In Japan, Colon Cancer Less Likely in Pre-Existing Adenoma
De novo cancers account for a high proportion of colorectal cancers in Japan
MONDAY, July 17 (HealthDay News) -- A new study suggests that patients in Japan are more likely than patients elsewhere to develop colorectal cancers that are not associated with a pre-existing adenoma, according to a report in the July issue of Gastroenterology. The findings suggest that the recommended interval for colonoscopies in Japan should be shorter than in the United States, due to the larger proportion of such de novo cancers, the authors note.
Hideyo Goto, M.D., of the Fukuoka University Hospital in Fukuoka, Japan, and colleagues reviewed data from 14,817 people who underwent colonoscopy between 1997 and 2001 at a single gastroenterology clinic in Japan. Overall, 189 patients had colorectal cancer, including 83 with early cancer.
In those with early cancer, there were no differences regarding size or location between the early cancers and adenoma-associated cancers, although morphology differed. De novo cancers were flat elevated or depressed as opposed to polypoid, and made up 22.9 percent of the early cancers.
The results suggestion that de novo cancers make up "a considerable proportion [of colorectal cancers] in Japan," and that information on de novo cancer will help determine the appropriate interval for a colonoscopy and establish the correct strategy for prevention and treatment of colorectal cancer, the authors write.