Risk-based stratification of carcinomas concurrently involving the endometrium and ovary

Abstract Objective Determining whether carcinomas concurrently involving endometrium and ovary are independent primary tumors (IPTs) or endometrial carcinomas with ovarian metastases (at least stage IIIA endometrial cancers, IIIA-EC) using clinicopathologic criteria is often challenging. Recent genomic studies showed that most such tumors are clonally related. We sought to identify clinicopathologic features associated with clinical outcomes, and to separate women with these tumors into clinically low-risk and high-risk groups. Methods We reviewed clinical and pathologic data from 74 women who, between 1993 and 2014, underwent primary surgery for endometrial cancer and had concurrent ovarian involvement. Results The endometrial carcinomas were endometrioid (EECs, n  = 41) or non-endometrioid (ENECs, n  = 33). Nineteen (26%) cases were originally classified as IPTs using clinicopathologic criteria. Multivariate analysis revealed that lymph node involvement (hazard ratio (HR) = 2.38, 95% CI 1.13–5.02, p  = 0.023) and non-endometrioid endometrial tumor histology (HR = 6.27, 95% CI 2.6–15.13, p n  = 21; median PFS 12.7 months, 95% CI, 9.24–19.8); and a low-risk group consisting of all EECs, as well as lymph node-negative ENECs with n  = 44, median PFS not reached). The risk-based classification was superior to the original classification of endometrial cancers as IPTs vs. IIIA-EC for predicting PFS (log-rank test, p p  = 0.07). Conclusion Our proposed risk-based stratification enables categorization of women with concurrent endometrial and ovarian tumors according to their likely clinical outcomes.