Introduction/Background Ovarian cancer (OC) has a low incidence, but high mortality due to a habitual diagnosis in advanced cancer stages. Regardless of the histological subtype, the main route of spread is the peritoneal cavity. Therefore, intraperitoneal chemotherapy has an important role where the advantages are still unknown.To determine whether patients treated with intraperitoneal chemotherapy have later recurrences and a different pattern of recurrence in patients with advanced ovarian cancer.

Methodology Retrospective cohort and observational study enrolling stage III-IV OC patients who underwent primary surgery and complete cytoreduction, with a minimum of 6 year follow up from 2011 to 2019. We examinate 2 groups: Group A (n=17) receiving intraperitoneal chemotherapy and Group B (n=22) receiving standard chemotherapy.

Results Following the FIGO 2021 histopathologic classification, most of our ovarian cancer cases were of epithelial origin. Serous carcinoma was the most common with 88% (n=15) in group A and 72% (n= 16) in group B. All patients with recurrence had moderately or poorly differentiated histological grading. Regardless of the chemotherapy, after a median follow-up of 54 month the risk of disease progression or death was 50%. In group A the progression-free survival after 12 months was 86% increasing up to 45.7% after 5 years. In group B the progression free survival after 12 months was 90% increasing up to 52.8% after 5 years. No significant progression-free survival increase was observed with either both chemotherapy regimen (log-rank p-value 0.74)

Conclusion Chemotherapy does not seem to have a direct impact on the recurrence time in advanced ovarian cancer patients. However, there is little evidence that needs to be confirmed with more studies.