Gastrointestinal Screening

Gastrointestinal Screening

What is gastrointestinal cancer?

Gastrointestinal cancer affects various parts of the gastrointestinal tract, which extends from the mouth to the anus. This includes the oesophagus, stomach, small intestine, and large intestine (colon and rectum). Interestingly, gastrointestinal cancer is uncommon in the small intestine, where most of the digestion process occurs.

• Colorectal cancer is the second leading cause of cancer-related deaths, affecting approximately 6 percent of people in Westernized countries. It accounts for about 3 percent of deaths in these regions, with about 25 percent of all cancer-related deaths attributed to gastrointestinal cancers.

• Stomach cancer contributes to about 8 percent of cancer-related deaths and predominantly affects men. While its incidence is decreasing, there's a concerning rise in oesophageal cancer, particularly adenocarcinoma, in men.

• Oesophageal cancer is responsible for around 3 percent of cancer-related deaths, with men being affected more than women at a ratio of 1.8:1.

• Pancreatic cancer contributes to about 4 percent of cancer deaths and affects both sexes almost equally.

• Primary liver cancer is strongly linked to hepatitis virus infection and is more common in developing countries with higher rates of hepatitis. In Western countries, it accounts for only about 0.7 percent of cancer deaths. However, the liver often becomes a site for other gastrointestinal cancers to spread.

How can I reduce my risk of these cancers?

Several lifestyle modifications can lower the risk of developing gastrointestinal cancer:

- Limit alcohol consumption

- Excessive alcohol intake is associated with higher risks of oesophageal, pancreatic, and liver cancers.

- Quit smoking

- Smoking significantly increases the risk of pancreatic cancer, especially when combined with heavy alcohol consumption.

- Consume green vegetables

- A diet rich in green vegetables is linked to a reduced risk of bowel cancer. Additionally, high vitamin C intake, found in fruits and green vegetables, lowers the risk of stomach cancer.

- Avoid preserved or burnt meats

- Salted, smoked, and burnt meats are associated with higher risks of stomach and bowel cancers due to their content of carcinogens.

- Maintain a healthy weight

- Obesity increases the risk of bowel cancer and is also linked to pancreatic cancer through its association with diabetes.

- Stay physically active

- Regular exercise reduces the risk of bowel cancer, irrespective of body weight.

Can screening tests detect gastrointestinal cancers early?

Screening aims to detect diseases in asymptomatic individuals, leading to more successful treatment outcomes. While screening programs exist for breast and cervical cancers, gastrointestinal cancers pose unique challenges.

• Screening for bowel cancer is feasible due to its prevalence and high cure rates if detected early. Faecal occult blood testing is commonly used, but its accuracy is limited, often necessitating follow-up colonoscopy.

• Individuals at high risk, such as those with a family history of colorectal cancer, benefit from more frequent screening, typically starting earlier than average-risk individuals.

• Oesophageal cancer screening is recommended for individuals with conditions like Barrett's oesophagus, often identified in those with chronic acid reflux.

• Stomach cancer screening is not widely practiced in Western countries due to its rarity, but in high-risk populations like Japan, gastroscopy has shown promise.

• Screening for pancreatic cancer remains experimental, primarily targeting those with a family history of the disease.

• Liver cancer screening focuses on individuals with liver cirrhosis, monitoring alpha-fetoprotein levels and conducting regular ultrasound examinations.

Prevention or screening?

While screening for gastrointestinal cancers is valuable, prevention through lifestyle changes and medications offers broader benefits. High vegetable diets, regular exercise, and medications like aspirin or COX-2 inhibitors show promise in reducing cancer risk. However, balancing benefits against potential risks is essential, emphasizing the need for individualized approaches to cancer prevention and screening.