Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + COLORECTAL CANCER Download Section PDF Listen +++ +++ Population ++ –Adults +++ Recommendations ++ AAFP 2018 ++ –Risk Factor CRC Diet: Cholesterol and fat intake: 2-fold increased risk of CRC with increased cholesterol intake, and 25% increased risk of serrated polyps with increased fat intake. Dairy intake: 15% reduced risk of CRC with more than 8 oz of cow’s milk per day. Fiber: Increased fiber intake does not reduce the risk of CRC or recurrent adenomatous polyps. Red meat intake: 22% increased risk of CRC with increasing red meat and processed meat intake. Lifestyle: Alcohol intake: 8% increased risk of CRC and 24% increased risk of serrated polyps. Cigarette smoking: 114% increased risk of high-risk adenomatous polyps and CRC in current smokers. Obesity: Bariatric surgery associated with 27% reduced risk of CRC. Physical activity: 26% decreased risk of colon cancer for occupational physical activity, and 20% decreased risk of colon cancer with recreational physical activity; 12% decreased risk of rectal cancer for occupational physical activity, and 13% decreased risk of rectal cancer with recreational physical activity. –Preventive Strategy Increased consumption of fruits and reduction in red meat and processed meat consumption may lower the risk of CRC. (JAMA. 2005;293:172) (Cancer Res. 2010;70:2401) B6 (pyridoxal-5ʹ-phosphate) levels are inversely associated with risk of colon CA. B6 found in cereals, meat, fish, vegetables, bananas, and avocado. (JAMA. 2010;303:1077) If family history of CRC (no genetic abnormality), increase frequency of surveillance. (Gastroenterology. 2015;149:1438) ++ Source ++ –Am Fam Physician. 2018;97(10):658-665. ++ Therapeutic Approaches ++ –NSAIDS: 63% decreased risk of CRC; although not recommended secondary to increased risk of GI and cardiovascular events; meta-analysis of 15 RCTs.a –Aspirin: Although aspirin use decreases CRC incidence by 40%, a 2016 USPSTF guideline including three RCTs recommended against aspirin use in the average-risk population due to increased risk of gastrointestinal bleeding and hemorrhagic stroke. Individuals 50–59 y of age with a 10-y cardiovascular event risk of at least 10% who are willing to take aspirin for at least 10 y (ie, the time it takes to accrue the cancer prevention benefit) may benefit from aspirin use for CRC risk reduction. A 2017 systematic review with meta-analysis found that the effect of aspirin was similar to FOBT and flexible sigmoidoscopy for reducing CRC incidence and mortality, and aspirin was more effective for cancers in the proximal colon. –USPSTF approves use of low-dose aspirin for prevention of colorectal cancer in adults 50- to 59-y-old. Benefits statistically shown after 10 y of daily aspirin use. In 60- to 69-y old patients, decision to take low-dose aspirin is individualized based on risk factors. Aspirin is not recommended in patients <50 or older than 70. (Ann Intern Med. 2016;164;836) (Ann Intern Med. 2016;164:777) –Statins: Statin use is associated with 17% decreased risk of advanced adenomatous polyps and 50% decreased risk of CRC; effect observed in individuals who had used a statin for at least 5 y. –Calcium: 26% reduced risk of adenomatous polyps and 22% reduced risk of CRC; no effect for serrated polyps; calcium use for 3–4 y is recommended to decrease risk of CRC or adenomatous polyps but not serrated polyps. ++ –Postmenopausal Combination Hormone Replacement (Not Estrogen Alone) Sixty-three percent reduced risk of CRC but no decreased risk of serrated polyps; harms outweigh potential benefits, and routine use of hormone therapy is not recommended at this time. –Polyp Removal Based on fair evidence, removal of adenomatous polyps reduces the risk of CRC, especially polyps >1 cm. (Ann Intern Med. 2011;154:22) (Gastrointest Endosc. 2014;80:471) Based on fair evidence, complications of polyp removal include perforation of the colon and bleeding estimated at 7–9 events per 1000 procedures. –Interventions without Benefit Vitamin D: Guideline from US Preventive Services Task Force found no benefit in vitamin D supplementation to decrease risk of CRC; a meta-analysis found 50% decreased risk of CRC or adenomatous polyps; conflicting evidence that vitamin D supplementation decreases risk of CRC or adenomatous polyps. Folic Acid: Increased folic acid intake does not decrease risk of adenomatous polyps. Antioxidants: No benefit for beta carotene; vitamins A, C, or E; or selenium; not recommended to decrease the risk of CRC or adenomatous polyps. + ++ aThere is solid evidence that NSAIDs reduce the risk of adenomas, but the extent to which this translates into a reduction in CRC is uncertain. + ESOPHAGUS CANCER Download Section PDF Listen +++ ++ Minimize Risk Factor Exposure ++ AAFP 2017 ++ –Common Risk Factors for Squamous Cell Carcinoma Age 60–70 y Achalasia (10-fold risk) Smoking (9-fold risk) Alcohol use (3- to 5-fold risk with ≥3 drinks per day) Black Race (3-fold risk) High-starch diet without fruits and vegetables –Common Risk Factors for Adenocarcinoma Age 50–60 y Male sex (8-fold risk) White race (5-fold risk) Gastroesophageal reflux disease (5- to 7-fold risk, depending on frequency of symptoms) Obesity (2.4-fold risk with BMI >30 kg per m2) Smoking (2-fold risk) Barrett esophagus ++ Therapeutic Approaches ++ –Risk Reduction Randomized controlled trial has shown that radiofrequency ablation of Barrett’s esophagus (BE) with moderate or severe dysplasia may lead to eradication of dysplasia and reduced risk of progression to malignancy. (N Engl J Med. 2009;360:2277-2288) Longstanding GERD associated with BE and increased risk of esophageal CA. (PLOS. 2014;9:e103508) Uncertain if elimination of GERD by surgical or medical therapy will reduce the risk of esophageal adenocarcinoma although a few trials show benefit. (Gastroenterology. 2010;138:1297) No trials in the United States have shown any benefit from the use of chemoprevention with vitamins and/or minerals to prevent esophageal cancer. (Am J Gastroenterol. 2014;109:1215) (Gut. 2016;65:548) + GASTRIC CANCER Download Section PDF Listen +++ ++ –Risk Factors Dietary (nitroso compounds, high salt diet with low vegetables) and lifestyle factors (smoking and alcohol consumption) probably account for one-third to one-half of all gastric cancers. Obesity: Excess body weight is associated with an increased risk of gastric cancer; in a meta-analysis, excess body weight (defined as a body mass index [BMI] ≥25 kg/m2) was associated with an increased risk of gastric cancer (OR 1.22, 95% CI 1.06–1.41). (Eur J Cancer. 2009;45(16):286) Smoking: A meta-analysis estimated that the risk was increased by approximately 1.53-fold and was higher in men (Cancer Causes Control. 2008 Sep;19(7):689-701). H. pylori: World Health Organization (WHO) classified H. pylori as a Group 1 or definite carcinogen; H. pylori can cause chronic active gastritis and atrophic gastritis, early steps in the carcinogenesis sequence. Testing for H. pylori infection is indicated in patients with active peptic ulcer disease, a past history of documented peptic ulcer, or gastric MALT lymphoma. (Am J Gastroenterol. 2007;102:1808-1825) ++ –Clinical Considerations Anti-H. pylori therapy may reduce risk but effect on mortality unclear. A study over 15 y showed a 40% reduction in risk of gastric CA with H. pylori eradication. (Ann Intern Med. 2009;151:121) (J Natl Cancer Inst. 2012;104:488) H. pylori eradication will also reduce the risk of mucosa-associated lymphoid tumor (MALT lymphoma). Dietary interventions—eating more fruits, vegetables, and less processed foods reduces risk of gastric cancer by 10%–15%. Smoking cessation will reduce risk by 20%–30%. Patients with hereditary susceptibility (HNPCC, e-cadherin mutation, Li–Fraumeni syndrome), pernicious anemia, atrophic gastritis, partial gastrectomy, or gastric polyps should be followed carefully for early cancer symptoms and for upper endoscopy at intervals according to risk. + LIVER CANCER Download Section PDF Listen +++ ++ NCI 2018 ++ –Risk Factors Hepatitis B or C; or both increases the risk further. Excessive alcohol use. Food with aflatoxin (poison from a fungus, such as grains and nuts, that have not been stored properly). –Hepatitis B Virus (HBV) Vaccination (Newborns of Mothers Infected with HBV) HBV vaccination of newborns of Taiwanese mothers reduced the incidence of hepatocellular carcinoma (HCC) from 0.7 to 0.36 per 100,000 children after about 10 y. (Clin Cancer Res. 2005;11:7953) New effective anti-viral therapy for hepatitis C. Ledipasvir and Sofobuvir (Harvoni) will very likely decrease the risk for HCC in near future. (N Engl J Med. 2013;368:1907) Eradication of HCV occurs in over 95% of patients treated with this new antiviral therapy.