Combined Assessment of Vascular and Myometrial Invasion As a Model to Predict Prognosis in Stage I Endometrioid Adenocarcinoma of the Uterine Corpus

The prognostic significance of vascular invasion as compared with other pathologic features was evaluated in 102 cases of endometrioid adenocarcinoma confined to the uterus (Stage I) treated by hysterectomy. By univariate analysis, survival most closely correlated with patient age, architectural grade, depth of myometrial invasion, vascular invasion, and the presence of perivascular lymphocytic infiltrates. Among these, vascular invasion and the presence of perivascular lymphocytic infiltrates were the best indicators of prognosis. In contrast to perivascular lymphocytic infiltrates, the presence of a lymphocytic infiltrate at the tumor-myometrial junction was not related to outcome. The presence of vascular invasion was found to be associated closely with perivascular lymphocytic infiltrates. These two features may be related biologically and were designated "vascular invasion-associated changes." By multivariate analysis with the Cox proportional hazards model, the depth of myometrial invasion and the presence of vascular invasion-associated changes were found to provide a highly reliable model for predicting outcome. The highly predictive value of vascular invasion as a prognostic factor in Stage I endometrial carcinoma suggests that it is the mechanism by which occult metastasis develops in patients whose disease progresses after hysterectomy. It is likely that other variables correlating with recurrence, such as the presence of deep myometrial invasion and high tumor grade, may act by increasing the probability of vascular invasion and subsequent metastasis.