Correlation of progression-free and post-progression survival with overall survival in advanced colorectal cancer
Annals of Oncology, 08/21/2012
Petrelli F et al. – Our findings indicate that in recent first-line, phase III, trials, OS becomes more associated with PPS than PFS. However, improvements in PFS are strongly associated with improvements in OS. In this setting so, PFS may be an appropriate surrogate for OS.
Methods- A PubMed search identified 34 randomized trials.
- The median PPS and PFS were 10.75 and 8.4 months, respectively.
- For all trials, PPS was strongly associated with OS [regression coefficient (R2) = 0.8; Spearman's rank correlation coefficient (r) = 0.88], whereas PFS was moderately associated with OS (R2 = 0.43; r = 0.64).
- In trials with targeted therapies, the correlation of PPS with OS was 0.88.
- However, across all trials, correlation between differences in median PFS (change in PFS) and median OS (change in OS) is 0.59 (P = 0.0007), confirming PFS/OS surrogacy.
