A study to investigate the most appropriate age for initial screening colonoscopy to improve detection of adenomas, advanced adenomas, and colorectal cancer, and lower colorectal cancer mortality found that the most appropriate age might be different for men and women.
“In our study, analysis of age- and sex-specific prevalence of adenomas, [advanced adenomas], and [colorectal cancer] indicates a significantly higher rate of these lesions among men compared with women in all age groups, suggesting that male sex constitutes an independent risk factor for colorectal carcinoma and indicating new sex-specific age recommendations for screening colonoscopy,” the researchers reported in the Journal of the American Medical Association.
Researchers from the Austrian Society for Gastroenterology and Hepatology and the Medical University of Vienna analyzed the results among 44,350 men and women participating in a national colonoscopy screening program. The median ages were 60.7 years for women, who constituted 51% of participants, and 60.6 years for men.
Adenomas were found in 19.7% of individuals screened, advanced adenomas in 6.3%, and colorectal cancer in 1.1%. The prevalence of adenomas was 24.9% for men and 14.8% for women; among 50- to 54-year-old men, the prevalence was 18.5%, which was greater than the prevalence among women in the same age group (10.7%) but similar to the prevalence among 65- to 69-year-old women (17.9%).
The prevalence of advanced adenomas in 50- to 54-year-olds was 5.0% in men but 2.9% in women, with no statistically significance difference between men aged 45 to 49 years (3.8%) and women aged 55 to 59 years (3.8%). Colorectal cancer prevalence was twice as high among men, 1.5% vs 0.7% among women. Colorectal cancer prevalence among women aged 65 to 69 was 1.2%, similar to the 1.3% rate among men aged 55-to 59.
The authors noted that the age for referring average-risk patients to screening colonoscopy is 50 years for both men and women because of the increase in the prevalence of colorectal cancer in the sixth decade of life. “Deciding whether to adjust the age at which screening begins also requires considering whether the recommended age for women should be older or the recommended age for men younger,” the researchers wrote.
In addition, the study offered support for complete colonoscopy. “In our study, 55% of polyps were found in the sigmoid colon or rectum and 45% proximal to the sigmoid colon or in both parts of colon,” they authors stated. “Approximately 50% of polyps would not be detected if only sigmoidoscopy were used for screening purposes. Therefore, our data support the importance of complete colonoscopy to cecum as a screening tool to find and remove all adenomas and [advanced adenomas].” ■
Ferlitsch M, et al: JAMA 306:1352-1358, 2011.