Are Uterine Risk Factors More Important Than Nodal Status in Predicting Survival in Endometrial Cancer?

OBJECTIVE: To evaluate factors associated with survival after lymphadenectomy for endometrial cancer and to address their effect relating to systemic therapy. METHODS: This was a retrospective, population-based cohort study of 316 women with endometrial cancer who underwent surgery including lymphadenectomy in Ontario, Canada, from 1996-2000. Data obtained from administrative databases included comorbidities, socioeconomic status, grade, myometrial invasion, cervical involvement, lymphovascular-space invasion, nodal status, and adjuvant pelvic radiotherapy. Primary outcome was 5-year overall survival. Factors associated with survival were identified in a multivariable Cox proportional hazards model. RESULTS: Mean age was 62.2 years (+/- 11.6 years). Thirty eight women (12%) had positive pelvic nodes. Seventy: five (23.7%) received adjuvant pelvic radiotherapy. Age older than 60, grade 3 tumor, deep myometrial invasion (greater than 50%), and cervical stromal involvement were associated with a higher risk of death compared with reference categories. There were no survival differences according to comorbidities, socioeconomic status, or lymphovascular-space invasion. Five-year overall survival was 53.1% for node-negative patients with two or three uterine risk factors and 75.0% for node-positive patients with none or only one uterine risk factor. Pelvic-node status was not an independent determinant of survival (positive nodes: hazard ratio 1.39, 95% confidence interval 0.89-2.18). CONCLUSION: High-risk uterine factors including grade 3 tumor, deep myometrial invasion, and cervical stromal involvement are more significant determinants of survival in endometrial cancer than pelvic-node status. Uterine risk factors should be considered, regardless of nodal status, when offering systemic therapy to maximize survival outcomes. (Obstet Gynecol 2009;114:736-43)