A growing number of younger patients are being diagnosed with aggressive colorectal cancer, even as the incidence of the disease among older patients is declining, new research shows.
The incidence of early-onset colorectal cancer (CRC) among patients younger than age 50 has been rising at an annual rate of 1.5% per year, compared with an annual decrease of 3.1% among older individuals over the past decade, according to the study. Individuals with early-onset disease tend to have larger tumors that are more likely to metastasize.
“Although the incidence in younger patients is still low compared with colorectal cancers in older populations, the trend is alarming and calls for more investigation and appropriate intervention,” said Xi Emily Zheng, MD, PhD, a study investigator and fellow in the Department of Healthcare Policy and Research at Weill Cornell Medical College, in New York City. Dr. Zheng’s group presented its findings at the 2014 annual meeting of the American College of Gastroenterology (abstract 7).
Using the Surveillance, Epidemiology, and End Results database from 2000 to 2011 (Figure), the researchers compared the incidence and characteristics of CRC among patients younger than age 50 (n=39,787) with those of CRC patients who were older than 50 (n=330,009).
The New York researchers also found that younger CRC patients were more likely to be male (odds ratio, 1.13 ; 95% confidence interval [CI], 1.11-1.16) and black or Hispanic rather than white. Blacks had a 1.6-fold higher risk for CRC than whites (95% CI, 1.57-1.67) and Hispanics had a 2.1-fold higher risk than whites (95% CI, 2.07-2.21), Dr. Zheng said.
In addition to the trends in cancer incidence, they also found that the rate of distant disease has increased 3% per year, whereas cases of localized or regional tumors have risen 1%. This trend, which is being seen in clinical practice, is disturbing, said Al B. Benson III, MD, professor of medicine and associate director for clinical investigations at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, in Chicago.
“We are seeing increasing numbers of younger patients and many are presenting with more advanced disease,” said Dr. Benson, who was not part of the study.
The tumors are more advanced in stage, of higher grade, larger size with more neural invasion compared with CRC in older patients. They also are more likely to metastasize, according to Dr. Zheng.
“The young-onset CRC is more likely to present with aggressive clinicopathologic characteristics compared with old-onset CRC. And the rising incidence of young-onset CRC stratified by stage shows greatest up-trend for the advanced/distant disease,” Dr. Zheng said, postulating that it could be due to the distinct underlying biology of this cancer in younger patients and/or a delay in diagnosis.
“It is not clear why this is happening and whether any of the associated risks for developing colon cancer are an issue, including diet, exercise, obesity, etc. This will have potential impact on how we screen patients for colorectal cancer and push a research agenda to find out how to precisely identify patients at risk to inform screening strategies,” Dr. Benson added.
Both doctors said more data are needed before baseline-screening policies can be changed. However, it would be reasonable to consider colonoscopy in younger black or Hispanic individuals with a family history of CRC, Dr. Benson said.
“Screening colonoscopies and removing polyps starting at a younger age would undoubtedly be helpful if we set aside cost,” Dr. Zheng told Gastroenterology & Endoscopy News. “Our study shows CRC diagnosed between 40 and 50 years of age accounts for more than 50% of young-onset CRC.”
However, expanding screening to this population would be cost-prohibitive and risk stratification would be needed to determine which people should be screened earlier. Dr. Zheng and her colleagues are trying to determine if young-onset CRC has a unique genetic profile.
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