Optimal timing of interval debulking surgery in advanced ovarian cancer: yet to be defined?

Objectives: Interval debulking surgery (IDS) following neo-adjuvant chemotherapy (NAC) is a treatment option in advanced ovarian cancer. It is recommended to perform IDS early, after 3 cycles of NAC, but late IDS (after 6 cycles) may yield better results. Delaying IDS, however, harbours the risk of loosing the opportunity for debulking surgery.

Study Design: Retrospective comparison of two groups of patients with advanced ovarian carcinoma (stages IIC-IV) treated by platinum-based chemotherapy (CT) having undergone early IDS (after 3.6 cycles, group 1, n=33) or late IDS (after 6.3 cycles, group 2, n=104). Contemporary patients who had undergone standard treatment by primary debulking surgery (PDS)+CT (group 3, n=446) and those treated by CT alone (group 4, n=64 patients) served as internal controls.

Results: Prognosis in IDS patients (groups 1+2) was comparable to that in PDS patients (group 3). Only a few patients in group 4 potentially had lost an opportunity for debulking surgery. Groups 1 and 2 were well-matched concerning usual prognostic factors. Surgery extent and post-operative outcomes were similar in both. In contrast, complete cytoreductions were significantly more frequent in late than in early IDS (group 2 vs.1: 58% vs. 36%, p=0.03) and survival was not inferior in the late IDS group compared to the early IDS group with 37 vs. 22 months, respectively (p=0.09).

Conclusion: Late IDS yields higher complete resection rates than early IDS and should be evaluated prospectively for outcome in further trials.