Objectives This was a retrospective population-based study investigating the demographic characteristics, clinical characteristics, and prognosis of patients with ovarian high-grade serous carcinoma displaying transitional cell carcinoma-like (TC-like) morphological features.

Materials and Methods A cohort of patients diagnosed with ovarian high-grade serous carcinoma from 1988 to 2012 was drawn from the National Cancer Institute's Surveillance Epidemiology and End Results Database. Patients with transitional cell histology were included in the study group, whereas patients with other serous tumors served as controls. Demographic and clinical characteristics between the study and the control groups were compared using χ² test. For surgically treated patients, survival was estimated by generation of Kaplan-Meier curves. Multivariate analysis was performed using the Cox regression method.

Results A total of 29,716 patients met the inclusion criteria. From these, 264 patients (0.9%) were included in the TC-variant group, whereas 29,452 (99.1%) composed the control group. Patients with TC-variant tumors were younger and more likely to present with larger, unilateral tumors at an early disease stage. Surgically treated patients with advanced stage had a median disease-specific survival of 50 months compared with 40 months in the control group (P = 0.013). In that group, multivariate analysis confirmed that TC-like morphological features were an independent predictor of survival.

Conclusions High-grade serous carcinoma with TC-like morphological features was associated with unique demographic and clinical characteristics. For patients with advanced stage-disease, the presence of TC-like morphological features was associated with a superior survival.