Mortality Patterns of Synchronous Uterine and Ovarian Cancers: A SEER Registry Analysis

The degree to which uterine cancer metastatic to the ovary is misdiagnosed as synchronous stage I uterine and ovarian cancers is unclear. We sought to determine whether patients with synchronous cancers had mortality patterns similar to either stage IIIA uterine, stage I uterine, or stage I ovarian cancers alone.

The Surveillance, Epidemiology, and End Results database was used to compare mortality of patients with synchronous stage I uterine and stage I ovarian cancers versus those with stage IIIA uterine, stage I uterine, or stage I ovarian cancers alone. We calculated age-adjusted mortality hazard ratios (HR) and 95% confidence intervals (CI) accounting for calendar year and grade, adjuvant treatment, grade 1 endometrioid cancers, grade 3 endometrioid cancers, and stage IA cancers.

Among the 9,321 patients, we observed lower age-adjusted mortality in patients with stage I synchronous cancers (n = 937) compared to those with stage IIIA uterine (n = 531; HR, 0.45 95% CI, 0.35-0.58), stage I uterine (n = 6,919; HR, 0.74; 95% CI, 0.60-0.91), and stage I ovarian cancers (n = 934; HR, 0.52; 95% CI, 0.41-0.67). Results were similar after taking into account diagnosis year and grade, and limiting to those receiving adjuvant therapy, grade 1 or grade 3 endometrioid cancers, or stage IA cancers.

We observed lower mortality for synchronous stage I uterine and ovarian cancers, which was not explained by younger age, earlier stage, lower grade, histology type, or adjuvant therapy.

The possible misdiagnosis associated with clinicopathologic of synchronous uterine and ovarian cancers does not appear to worsen survival on a population level.