European Journal of Surgical Oncology 2000; 26: 329–337 doi:10.1053/ejso.1999.0894, available online at http://www.idealibrary.com on Colorectal cancer follow-up: perspectives for future studies R. A. Audisio*† and C. Robertson‡ ‡Division of Epidemiology and Biostatistics, European Institute of Oncology, 435, via Ripamonti, 20141 Milan, Italy, *Department of General Surgery, Whiston Hospital, Prescot, UK This paper reviews some of the issues involved in the planning and execution of studies to assess the effect of different follow-up strategies for colorectal 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 follow-up strategies, at present, within the different Dukes’ stages, extremely large trials are required and none of the previous studies have satisfied this criterion, though recently planned studies will, if recruitment targets are met. The large number of patients required, the length of time the study 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 trial. 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 have enormous benefits and implications if it is managed and completed successfully.  2000 Harcourt Publishers Ltd Key words: Colorectal cancer; randomized controlled trials; follow-up; clinical studies. Introduction group the estimated annual incidence rate of colon cancer is 167 per 100 000 for males and 143 per 100 000 for females. 37 Colorectal cancer treatment and follow-up are major issues Evidence Based Medicine stresses systematic clinical experience and pathophysiological rationale as the best in health care everywhere. Not only are there a large number of patients, but some grounds for clinical decision making. 1 Thus, clinical researchers have an interest in finding the best way to of the follow-up techniques are expensive. The enormous costs of follow-up have been clearly estimated. 23,29,37,40 Health follow-up radically resected colorectal cancer patients. There are numerous published studies, 2–39 but the results are not authorities do not work in a climate of unlimited resources, and it is debatable whether a follow-up strategy which has consistent. To date there have been few prospective randomized trials of different follow-up schedules 15–19 and not been shown to be (cost-)effective should continue to be used when limited resources could be diverted to other there is little evidence to support intensive follow-up with the available methods. patients. This emphasizes the need for clinical practice to be based on objective data, rather than on personal or local The epidemiological burden underlines the relevance of the question—is extensive follow-up necessary for patients or institutional policies. In addition to survival, the psychological impact of the with colorectal cancer? Currently 137 000 new cases affect European Community (EC) members every year, and it is follow-up, and the related quality of life, must be monitored, in keeping with the World Health Organization (WHO) one of the leading causes of cancer mortality worldwide. Its incidence is slowly increasing and the mortality rate has definition of health, namely ‘the presence of physical, mental and social well-being and not merely the absence of disease minimally decreased. Approximately 125 000 EC members/ year are candidates for surgical cure of colorectal cancer, and infirmity’. 41 One might argue that extensive and invasive follow-up may have a detrimental effect on the quality of but only 70 000 of these will survive a full 5 year period after life of the patient after curative surgery. Alternatively, the surgery without recurrence or second primaries. Colorectal absence of any follow-up may also have a detrimental cancer is most prevalent in the elderly population. When effect on quality of life as patients appreciate continued subjects over 65 year old are considered, the estimated reassurance. It is not sufficient to address survival issues annual incidence rate of rectal cancer is 95 per 100 000 for alone, but quality of life issues need to be addressed also. males and 53 per 100 000 for females in the EC. In this age Present and future tests and examinations Correspondence to: Mr Riccardo A. Audisio, Consultant A large number of laboratory tests, markers and radiological Surgeon-Surgical Oncologist, Whiston Hospital, Prescot, Merseyside, L35 5DA, UK. E-mail: raudisio@doctors.org.uk and endoscopic investigations can be employed. Currently 0748–7983/00/040329+09 $35.00/0  2000 Harcourt Publishers Ltd