Comparison of Myometrial Invasion and Tumor Free Distance from Uterine Serosa in Endometrial Cancer

Background: We aimed to investigate whether the tumor free distance (the distance between the uterine serosa and the tumor at its deepest point) is useful in surgical staging and in predicting prognosis. Materials and Methods: Data from patients who underwent complete surgical staging for endometrial cancer between January 2006 and June 2011 were reviewed retrospectively. All demographic findings, surgical stages, histological type and grade, myometrial invasion, lymphovascular space invasion as well as abdominal cytology, cervical, adnexal, and omental involvement, and lymph node metastasis were recorded. The relations between myometrial invasion and tumor free distance from uterine serosa with prognostic factors were investigated. Results: Seventy patients were included in the study. Sixty-four (91.5%) had endometrioid type cancers and forty-four (62.9%) were grade 1. The deepest myometrial invasion was less than 1/2 in 42 patients (60%). In 18 patients (25.8%) lymphovascular invasion was noted. Eight (11.4%) were found to have cervical involvement, five (7.1%) had adnexal involvement and in 4 cases (5.7%) the peritoneal washings included malignant cells. Four patients had pelvic and one para-aortic node metastasis. We recognized that an invasion of more than 1/2 was correlated significantly with lymphovascular space involvement, histological grade, positive abdominal washing cytology, nodal and cervical involvement, but not with adnexal involvement. Tumor-free myometrial thickness was negative and statistically significant correlated with surgical stage, histological grade, lymphovascular space involvement, positive abdominal washing cytology, cervical and adnexal involvement. The importance of tumor-free myometrial thickness in determinating the lymphovascular space invasion was found to be highest in terms of sensitivity and specificity when crossing the ROC curve at 11 millimeters. Conclusions: Depth of myometrial invasion is more valuable for predicting lymph node metastasis than tumor-free myometrial thickness. The tumor-free myometrial thickness provides a better prediction for adnexal involvement.