Colorectal cancer, the second leading cause of cancer deaths in the United States, can be prevented before it starts. And when it’s caught at the earliest stage, the treatment success rate is greater than 90 percent.

Both prevention and successful treatment require regular screenings - a health check that many avoid. Fewer than four in 10 eligible people undergo regular colorectal screenings.

The December issue of Mayo Clinic Health Letter describes how screenings can catch cancer before it spreads or even starts.

The large intestine, which consists of the colon and rectum, is a muscular tube at the end of the digestive system. The inside lining of these organs is usually smooth. As a person ages, precancerous clumps of cells, called polyps, may grow in the lining. Some are considered harmless, and others pose a risk. Adenomatous polyps have cells that typically look and act differently from normal cells and can become cancerous as they grow. The progression to cancer is more likely when a polyp’s diameter exceeds 10 millimeters.

Polyps can grow anywhere in the colon. Of the many screening options available, colonoscopy is considered the tool of choice, because the entire colon - about four feet - is examined. During a colonoscopy, a flexible, slender tube equipped with a tiny camera, is used to look for polyps. The doctor can remove precancerous polyps during the exam. If needed, tissue samples (biopsies) can be taken to check for cancer. The test takes 15 to 30 minutes, requires colon cleansing, and may involve the use of a mild sedative for comfort. Generally, the test is recommended every 10 years.

Eventually, colorectal cancer can cause symptoms such as rectal bleeding or blood in the stool, persistent abdominal discomfort, unexplained loss of weight or appetite, or bowel habit changes such as persistent diarrhea or constipation. But the signs and symptoms often don’t show up until the disease is advanced, when it’s more difficult to treat. Because many avoid screening, only one-third of all colorectal cancers are diagnosed in the early stages.

Talk to a care provider about screening options, including colonoscopy and any concerns you might have about bowel preparation or discomfort. Men and women at average risk of developing colon cancer should be screened starting at age 50. It’s not hard to imagine that the death rate due to colon cancer would drop substantially if all people eligible for screening had a colonoscopy.

Mayo Clinic Health Letter is an eight-page monthly newsletter of reliable, accurate and practical information on today’s health and medical news.

Source: Mayo Clinic