Colorectal cancer, also referred to as bowel cancer, is the third most common cancer in males and the second most common in females worldwide.1 The most prominent non-modifiable risk factor is age, with over 90% of cases being diagnosed in people over 50 years of age.2 Another established non-modifiable risk is adult-attained height[a].3
A personal or family history of colorectal cancer, polyps and specific inherited genetic conditions and a personal history of inflammatory bowel disease increase bowel cancer risk.2, 4 Processed meat, and to a lesser extent red meat, consumption increases risk of bowel cancer as well as alcohol and tobacco consumption. 3, 5-8 Obesity also increases risk whereas physical activity decreases risk.3 Occupational exposure to asbestos and X- and γ-radiation also increase risk.9, 10
Early-stage colorectal cancer typically has no symptoms, therefore screening is currently the only method for early diagnosis.2 The Australian screening program started in 2006 and the target age groups are being expanded to provide access for all people aged 50-74 to biennial screening by 2019-20.11-13
Our analysis showed a small overall increase in bowel cancer incidence (2%). In contrast, there was a statistically significant decline of 47% in mortality. Reduced mortality is probably due to improved treatment technology and better adherence to national management and treatment guidelines.14-17 The greatest future reductions in bowel cancer mortality across the whole population are expected to be gained from screening.18 Attaining sufficient coverage of screening is, however, an ongoing challenge in countries that have tried to implement such programs.
Colorectal cancer deaths and incident cases in Australia 1987–2007
|Deaths+||Incident Cases +
|Observed in 2007 (O)#||1,197||791||1,988||5,121||3,653||8,774|
|Expected in 2007 (E) §||2,205||1,580||3,785||4,921||3,680||8,600|
|Change in (O-E)/E (%)||-47||-50||-47||4||-1||2|
#An average of the observed rates for 2006 to 2008 was applied to the 2007 population of Australians aged 74 and under to calculate the observed number of deaths and incident cases for 2007.
§An average of the observed rates for 1986 to 1988 was applied to the 2007 population of Australians aged 74 and under to calculate the expected number of deaths and incident cases for 2007.
+All figures have been rounded to the nearest whole number.
[a] This refers to how tall a person becomes as an adult, largely determined by genetics and environment factors in early life. When indicated as a risk factor, adult-attained height suggests that taller adults have higher risk.
- Ferlay J, Shin H, Bray F, Forman D, Mathers C, Parkin D. GLOBOCAN 2008 v2.0, Cancer incidence and mortality worldwide: IARC CancerBase No. 10: Lyon, France: IARC, 2010.
- American Cancer Society. Cancer facts & figures 2012. Atlanta: American Cancer Society; 2012
- World Cancer Research Fund / American Institute for Cancer Research. Continuous Update Project Report. Food, Nutrition, Physical Activity, and the Prevention of Colorectal Cancer. Washington, DC: American Institute for Cancer Research; 2011
- van Wezel T, Middeldorp A, Wijnen JT, Morreau H. A review of the genetic background and tumour profiling in familial colorectal cancer. Mutagenesis. 2012;27 (2):239-45.
- Gong J, Hutter C, Baron JA, Berndt S, Caan B, Campbell PT, Casey G, Chan AT, Cotterchio M, Fuchs CS, Gallinger S, Giovannucci E, et al. A pooled analysis of smoking and colorectal cancer: timing of exposure and interactions with environmental factors. Cancer Epidemiol Biomarkers Prev. 2012;21 (11):1974-85.
- Tsoi KK, Pau CY, Wu WK, Chan FK, Griffiths S, Sung JJ. Cigarette smoking and the risk of colorectal cancer: a meta-analysis of prospective cohort studies. Clin Gastroenterol Hepatol. 2009;7 (6):682-8.
- Zhao J, Halfyard B, Roebothan B, West R, Buehler S, Sun Z, Squires J, McLaughlin JR, Parfrey PS, Wang PP. Tobacco smoking and colorectal cancer: a population-based case-control study in Newfoundland and Labrador. Can J Public Health. 2010;101 (4):281-9.
- IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. IARC Monographs: Personal habits and indoor combustions. Volume 100E A review of human carcinogens. Lyon: IARC; 2012
- IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. IARC Monographs: Arsenic, Metals, Fibres and Dusts. Volume 100C A review of human carcinogens. Lyon: IARC; 2012
- IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. IARC Monographs: Radiation. Volume 100D A review of human carcinogens. Lyon: IARC; 2012
- Australian Government Department of Health and Ageing. National Bowel Cancer Screening Program: About the Program. Canberra: Australian Government Department of Health and Ageing; 2012 [updated June 14; cited 2012 November 5]; Available from: http://www.cancerscreening.gov.au/internet/screening/publishing.nsf/Content/bowel-about.
- Pignone MP, Flitcroft KL, Howard K, Trevena LJ, Salkeld GP, St John DJ. Costs and cost-effectiveness of full implementation of a biennial faecal occult blood test screening program for bowel cancer in Australia. Med J Aust. 2011;194 (4):180-5.
- Australian Government. Budget 2014-15: Health. Canberra: Commonwealth of Australia; 2014 [updated August 26; cited 2014 August 26]; Available from: http://www.budget.gov.au/2014-15/content/bp2/html/bp2_expense-14.htm.
- Australian Cancer Network Colorectal Cancer Guidelines Revision Committee. Guidelines for the Prevention, Early Detection and Management of Colorectal Cancer. Sydney: The Cancer Council Australia and Australian Cancer Network; 2005
- Clinical Oncological Society of Australia and Australian Cancer Network. The prevention, early detection and management of colorectal cancer. Canberra: Commonwealth of Australia; 1999
- Jeffery GM, Hickey BE, Hider P. Follow-up strategies for patients treated for non-metastatic colorectal cancer. Cochrane Database Syst Rev. 2002 (1):CD002200.
- Renehan AG, Egger M, Saunders MP, O’Dwyer ST. Impact on survival of intensive follow up after curative resection for colorectal cancer: systematic review and meta-analysis of randomised trials. BMJ. 2002;324 (7341):813.
- Olver I, Grogan P. Early success for Australia’s bowel screening program: let’s move it along. Med J Aust. 2013;198 (6):300-1.