Histologic Grade Histologic grade of the endometrial tumor is strongly associated with prognosis (132,141,149,152–156). In one study, recurrences developed in 7.7% of grade 1 tumors, 10.5% of grade 2 tumors, and 36.1% of grade 3 tumors. Patients with grade 3 tumors were in excess of fivetimes more likely to have a recurrence than were patients with grades 1 and 2 tumors. The 5-year disease-free survival rates for patients with grades 1 and 2 tumors were 92% and 86%, respectively, compared with 64% for patients with grade 3 tumors (149). Another study reported similar results, noting recurrences in 9% of patients with grades 1 and 2 tumors compared with 39% of patients with grade 3 lesions (153). Increasing tumor anaplasia is associated with deep myometrial invasion, cervical extension, lymph node metastasis, and both local recurrence and distant metastasis.
Tumor Size Tumor size is a significant prognostic factor for lymph node metastasis and survival in patients with endometrial cancer (142,157). One report determined tumor size in 142 patients with clinical stage I endometrial cancer and found lymph node metastasis in 4% of patients with tumors 2 cm or smaller, in 15% of patients with tumors larger than 2 cm, and in 35% of patients with tumors involving the entire uterine cavity (156). Tumor size better defined an intermediate-risk group for lymph nodes metastasis (i.e., patients with grade 2 tumors with less than 50% myometrial invasion). Overall, these patients had a 10% risk for lymph node metastasis, but there was no nodal metastasis associated with tumors 2 cm or smaller, compared with 18% when tumors were larger than 2 cm. Five-year survival rates were 98% for patients with tumors 2 cm or smaller, 84% for patients with tumors larger than 2 cm, and 64% for patients with tumors involving the whole uterine cavity (137,157).
Hormone Receptor Status Estrogen receptor and progesterone receptor levels are prognostic indicators for endometrial cancer independent of grade in several studies (158–164). Patients whose tumors are positive for one or both receptors have longer survival times than patients whose carcinomas lack the corresponding receptors. Even patients with metastasis have an improved prognosis with receptor-positive tumors (161). Progesterone receptor levels appear to be stronger predictors of survival than estrogen receptor levels, and the higher the absolute level of the receptors, the better the prognosis.
About two-thirds of endometrial adenocarcinomas have a diploid DNA content as determined by ﬂow cytometric analysis (162,165–174). The proportion of nondiploid tumors increases with stage, lack of tumor differentiation, and depth of myometrial invasion. In several studies, DNA content was related to clinical course of the disease, with death rates reported to be higher in women whose tumors contained aneuploid populations of cells. The proliferative index is related to prognosis.