Colonoscopy is consistently associated with reduced left-sided, but not right-sided, colorectal cancer incidence and mortality.
This might be because polyps with advanced pathology are smaller and more easily missed in the right vs left colon.
Dr Samir Gupta and colleagues from Texas, USA evaluated the relationship among size, location, and histology of polyps from a large nationwide sample.
The researchers conducted a cross-sectional study of 233,414 polyps from 142,686 patients, which were reviewed by Miraca Life Sciences in 2009.
The team assessed polyp histology, location, and size of largest fragment submitted.
The researchers compared size distribution of right vs left polyps with high-grade dysplasia or adenocarcinoma, as well as any advanced neoplasia.
|Polyps with advanced pathology were 5-fold more likely to be 6 mm in the right |
|Clinical Gastroenterology & Hepatology|
The doctors found that the average size of right-sided polyps was smaller than that of left-sided polyps with high-grade dysplasia or adenocarcinoma.
The team found the same to be true for polyps with advanced neoplasia.
Most right-sided polyps with high-grade dysplasia , adenocarcinoma, or any advanced neoplasia were 9 mm, whereas most left-sided polyps with these findings were 9 mm.
Polyps with advanced pathology were 5-fold more likely to be 6 mm in the right vs left colon.
Dr Gupta's team concludes, "Polyps with features of high-grade dysplasia, adenocarcinoma, or advanced neoplasia were significantly smaller in the right vs left colon."
"Strategies to prevent right-sided colorectal cancer require more accurate detection of small, advanced polyps."