Impact of operative start time on surgical outcomes in patients undergoing primary cytoreduction for advanced ovarian cancer

Objectives: To evaluate the impact of operative start time (OST) on surgical outcomes in patients with advanced ovarian cancer. Methods: All stage IIIB-IV serous ovarian cancer patients who underwent primary surgery at our institution from 1/01 to 1/10 were identified. Fourteen factors were evaluated for an association with surgical outcomes including OST and OR tumor index (1 point each for carcinomatosis and/or bulky [≤ 1 cm] upper abdominal disease). Univariate logistic regression considering within-surgeon clustering was performed for cytoreduction to ≤ 1 cm versus > 1 cm residual disease. In patients with ≤ 1 cm residual disease, univariate logistic regression considering within-surgeon clustering was performed for 1-10 mm residual disease versus complete gross resection (CGR, 0 mm residual). A multivariate logistic model was developed based on univariate analysis results in the ≤ 1 cm residual disease cohort. Results: Of 422 patients, residual disease was: 0 mm, 144 (34.1%); 1-10 mm, 175 (41.5%); > 10 mm, 103 (23.3%). OST was not associated with cytoreduction to ≤ 1 cm residual disease on univariate analysis. In the ≤ 1 cm residual disease cohort, albumin, CA-125, ascites, ASA score, stage, OR tumor index, and OST were associated with CGR on univariate analysis. Earlier OSTs were associated with increased rates of CGR. On multivariate analysis, CA-125 was independently associated with CGR. OST was associated with CGR in patients with an OR tumor index of 2 but not an OR tumor index < 2. Conclusions: OST was not associated with cytoreduction to ≤ 1 cm residual disease in patients with advanced serous ovarian cancer. In the cohort of patients with ≤ 1 cm residual disease, later OSTs were associated with reduced rates of CGR in patients with greater tumor burden.