The colorectal adenoma is the precursor lesion in virtually all colorectal cancers, however their occurrence in younger adults has not been studied.
In this study, doctors from the United States and the Netherlands investigated the occurrence of colorectal adenomas in 3558 subjects, aged 20 to 89, using epidemiologic necropsy. All patients were autopsied between 1985 and 2004 at the Johns Hopkins Hospital.
Dr Cheryl Pendergrass and colleages looked at prevalence of colorectal adenomas by age, sex, race, and location, then standardized the results to the general population.
They compared adults aged 20 to 49 years with older adults (aged 50 to 89 years).
The researchers found that the prevalence of colorectal adenomas in younger adults increased from 2% to 4% from the third to the fifth decade of life and then sharply increased after age 50.
In younger adults, adenomas were more prevalent in men than in women (risk ratio 1.09), and more prevalent in whites than in blacks (risk ratio 1.28).
Overall, both younger and older adults had predominately left-sided adenomas, but blacks in both age groups had more right-sided adenomas.
|Adenomas were more prevalent in young men than young women.|
|Clinical Gastroenterology and Hepatology|
Dr Cheryl Pendergrass's team concluded, "Colorectal adenomas infrequently occur in younger adults and are more prevalent in the left colon".
"Irrespective of age, blacks have more right-sided adenomas, suggesting the need for screening the entire colorectum".
"Two or more adenomas in younger adults and 5 or more in older adults represents polyp burden outside the normal expectation".