# Meta‐Analysis of Recurrence‐Free Survival or Disease‐Free Survival as a Potential Surrogate Endpoint for Overall Survival in Esophageal Cancer Trials

## TL;DR

This paper investigates whether recurrence-free or disease-free survival can reliably predict overall survival in esophageal cancer trials.

## Contribution

It provides evidence that recurrence-free or disease-free survival may serve as a valid surrogate for overall survival in resectable esophageal cancer.

## Key findings

- The pooled hazard ratio for OS and RFS/DFS was 0.90 and 0.87, respectively.
- A strong correlation (ρ = 0.89) was found between RFS/DFS and OS in esophageal cancer trials.

## Abstract

Cancer trials increasingly use surrogate endpoints, but it is unclear how well recurrence‐free survival (RFS) or disease‐free survival (DFS) specifically predict overall survival (OS) in resectable esophageal cancer (EC).

A systematic literature review identified trials with RFS/DFS and OS endpoints. A meta‐analysis assessed RFS/DFS as surrogates for OS, estimating pooled hazard ratios (HRs) from trial HRs. Forest plots and heterogeneity tests showed effect sizes and pooled estimates. Unweighted linear regression and weighted sensitivity analysis estimated the correlation between OS and RFS/DFS, producing a regression plot.

Of 975 articles identified, 11 met the criteria. The pooled HR for OS and RFS/DFS was 0.90 and 0.87, respectively. The primary analysis showed a strong Pearson correlation between RFS/DFS and OS (ρ = 0.89, p < 0.001).

Subject to known methodological limits, RFS/DFS was demonstrated to be a potentially suitable surrogate endpoint for OS in resectable EC.