Colorectal cancer: key points

• In Scotland, after non-melanoma skin cancer, lung cancer, and prostate cancer, colorectal cancer is the fourth most commonly diagnosed cancer in men, and the fourth most common in women after non-melanoma skin cancer, breast cancer, and lung cancer.  It is the second most common cause of death from cancer in men after lung cancer, and the third most common in women after lung and breast cancer.
• Currently, around 1890 men and 1590 women are diagnosed with colorectal cancer in Scotland every year.
• Excluding non-melanoma skin cancer, colorectal cancer accounts for just over 14% of all cancers diagnosed in men, and just over 11% of all cancers diagnosed in women.
• Based on current rates of disease, an estimated 1 in 16 men, and 1 in 20 women develop colorectal cancer during their lifetime.
• Between 1994 and 2004, the age-standardised incidence rate of colorectal cancer decreased by an estimated 0.5% in men, and 9.6% in women.  Between 1995 and 2005, the age-standardised mortality rate of colorectal cancer decreased by an estimated 14.1% in men, and 24.5% in women. 
• The incidence of colorectal cancer is higher in Scotland than England.  The incidence rates for Scotland fall within the mid-upper range of rates for other countries that have data available for comparison. 
• The main risk factors for colorectal cancer are genetic factors, dietary factors (vegetables and fibre are probably protective, red meat may increase risk), obesity, lack of physical activity, and (probably) long-term smoking.
• Randomized controlled trials carried out in Minnesota, USA, Funen, Denmark, and Nottingham, UK have shown that it is possible to reduce mortality from colorectal cancer by screening based on faecal occult blood testing (FOBT). Pilot studies carried out in Grampian, Tayside, and Fife, and in parts of West Midlands have demonstrated that screening with FOBT is feasible in the UK, and that it should reduce deaths from colorectal cancer.  It is anticipated that the Scottish Bowel Screening Programme will rollout to the rest of Scotland from 2007 onwards.
• Survival from colorectal cancer has increased substantially over the last 30 years. For both men and women, the relative survival at five years increased from around 32% for patients diagnosed during 1977-81 to over 50% for those diagnosed during 1997-2001.
• There are no substantial differences in incidence of or mortality from colorectal cancer between socioeconomic categories, but survival is significantly lower among people living in areas of socioeconomic deprivation.
• Although there is no recent evidence of any health boards in Scotland having worse survival from colorectal cancer than the average for Scotland, previous audits and international comparisons have suggested possible scope for improving outcomes from colorectal cancer in Scotland.
  

Key statistics:

	Males	Females
Number of cases diagnosed in 2004	1,892	1,595
Prevalence at 31st Dec 2003 (cases / 100,000 pop) (1)	380	347
Number of deaths in 2005	855	695
% surviving 5 years after diagnosis (2)	51.2%	50.6%
Lifetime risk of developing colorectal cancer (from birth)	5.5%	4.5%
Lifetime risk of developing colorectal cancer (from age 54)	5.6%	4.4%

Notes:
(1) Number of colorectal cancer survivors at 31 Dec 2003 who had been diagnosed in the previous 20 years per 100,000  population.
(2) Five year relative survival for patients diagnosed during the period 1997-2001 (not standardised).