Does the primary treatment sequence affect post-relapse survival in recurrent epithelial ovarian cancer? A real-world multicentre retrospective study

Objective: To explore the impact of the primary treatment sequence (primary debulking surgery, PDS, versus neoadjuvant chemotherapy and interval debulking surgery, NACT-IDS) on post-relapse survival (PRS) and recurrence characteristics of recurrent epithelial ovarian cancer (REOC).

Design: Real-world retrospective study.

Setting: Tertiary hospitals in China.

Population: A total of 853 patients with REOC at International Federation of Gynaecology and Obstetrics stages IIIC-IV from September 2007 to June 2020. Overall, 377 and 476 patients received NACT-IDS and PDS, respectively.

Methods: Propensity score-based inverse probability of treatment weighting (IPTW) was performed to balance the between-group differences.

Main outcome measures: Clinicopathological factors related to PRS.

Results: The overall median PRS was 29.3 months (95% CI 27.0-31.5 months). Multivariate analysis before and after IPTW adjustment showed that NACT-IDS and residual R1/R2 disease were independent risk factors for PRS (p < 0.05). Patients with diffuse carcinomatosis and platinum-free interval (PFI) ≤ 12 months had a significantly worse PRS (p < 0.001). Logistic regression analysis revealed that NACT-IDS was an independent risk factor for diffuse carcinomatosis (OR 1.36, 95% CI 1.01-1.82, p = 0.040) and PFI ≤ 12 months (OR 1.59, 95% CI 1.08-2.35, p = 0.019). In IPTW analysis, NACT-IDS was still significantly associated with diffuse carcinomatosis (OR 1.29, 95% CI 1.05-1.58, p = 0.015) and PFI ≤ 12 months (OR 1.90, 95% CI 1.52-2.38, p < 0.001).

Conclusions: The primary treatment sequence may affect the PRS of patients with REOC by altering the recurrence pattern and PFI duration.