We present the largest multicenter study evaluating whether intraoperative visual estimation can accurately assess the depth of myometrial invasion in patients with endometrial cancer. The study population consisted of 403 consecutive women who underwent total hysterectomy for endometrial cancer. After the uterus was removed, a visual estimate of depth of gross myometrial invasion was recorded. The uterus was opened, the endometrial cavity was inspected, and one or more full-thickness incisions were made through the tumor, myometrium, and serosa. An intraoperative estimation of gross myometrial invasion was made and classified as more or less than 50% of the uterine wall. Gross visual estimation accurately identified the microscopic myometrial invasion in 85.3% (344/403) of cases. Sensitivity, specificity, and positive and negative predictive values of gross estimation in determining a microscopic myometrial invasion greater than 50% were 73.0, 92.5, 85.0, and 85.5%, respectively. Among patients in whom the myometrial invasion was underestimated at gross examination the tumoral invasion was limited to the inner two thirds of the myometrium in 45% (18/40) of cases and the distance from the tumor-myometrial junction to the uterine serosa was greater than 3 mm in 65% (26/40) of cases. We conclude that gross estimation of myometrial invasion is a reliable and inexpensive method for evaluating the invasiveness of uterine carcinomas and that deciding to perform an extensive surgical staging upon gross estimation will be in accordance with the final histopathologic report in about 9 of 10 cases.
Copyright 2000 Academic Press.