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.

LEVEL OF EVIDENCE: II.