Introduction Investigate the role ICS for ovarian cancer patients receiving NACT.

Methods Patients diagnosed between 2010–2015 with stage III-IV ovarian carcinoma who received NACT and ICS with known status of residual disease were identified in the National Cancer Database. Median overall survival was compared with the log-rank test while Cox models were constructed to control for confounders (aHR).

Results A total of 5055 patients were identified; after controlling for confounders those with gross residual disease (n=2366) had worse OS compared to patients with complete gross resection, CGR (n=2689) (aHR 1.36, 95% CI: 1.26, 1.47). Patients with gross disease ≥ 1 cm (n=1050) had comparable OS to those with < 1 cm (n=1316) (33.84 vs 33.08 months, p=0.27; aHR 1.06, 95% CI: 0.95, 1.18). Patients who underwent high-complexity ICS and achieved CGR (n=570) did not have better OS compared to those who had low-complexity ICS and gross residual disease (n=724) (38.28 vs 35.84 months, p=0.11; aHR: 1.08, 95% CI: 0.93, 1.26). However, they had higher rates of prolonged hospital stay (11.8% vs 4.1%, p<0.001), and unplanned re-admission (3.5% vs 1.8%, p=0.056). CGR was associated with borderline survival benefit for high-risk patients (defined as those aged >=80 years or those aged 75–79 years with at least other risk factor (stage IV disease, comorbidity index score 2+, or complex surgery)) (33.25 vs 30.46 months, p=0.035; aHR: 1.22, 95% CI: 1.02, 1.47).

Conclusion/Implications While CGR following ICS is associated with improved OS, elderly patients, those with comorbidities or those requiring extensive surgical procedures appear to benefit the least.