Rösch T, et al. - This study draws on data from the German National Screening Colonoscopy Registry to evaluate the risk of malignancy in proximal vs distal adenomas in patients included in a large screening colonoscopy database, as well as to examine adenoma shape and the patients’ age and sex distribution. Results revealed that high-grade dysplasia (HGD) histology was observed in 20,873 adenomas. Researchers reported that the rates of adenomas with HGD were similar in the proximal and distal colon in this large screening database. It was noted that the presence of HGD as a risk marker alone did not explain higher rates of proximal interval colorectal cancer. They suggested that certain lesions (flat, serrated lesions) might be missed in the proximal colon and might acquire a more aggressive biology over time. Therefore, a combination of endoscopy-related factors and biology could represent higher rates of proximal vs distal interval colorectal cancer.