Abstract Aim This study characterizes Colorectal Cancer (CRC) incidence in the University Hospital Ramon and Cajal, Madrid, and analyzes variations over time. It establishes risk groups, aiming to discover whether diagnosis can be determined in less advanced stages of disease.

Method Evolutionary epidemiological study of genetic and environmental factors contributing to the development of CRC in this district that enables the comparison of two cohorts of patients separated by 37 years:

G1 (patients of current group) and G2 (patients of historical group). The main risk variables gleaned retrospectively were analyzed and the statistical association between cohorts was determined. Results The mean age of patients increased significantly from 64 to 71 along with the incidence of ascending colon cancer.

G1 scored higher than G2 for:

the incidence of colon cancer in men, detection of adenomatous polyps (48.1%), percentage of resectability with curative intent (80.4%), and Dukes A stage (34.1%) (p < 0.001). Conclusion Biological aspects of CRC have been compared against its profile three decades earlier. We can confirm the existence of concrete changes in the manifestation and staging at the time of diagnosis or following earlier treatment. (AU)