# Real-World Outcomes of Primary Versus Interval Debulking Surgery in a Multicenter Cohort of Advanced Ovarian Cancer Patients Treated with Bevacizumab

## TL;DR

This study found that interval debulking surgery for advanced ovarian cancer, compared to primary surgery, is linked to worse survival outcomes when patients receive bevacizumab.

## Contribution

The study provides real-world evidence comparing primary and interval debulking surgeries in ovarian cancer patients treated with bevacizumab.

## Key findings

- IDS was independently associated with significantly poorer progression-free and overall survival compared to PDS.
- Poor chemotherapy response and age over 70 years were independent predictors of worse outcomes.
- IDS patients had higher CA-125 levels, more advanced stage disease, and received fewer bevacizumab cycles.

## Abstract

This study investigated the real-world outcomes of two surgical approaches for advanced ovarian cancer—primary debulking surgery (PDS) and interval debulking surgery (IDS)—in patients receiving first-line chemotherapy with bevacizumab. Patients who underwent IDS were typically older, had higher initial CA-125 levels, and presented with more advanced (stage IV) disease compared to those receiving PDS. The key finding was that IDS was independently associated with significantly poorer progression-free survival (PFS) and overall survival (OS) compared to PDS. Poor chemotherapy response and age over 70 years were also identified as independent predictors of worse outcomes.

Background: With an ongoing debate concerning the optimal timing of advanced ovarian cancer surgical treatment, primary debulking surgery (PDS) versus neoadjuvant chemotherapy followed by interval debulking surgery (IDS), this study aimed to compare survival outcomes between PDS and IDS populations and evaluate prognostic factors in a real-world cohort of patients treated with first-line chemotherapy and bevacizumab. Methods: A retrospective multi-center study was conducted involving 369 patients with newly diagnosed advanced ovarian cancer. Patient data included demographics, histology, treatment details, chemotherapy response, and survival outcomes. Kaplan–Meier estimates with log-rank tests were used for univariate analyses, as well as Cox proportional hazard models for multivariate analyses. Results: Patients undergoing IDS were older (62.5 vs. 60.0 years), had higher pretreatment CA-125 (1846 vs. 395.6 IU/mL), an increased proportion were at with stage IV (36.25% vs. 21.10%), and they received fewer bevacizumab cycles (12 vs. 18) compared to those undergoing PDS. Median progression-free survival (PFS) was 18.6 months (95% CI: 17.3–20.2) and overall survival (OS) was 45.4 months (95% CI: 41.1–52.1). Multivariate analysis confirmed poor chemotherapy response (HR 1.80, 95% CI: 1.36–2.37; p < 0.0001) and IDS (HR 1.65, 95% CI: 1.37–2.39; p < 0.0001) as independent predictors of shorter PFS. For OS, independent risk factors were age > 70 (HR 1.62; p = 0.0202), poor response (HR 2.03; p < 0.0001), and IDS (HR 1.75; p = 0.0006). Conclusions: In this real-world cohort treated with first-line chemotherapy and bevacizumab, interval debulking surgery was associated with inferior progression-free and overall survival compared with primary debulking surgery. However, these findings reflect a high-risk population and are strongly influenced by patient selection and treatment pathways, underscoring the need for cautious interpretation.