Correlation between recurrence-free survival and overall survival after upfront surgery for resected colorectal liver metastases

Background The role of recurrence-free survival (RFS) as a valid surrogate endpoint for overall survival (OS) in patients who underwent upfront surgery for colorectal liver metastases remains uncertain. The aim of the study was to compare the two survival measures in a nationwide cohort of upfront resected colorectal liver metastasis. Methods Data from patients with colorectal liver metastases without extrahepatic metastases who underwent curative surgery for liver metastases were retrieved from the Japanese nationwide database (data collection 2005-2007 and 2013-2014). RFS, OS, and survival after recurrence were estimated using the Kaplan-Meier method. The correlation (rho) between RFS and OS was assessed using the rank correlation method combined with iterative multiple imputation, to account for censoring. As a secondary analysis, the correlation was evaluated according to adjuvant chemotherapy regimen. In sensitivity analysis, the pairwise correlation between RFS and OS was calculated. Results A total of 2385 patients with colorectal liver metastases were included. In the primary analysis, there was a moderately strong correlation between RFS and OS (rho = 0.73, 95 per cent c.i. 0.70 to 0.76). The strength of the correlation was similar regardless of the adjuvant treatment regimen (oxaliplatin plus 5-fluorouracil: rho = 0.72, 0.67 to 0.77; 5-fluorouracil alone: rho = 0.72, 0.66 to 0.76; observation: rho = 0.74, 0.69 to 0.78). The mean(s.d.) pairwise correlation coefficient between 3-year RFS and 5-year OS was 0.87(0.06). Conclusion In surgically treated patients with colorectal liver metastases, there was a moderately strong correlation between RFS and OS, which was unaffected by the treatment regimen. Further validation using a trial-level analysis is required. Correlation between recurrence-free survival (RFS) and overall survival (OS) was assessed using Japanese nationwide data from patients who underwent surgical resection of colorectal liver metastases. Rank correlation with iterative multiple imputation showed a moderately strong correlation between RFS and OS. The pairwise correlation coefficient between 3-year RFS and 5-year OS was high.

Automated summary

This study compared the correlation between recurrence-free survival (RFS) and overall survival (OS) in patients who underwent surgery for colorectal liver metastases. The results showed a strong correlation between RFS and OS, regardless of the adjuvant chemotherapy regimen used.