Colorectal cancer follow-up: a reassessment of empirical evidence on effectiveness

Colorectal cancer is an important cause of death in the Western world, with a propensity of cancer recurrence even after resection with curative inten t. Active follow-up has been advocated as a means to detect cancer recurren ce at an earlier stage and thereby improve the survival of colorectal cance r patients. The present study assesses published evidence on the effectiven ess of follow-up. Articles were obtained from a 20-year Medline search and from cross-referen ces between articles. Articles were included, scored for quality, and extra cted by explicit criteria. Regression analysis and chi-squared analysis was performed to assess (1) whether detection of recurrence at earlier asympto matic disease stage leads to better post-treatment prognosis, and (2) wheth er active follow-up does improve overall (quality adjusted) survival, as co mpared to symptom-guided care only. The relationship between disease stage of recurrence (symptoms, number and size) and survival was analysed from 42 articles, 10 of which provided adeq uate data. Absence of symptoms and small number of recurrence were signific antly related to better survival, smaller size insignificantly so. The pote ntial of active follow-up seemed related to a marginally better outcome, la rger gains being found in lower quality studies. Available data do suggest that survival gains vary between 0.5 and 2%, 1% seeming to be a best estima te of overall survival gain. Neither the notion that earlier detection of r ecurrences does significantly improve outcome, nor the hope that active fol low-up provides a statistically and clinically significant gain in (quality adjusted) survival, are so far supported by adequate evidence. Colorectal cancer follow-up still fails to meet the criteria for evidence based medici ne. (C) 2000 Harcourt Publishers Ltd.