Introduction/Background To investigate time to chemotherapy (TTC) from primary debulking surgery (PDS) and relative survival (RS) in advanced epithelial ovarian cancer (EOC) in a nationwide population-based cohort.

Methodology All women diagnosed with EOC, stage IIIC-IV and registered in the Swedish Quality Register for Gynecologic Cancer between 2008–2018 with PDS performed followed by chemotherapy were included. Patient and tumor characteristics including no (R0) or residual disease (RD), were retrieved. The TTC was categorized into five groups. The 2- and 5-year RS (95%CI) were calculated and uni- and multivariable Poisson regression of excess mortality rate ratios (EMRRs) analyzed with covariates; TTC, age, FIGO stage, serous and non-serous histology and residual disease.

Results In total, 1710 women were included. The mean age was 64.3 years. R0 was achieved in 47.7%; 39.0% of 292 women with TTC <21 days, 46.9% of 360 with 22–28 days, 48.5% of 392 (29–35 days), 52.1% of 303 with 36–42 days and 51.0% of 363 women with TTC >42 days, respectively. In the total cohort, age <70 years, stage IIIC, serous histology and R0 were found significant prognostic factors for 5-year RS but not TTC. Two-year RS for FIGO stage IV and R0 was 92.9% (82.8–1.00) for TTC <21 days compared with 66.3% (50.8–81.8) for TTC >42 days. The corresponding figures for stage IIIC and R0 were 91.0% (84.7–97.4) and 82.4% (75.8–89.0), respectively. Five-year RS for FIGO stage IV and R0 was 67.2% (48.0–86.3) for TTC <21 days and 42.6% (25.2–59.9) for TTC > 42 days. The corresponding 5-year RS for stage IIIC and R0 were 56.4% (45.2–67.6) and 51.6% (42.8–60.5), respectively.

Conclusion Our data indicate that TTC after PDS may be associated with short-term survival among stage IV disease without residual disease. Updated results with EMRR data for subgroups will be presented.

Disclosures The authors declare no conflicts of interest.