Wednesday, April 22, 2009
WEDNESDAY, April 22 (HealthDay News) -- In older women, hormone replacement therapy (HRT) may help protect against colon cancer, but the mechanism is unclear, according to research presented this week at the 100th Annual Meeting of the American Association for Cancer Research held from April 18 to 22 in Denver.
David Limsui, M.D., of the Mayo Clinic in Rochester, Minn., and colleagues studied 37,285 women from the Iowa Women's Health Study, including 1,398 who developed incident colorectal cancer. They also examined tumor tissue from 553 patients to assess associations between self-reported hormone use, CpG-island methylator phenotype (CIMP) or BRAF gene mutations.
The researchers found that HRT was associated with a 28 percent decreased risk of colorectal cancer, but found no evidence that the association was modified by CIMP or BRAF-mutation status. They also found that oral contraceptive use was not associated with any protective effects, overall or by CIMP or BRAF subtypes.
"We still don't know how estrogen compounds work in cancer prevention, which is intriguing," Limsui said in a statement. "Based on our findings, we need to continue exploring the cancer pathways that might be affected by these hormones."
Diabetes & Endocrinology
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