Bowel cancer risk

The estimated lifetime risk of being diagnosed with bowel cancer is 1 in 20 (5%) for females, and 1 in 17 (6%) for males born in 1961 in the UK. [1]

These figures take account of the possibility that someone can have more than one diagnosis of bowel cancer in their lifetime ('Adjusted for Multiple Primaries' (AMP) method).[2]

See also

Lifetime risk for all cancers combined and cancers compared

Bowel cancer incidence statistics

How risk is calculated

Want to generate bespoke preventable cancers stats statements? Download our interactive statement generator.

References

1. Lifetime risk estimates calculated by the Cancer Intelligence Team at Cancer Research UK 2023.
2. Sasieni PD, Shelton J, Ormiston-Smith N, et al. What is the lifetime risk of developing cancer?: The effect of adjusting for multiple primaries. Br J Cancer, 2011.105(3): p.460-5

About this data

Data is for UK, past and projected cancer incidence and mortality and all-cause mortality rates for those born in 1961, ICD-10 C00-C14, C30-C32.

Calculated by the Cancer Intelligence Team at Cancer Research UK, 2023 (as yet unpublished). Lifetime risk of being diagnosed with cancer for people in the UK born in 1961. Based on method from Ahmad et al. 2015, using projected cancer incidence (using data up to 2018) calculated by the Cancer Intelligence Team at Cancer Research UK and projected all-cause mortality (using data up to 2020, with adjustment for COVID impact) calculated by Office for National Statistics. Differences from previous analyses are attributable mainly to slowing pace of improvement in life expectancy, and also to slowing/stabilising increases in cancer incidence.

Last reviewed: 14 December 2023

54% of bowel cancer cases in the UK are preventable.[1]

See also

Want to generate bespoke preventable cancers stats statements? Download our interactive statement generator.

Find out more about the definitions and evidence for this data

Learn how attributable risk is calculated

References

1. Brown KF, Rumgay H, Dunlop C, et al. The fraction of cancer attributable to known risk factors in England, Wales, Scotland, Northern Ireland, and the UK overall in 2015(link is external). British Journal of Cancer 2018. 

Last reviewed: 14 June 2018

International Agency for Research on Cancer (IARC) and World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) classify the role of this risk factor in cancer development.[1,2] 13% of bowel cancer cases in the UK are caused by eating processed meat.[3]

Colon cancer risk is 22% higher per 100/day of red meat intake, a meta-analysis of cohort studies has shown.[4] Rectal cancer risk was not associated with red meat consumption.[4]

Bowel cancer risk is 18% higher per 50g/day of processed meat intake, a meta-analysis of cohort studies has shown.[4] Colon cancer risk is 23% higher per 50g/day of processed meat intake while rectal cancer risk may be 8% higher but this is only marginally significant, a meta-analysis of cohort studies has shown.[4] Colon cancer risk is 12% higher per 1mg/day of haem iron intake, a meta-analysis showed;[5] though bowel cancer risk was not associated with dietary iron intake in a pooled analysis of UK cohort studies.[6]

Serrated bowel polyp risk is 23% higher in people with the highest versus lowest levels of red meat intake, a meta-analysis showed.[7]

See also

Find out more about the definitions and evidence for this data

Learn how attributable risk is calculated

National Diet and Nutrition Survey

View our health information on diet and cancer

References

1. International Agency for Research on Cancer. List of Classifications by cancer sites with sufficient or limited evidence in humans, Volumes 1 to 119*. Accessed September 2017. 
2. World Cancer Research Fund / American Institute for Cancer Research. Continuous Update Project Findings & Reports. Accessed September 2017.
3. Brown KF, Rumgay H, Dunlop C, et al. The fraction of cancer attributable to known risk factors in England, Wales, Scotland, Northern Ireland, and the UK overall in 2015. British Journal of Cancer. Annals of Oncology, Volume 28, Issue 8, August 2017, Pages 1788-1802.
4. Vieira A, Abar L, Chan D, et al. Foods and beverages and colorectal cancer risk: a systematic review and meta-analysis of cohort studies, an update of the evidence of the WCRF-AICR Continuous Update Project. Annals of Oncology 2017;28(8):1788-1802.
5. Fonseca-Nunes A, Jakszyn P, Agudo A. Iron and Cancer Risk - A systematic review and meta-analysis of the epidemiological evidence. Cancer Epidemiol Biomarkers Prev. 2013 Nov 15. 
6. Key TJ, Appleby PN, Masset G, et al. Vitamins, minerals, essential fatty acids and colorectal cancer risk in the United Kingdom dietary cohort consortium. Int J Cancer 2011.
7. Bailie L, Loughrey MB, Coleman HG. Lifestyle Risk Factors for Serrated Colorectal Polyps: A Systematic Review and Meta-analysis.

Last reviewed: 16 April 2019

International Agency for Research on Cancer (IARC) and World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) classify the role of this risk factor in cancer development.[1,2] 11% of bowel cancer cases in the UK are caused by overweight and obesity.[3]

Body-mass index (BMI)

Colon cancer risk is 30% higher in men per 5-unit body mass index (BMI) increase, an umbrella study of meta-analyses showed.[4] Colon cancer risk is 12% higher in women per 5-unit body mass index (BMI) increase, an umbrella study of meta-analyses showed.[4]  the association in obese women may be stronger in premenopausal than postmenopausal women.[5]

Rectal cancer risk is 9% higher in men per 5-unit body mass index (BMI) increase, an umbrella study of meta-analyses showed.[4] There is no association between BMI and rectal cancer in women.[4]

Bowel cancer risk among men is 10% higher per 5 kg gained during adulthood, a meta-analysis showed.[6] Bowel cancer risk among women is not associated with weight gain during adulthood.[6]

Bowel adenoma risk is 47% higher in people who are obese by BMI compared with those who are healthy-weight, a meta-analysis showed.[7]

Waist circumference

Colon cancer risk is 25% higher in people per 10cm increase in waist circumference, an umbrella study of meta-analyses showed.[4]

Bowel cancer risk is 46% higher in people with the largest waist circumference, versus those with the smallest, a meta-analysis showed.[8]

Bowel adenoma risk is 39% higher in people with the largest waist circumference, versus those with the smallest, a meta-analysis showed.[9]

See also

Find out more about the definitions and evidence for this data

Learn how attributable risk is calculated

View our statistics on obesity and cancer

View our health information on obesity, weight and cancer

References

1. Lauby-Secretan B, Scoccianti C, Loomis D, et al. Body Fatness and Cancer--Viewpoint of the IARC Working Group. N Engl J Med. 2016 Aug 25;375(8):794-8.
2. World Cancer Research Fund / American Institute for Cancer Research. Continuous Update Project Findings & Reports. Accessed September 2017.
3. Brown KF, Rumgay H, Dunlop C, et al. The fraction of cancer attributable to known risk factors in England, Wales, Scotland, Northern Ireland, and the UK overall in 2015. British Journal of Cancer.
4. Kyrgiou M, Kalliala I, Markozannes G, et al. Adiposity and cancer at major anatomical sites: umbrella review of the literature. BMJ 2017;:j477.
5. Ning Y, Wang L, Giovannucci EL. A quantitative analysis of body mass index and colorectal cancer: findings from 56 observational studies. Obes Rev. 2010 Jan: 11(1):19-30.
6. Chen Q, Wang J, Yang J et al. Association between adult weight gain and colorectal cancer: A dose-response meta-analysis of observational studies.Int J Cancer. 2014 Nov 14.
7. Omata F, Deshpande GA, Ohde S, et al. The association between obesity and colorectal adenoma: systematic review and meta-analysis. Scand J Gastroenterol. 2013 Feb;48(2):136-46.
8. Ma Y, Yang Y, Wang F, et al. Obesity and risk of colorectal cancer: a systematic review of prospective studies. PLoS One. 2013;8(1):e53916.
9. Hong S, Cai Q, Chen D, et al. Abdominal obesity and the risk of colorectal adenoma: a meta-analysis of observational studies. Eur J Cancer Prev. 2012 Nov;21(6):523-31.

Last reviewed: 20 January 2020

International Agency for Research on Cancer (IARC) and World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) classify the role of this risk factor in cancer development.[1,2] 6% of bowel cancer cases in the UK are caused by alcohol drinking.[3]

Bowel cancer risk is 4% higher in people who consume up to 15g (2 units) of alcohol per day, 10-17% higher in people who consume 12-50g (1.5-6 units) of alcohol per day, and 33% higher in those who consume 50g+ (6+ units) of alcohol per day, compared with non or occasional drinkers, meta-analyses have shown.[4,5] Bowel cancer risk increases by 7% per unit of alcohol consumed per day.[6]

Bowel cancer risk is 49% higher in people who consume the highest intake of alcohol during their lifetime/over time compared to those who consume the lowest intake of alcohol, a meta-analysis showed.[7]

Bowel adenoma risk is 27% higher in people who drink around 3 units per day, a meta-analysis showed; the association is limited to colon adenoma, not rectal.[8]

See also

Learn how attributable risk is calculated

View our statistics on alcohol and cancer

View our health information on alcohol and cancer

References

1. International Agency for Research on Cancer. List of Classifications by cancer sites with sufficient or limited evidence in humans, Volumes 1 to 119*. Accessed September 2017.
2. World Cancer Research Fund / American Institute for Cancer Research. Continuous Update Project Findings & Reports. Accessed September 2017.
3.  Brown KF, Rumgay H, Dunlop C, et al. The fraction of cancer attributable to known risk factors in England, Wales, Scotland, Northern Ireland, and the UK overall in 2015. British Journal of Cancer 2018.
4. Bagnardi V, Rota M, Botteri E, et al. Alcohol consumption and site-specific cancer risk: a comprehensive dose-response meta-analysis. Br J Cancer. 2015 Feb 3;112(3):580-93.
5. Yoon-Jung Choi, Seung-Kwon Myung, Ji-Ho Lee. Light Alcohol Drinking and Risk of Cancer: A Meta-Analysis of Cohort Studies. Cancer Research and Treatment : Official Journal of Korean Cancer Association 2018; 50(2): 474-487.
6. Fedirko V, Tramacere I, Bagnardi V, et al. Alcohol drinking and colorectal cancer risk: an overall and dose-response meta-analysis of published studies. Ann Oncol 2011;22(9):1958-72.
7. Harindra Jayasekara, Robert J. MacInnis, Robin Room. Long-Term Alcohol Consumption and Breast, Upper Aero-Digestive Tract and Colorectal Cancer Risk: A Systematic Review and Meta-Analysis. Alcohol and Alcoholism, Volume 51, Issue 3, 1 May 2016, Pages 315–330.
8. Ben Q, Wang L, Liu J et al. Alcohol drinking and the risk of colorectal adenoma: a dose-response meta-analysis. Eur J Cancer Prev. 2015 Jul;24(4):286-95.

Last reviewed: 1 October 2018

International Agency for Research on Cancer (IARC) classifies the role of this risk factor in cancer development.[1] 7% of bowel cancer cases in the UK are caused by smoking.[2]

Bowel cancer risk is 17-21% higher in current cigarette smokers compared with never-smokers, meta-analyses of cohort studies have shown.[3-5] The association may be stronger in males than females, and stronger for rectal than colon cancer.[3-6]

Bowel cancer risk increases with the number of cigarettes smoked per day, by 7-11% per 10 cigarettes per day, a meta-analysis has shown.[4] Bowel cancer risk is higher in people who start smoking younger.[5] 

Adenomatous bowel polyp risk is around twice as high in current smokers compared with never-smokers, a meta-analysis showed.[7]

Serrated bowel polyp risk is more than twice as high in current smokers compared with never- and ex-smokers, a meta-analysis showed.[8]

See also

Learn how attributable risk is calculated

View our statistics on tobacco and cancer

View our health information on smoking and cancer

References

1.  International Agency for Research on Cancer. List of Classifications by cancer sites with sufficient or limited evidence in humans, Volumes 1 to 119*. Accessed September 2017.
2. Brown KF, Rumgay H, Dunlop C, et al. The fraction of cancer attributable to known risk factors in England, Wales, Scotland, Northern Ireland, and the UK overall in 2015. British Journal of Cancer 2018. 
3. Huxley RR, Ansary-Moghaddam A, Clifton P, et al. The impact of dietary and lifestyle risk factors on risk of colorectal cancer: a quantitative overview of the epidemiological evidence. Int J Cancer 2009;125(1):171-80. 
4. Tsoi KK, Pau CY, Wu WK, et al. Cigarette smoking and the risk of colorectal cancer: a meta-analysis of prospective cohort studies. Clin Gastroenterol Hepatol 2009;7(6):682-88 e1-5. 
5. Liang PS, Chen TY, Giovannucci E. Cigarette smoking and colorectal cancer incidence and mortality: systematic review and meta-analysis. Int J Cancer 2009;124(10):2406-15.
6. Cheng J, Chen Y, Wang X, et al. Meta-analysis of prospective cohort studies of cigarette smoking and the incidence of colon and rectal cancers. Eur J Cancer Prev. 2014.
7. Botteri E, Iodice S, Raimondi S, et al. Cigarette smoking and adenomatous polyps: a meta-analysis. Gastroenterology 2008;134(2):388-95.
8. Bailie L, Loughrey MB, Coleman HG. Lifestyle Risk Factors for Serrated Colorectal Polyps: A Systematic Review and Meta-analysis. Gastroenterology. 2017 Jan;152(1):92-104.

Last reviewed: 1 October 2018

Diabetes

Bowel cancer risk is 22-30% higher in people with type II diabetes, compared with non-diabetics, meta-analyses show.[1-5] 

Bowel cancer risk among diabetics may vary by treatment type, though treatment type often relates to diabetes stage, which may further confound findings. Bowel cancer risk is lower in metformin users compared with non-users, meta-analyses have shown;[6-8] however this may be for women only.[9] Bowel cancer risk is not associated with insulin use compared with non-use, meta-analyses of cohort studies have shown.[10,11]

Inflammatory bowel disease

Bowel cancer risk is 70% higher in people with inflammatory bowel disease (IBD) (ulcerative or Crohn's colitis) compared with the general population, a meta-analysis showed.[12] Bowel cancer risk increases with extent and duration of IBD; patients who have IBD for 20 years or more have a 5% risk of developing bowel cancer.[12,13] Bowel cancer risk may vary by location of IBD lesions.[14]

Adenomas

Around 1% of people with larger (20mm+) adenomas, or adenomas with high-grade dysplasia, develop bowel cancer within around 4 years of having their adenomas removed, a pooled analysis showed.[15] Risk of advanced bowel cancer is 80% higher in people with low-risk polyps detected at first colonoscopy, compared with people with no polyps detected at first colonoscopy, a meta-analysis showed.[16]

Aspirin

Bowel cancer risk is 17% lower in people who have ever used aspirin, compared with non-users, a meta-analysis of cohort studies showed.[17] The longer the duration of use, the lower the risk.[17]

See also

Find out more about the definitions and evidence for this data

Learn how attributable risk is calculated

References

1. Jiang Y, Ben Q, Shen H, et al. Diabetes mellitus and incidence and mortality of colorectal cancer: a systematic review and meta-analysis of cohort studies. Eur J Epidemiol 2011;26(11):863-76.
2. Kramer HU, Schottker B, Raum E, et al. Type 2 diabetes mellitus and colorectal cancer: Meta-analysis on sex-specific differences. Eur J Cancer 2011.
3. Larsson SC, Orsini N, Wolk A. Diabetes mellitus and risk of colorectal cancer: a meta-analysis. J Natl Cancer Inst 2005;97(22):1679-87.
4. Luo W, Cao Y, Liao C, et al. Diabetes mellitus and the incidence and mortality of colorectal cancer: A meta-analysis of twenty four cohort studies. Colorectal Dis 2011.  
5. Wu L, Yu C, Jiang H, et al. Diabetes mellitus and the occurrence of colorectal cancer: an updated meta-analysis of cohort studies. Diabetes Technol Ther. 2013 May;15(5):419-27.
6. Singh S, Singh H, Singh PP, et al. Antidiabetic Medications and the Risk of Colorectal Cancer in Patients with Diabetes Mellitus: A Systematic Review and Meta-analysis. Cancer Epidemiol Biomarkers Prev. 2013 Nov 12.
7. Gandini S, Puntoni M, Heckman-Stoddard BM et al. Metformin and cancer risk and mortality: a systematic review and meta-analysis taking into account biases and confounders. Cancer Prev Res (Phila). 2014 Sept; 7(9)867-85
8. Rokkas T, Portincasa P. Colon neoplasia in patients with type 2 diabetes on metformin: A meta-analysis. Eur J Intern Med. 2016 Jun 15.
9. Cardel M, Jensen SM, Pottegard A et al. Long-term use of metformin and colorectal cancer risk in type II diabetics: a population-based case-control study. Cancer Med. 2014 Oct;3(5)1458-66.
10. Wang L, Cai S, Teng Z. Insulin therapy contributes to the increased risk of colorectal cancer in diabetes patients: a meta-analysis. Diagn Pathol. 2013 Oct 31;8(1):180.
11. Sun A, Liu R, Sun G. Insulin therapy and risk of colorectal cancer: an updated meta-analysis of epidemiological studies. Curr Med Res Opin. 2013 Nov 6.
12. Lutgens MW, van Oijen MG, van der Heijden GJ, et al. Declining risk of colorectal cancer in inflammatory bowel disease: an updated meta-analysis of population-based cohort studies. Inflamm Bowel Dis. 2013 Mar-Apr;19(4):789-99.
13. Castao-Milla C, Chaparro M, Gisbert JP. Systematic review with meta-analysis: the declining risk of colorectal cancer in ulcerative colitis. Aliment Pharmacol Ther. 2014 Feb 9.
14. Canavan C, Abrams KR, Mayberry J. Meta-analysis: colorectal and small bowel cancer risk in patients with Crohn's disease. Aliment Pharmacol Ther 2006;23(8):1097-104.
15. Martinez ME, Baron JA, Lieberman DA, et al. A pooled analysis of advanced colorectal neoplasia diagnoses after colonoscopic polypectomy.Gastroenterology. 2009;136(3):832-41.
16. Hassan C, Gimeno-Garcia A, Kalager M, et al. Systematic review with meta-analysis: the incidence of advanced neoplasia after polypectomy in patients with and without low-risk adenomas. Aliment Pharmacol Ther. 2014;39(9):905-12.
17. Qiao Y, Yang T, Gan Y, et al. Associations between aspirin use and the risk of cancers: a meta-analysis of observational studies. BMC Cancer 2018;18(1).

Last reviewed: 10 April 2019

Bowel cancer risk is 14-19% lower in ever-users versus never-users of oral contraceptives, meta-analyses have shown.[1,2]

See also

Learn how attributable risk is calculated

View our health information on hormones and cancer

References

1. Bosetti C, Bravi F, Negri E, et al. Oral contraceptives and colorectal cancer risk: a systematic review and meta-analysis. Hum Reprod Update 2009;15(5):489-98.
2. Gierisch JM, Coeytaux RR, Urrutia RP, et al. Oral contraceptive use and risk of breast, cervical, colorectal, and endometrial cancers: a systematic review. Cancer Epidemiol Biomarkers Prev 2013;22(11):1931-43.

Last reviewed: 1 October 201

International Agency for Research on Cancer (IARC) classifies the role of this risk factor in cancer development.[1] 2% of bowel cancer cases in the UK are caused by ionising radiation.[2]

Colon cancer risk is 53% higher in atomic bomb survivors compared with the general population, a cohort study has shown.[3] Rectal cancer is 43% higher in people who have received radiotherapy to the pelvic region for a primary cancer compared to patients who were not irradiated, a meta-analysis showed.[4]

Bowel cancer risk decreases with increasing age at radiation exposure.[4] Less than 1% of people chronically exposed to 0.1Gy radiation in early childhood will develop bowel cancer in their lifetime.[5]

See also

Learn how attributable risk is calculated

References

1. International Agency for Research on Cancer. List of Classifications by cancer sites with sufficient or limited evidence in humans, Volumes 1 to 119. Accessed September 2017.
2. Brown KF, Rumgay H, Dunlop C, et al. The fraction of cancer attributable to known risk factors in England, Wales, Scotland, Northern Ireland, and the UK overall in 2015. British Journal of Cancer.
3. Semmens EO, Kopecky KJ, Grant E et al. Relationship between anthropometric factors, radiation exposure, and colon cancer incidence in the Life Span Study cohort of atomic bomb survivors.Cancer Causes Control. 2013 Jan;24(1):27-37.
4. Rombouts A, Hugen N, van Beek J, et al. Does pelvic radiation increase rectal cancer incidence? A systematic review and meta-analysis. Cancer Treatment Reviews 2018;68:136-144.
5. Berrington de Gonsalez A, Iulian Apostoaei A, Veiga LH et al. RadRAT: a radiation risk assessment tool for lifetime cancer risk projection. J Radiol Prot. 2012 Sept;32(3):205-22

Last reviewed: 10 April 2019

Family history

Around 20% of bowel cancers are associated with hereditary factors other than Familial adenomatous polyposis (FAP) and Hereditary non-polyposis colorectal cancer (HNPCC).[1]

Bowel cancer risk is more than doubled in people with a first-degree relative (parent, sibling, child) with the disease, a meta-analysis showed.[2] Bowel cancer risk among people with a first-degree family history is higher in those with more than one affected relative, or a relative diagnosed at a younger age.[2,3]

Bowel adenoma risk is 70% higher in people with a first-degree relative with bowel cancer, a meta-analysis showed.[4]

Bowel cancer risk is not associated with having an adoptive parent with the disease, a cohort study showed; this may indicate genetic/biological factors rather than environmental factors underpin the familial risk.[5]

Familial adenomatous polyposis (FAP)

Familial adenomatous polyposis (FAP) accounts for less than 1% of bowel cancers.[6] Almost all FAP patients develop bowel cancer by age 40.[7]

Hereditary non-polyposis colorectal cancer (HNPCC)

Hereditary non-polyposis colorectal cancer (HNPCC) accounts for 1-4% of colon cancers.[6] Around 9 in 10 males and 7 in 10 females with HNPCC develop bowel cancer by age 70.[8]

BRCA1

BRCA1 mutations may account for some bowel cancers, particularly in younger women.[9]

See also

Learn how attributable risk is calculated

See more information on how genetics can be a cause of cancer

References

1. Fearnhead NS, Wilding JL, Bodmer WF. Genetics of colorectal cancer: hereditary aspects and overview of colorectal tumorigenesis. Brit Med Bull 2002;64(1):27-43. 
2. Butterworth AS, Higgins JP, Pharoah P. Relative and absolute risk of colorectal cancer for individuals with a family history: a meta-analysis. Eur J Cancer 2006;42(2):216-27.  
3. Johns LE, Houlston RS. A systematic review and meta-analysis of familial colorectal cancer risk. Am J Gastroenterol 2001;96(10):2992-3003. 
4. Wilschut JA, Habbema JD, Ramsey SD, et al. Increased risk of adenomas in individuals with a family history of colorectal cancer: results of a meta-analysis. Cancer Causes Control 2010;21(12):2287-93. 
5. Zoller B, Li X, Sundguist J et al. Familial transmission of prostate, breast and colorectal cancer in adoptees is related to cancer in biological but not in adoptive parents: a nationwide family study.Eur J Cancer. 2014 Sept:50(13):2319-27
6. Gala M, Chung DC. Hereditary colon cancer syndromes(link is external). Semin Oncol 2011;38(4):490-9. 
7. Galiatsatos P, Foulkes WD. Familial adenomatous polyposis. Am J Gastroenterol 2006;101(2):385-98. 
8. Dunlop MG, Farrington SM, Carothers AD, et al. Cancer risk associated with germline DNA mismatch repair gene mutations. Hum Mol Genet 1997;6(1):105-10.
9. Phelan CM, Iqbal J, Lynch HT, et al. Incidence of colorectal cancer in BRCA1 and BRCA2 mutation carriers: results from a follow-up study. Br J Cancer. 2014 Jan 21;110(2):530-4.

Last reviewed: 12 February 2015

World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) classifies the role of this risk factor in cancer development.[1] 5% of bowel cancer cases in the UK are caused by too little physical activity.[2]

Colon cancer risk is 19% lower in individuals with the highest level of total physical activity (recreational, commuting, occupational and household) compared to individuals with the lowest level, an umbrella of systematic reviews showed [3] Colon cancer risk is 11% lower in individuals in the low active group (600-3999 MET minutes/week), 19% lower in the moderately active group (4000-7999 MET minutes/week) and 21% lower in the highly active group (≥8000 MET minutes/week) compared to insufficiently active individuals (≤ 600 MET minutes/week of total physical activity across all domains), a meta-analysis showed.[4]

Rectal cancer risk is 12% lower in people with the highest category of occupational physical activity compared to people in the lowest category, a meta-analysis showed.[5] No effect on rectal cancer risk was seen for recreational physical activity, transport-related physical activity or household-related physical activity, the meta-analysis showed.[5] Rectal cancer risk is 6% higher in the most sedentary people compared with the least, a meta-analysis of cohort studies showed.[6]

Colorectal cancer risk is 17% higher in people with the highest daily TV viewing time, 6% higher in people with the highest daily total sitting time and 15% higher in people with the highest daily occupational sitting time compared to the those in the lowest groups, a meta-analysis showed.[7]

See also

Learn how attributable risk is calculated

See more information on how insufficient physical activity can be a cause of cancer

References

1. World Cancer Research Fund / American Institute for Cancer Research. Continuous Update Project Findings & Reports. Accessed September 2017.
2. Brown KF, Rumgay H, Dunlop C, et al. The fraction of cancer attributable to known risk factors in England, Wales, Scotland, Northern Ireland, and the UK overall in 2015. British Journal of Cancer.
3. Rezende LFMD, Sá THD, Markozannes G, et al. Physical activity and cancer: an umbrella review of the literature including 22 major anatomical sites and 770 000 cancer cases. British Journal of Sports Medicine 2017;52(13):826–33.
4. Kyu HH, Bachman VF, Alexander LT, et al. Physical activity and risk of breast cancer, colon cancer, diabetes, ischemic heart disease, and ischemic stroke events: systematic review and dose-response meta-analysis for the Global Burden of Disease Study 2013. Bmj 2016;:i3857.
5. Mahmood S, Macinnis RJ, English DR, et al. Domain-specific physical activity and sedentary behaviour in relation to colon and rectal cancer risk: a systematic review and meta-analysis. International Journal of Epidemiology 2017;46(6):1797–813.
6. Cong YJ, Gan Y, Sun HL, et al. Association of sedentary behaviour with colon and rectal cancer: a meta-analysis of observational studies. Br J Cancer. 2013 Nov 21.
7. Ma P, Yao Y, Sun W. Daily sedentary time and its association with risk for colorectal cancer in adults. Medicine 2017;96(22):e7049.

Last reviewed: 10 April 2019

World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) classifies the role of this risk factor in cancer development.[1]

Bowel cancer risk is lower in people with higher intake of the following foods, meta- and pooled analyses, systematic reviews or cohort studies have shown:

• Dietary fibre - 28% of bowel cancer cases in the UK are caused by eating too little fibre.[2] 10% decreased risk per 10g/day total dietary fibre and cereal fibre (no association with fruit and vegetable fibre.[3]
• Whole grains - 20% lower risk per 90g/day.[3]
• Dietary fibre (bowel adenoma) - 9% lower risk per 10g/day of total dietary fibre (cereal and fruit fibre only, not vegetable fibre some evidence no association with serrated bowel polyps[4]).[5]

See also

Learn how attributable risk is calculated

See more information on how insufficient fibre can be a cause of cancer

References

1. World Cancer Research Fund / American Institute for Cancer Research. Continuous Update Project Findings & Reports. Accessed September 2017.
2. Brown KF, Rumgay H, Dunlop C, et al. The fraction of cancer attributable to known risk factors in England, Wales, Scotland, Northern Ireland, and the UK overall in 2015. British Journal of Cancer.
3. Aune D, Chan DS, Lau R, et al. Dietary fibre, whole grains, and risk of colorectal cancer: systematic review and dose-response meta-analysis of prospective studies. BMJ 2011;343:d6617. 
4. Bailie L, Loughrey MB, Coleman HG. Lifestyle Risk Factors for Serrated Colorectal Polyps: A Systematic Review and Meta-analysis. Gastroenterology. 2017 Jan;152(1):92-104.
5. Ben Q, Sun Y, Chai R, et al. Dietary Fiber Intake Reduces Risk for Colorectal Adenoma: a Meta-Analysis. Gastroenterology. 2013 Nov 8. pii: S0016-5085(13)01586-2.  

Last reviewed: 1 October 2018