Objective The aim of the study is to demonstrate the prognostic value of pleural carcinosis and effusion in a large cohort of advanced epithelial ovarian cancer(EOC) patients operated within a maximal-effort setting and the hereby associated therapeutic implications.

Methods Overall, 388 EOC patients with confirmed malignant pleural effusion (MPE) and/or carcinosis were retrospectively analysed. Exclusion criteria were non-epithelial ovarian malignancies and presence of other comorbidities associated with pleural effusions.

Results The incidence of the pleural involvement at the time of diagnosis in our institution was 9.4%. The majority of the patients (82.3%) were symptomatic with a poorer performance status due to the pleural effusion/carcinosis. The prognosis after the occurrence of the MPE during the EOC in relapsed cases was poor with 9,9 months. In the multivariate analysis, the time point of the manifestation of the pleural effusion (primary vs relapse) (p<0.001), platinsensitivity (yes vs no) (p=0.003), performance status (0/1 vs 2/3) (p=0.045) and presence of ascites (yes vs no) (p=0.004) were significant prognostic factors for overall survival (OS). Patients with FIGO stage IVA and IVB who were operated tumor free had longer OS rates.

Conclusion Even in this less favourable patient collective, the otherwise well-established prognostic factors of EOC were associated with a significantly better OS. This suggests that the overall behavioral pattern of the disease has strong similarities in patients with and without pleural effusion/carcinosis and merits an equally high therapeutic effort approach.