Michelle Kang Kim, MD, MSc
Associate Director of Endoscopy, Mount Sinai Hospital
Assistant Professor of Medicine, Icahn School of Medicine at Mount Sinai
Gastrointestinal cancers occur in the digestive system, including both the upper and lower digestive tracts. Older people and those with a strong family history -- a parent or first-degree relative diagnosed with esophageal, stomach, pancreatic, liver, colon, or rectal cancer -- have an increased risk. However, there is compelling evidence that eating well, maintaining a healthy weight, exercising, and screenings when appropriate, can help prevent cancer.
Studies show that obesity, poor nutrition, and lack of exercise contribute to all cancers, including those of the gastrointestinal tract. Obesity now ranks second only to smoking as the leading cause of cancer, according to a recent report published in the Lancet.
A comprehensive report produced by the World Cancer Research Fund (WCRF) in conjunction with the American Institute for Cancer Research (AICR), titled "Food, Nutrition, Physical Activity and the Prevention of Cancer: A Global Perspective, second edition," was published in 2007. Building upon this report, the WCRF/AICR Continuous Update Project (CUP) continues to review cancer prevention research to ensure its recommendations remain current. The panel's recommendations for lifestyle changes to prevent the following gastrointestinal cancers include:
• Colorectal cancer:
o Convincing evidence suggests choosing foods containing dietary fiber (fruit, grains, and legumes); engaging in physical activity; avoiding red meat, processed meat, alcoholic drinks (men); and abdominal fatness.
o Probable evidence suggests choosing garlic, milk, and calcium, and avoiding alcoholic drinks (women).
• Esophageal cancer:
o Convincing evidence suggests avoiding alcoholic drinks, cigarette smoking, and the beverage Mate (as drunk traditionally in South America, scalding hot through a straw); and poor oral health.
o Probable evidence suggests choosing non-starchy vegetables (artichoke, avocado, lettuce), garlic, whole fruits, and foods containing beta carotene (sweet potatoes, carrots, spinach) and/or vitamin C (citrus fruit, broccoli, bell peppers).
• Liver cancer:
o Convincing evidence suggests avoiding foods (cereals, grains, legumes) contaminated with aflatoxins.
o Probable evidence suggests avoiding excessive alcohol.
o Limited evidence suggests choosing fruits and avoiding obesity.
• Pancreatic cancer:
o Convincing evidence suggests avoiding obesity.
o Limited evidence suggests choosing fruits, vegetables, and fish, and avoiding red meat, processed meat, fructose, saturated fatty acids, and heavy drinking.
• Stomach cancer:
o Convincing evidence suggests avoiding tobacco.
o Probable evidence suggests avoiding too much salt -- the risk is more pronounced in those with H pylori infection -- and choosing fruits, non-starchy leafy green vegetables, and allium vegetables (garlic, onions, scallions, leeks and chives).
Colorectal cancer, the most common of the gastrointestinal cancers, ranks worldwide as the third most common cancer and the second leading cause of cancer death in the United States. It is also one of the most preventable.
Current available screenings include:
- Flexible sigmoidoscopy, and
- Virtual colonoscopy, or CT colonography.
A new, non-invasive, stool-based DNA technique, called Cologuard, from Exact Sciences, a patient-friendly test requiring no dietary restrictions or bowel preparation, is currently pending government approval.
Everyone should discuss the right time to begin screening with a physician. However, the general consensus is to begin screenings at age 50.
Colonoscopy is generally considered the gold standard. It provides a good view of both the rectum and the entire colon, and serves both diagnostic and therapeutic purposes. If pre-cancerous polyps are found during the screening, they can be removed. The procedure, which is featured as an interactive tutorial on Medline Plus, rarely has complications.
When caught early, colorectal cancer has a very good prognosis.