Screening prevents thousands of colorectal cancers

Have you ever had a colonoscopy to screen for colorectal cancer? There are many horror stories around about the preparation for this test, but despite the discomfort, there's no doubt that screening colonoscopies do save lives.

A study published this month in the journal Cancer reports that screening data from 1987 to 2010 showed that more people 50 years old and over were undergoing screening colonoscopies (from 34.8% to 66.1%) and the incidence of colorectal cancer was dropping (from 118 cases per 100,000 population to 74 cases per 100,000 population). The authors added:

The incidence of early-stage colorectal cancer also decreased, from 77 to 67 cases per 100,000 population. After adjusting for underlying trends in cancer incidence, colorectal screening was associated with a reduction of approximately 550,000 cases of colorectal cancer over the past 3 decades in the United States.

Colorectal cancer screening recommendations are the same in the United States and Canada. Those at high risk of colorectal cancer normally should begin screening earlier, but in general, at age 50, people should either have their stool tested for blood, a sigmoidoscopy, or a colonoscopy. These tests should continue every two years until the age of 75. After 75, individuals should discuss with their physicians if they should continue screening and, if so, how often.

Why is age 50 the recommended year to begin screening? According to the CDC, 90% of colorectal cancers occur in people who are 50 years old or older. There are other factors that increase the risk of developing colorectal cancer. Non-modifiable factors include:

• Family history of colorectal cancer or colorectal polyps,
• Personal history of colorectal cancer or colorectal polyps,
• History of inflammatory bowel disease, Crohn’s disease, or ulcerative colitis, and
• Genetic syndrome such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (Lynch syndrome).

Other risk factors are related to lifestyle and are often modifiable, which means you have some control:

• Sedentary lifestyle, little regular physical activity.
• Few fruits and vegetables in the diet,
• A low-fiber and high-fat diet,
• Being overweight or obese,
• Excessive alcohol consumption,
• Smoking.