Objectives Patients with mucinous ovarian carcinoma (MOC) generally have a favorable prognosis, although in advanced stage, prognosis is significantly worse compared to patients with serous ovarian carcinomas (SOCs). This might be due to the difficulties in distinguishing MOC from metastatic tumors. In the current study, we investigate prognosis of MOC compared to other types of ovarian cancer and to synchronous metastases to the ovary (sMO).

Materials and Methods Age, laterality, International Federation of Gynecology and Obstetrics stage, tumor grade, treatment, and survival were extracted from the Eindhoven Cancer registry for all patients diagnosed with ovarian carcinomas or sMO between 1990 and 2012. Five-year survival analysis and Cox proportional hazards analysis were conducted.

Results A total of 3556 patients with primary ovarian carcinoma (of which 474 mucinous) and 289 with sMO were identified. In advanced stage, 5-year survival of patients with MOC was comparable to survival of patients with sMO (11% vs 11%, P = 0.32) and decreased compared to patients with SOC (26%, P < 0.01). For MOC, there was no clinically significant effect on 5-year survival of either debulking (12% vs 8%, P < 0.01) or chemotherapy (12% vs 10%, P = 0.02).

Conclusions Patients with advanced stage MOC have a worse prognosis than advanced stage SOC. Survival is almost identical to that of patients with sMO. Effects of chemotherapy and debulking are limited in patients with MOC, which may be explained by suboptimal treatment due to the admixture of metastases in advanced stage MOC. Methods to differentiate between primary MOC and metastatic disease are needed to provide optimal treatment and insight in prognosis.