HORMONAL FACTORS INFLUENCE ENDOMETRIAL CANCER RISK IN LYNCH SYNDROME

NEW YORK (Reuters Health) - Hormonal factors have a similar impact on endometrial cancer risk in women with and without Lynch syndrome, according to data from the Colon Cancer Family Registry.

"Women with Lynch syndrome have a genetic mutation that gives them a high risk of cancers including uterine cancer," Dr. Aung Ko Win, from Melbourne School of Population and Global Health, Melbourne, Victoria, Australia, told Reuters Health by email. "Until now, there was almost no information to indicate which women with Lynch syndrome were most likely to develop uterine cancer."

Lynch syndrome results from autosomal dominant germline mutations in one of the DNA mismatch repair genes. In women without Lynch syndrome, factors that increase the bioavailability of estrogen unopposed by progesterone increase endometrial cancer risk.

Dr. Win and colleagues used data from 1128 women with Lynch syndrome in the Colon Cancer Family Registry to estimate the associations between endometrial cancer risk and hormonal factors, including number of live births, age at first live birth, age at menarche, age at menopause, contraceptive and postmenopausal hormone use, and estrogen use.

The incidence of endometrial cancer was 0.29 cases per 100 person-years, with a mean age at diagnosis of 45.9 years. This is about 10 times higher than estimates for the general female population (0.025 per 100 person-years), according to the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program.

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The researchers found no association between endometrial cancer risk and age at first live birth, age at last live birth, or age at menopause.

Use of hormonal contraceptives appeared to lower the risk of endometrial cancer by half, but there was no significant association between postmenopausal hormone use and endometrial cancer risk (although the study lacked statistical power for this last comparison).

"Our findings show that the effects of hormonal factors for women with Lynch syndrome are similar to those for women from the general population who do not have Lynch syndrome," Dr. Win said. "Further studies will be needed to confirm the study findings. Women with Lynch syndrome may then be counseled like other women from the general population, regarding hormonal influences on uterine cancer risk."

"The only way to prevent the disease is removal of the uterus," Dr. Win added.

The National Cancer Institute and the Colon Cancer Family Register supported this research. One coauthor reported advising EXACT Sciences and Cancer Prevention Pharmaceuticals.

SOURCE: http://bit.ly/1dK5cCE