Hereditary Non-Polyposis Colorectal Cancer Syndrome (HNPCC)
The HNPCC (also known as Lynch II) syndrome is an inherited risk for certain cancers caused by mutation of one of the genes that is responsible for repair of damaged DNA. Patients with HNPCC have higher than average risk of endometrial and ovarian cancers; and cancers of the colon, stomach, small intestine, liver, brain and urinary system. The lifetime risk of ovarian cancer for women with HNPCC is 10%. The risk for endometrial cancer for women with HNPCC is approximately 40%.
Multiple members of a gene family have been linked to this hereditary condition, most notably MLH1, MSH2 and MSH6 genes. When a member of this family of genes is mutated, the every day damage that happens in DNA cannot be repaired. Eventually the regulation of cell growth becomes uncontrolled in a cell due to DNA damage, and a cancer begins to grow from that damaged cell.
Genetic testing is available for the mutations that cause HNPCC. Women concerned about their personal or family history for the cancers mentioned above, especially a combination of colon and endometrial cancers, should ask about genetic counseling to find out what testing is appropriate for them.
Screening and Prevention Recommendations for Women with HNPCC
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Have an evaluation of the colon by colonoscopy at age 20-25 or younger, repeated every 1-2 years.
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Have a gynecology exam 1-2 times per year.
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Have both a transvaginal ultrasound and the CA 125 blood test two times per year. starting at age 25-35 until the ovaries and fallopian tubes are removed.
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Be aware of the symptoms of ovarian cancer.
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Report any abnormal vaginal bleeding to your doctor.
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If a woman with HNPCC requires surgical removal of the colon (colectomy) because of cancer or pre-cancer changes, then it is appropriate to remove the uterus and ovaries at the same time to reduce the risk of ovarian and endometrial cancer.
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Undergo preventive removal of the ovaries and fallopian tubes after you after childbearing is done.
