Background: 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.
Methods: 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.
Results: 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.
Conclusions: 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.
Impact: The possible misdiagnosis associated with clinicopathologic of synchronous uterine and ovarian cancers does not appear to worsen survival on a population level.
©2022 American Association for Cancer Research.