Earlier is not always better: Optimal time to initiate adjuvant chemotherapy after surgery for ovarian cancer.

Abstract

Objective: Tumor resection followed by adjuvant chemotherapy constitutes the cornerstone of ovarian cancer (OC) treatment. This study aimed to evaluate the impact of the time to chemotherapy (TTC) after primary surgery on the survival outcomes of patients with OC.

Methods: Patients with OC at any stage who underwent primary surgery followed by adjuvant chemotherapy between 2000 and 2021 were included in the analysis. Data were obtained from the Cancer Registries of Aachen and nine hospitals in Saxony-Anhalt. Patients were stratified into three subgroups based on the timing of chemotherapy initiation: early (≤ 21 days), intermediate (22-35 days) and late (> 35-180 days). The impact of TTC on progression-free survival (PFS) and overall survival (OS) was assessed using multivariate Cox proportional hazard models, both in complete case analysis and with multivariate imputation by chained equations to account for missing data.

Results: A total of 1699 patients with OC (mean age: 61.4 ± 12 years) started adjuvant chemotherapy 32.2 ± 24.6 days after surgery. For OS, the optimal TTC was identified at 26 days post-surgery. Compared with the intermediate group, both earlier and later initiation of chemotherapy were associated with worsened OS (Hazard Ratio (HR) = 1.34, 95%CI 1.23-1.60, p < 0.05 and HR = 1.38 95%CI 1.14 -1.68; p < 0.001, respectively).

Conclusion: The optimal timing for initiating adjuvant chemotherapy appears to be between 22 and 35 days after primary surgery for ovarian cancer. Remarkably, an earlier start of chemotherapy did not confer a survival advantage, possibly due to the need for adequate recovery after surgery.