Surgery to reduce the risk of cancer in women with Lynch Syndrome

Women with the genetic mutation that causes hereditary colorectal cancer — hereditary non-polyposis colon cancer or Lynch syndrome — are also at increased risk for endometrial and ovarian cancer.  Research reported in the January 19, 2005, issue of the New England Journal of Medicine found that hysterectomy and removing the ovaries reduced the incidence of gynecological cancers in these high-risk women.

Researchers, led by Dr. Karen Lu at M.D. Anderson Cancer Center, identified 315 women who had inherited a mutated gene for Lynch syndrome.  They then matched those who had undergone prophylactic hysterectomy or prophylactic removal of both ovaries with mutation-positive women who had not had protective surgery.  Over the time of the study, no one who had had prophylatic surgery developed endometrial, ovarian, or peritoneal cancer.  However, among the controls 69 women (33%) were diagnosed with endometrial cancer and 12 (5%) with ovarian cancer.

The research team concluded:

These findings suggest that prophylactic hysterectomy with bilateral salpingo-oophorectomy is an effective strategy for preventing endometrial and ovarian cancer in women with the Lynch syndrome

Lynch Syndrome was first identified by Henry T. Lynch M.D, who is one of the authors of the NEJM article. Also called hereditary non-polyposis colon cancer, a mutated gene directly inherited from a parent increases the lifetime risk of colon cancer to about 80%.  In addition, there is an increased risk of related cancers including endometrial (40% to 60%) and ovarian (10% to 12%).  There is also higher risk of other cancers of the gastrointestinal tract, pancreas, brain, and kidney.

Lynch syndrome is more frequently diagnosed at a young age than non-inherited colon cancer and is associated with a strong family history of colorectal and related cancers.  Diagnosis depends on a identifying one of the mutated mismatch repair genes that fail to repair damaged DNA and allow cells to develop into cancer.

A Lynch syndrome mutation is suspected when

• There are at least 3 directly related family members with colon or a related cancer.
• Cancer occurs in at least 2 generations.
• At least 1 individual is diagnosed under the age of 50.

However, not all colorectal cancer patients with a Lynch syndrome mutation will fit this criteria.  Some researchers are now recommending that people diagnosed with colorectal cancer under the age of 50 have their tumors tested for microsatellite instability, a change in genetic appearance, to screen for possible Lynch syndrome.

Read more about the study on Medpage Today.  Reuters.