Colorectal cancer follow-up: perspectives for future studies

This paper reviews some of the issues involved in the planning and executio n of studies to assess the effect of different follow-up strategies for col orectal cancer patients. Mathematical models and many previous studies have failed to indicate strong support for the hypothesis that extensive follow -up leads to an increase in survival rates. In order to assess the best fol low-up strategies, at present, within the different Dukes' stages, extremel y large trials are required and none of the previous studies have satisfied this criterion, though recently planned studies will, if recruitment targe ts are met. The large number of patients required, the length of time the s tudy must run, existing accepted follow-up practices in different countries , and the difficulty of managing patients on different follow-up strategies within the same centre all pose problems for the design of a randomized tr ial. These are not insurmountable, but do contribute to a possible downfall of a large multicentre randomized trial of follow-up strategies. Although such a trial will require considerable international cooperation it will ha ve enormous benefits and implications if it is managed and completed succes sfully. (C) 2000 Harcourt Publishers Ltd.