Risks for small intestine cancer

Last medical review:

Certain behaviours, substances or conditions can affect your risk, or chance, of developing cancer. Some things increase your risk and some things decrease it. Most cancers are the result of many risks. But sometimes cancer develops in people who don't have any risks.

This information is about risks for a type of small intestine cancer called adenocarcinoma. To find out more about other types of cancers in the small intestine, see, for example, neuroendocrine cancer, non-Hodgkin lymphoma, gastrointestinal stromal tumours (GISTs) and melanoma skin cancer.

The risk of developing small intestine cancer increases with age. Most people are diagnosed when they are 60 years or older.

Slightly more men than women develop small intestine cancer.

Small intestine cancer occurs in Black people (including people of African or Caribbean ancestry) more often than people of other ethnicities.

The following can increase your risk for small intestine cancer. None of these risks can be changed. Until we learn more about other risks, there are no specific ways you can lower your risk for small intestine cancer.

Genetic conditions

Crohn's disease

Celiac disease

History of colorectal and other cancers

Genetic conditions

A genetic condition is a disease caused by a change (mutation) in one or more genes. Having certain genetic conditions increases the risk of developing small intestine cancer. Talk to your doctor about your risk. You may need to visit your doctor more often to check for small intestine cancer. Your doctor will recommend what tests you should have and how often you should have them.

Familial adenomatous polyposis (FAP) is an inherited condition that causes hundreds to thousands of polyps to develop, mainly on the lining of the colon and rectum.

People with FAP have a higher risk of developing colorectal cancer and small intestine cancer. It also increases the risk of stomach, adrenal gland and thyroid cancers.

Lynch syndrome is an inherited condition that causes a large number of polyps to develop in the lining of the colon and rectum, but not as many polyps as are found in FAP. Lynch syndrome is also called hereditary non-polyposis colorectal cancer (HNPCC).

There are 2 types of Lynch syndrome. Type A increases the risk for colorectal cancer, while type B increases the risk of several cancers, including colorectal cancer, small intestine cancer, other digestive system cancers, and ovarian and uterine cancers.

Peutz-Jeghers syndrome is an inherited condition that causes dark spots on the mouth and fingers and polyps in the large and small intestines.

Peutz-Jeghers syndrome increases the risk of developing colorectal, small intestine, stomach, pancreatic, breast and other types of cancer.

Cystic fibrosis (CF) is a condition that affects the lungs and often the digestive system.

People with CF have an increased risk of small intestine cancer.

Crohn’s disease

Crohn's disease is a condition where the immune system attacks the gastrointestinal (GI) tract and can cause inflammation to these organs.

People with Crohn's disease have an increased risk of small intestine cancer, especially in the last part of the small intestine (called the ileum).

Celiac disease

Celiac disease (also called sprue) damages the small intestine so that it doesn't absorb nutrients from food as well as it should. People with celiac disease are sensitive to gluten. Gluten is a protein found in grains such as wheat, rye and barley. People with celiac disease have an increased risk of small intestine cancer.

History of colorectal and other cancers

People who had colorectal cancer have a higher risk of developing small intestine cancer. Having other cancers, such as ovarian, soft tissue sarcoma and pancreatic cancer, also increases the risk for small intestine cancer, but the overall risk is still low.

Understanding your cancer risk

To make the decisions that are right for you, ask your doctor questions about risks. Learn how cancer can be prevented and what you can do to reduce your risk.

Expert review and references

  • Canadian Cancer Society | Société canadienne du cancer
  • American Cancer Society. Risk Factors for Small Intestine Cancer (Adenocarcinoma). 2018: www.cancer.org.
  • American Society of Clinical Oncology (ASCO). Cancer.net: Small Bowel Cancer: Risk Factors. 2018: https://www.cancer.net/.
  • American Society of Clinical Oncology (ASCO). Cancer.net: Small Bowel Cancer: Statistics. 2021: https://www.cancer.net/.
  • Beebe-Dimmer JL, Vigneau FD, Schottenfeld D. Small intestine cancer. Thun MJ, Linet MS, Cerhan JR, Haiman CA Schottenfeld D, eds.. Schottenfeld and Fraumeni Cancer Epidemiology and Prevention. 4th ed. New York, NY: Oxford University Press; 2018: Kindle version, 35 https://read.amazon.ca/?asin=B0777JYQQC&language=en-CA.
  • Bennett CM, Coleman HG, Veal PG, Cantwell MM, Lau CC, Murray LJ . Lifestyle factors and small intestine adenocarcinoma risk: A systematic review and meta-analysis. Cancer Epidemiology. 2015.
  • Boffetta P, Hazelton WD, Chen Y et al . Body mass, tobacco smoking, alcohol drinking and risk of cancer of the small intestine - a pooled analysis of over 500,000 subjects in the Asia Cohort Consortium. Annals of Oncology. 2012: http://annonc.oxfordjournals.org/content/23/7/1894.long.
  • International Agency for Research on Cancer (IARC). Volume 75: Ionizing Radiation Part 1: X- and Gamma (y)-Radiation, and Neutrons. 2000: http://monographs.iarc.fr/ENG/Monographs/vol75/mono75.pdf.
  • Lu Y, Cross AJ, Murphy N, et al . Comparison of abdominal adiposity and overall obesity in relation to risk of small intestinal cancer in a European Prospective Cohort. Cancer Causes and Control. 2-16: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4923177/.
  • Macmillan Cancer Support. Small Bowel Cancer. 2020: https://www.macmillan.org.uk/.
  • Maisonneuve P, Marshall BC, Knapp EA, Lowenfels AB . Cancer risk in cystic fibrosis: a 20-year nationwide study from the United States. Journal of the National Cancer Institute. Oxford University Press; 2013.
  • McWilliams, RR, Smyrk TC, and Grothey A . Gastrointestinal tumors: cancer of the small bowel. Raghavan, E., Brecher, M. L., Johnson, D. H., et al. (Eds.). Textbook of Uncommon Cancer. 3rd ed. Chichester, England: John Wiley & Sons; 2006: 6.34: pp. 391-400.
  • Ooi CY & Durie PR . Cystic fibrosis from the gastroenterologist's perspective. Nature Reviews Gastroenterology and Hepatology.
  • Sai Yi Pan and Howard Morrison . Epidemiology of cancer of the small intestine. World Journal of Gastrointestinal Oncology. Baishideng Publishing; 2011.