Key points are not available for this paper at this time.
This reports an investigation of the changing relative frequency of cancers of the colon and rectum between 1940 and 1962 from data submitted to the End Results Group sponsored by the National Cancer Institute. A consistent and substantial increase in the magnitude of the ratio of colon to rectal cancer was observed. The ratio of colon/rectum age-adjusted incidence rates for New York and Connecticut showed similar trends. This changing colon/rectum ratio seems to reflect an increased incidence of colonic cancer. The percentage distribution for the End Results Group “analytic” cases showed little change in the proportion of cases assigned to the sigmoid colon during the period of greatest increase in the colon/rectum ratio. From these data it appears very unlikely that this increase is a result of changing criteria in the assignment of digestive tract cancers to the various sub-sites. Changes which have resulted in the decreased incidence and mortality from stomach cancer in the United States may be related to the increase in intestinal cancer.
Axtell et al. (Wed,) studied this question.