1.1 Background

Scotland has one of the highest incidences of colorectal cancer in the world (41 per 100,000 in men, 29 per 100,000 in women),¹ and, as with many Western countries, the disease represents the second most common cause of cancer death.² Between 1989 and 1998 there was an increase in incidence in men (21.2%) and a slight increase in women (1.5% during the same period).³ The causes for this are unclear, although there is evidence that excess weight may increase risk, whereas a diet with high levels of vegetable intake may be protective, as is exercise. Long term smoking is emerging as a possible risk factor. Interestingly, despite the increased incidence, age-standardised mortality from colorectal cancer has decreased over the last 20 years,³ indicating an improvement in prognosis. Again, the reasons underlying this observation are not known, but improvements in disease management may have played a role.

1.2 The need for a guideline

The first SIGN colorectal cancer guideline was published in 1996, and was prompted by the poor survival from colorectal cancer in Scotland relative to the United States of America (USA) and parts of Europe.^{4, 5} More recent comparative data indicate that survival in Scotland continues to rank below average in Europe, although at least part of this may be accounted for by variations in data quality.⁶ There is little doubt that delivery of certain aspects of colorectal cancer care varies between health boards throughout Scotland, and the evidence relating to the optimal management of this condition has changed substantially over the last five years.¹ This, coupled with the remit of NHS Quality Improvement Scotland (QIS) which includes the former Clinical Standards Board for Scotland (CSBS) to review standards of colorectal cancer care across the country, has made it imperative to completely rewrite the guideline employing the latest SIGN methodology.

1.3 Remit of the guideline

As with the previous guideline, the main aims are as follows:

• to encourage measures to reduce the risk of developing colorectal cancer in the general population and in high risk groups
• to encourage early diagnosis in the general population and in high risk groups
• to improve the consistency of referral patterns
• to improve all aspects of the management of colorectal cancer patients in order to improve overall and disease-free survival and health-related quality of life.

1.4 Target users of the guideline

It is recognised that the effective management of colorectal cancer requires a multidisciplinary approach. It follows that any unit treating this disease must form an appropriate core multidisciplinary team (MDT) consisting of surgeon(s), oncologist(s), pathologist(s), radiologist(s) and nurse(s). In addition this team should interact with a wider team including gastroenterologists, palliative care specialists and general practitioners (GPs). This guideline will be of interest to all of these professionals, as well as to patients, managers and policy makers.

1.5 Statement of intent

This guideline is not intended to be construed or to serve as a standard of medical care. Standards of care are determined on the basis of all clinical data available for an individual case and are subject to change as scientific knowledge and technology advance and patterns of care evolve. These parameters of practice should be considered guidelines only. Adherence to them will not ensure a successful outcome in every case, nor should they be construed as including all proper methods of care or excluding other acceptable methods of care aimed at the same results.

The ultimate judgement regarding a particular clinical procedure or treatment plan must be made by the doctor, following discussion of the options with the patient, in light of the diagnostic and treatment choices available. However, it is advised that significant departures from the national guideline or any local guidelines derived from it should be fully documented in the patient’s case notes at the time the relevant decision is taken.

1.6 Review and updating

This guideline was issued in 2003 and will be reviewed periodically as required to reflect new evidence. All updates to the guideline will be noted on the SIGN website: www.sign.ac.uk