Objectives To compare the survival outcomes between primary debulking surgery (PDS) and interval debulking surgery (IDS) in advanced epithelial ovarian cancer (EOC).

Methods Data of 117 patients treated for a FIGO stage III-IV EOC between January 2000 to December 2010 were retrospectively reviewed.

Results PDS was performed in 95 patients (81.2%) and IDS in 22 patients (18.8%). From all, 33 cases (28.2%) had maximal cytoreduction (R0), 39 had a residual disease (RD) ≤1 cm (33.3%) and 45 patients (38.5%) had a RD >1 cm.The 5-years OS was significantly associated the quality of resection (R0 resection:36.4%, RD ≤1 cm:25.5%, RD >1 cm:18.2%; p=0.041).The rate of complete and suboptimal resection (≤1 cm) was significantly higher in case of IDS compared to PDS (86.4% vs 55.8%, p=0.008). No significant difference on OS was found between PDS and IDS (28.2% vs 15.8%, p=0.364). Nonetheless, in the subgroup of patients with complete resection, PDS resulted in a significantly higher 5 years OS compared to IDS (44% vs 12.4%, p=0.045) with no significant difference in case of sub-optimal resection (28.6% vs 13.3%, p=0.830). However, IDS increased the 5 years OS of patient who had a RD greater than 1 cm compared to PDS (33% vs 17%, p=0.245). Neoadjuvant chemotherapy improved significantly the 5-year OS of patients staged FIGO IV compared to PDS (40% vs 12.5%, p=0.032).

Conclusions Because of the lack of survival benefit of either treatment modality, the indication of PDS or IDS should depend on the extent of peritoneal carcinomatosis and the possibility of complete surgical resection.