Epidemiology of cancer of the large bowel - The 12-year experience of a specialized registry in Northern Italy

Background. In 1984 a specialized colorectal cancer registry was instituted in Modena; aims of the Registry were: the evaluation of incidence and mort ality, the study of morphological aspects, staging, staging and familiarity of the registered patients. Aims. Purpose of the research was to provide an updated description of the main findings (in particular incidence, staging, morphology and survival) o bserved in the 12-year registration period. Patients and methods. Between January 1984 and December 1995, 1,899 maligna ncies of the large bowel in 1,831 patients were registered. Tumours were cl assified according to the International Classification of the Diseases for Oncology (ICD-O) and staged with the TNM system Cancer specific srm il nl w as assessed with life table analysis and Log-Rank tests. Results. Crude incidence rare showed minor fluctuations between 1984 and 19 89, but tended to rise in the following pears. Tumours were mostly located distal to the splenic flexure (73.3% of the total), with a slight tendency over time to a gradual "shift" to the right colon. Staging became progressi vely more favourable throughout the registration; in 1984 both stages I, II and stage IV + unstaged lesions represented 40% of the total, but in 1995 the former rose to 50% whereas the latter fell to 21.6% (p<0.001). This mor e to earlier stages resulted in an improved survival of patients registered in 1990-91 versus 1983-85 (Log-Rank 14.3 p<0.002). Factors associated with a poor survival were the advanced age of patients at diagnosis (>74) and c linical stage. Conclusions. Main aspects of the investigation were the increasing crude in cidence rates of colorectal turnovers and the gradual increase of neoplasms diagnosed irt a more favourable staging. It is like likely that the improv ement of staging and survival observed in the 12 fears of registration can be attributed to the improved attitude to health care of the population, an d possibly to the improvement of surgical techniques.