A modern assessment of the surgical pathologic spread and nodal dissemination of endometrial cancer.

ABSTRACT

OBJECTIVE: To examine the risk of nodal metastases in a contemporary cohort of women based on pathologic risk factors including histology, depth of invasion, tumor grade, and lymphovascular space invasion. METHODS: Women with endometrial cancer who underwent hysterectomy from 2004 to 2016 who were registered in the National Cancer Database were analyzed. Patients were stratified by T stage T1A (<50% myometrial invasion), T1B (>50% myometrial invasion) and T2 (cervical involvement). Lymph node metastases were assessed in relation to tumor T stage and grade, and further stratified by lymphovascular space invasion. RESULTS: We identified 161,960 patients. The rate of nodal metastases within the endometrioid histology cohort was 2.2% for T1A cancers, 12.8% for T1B cancers and 19.9% for T2 cancers. For stage TIA cancers, the percent of patients with positive nodes increased from 1.1% for grade 1 cancers, to 2.9% for grade 2 cancers to 4.8% for grade 3 cancers. The corresponding rates of nodal metastases for stage T1B cancers were 8.6%, 13.7%, and 16.9%, respectively. For T1A cancers without lymphovascular space invasion, nodal metastases ranged from 0.6% in those with grade 1 cancers to 3.0% for grade 3 cancers. The corresponding risk of nodal disease ranged from 11.8% to 13.9% for T1A cancers with lymphovascular space invasion. CONCLUSIONS: There was a sequential increase in the risk of lymph node metastases based on depth of uterine invasion, tumor grade, and the presence of lymphovascular space invasion. The overall rate of nodal metastasis is lower than reported in the original GOG 33.