Introduction/Background To compare the chemoresistance and survival in patients with stage IIIC or IV epithelial ovarian cancer (EOC) who were treated with neoadjuvant chemotherapy (NACT) followed by interval debulking surgery (IDS) or primary debulking surgery (PDS). The clinical characteristics of patients who benefited from NACT were further evaluated.

Methodology We retrospectively analyzed 220 patients who underwent NACT followed by IDS or PDS from January 2002 to January 2017 treated at Peking University Third Hospital. Differences in clinicopathological features, chemoresistance and prognosis were analyzed.

Results The incidence rate for optimal cytoreduction and chemoresistance in the NACT group was relatively higher than those in PDS group. No differences were observed in progression free survival (PFS) or overall survival (OS). Patients without macroscopic RD in the NACT group (NACT-R0) had a similar prognosis compared to patients in the PDS group who had RD <1 cm, and a relatively better prognosis compared to the PDS group that had RD ≥1 cm. The survival curve demonstrated that patients in the NACT-R0 group that were chemosensitive seemed to have a better prognosis compared to patients in the PDS group that had RD.

Conclusion Patients without RD after PDS had the best prognosis, whereas patients with RD after NACT followed by IDS had the worst. However, even if patients achieved no RD, their prognosis varied depending on chemosensitivity. Survival was better in patients who were chemosensitive compared to patients who underwent PDS but had macroscopic RD. Hence evaluating the chemosensitivity and feasibility of complete cytoreduction in advance is crucial.

Disclosure Nothing to disclose.