family history is important." (Obesity is a risk factor for the more common, non-genetic form of uterine cancer.)
Although the term Lynch syndrome is now preferred, people in previous generations might have been diagnosed with hereditary non-polyposis colorectal cancer, which is part of the same syndrome. If you have a history of cancer in your family and you find this diagnosis in your relatives' medical records, there's a strong possibility that Lynch syndrome runs in your family.
Lynch Syndrome and Uterine Cancer: The Connection
People with Lynch syndrome have genetic defects in three genes, known as repair genes. These genes are MLH1, MSH2, and MSH6. This defect means that some of your DNA is not able to repair errors that occur when cells reproduce, which can lead to the growth of cancer cells. With Lynch syndrome, the odds are 50-50 that you will pass on this defect to your birth children.
This genetic trait causes multiple tumors to appear much earlier than normal. Colorectal cancer and uterine cancer are two of the most common cancers caused by this syndrome. Uterine cancer usually occurs in women over age 50, but women with Lynch syndrome can be much younger when they are diagnosed.
Lynch Syndrome and Uterine Cancer: Whom to Test
There is a test that can tell you if you have the genetic defects that could lead to cancer as a result of Lynch syndrome. You should talk to your doctor about getting tested if:
- You have at least three relatives who have been diagnosed with uterine or endometrial cancer, colorectal cancer, renal (kidney) cancer, or cancer of the small bowel.
- At least one relative was diagnosed with cancer before age 50.
- Cancers have occurred in two first-degree relatives (for example, parent-child, brother-sister).
- Your tumor or one of your relatives' tumors tested positive for a relationship to Lynch syndrome.
Early screening and monitoring of people with Lynch syndrome has been shown to reduce cancer deaths. Because many doctors are not aware of the syndrome or do not ask for a detailed family cancer history beyond immediate relatives, they may not see a family pattern unless you bring it up.
There is also computer software, called MMRPro, that can help identify whether Lynch syndrome runs in your family. Developed by researchers using cancer history information from 279 people from numerous medical institutions, MMRPro was shown in a study published in the Journal of the American Medical Association to be better at predicting cancer risk than simply asking about family history.
Lynch Syndrome and Cancer Screenings
If you have Lynch syndrome, or suspect that you do based on a family history of colorectal and uterine cancer, the best way to protect your health is to get regular cancer screenings. Talk to your doctor about which cancer screenings you should get and how often to get them. You should also learn the early warning signs of the cancers for which you are at increased risk.
Learning that you have Lynch syndrome does not mean you will develop cancer. But it does allow you to plan for your long-term health.
Last Updated: 2/18/2009