Follow-up of colorectal cancer: a meta-analysis.

PURPOSE: The value of intensive follow-up for patients after resection of colorectal cancer remains controversial. This study reviews all randomized and prospective cohort studies to assess the value of aggressive follow-up.
METHODS: The literature was searched from the years 1972 to 1996 for studies reporting on the follow-up of patients with colorectal cancer. Randomized and comparative-cohort studies that included history, physical examination, and carcinoembrionic antigen values at least three times a year for at least two years were included in a meta-analysis. Single-cohort studies with intensive follow-up and traditional follow-up were also included in a two-group comparative analysis for each outcome indicator. Outcome indicators were 1) curative resection rates after recurrent cancer, 2) survival rates of curative re-resections, 3) length of survival after recurrence, and 4) cumulative five-year survival.
RESULTS: Two randomized and three comparative-cohort studies met these criteria and included 2,005 patients, which were evaluated in the meta-analysis. The cumulative five-year survival was 1.16 times higher in the intensively followed group (P = 0.003). Two and one-half times more curative re-resections were performed for recurrent cancer in those patients undergoing intensive follow-up (P = 0.0001). Those patients in the intensive follow-up group with a recurrence had a 3.62-times higher survival rate than the control (P = 0.0004). Fourteen single-cohort studies were also included in the comparative analysis of 6,641 patients. The findings from these aggregated studies support the results of the meta-analysis.
CONCLUSION: Our study concludes that intensive follow-up detects more recurrent cancers at a stage amenable to curative resection, resulting in an improvement in survival of recurrences and an increased overall five-year cumulative rate of survival.