Invasive endometrial cancer in uteri resected for atypical endometrial hyperplasia.

Endometrial hyperplasia (EH) includes a spectrum of lesions with unclear malignant potential. To examine the association between the most advanced forms of hyperplasia and the occurrence of endometrial cancer, we compared the findings of endometrial biopsies or curettings with the subsequent hysterectomy specimens in 44 women who underwent hysterectomy for "atypical" EH in the 39-month period from January 1, 1989 through April 1, 1992. Endometrial cancer was found in 19 (43%) of 44 hysterectomy specimens obtained within a mean of 10 weeks of uterine sampling. Myometrial invasion was present in 17 (89%) of the 19 specimens with cancer, while significant myometrial invasion (FIGO Stage IC or higher) was present in 7 (37%), and 4 (21%) were Grade 2 or higher. Preoperative sampling method and type of atypical hyperplasia (simple vs complex) were not significantly associated with the finding of cancer at hysterectomy. Although over one-third of the cancers found were in the less than 50 age group, an age of 70 or greater was significantly associated with cancer at hysterectomy (P < 0.05, Fisher's exact test). In a limited set of hysterectomy specimens for which estrogen and progesterone receptor status was assayed (n = 11), there was no significant difference between the invasive cancer and EH subsets. Our findings suggest that women who are candidates for hysterectomy on the basis of atypical EH should be carefully evaluated for the possibility of advanced disease. The specimens in these circumstances should be opened upon removal to determine if myometrial invasion is present and if further surgical staging is indicated.