THURSDAY, Jan. 14 (HealthDay News) -- Women with endometrial hyperplasia are at much higher long-term risk of developing endometrial cancer if their hyperplasia is atypical, according to a study published online Jan. 11 in the Journal of Clinical Oncology.
James V. Lacey Jr., Ph.D., from the National Cancer Institute in Rockville, Md., and colleagues assessed the risk of carcinoma progression among 7,947 women diagnosed with endometrial hyperplasia (simplex, complex, or atypical).
The researchers found that 138 women were diagnosed with carcinoma an average of six years later. Compared with 241 matched control women, the cumulative progression risk in women with non-atypical endometrial hyperplasia increased from 1.2 percent through four years to 4.6 percent through 19 years after diagnosis. In contrast, the cumulative progression risk in women with atypical endometrial hyperplasia was 8.2 percent through four years to 27.5 percent through 19 years after diagnosis.
"In conclusion, our rigorous, population-based study of women with endometrial hyperplasia who remained at risk for at least one year indicates that the overall progression risk for endometrial hyperplasia is three times higher than the average population risk of endometrial carcinoma," Lacey and colleagues write. "Fewer than 5 percent of women with non-atypical endometrial hyperplasia will experience progression to carcinoma, but 28 percent of women with atypical hyperplasia progress to carcinoma during 20 years."