Prognostic Value of Residual Disease after Interval Debulking Surgery for FIGO Stage IIIC and IV Epithelial Ovarian Cancer

Although complete debulking surgery for epithelial ovarian cancer (EOC) is more often achieved with interval debulking surgery (IDS) following neoadjuvant chemotherapy (NACT), randomized evidence shows no long-term survival benefit compared to complete primary debulking surgery (PDS). We performed an observational cohort study of patients treated with debulking surgery for advanced EOC to evaluate the prognostic value of residual disease after debulking surgery. All patients treated between 1998 and 2010 in three Dutch referral gynaecological oncology centres were included. The prognostic value of residual disease after surgery for disease specific survival was assessed using Cox-regression analyses. In total, 462 patients underwent NACT-IDS and 227 PDS. Macroscopic residual disease after debulking surgery was an independent prognostic factor for survival in both treatment modalities. Yet, residual tumour less than one centimetre at IDS was associated with a survival benefit of five months compared to leaving residual tumour more than one centimetre, whereas this benefit was not seen after PDS. Leaving residual tumour at IDS is a poor prognostic sign as it is after PDS. The specific prognostic value of residual tumour seems to depend on the clinical setting, as minimal instead of gross residual tumour is associated with improved survival after IDS, but not after PDS.