Objective: To determine if tumor-free distance (TFD) from the uterine serosa predicts surgicopathologic factors and outcome in surgically staged endometrial cancer, and to compare TFD with the traditional estimate of depth of myometrial invasion (DOI).
Methods: Patients who underwent complete surgical staging for primary endometrial cancer at a single institution were identified from 2002-2005. During this time, TFD was prospectively measured at the time of pathologic evaluation of the uterine specimen. Tumor-free distance (TFD) was defined as distance from deepest myometrial invasion to the serosal surface, whereas DOI was defined as the distance between the endomyometrial junction and deepest myometrial invasion. DOI and TFD were shown as continuous variables and compared to traditional surgicopathologic factors and evaluated for their ability to predict recurrence and death from disease. Univariate and multivariate analysis were used to examine the data. Receiver-operator characteristic curve was created to evaluate optimal TFD.
Results: We identified 99 patients that met the study criteria. Mean DOI was 0.6 cm and mean TFD was 1.3 cm. 77 patients were stage I, 11 were stage II, and 11 were stage III. Tumor grade was distributed as 68, 21 and 10 for grades 1, 2, and 3 respectively. Median follow up time was 2.7 years (1002 days) with 9 episodes of recurrence and 7 deaths. Univariate analysis demonstrated DOI to be a significant predictor of death, grade, lymph node metastasis, lymphovascular space involvement (LVSI), stage, lower uterine segment (LUS) involvement and adnexal involvement. TFD significantly predicted lymph node metastasis, LVSI, and grade. Using Cox proportional hazards model, DOI more significantly predicted recurrence (hazard ratio 3.11, p=0.0007). Both DOI and TFD predicted death from disease (hazard ratio 3.58, p=0.0006 and 0.22, p=0.0365, respectively). Although the performance characteristics of TFD were modest, the balance of sensitivity and specificity for TFD in predicting recurrence was 1 cm.
Conclusions: TFD, like DOI, is predictive of many surgicopathological variables and patient outcome in surgically staged endometrial cancer. Although the performance characteristics may not be as powerful as DOI, the ease and reproducibility of this measurement may justify its inclusion in synoptic reporting of endometrial cancer.