Many colorectal cancer patients are being diagnosed when they are younger than 50 years old, the age at which most guidelines say screening should begin, according to a new analysis of U.S. patients in Cancer. The findings raise questions about how -- and whether -- screening should be addressed in younger adults.
The population-based, retrospective study of more than 250,000 colorectal cancer patients showed that almost 15% were younger than 50 at the time of diagnosis -- a far larger proportion of patients, for example, than the 5% who are diagnosed with breast cancer at age 40, 10 years before some guidelines say breast cancer screening should begin. Younger colorectal cancer patients were also more likely to be diagnosed with advanced-stage disease (Cancer, January 25, 2016).
"This study is really a wake-up call to the medical community that a relatively large number of colorectal cancers are occurring in people under 50," senior author Dr. Samantha Hendren said in a release from the University of Michigan. "In a practical sense, this means that we should look out for warning signs of colorectal cancer such as anemia, a dramatic change in the size or frequency of bowel movements, and dark blood or blood mixed with the stool in bowel movements."
The study examined data from 258,024 colorectal patients in the Surveillance, Epidemiology, and End Results (SEER) registry between 1998 and 2011. The researchers found that 37,847 patients, or almost 15%, were younger than 50 at the time of their diagnosis.
The younger patients were more likely to be diagnosed with regional or distant disease, more serious forms of colorectal cancer than localized disease. Patients under 50 with distant metastases were also more likely to undergo surgery for their primary tumor (72% versus 63% of older patients). In addition, radiation therapy was more commonly used in younger versus older patients (53% versus 48%).
In addition to watching for signs of cancer, people with a positive family history of colorectal cancer should be screened before they reach 50, according to Hendren.
"This is already recommended, but we don't think this is happening consistently, and this is something we need to optimize," she said.
