Abstract 754P
Background
Since several randomized controlled studies have demonstrated that neoadjuvant chemotherapy (NAC) was non-inferior to primary debulking surgery (PDS) with respect to survival in patients with advanced ovarian cancer, many patients are now treated with NAC followed by interval debulking surgery (IDS). We examined the actual status and effectiveness of treatment strategy using NAC followed by IDS in Japanese clinical practice.
Methods
We conducted a multi-institutional observational study of 940 women with FIGO stage III to IV epithelial ovarian cancer treated at 9 centers from 2010 to 2015. In 486 propensity-score matched samples extracted from the participants, progression-free survival (PFS) and overall survival (OS) were compared between women who received NAC and PDS. In addition, we examined the impact of residual tumors at IDS or PDS on survival.
Results
Among 940 patients, 455 (48.4%) received dose-dense paclitaxel and carboplatin. The adoption of NAC varied by institution from 21 to 67%, and overall, 512 patients (54.5%) received NAC. NAC was associated with shorter OS in FIGO stage IIIC [median OS: 48.1 vs. 68.2 months, hazard ratio (HR): 0.75; 95% confident interval (CI): 0.55–1.02, p =0.06], but not PFS (median PFS: 19.7 vs. 19.4 months, HR: 0.98; 95% CI: 0.77–1.26, p =0.88). NAC and PDS were comparable in PFS (median PFS: 16.6 vs. 14.7 months, HR: 0.94; 95% CI: 0.65–1.35, p =0.73) and OS (median OS: 45.2 vs. 35.7 months, HR: 0.98; 95% CI: 0.68–1.53, p =0.93) among patients with FIGO stage IV. Median PFS in patients with complete, optimal (macroscopic residual tumor <1cm), suboptimal surgery at IDS or PDS were 21.5, 16.8, 17.7, and 43.1, 18.6, 14.3 months, median OS were 57.2, 46.0, 42.2, and not reached, 68.2, 34.6 months, respectively.
Conclusions
NAC followed by IDS was associated with shorter OS in stage IIIC, but not in stage IV. Complete surgery at IDS had only an impact on survival comparable to optimal surgery at PDS.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Gynecologic Oncology Trial and Investigation Consortium.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.