Changing distribution of primary cancers in the large bowel
J. B. Rhodes, F. F. Holmes and G. M. Clark
Analysis of the changing distribution of origin site of 1,990 colorectal
cancers observed at a large midwestern hospital shows a statistically
significant trend of a decreasing percentage of distal (rectum, P=.0192)
and an increasing percentage of proximal (cecum, P=.0015) large-bowel
lesions during a period of at least 30 years. Mortality data for 11,635
colorectal cancers in the state of Kansas for this period confirm this
trend (P less than .0001). The respective decrease and increase may well be
the result of more than one factor. Results of digital examination of the
rectum and sigmoidoscopy are less likely to diagnose large-bowel cancer as
they did 30 years ago. Stool screening for occult blood, barium enema
roentgenographic examination, and colonoscopy become more important
diagnostic tools in light of this trend.
