Screening Colonoscopy Prevents Cancer in Both Proximal and Distal Colon

Previous studies have suggested that colonoscopy decreases distal but not proximal colorectal cancer (CRC; JW Gastroenterol Feb 20 2009 and J Natl Cancer Inst 2010; 102:89), but more recent studies report reductions in proximal CRC incidence as well, although the reductions are smaller than for distal CRC (JW Gastroenterol Feb 4 2011 and Gastroenterology 2011; 140:65). These latter studies are from countries in which colonoscopy is performed largely by gastroenterologists.

To further investigate whether screening colonoscopy reduces proximal as well as distal colorectal cancers, researchers in the U.S. examined temporal trends in resection rates for distal and proximal colorectal cancer as a reflection of trends in CRC incidence. They used h…