Histological response is not a prognostic factor after neoadjuvant chemotherapy in advanced-stage ovarian cancer with no residual disease

Objective: The aim of this study was to evaluate the prognostic impact of the histological response at the time of interval debulking surgery (IDS) in patients treated with neoadjuvant chemotherapy (NACT) for unresectable advanced-stage ovarian cancer (ASOC). Study design: A retrospective study to select cases fulfilling 4 inclusion criteria: (1) patients with unresectable ASOC; (2) at least 3 courses of platinum and paclitaxel NACT; (3) patients who underwent IDS after NACT and who were free of macroscopic residual disease at the end of debulking surgery and (4) histologic analysis of specimens performed in the same institution. Patients were classified into 3 groups according to the histological response to NACT group 1: no histologic residual disease; group 2: persistent residual disease but with marked histological changes and group 3: persistence of at least 1 site with no changes in the tumour. Survival was compared. Results: Fifty-eight patients (49 stage IIIC and 9 stage IV) fulfilled inclusion criteria. Respectively 8, 14 and 36 patients were in groups 1, 2 and 3. The median duration of follow-up was 41 months. Three-year event-free survival in groups 1, 2 and 3 was respectively: 63%, 12% and 19% (p = .02). Conclusions: These results suggest that the degree of the histological response has a limited impact on survival when complete debulking surgery is achieved at IDS. The degree of tumour cell viability after initial chemotherapy is not a reliable marker for modifying chemotherapy after debulking surgery in such patients.