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Colorectal Cancer Prevention
Aka: Colorectal Cancer Prevention, Colon Cancer Risk Factor
- See Also
- Colorectal Cancer Screening
- Risk Factors: Colorectal Cancer
- Age >45 years (accounts for 90% of Colon Cancer)
- Universal screening is now recommended to start at age 45 years old if no additional risk factors (average risk)
- Of new Colon Cancer cases, 10% are found at age 50 years old
- (2021) JAMA 325(19):1965-77 +PMID: 34003218 [PubMed]
- Inflammatory Bowel Disease
- Ulcerative Colitis
- Risk increases with duration since diagnosis (2% at 10 years of disease, 18% at 30 years of disease)
- Crohns Disease
- Lifetime risk of Colorectal Cancer: 4-5%
- Past Medical History
- Adenomatous polyps >5mm (Confers RR of 2-3 times)
- Hamartomatous Polyposis syndromes
- Cholecystectomy
- Pelvic irradiation
- Family History (non-syndrome related)
- Higher risk Family History Criteria (RR 3-4x)
- One first degree relative with Colorectal Cancer or advanced adenoma before age 60 years
- Two first degree relatives with Colorectal Cancer or advanced adenoma at any age
- Moderate risk Family History Criteria (RR 2-3x)
- One first degree relative with Colorectal Cancer or advanced adenoma age 60 years or older
- Two second degree relatives with Colorectal Cancer or advanced adenoma at any age
- Hereditary Syndromes
- Attenuated Familial Adenomatous Polyposis (10-99 synchronous advanced adenomas)
- Diagnosed on average by age 58 years, and 69% develop Colon Cancer by age 80 years old
- Familial Adenomatous Polyposis (>100 synchronous advanced adenomas)
- Diagnosed on average by age 39 years, and 87% develop Colon Cancer by age 45 years old
- Hereditary non-polyposis Colon Cancer (Lynch Syndrome)
- Diagnosed on average by age 45 years, and 75-80% lifetime Colon Cancer risk
- Autosomal Dominant condition
- Most common cause of inherited Colorectal Cancer
- MUTYH-Associated Polyposis (<100 Colorectal Adenomas)
- Autosomal Recessive risk for Colorectal Cancer
- Colorectal Cancer risk 19% by age 50, and 43% by age 60 years
- Peutz-Jeghers Syndrome (Hamartomatous Polyposis)
- Symptomatic polyps by age 10 to 30 years
- Sessile Serrated Adenomatous Polyposis
- Diagnosed on average by age 62 years, and 25-70% have Colon Cancer at time of diagnosis
- Lifestyle related risks
- Tobacco Abuse
- Current smokers have a 2 fold higher Relative Risk of high-risk adenomas or Colorectal Cancer
- Botteri (2008) Gastroenterology 134(2):388-95 [PubMed]
- Obesity
- BMI 35-40 associated with Colorectal Cancer mortality Relative Risk 1.8 in men, 1.4 in women
- Calle (2003) N Engl J Med 348(17): 1625-38 [PubMed]
- Bariatric Surgery reduced Colorectal Cancer rtisk by 27%
- Afshar (2014) Obes Surg 24(10): 1793-99 [PubMed]
- Dietary Risk Factors
- Coffee does not have a consistent impact on Colorectal Cancer risk
- Dairy products have a minimal impact on Colorectal Cancer risk
- High Dietary Fat
- Saturated and polyunsaturated fat increases adenomatous polyp development
- High fat diet is not associated with Colorectal Cancer development
- Howe (1997) Cancer Causes Control 8:215-28 [PubMed]
- Low Fat Diet does not appear to lower Colorectal Cancer risk
- Prentice (2007) J Natl Cancer Inst 99(20): 1534-3 [PubMed]
- Red Meat
- Foods with possible higher risk: Salt-cured, pickled, smoked, barbeque
- Red meat consumption does increase Colorectal Cancer risk
- Chan (2011) PLoS One 6(6): e20456 [PubMed]
- Prevention: Colorectal Cancer
- High Physical Activity
- Mahmood (2017) Int J Epidemiol 46(6): 1797-13 [PubMed]
- High fruit and vegetable intake
- High Dietary Fiber intake
- Previously recommended for longterm prevention
- However no data to support fiber in prevention of adenomas or Colorectal Cancer
- Does not prevent Colorectal Cancer or adenomatous polyps
- Schatzkin (2000) N Engl J Med 342:1149-55 [PubMed]
- Yao (2017) Cochrane Database Syst Rev (1):CD003430 [PubMed]
- Sources
- Whole grain cereals
- Legumes
- Fruits and vegetables
- Water insoluble (wheat bran) fiber may be best
- High Dietary Calcium intake (1200 mg qd)
- Prevents adenoma recurrence
- Baron (1999) N Engl J Med 340:101-7 [PubMed]
- Decreases risk of histologically advanced polyps
- Wallace (2004) J Natl Cancer Inst 96:921-5 [PubMed]
- Medications: None are recommended for routine prevention (unless indicated for other reason)
- General
- Aspirin, NSAIDs, COX-2 Inhibitors not recommended
- Despite effectiveness in prevention, risks are high
- (2007) Am Fam Physician 76:109-113 [PubMed]
- Aspirin
- More effective in reduction of proximal Colorectal Cancers
- Reduces adenoma Incidence in high risk patients
- Greatest risk reduction at >14 tablets per week
- Chan (2004) Ann Intern Med 140:157-66 [PubMed]
- However, increased risk of Gastrointestinal Bleeding and Hemorrhagic CVA
- Not recommended for CRC prevention in average-risk patients
- Consider in those with other indications (esp. 10 year cardiovascular risk >10%)
- NSAIDs
- Adverse effects (e.g. Gastrointestinal Bleeding, nephrotoxicity) limit chronic preventive use
- Sulindac prevented neoplasia in familial polyposis
- Janne (2000) N Engl J Med 342:1960-8 [PubMed]
- COX-2 Inhibitors
- Celecoxib prevented neoplasia in familial polyposis
- Steinbach (2000) N Engl J Med 342:1946-52 [PubMed]
- Postmenopausal Hormone Replacement
- Studies demonstrate lower overall Colon Cancer risk
- However, those diagnosed with Colon Cancer were at a more advanced stage
- Chlebowski (2004) N Engl J Med 350:991-1004 [PubMed]
- Antioxidants
- No benefit with Beta Carotene, Vitamin A, Vitamin C, Vitamin E, Selenium
- Increased adenomatous polyp risk with Vitamin E
- Bjelakovic (2006) Aliment Pharmacol Ther 24:281-91 [PubMed]
- High Folate or methionine intake
- No significant benefit in Colorectal Cancer Prevention
- Cole (2007) JAMA 297(21): 2351-9 [PubMed]
- Vitamin D
- No consistent benefit in Colorectal Cancer Prevention
- Chung (2011) Ann Intern Med 155(12): 827-38 [PubMed]
- Statins
- Observational studies demonstrate a 30% reduction in Colon Cancers
- Randomized controlled studies needed before a recommendation can be made
- Poynter (2005) N Engl J Med 352: 2184-2192 [PubMed]
- References
- Giovannucci (1995) N Engl J Med 333:609-14 [PubMed]
- Wilkins (2018) Am Fam Physician 97(10): 658-65 [PubMed]
- Wilkins (2008) Am Fam Physician 78(12): 1385-92 [PubMed]