Delays from neoadjuvant chemotherapy to interval debulking surgery and survival in ovarian cancer.

Abstract

5552 Background: Prolonged time from primary surgery to chemotherapy is associated with worse survival in ovarian cancer (OC); however, the impact of prolonged time from neoadjuvant chemotherapy (NACT) to interval debulking surgery (IDS) is unknown. Given increasing utilization of NACT, we seek to evaluate the role of delays from NACT to IDS (TIDS) on survival. Methods: At a single center, we prospectively identified 224 women with newly diagnosed stage III/IV OC given NACT from 7/1/15 to 12/1/17. Clinical characteristics were abstracted by two independent reviewers. Delays in TIDS were defined as time from last preoperative carboplatin to IDS > 6 weeks. Fisher’s exact/Wilcoxon rank sum tests were used to compare clinical characteristics by delay in TIDS. Kaplan Meier method was used to estimate progression-free (PFS) and overall survival (OS) from date of IDS. Log-rank test/multivariate CoxPH models were used to examine differences by delay groups, adjusting for covariates. Results: Of the 224 women, 159 underwent IDS, and 34 (21%) experienced TIDS delays. These women were older (median 68 vs. 65 years, p = 0.05) and had more preoperative NACT cycles (median 6 vs. 4, p = 0.003). Patients with delays in TIDS also had a longer interval from pathological diagnosis to start of NACT (TNACT), median 22 vs. 17 days, p = 0.01, and interval from IDS to postoperative chemotherapy (TPOC), median 37 vs. 30 days, p = 0.01; however, neither TNACT nor TPOC predicted survival, p > 0.05. On univariate analysis, delays in TIDS were significantly associated with worse OS (HR 2.4 95% CI 1.2-4.8, p = 0.01); however, this was attenuated in multivariate models (HR 1.66 95% CI 0.8-3.4, p = 0.17), adjusting for age, stage and complete gross resection (CGR). On univariate analysis, delays in TIDS were not associated with PFS (HR 1.55 95% CI 0.97-2.5, p = 0.062), and in multivariate models, increase in number of preoperative NACT cycles (p = 0.005) and lack of CGR (p < 0.001) were the only variables predictive of worse PFS. Conclusions: Delays in TIDS are associated with OS, but not after adjustment for age, stage and CGR, suggesting a need to maximize cytoreduction regardless of delays in NACT. The role of preoperative NACT cycles on survival should be further studied.