The good news: The rate of colorectal cancer has been falling steadily.
The bad news: The colorectal cancer rate for young adults has been rising for the past 20 years.
Researchers who analyzed U.S. National Cancer Institute data found that the U.S. colon cancer rate fell 1 percent annually from 1975 to 2010. However, rates rose by 2 percent a year among those aged 20-34 and about .5 percent for those aged 35-49.
The study estimated that the rate among the 20–34 age group would rise 38 percent by 2020 and 90 percent by 2030. By 2030 about 1 in 10 colon cancers and nearly 1 out of 4 rectal cancers will be diagnosed in patients younger than 50. That is twice as high as the current incidence in younger adults.
The troublesome aspect of this development is that adults below age 50 are not covered by public health guidelines for colon cancer screening. Despite the rise in the colorectal cancer rate among young adults, the incidence rate is low and widespread screening would add significantly to U.S. national health expenditures with little benefit because this disease, although rising, is still rare in young people.
The use of colonoscopy has been rising among young adults, especially since 2000. About 5 percent have had one by the time they reach age 50. Increasing awareness of colon cancer symptoms and better measurement of family history have fueled the screening increase.
More than 90 percent of those receiving colonoscopies are 50 and older. Federal guidelines recommend Americans receive a colonoscopy every 10 years. An increase in the screening rate has been a key reason for the falling colorectal cancer rate.
Colorectal cancer remains the third most-common U.S. cancer, and the second-leading cause of cancer death behind lung cancer. It is highly preventable with regular screening and treatable with early detection.
Noted colon cancer researcher C. Richard Boland, MD, chief of the division of gastroenterology services at Baylor University Medical Center at Dallas, was credited with naming a more common inherited condition called Lynch syndrome, which increases the risk of colon and other cancers. The condition is responsible for about 3 percent of colon cancers and, if left untreated, can cause cancer in 90 percent of men and 70 percent of women, he says.
However, Dr. Boland says, “Careful follow-up of family members when hereditary colorectal cancer syndromes are found makes the diagnosis cost-effective and can dramatically alter the natural history of the disease. With colonoscopies and some occasional extra surgery clinicians can potentially turn Lynch syndrome into a fairly ‘boring’ disease – without the big surprise of cancer.”
For younger colorectal cancer patients who do not have inherited conditions, Dr. Boland says, “We don’t know what makes it happen or how to prevent it. If we can understand the tumors, we can use specific therapies to combat them. We are working very hard on it, and using advanced techniques. Baylor is providing us with the best equipment and opportunity to solve this.”
Clifford Simmang, MD, a colorectal surgeon on the medical staff at Baylor Regional Medical Center at Grapevine, said he noticed a high number of young colon cancer patients when he served as director of a colon and rectal surgery training program 15 years ago. He says his analysis found that more than 15 percent of cancer cases were people under age 50.
Dr. Simmang recommends that patients with familial polyposis –an inherited condition that causes a profusion of polyps, one of which will inevitably become cancerous if left untreated—have surgery after high school or in their early 20s.
Dr. Simmang says patients and primary care physicians need to be more vigilant about following through on evaluating symptoms and not pass them off as “benign” because the patient is young. He says young colorectal cancer patients often ignore bowel changes that persist for months.
Clyde Collins, MD, a gastroenterologist on the medical staff at Baylor Medical Center at McKinney, called the rise in colon cancer among the young “very alarming. Colon Cancer is often an unexpected finding, as most patients will see their doctor for a common complaint such as diarrhea. Younger patients can have a tendency to ignore symptoms as a result they can present with more advanced cases when it is found.”
March is Colorectal Cancer Awareness Month. This one of a series of Scrubbing In posts related to this deadly disease.