Objective: To analyze the survival of women with malignant, mixed mullerian tumors of the ovary (OMMMT) compared to women with epithelial ovarian cancer (EOC).
Methods: Data from the Surveillance, Epidemiology and End Results (SEER) Program on 14025 women diagnosed with primary invasive ovarian cancer between 1988 and 1997 were used for this analysis (382 had OMMMT). Differences in distribution of prognostic variables by histological type were compared using a chi-square test. Multivariable survival models were fit using Cox proportional hazards regression analysis to compare risk of death for OMMMT compared to EOC. Analyses were also performed using cases with OMMMT compared to high-grade EOC only.
Results: Women with OMMMT were older at diagnosis and were more likely to have primary surgery compared to women with EOC. The majority of women in either histological group had advanced-stage disease at diagnosis. Women with OMMMT had a significant increased risk of death from any cause whether being compared to all women with EOC (HR = 1.69, 95% CI = 1.50,1.90) or to women with high-grade EOC only (HR = 1.58, 95% CI = 1.40,1.79). Women with advanced-stage OMMMT were at a 60% increased risk of death compared to women with advanced-stage, high-grade EOC, after adjustment for other variables of interest (adjusted HR = 1.60, 95% CI = 1.40,1.84). There was no difference in risk of death for these two groups of women with early-stage disease.
Conclusion: OMMMT is a rare malignancy compared to EOC and had a significantly worse prognosis compared to EOC.