Early initiation of chemotherapy after primary surgery as an adverse prognostic factor in patients with ovarian cancer

Objective: For patients with ovarian cancer (OC), the optimal time to initiate chemotherapy (TTC) after primary surgery is unknown. The aim of this study was to determine the effect of shorter TTC than 14 days on survival after primary surgery for OC among Polish women in 2011. Materials and Methods: All Polish women who underwent a surgical procedure for OC in the period from January 1, 2011 to December 31, 2011 recorded in the Polish National Health Fund Database (PNHFD) were included. The Cox proportional hazard regression analysis was used to compute the adjusted hazard ratio (HR). Results: The 25%, 50%, and 75% quantiles of intervals from surgery to TTC were 21, 30, and 43 days, respectively. In the multivariate analysis, it was observed that the adverse independent prognostic factors were: TTC <= 14 days [HR: 1.58 (95% CI: 1.24-2,01); p = 0.0002)] and a surgical procedure other than complex and very extensive excision of the upper part of the sex organs [HR: 2.02 (95% CI: 1.70-2.39); p < 0.0001]. The overall three-year survival rate for longer and shorter TTC than 14 days were 67.8% and 50.3%, respectively (p < 0.0001). Conclusions: This nationwide population-based cohort study revealed a significantly increased risk of death in patients with TTC = 14 days after primary surgery compared with a TTC > 14 days. In order to explain the causes of this phenomenon, it is necessary to conduct a prospective study that randomizes patients to different time intervals. Conclusions: The early initiation of chemotherapy after a primary surgery within 14 days is not a favourable prognostic factor. The nationwide population-based cohort study showed that complex and very extensive excision of the upper part of the sex organs due to ovarian cancer significantly decreased risk of death. In patients with ovarian cancer with comorbidities, the use of chemotherapy shortly, within 14 days, after surgery had unfavourable impact on survival.