Epidemiology of colorectal cancer: the 21-year experience of a specialised registry.

Cancer registries can be viewed as one of the main strategies for improving our understanding of cancer, as they may reveal the importance of specific trends in cancer incidence and survival; in addition, the information obtained from the registries can be translated into preventive measures that might lead to a better control of neoplasms. A colorectal cancer registry was instituted in Northern Italy in 1984. The purpose of this study is to provide a description of the main findings observed in a 21-year period of continuous registration. RESULTS: A total of 3951 malignancies of the large bowel were registered in 3817 patients, for a crude incidence rate of 75.1/100 000/year in men and 59.0 in women. Overall incidence (crude and age-adjusted) of colorectal tumours increased remarkably throughout the registration period. This increase was mainly due to early (Stage I and II) tumours and to lesions with lymph nodal involvement (Stage III). There was a tendency over time towards a progressive increase of colonic tumours, whereas the fraction of rectal neoplasms tended to decline. Colorectal cancer-specific survival increased significantly over time in each of the main TNM/Dukes classes (p<0.006 and