Correlation Between Progression-free Survival and Overall Survival in Patients with Ovarian Cancer After Cytoreductive Surgery: a Systematic Literature Review

Objectives: This analysis aimed to better define the relationship between progression-free survival and overall survival in adult patients with ovarian cancer (including fallopian tube or primary peritoneal cancer) following primary cytoreductive surgery or interval cytoreductive surgery.

Methods: A systematic literature review was carried out across the Medline, Embase, and Cochrane Central databases on 7 July 2020 (date limits 1 January 2011 to 7 July 2020) to identify studies with the following eligibility criteria: clinical trials/observational studies including >200 patients with ovarian cancer aged ≥18 years, evaluating overall survival/progression-free survival following cytoreductive surgery by residual disease status in the United States, Europe, Japan, or China. Weighted linear regression models were used to assess any correlation between median progression-free survival and overall survival, and between logHR for progression-free survival and logHR for overall survival. Risk of bias was assessed for all included studies.

Results: Of the 50 studies reported, 43 were observational studies (41 retrospective and two prospective cohort studies), and seven were reporting for randomized clinical trials-of which four were retrospective data analyses. For analyses of the relationship between overall survival and progression-free survival, 21 studies were eligible. The weighted linear regression model showed a strong positive association between the two survival endpoints. Goodness-of-fit analysis measured the adjusted R as 0.84 (p<0.001); a positive association was also observed between logHRs for overall survival and progression-free survival in the included studies.

Conclusions: Median progression-free survival was predictive of median overall survival. This correlation between progression-free survival and overall survival after primary treatment for ovarian cancer highlights the validity of progression-free survival as a primary endpoint. Observational studies contributed most data, with limited information on disease stage and histology.