AEH biopsies led to diagnosis of invasive adenocarcinoma in 40%.(News)

UNIVERSAL CITY, CALIF. -- Invasive adenocarcinoma was found at hysterectomy in more than 40% of patients who had been diagnosed with atypical endometrial hyperplasia (AEH) at specialized centers of the Gynecology Oncology Group, shocking study investigators who had intended to explore more conservative treatment options for women diagnosed with the condition.

"The bottom line is you have to treat these patients as if they have cancer," said John P. Curtin, M.D., who shared the study results at a meeting of the Obstetrical and Gynecological Assembly of Southern California.

Dr. Curtin is director of the division of gynecologic oncology and professor and chair of obstetrics and gynecology at New York University in New York.

He explained that AEH is a precursor to the most common type of endometrial adenocarcinoma, but is paradoxically diagnosed at a much lower rate than the disease it is supposed to presage.

The difficulty of accurately and reliably making a histologic diagnosis of AEH was demonstrated by a study conducted by the Gynecology Oncology Group (GOC), a cooperative research group of more than 50 institutions, mostly academic medical centers.

Four expert gynecologic pathologists involved in the study questioned the AEH diagnosis in two-thirds of 360 endometrial biopsy samples submitted for study GOG 167.

The experts decided that 27% of the slides represented "less than AEH," 29% represented carcinoma, and 39% justified the AEH diagnosis. In 5% of cases, the experts could not reach a consensus.