Colorectal cancer (CRC) rates overall have been dropping steadily for more than a decade, but younger patients are bucking the trend.
A new report by American Cancer Society (ACS) researchers analyzes incident CRC rates among adults 20-49 years old using data from 13 Surveillance, Epidemiology, and End Results (SEER) cancer registries across the country (Cancer Epidemiol Biomarkers Prev. 2009;18:1695-1698).
When people ≥50 years old were included, rates declined 2.8% in men and 2.2% in women per year from 1992 through 2005. But among 20- to 49-year-olds, the rates rose per year by 1.5% in men and 1.6% in women.
Rates also increased in each 10-year age group (20-29, 30-30, and 40-49 years), culminating in annual increases of 5.2% in men and 5.6% in women for people in their 20s. However, in terms of actual cases, 40- to 49-year-olds accounted for almost three-quarters (73%) of CRC patients younger than 50.
Current guidelines recommend that routine CRC screenings begin at age 50. Does the new data mean you should recommend testing for younger patients? Not necessarily, says Durado Brooks, MD, MPH, director of colorectal and prostate cancer for ACS.
“More than 90% of CRC cases occur in people age 50 and older, but as the paper points out, there are certain younger people who need to be screened,” he says. And primary-care providers have a critical role in identifying them.
“A good family history has to be taken,” Dr. Brooks explains. “Often these questions are not asked.” Patients who had a family history of CRC, colon polyps, or other cancer should have colonoscopies in their 40s or even younger, if the history warrants.
Other younger patients present with actual symptoms, such as rectal bleeding, blood in the stool, or vague abdominal pain. They should be evaluated immediately by colonoscopy.
“There's been lots of confusion among primary-care providers (PCPs) about screening vs. diagnostic testing,” Dr. Brooks warns. “Screening is for when you have no reason to suspect disease, when there are no signs and no symptoms. If there are symptoms, then screening recommendations no longer apply; a diagnostic evaluation, often including colonoscopy, is needed regardless of age.
“I've heard stories about patients who present with rectal bleeding who are told it must be hemorrhoids because the patient is too young to have CRC. Some newly diagnosed patients have had symptoms for years,” he adds.
Meanwhile, a study that focused on the upper end of the age spectrum suggests that PCPs carefully weigh benefits and risks when recommending colonoscopies for elderly patients.
The risk of adverse GI or cardiovascular events is small, but it does rise with age, comorbid conditions, and the need for a polypectomy, report Joan L. Warren, PhD, of the National Cancer Institute in Bethesda, Md., and colleagues. For example, the unadjusted risk for GI bleeding per 1,000 procedures was >4 times higher for the polypectomy group than the screening group (8.7 vs. 2.1)
Warren's team drew a random sample of Medicare beneficiaries (age 66 to 95 years) who had colonoscopies as outpatients between July 2001 and October 2005 (n=53,220). They used matched beneficiaries who did not undergo the procedure to isolate colonoscopy as precipitating cause for event vs. “what normally occurs in the elderly population.
“The U.S. Preventive Services Task Force does not recommend CRC screening for persons age 75-85 and recommends against screening for persons ≥85 years. Our findings support these recommendations,” the researchers conclude (Ann Intern Med. 2009;150:849-857).