Introduction/Background Early post-operative chemotherapy improves the survival of advanced-stage epithelial ovarian cancer (AEOC) patients by increasing the benefit of systemic therapy. As a result, recovery time after surgery and time to chemotherapy (TTC) are crucial endpoints for ovarian cancer treatment. The present study aimed to evaluate predictors for 30-day severe post-operative complications classified by Clavien-Dindo classification (CDC) grade ≥IIIa and TTC after cytoreductive surgery for primary AEOC.

Methodology Patients undergoing cytoreductive surgery for primary AEOC were enrolled from February 2018 to September 2020. Post-operative complications were graded according to CDC. Logistic regression analysis was performed to evaluate factors predicting CDC grade ≥IIIa and TTC>42 days.

Results CDC grade ≥IIIa occurred in 51(17%) patients. In multivariable analysis, age (p=0.037), cardiovascular comorbidity (p<0.001), diaphragmatic surgery (p<0.001), intra-operative urinary tract injury (p=0.017), and other visceral injury (e.g., pancreas, stomach, liver or spleen) (p=0.013) were factors related to CDC grade ≥IIIa. Of 300 patients, 25 patients did not receive chemotherapy after surgery and were excluded from TTC analysis. In 26% (72/275) TTC was > 42 days: median (IQR) 39 days (29–50) in patients with CDC grade ≥IIIa versus 33 days (25–41) in patients without CDC grade ≥IIIa, p=0.008. Patients with the following factors: WHO performance grade ≥2 (p=0.045), intra-operative bowel injury (p=0.043), other visceral injury (p=0.008) and post-operative CDC grade ≥IIIa (p=0.032) had a significantly higher adjusted odds of developing TTC >42 days.

Conclusion Patients with advanced age, cardiovascular comorbidity, and those who required diaphragmatic surgery had a greater adjusted odds of develop CDC grade ≥IIIa. CDC grade ≥IIIa was independently associated with TTC >42 days. A proper pre-operative risk assessment and prevention of intra-operative morbidity are essential in order to prevent severe post-operative complications and the delayed time to chemotherapy.