Impact on survival of intensive follow up after curative resection for colorectal cancer: systematic review and meta-analysis of randomised trials

Objective To review die evidence from clinical trials of follow up of patients after curative resection for colorectal cancer. Design Systematic review and meta-analysis of randomised controlled trials of intensive compared with control follow up. Main outcome measures All cause mortality at five years (primary outcome). Rates of recurrence of intraluminal, local, and metastatic disease and metachronous (second colorectal primary) cancers (secondary outcomes). Results Five trials, which included 1342 patients, met the inclusion criteria. Intensive follow up was associated with a reduction in all cause mortality (combined risk ratio 0.81, 95% confidence interval 0.70 to 0.94, P=0.007). The effect was most pronounced in the four extramural detection trials that used computed tomography and frequent measurements of serum carcinoembryonic antigen (risk ratio 0.73, 0.60 to 0.89, P=0.002). Intensive follow up was associated with significantly earlier detection of all recurrences (difference in means 8.5 months, 7.6 to 9.4 months, P < 0.001) and an increased detection rate for isolated local recurrences (risk ratio 1.61, 1.12 to 2.32, P=0.011). Conclusions Intensive follow up after curative resection for colorectal cancer improves survival. Large trials are required to identify which components of intensive follow up are most beneficial.