Carcinosarcoma of the ovary compared to ovarian high-grade serous carcinoma: impact of optimal cytoreduction and standard adjuvant treatment.

Objective: The purpose of this retrospective study was to compare the prognoses of women with ovarian carcinosarcoma (OCS) who had optimal cytoreductive surgery followed by platinum plus taxane combination chemotherapy to those of women with ovarian high-grade serous carcinoma (HGSC) treated in the same manner.
Methods: A multicenter, retrospective department database review was performed to identify patients with OCS at eight gynecologic oncology centers in Turkey. A total of 54 women with OCS who had undergone optimal cytoreductive surgery followed by platinum plus taxane combination chemotherapy between 1999 and 2017 were included in this case-control study. Each case was matched to two women with ovarian HGSC who had undergone optimal cytoreductive surgery followed by platinum plus taxane combination chemotherapy. The Kaplan-Meier method was used to generate survival data. Factors predictive of outcome were analysed using Cox proportional hazards models.
Results: Median disease-free survival (DFS) was 29 months [95% confidence interval (CI) 0-59, standard error (SE) 15.35] versus 27 months (95% CI 22.6-31.3, SE 2.22; p = 0.765) and median overall survival (OS) was 62 versus 82 months (p = 0.53) for cases and controls, respectively. For the entire cohort, the presence of ascites [hazard ratio (HR) 2.32; 95% CI 1.02-5.25, p = 0.04] and platinum resistance [HR 5.05; 95% CI 2.32-11, p < 0.001] were found to be independent risk factors for decreased OS.
Conclusion: DFS and OS rates of patients with OCS and HGSC seem to be similar whenever optimal cytoreduction is achieved and followed by platinum plus taxane combination chemotherapy.