Colonoscopic screening in average-risk individuals ages 40 to 49 vs 50 to 59 years

Screening guidelines for colorectal cancer include colonoscopy starting at age 50 years based on the prevalence of adenomas and the incidence of colon cancer at that age. However, only one prior study has investigated the prevalence of colorectal neoplasia with colonoscopic screening in asymptomatic average-risk individuals ages 40-49 years in the United States.

We analyzed the results of screening colonoscopies offered to patients of a health care provider that offers screening services as part of an employer-provided wellness program. The primary end points were prevalence of adenomas and cancers for those aged 40-49 years vs those 50-59 years.

We analyzed 553 screening colonoscopies for patients ages 40-49 years and 352 screening colonoscopies for patients ages 50-59 years. In the 40-49 years age group, 79 patients (14%) had 1 or more adenomas, of which 11 (2% of screened) had an advanced neoplasm (>1 cm). In the 50-59 years age group, 56 patients (16%) had 1 or more adenomas detected. Of those patients, 13 (3.7% of screened) had an advanced neoplasm, and 1 patient (0.3%) had an adenocarcinoma detected.

We found on colonoscopic screening that the prevalence of total adenomas was similar in individuals ages 40-49 and in those 50-59 years, although the prevalence of advanced neoplasia in the 50-59 years age group may be higher than that in the 40-49 years age group.