Background: Occurrence of and prognosis for tumours of the colon and rectum are thought to be changing rapidly due to simultaneous changes in risk factor prevalence, early diagnosis and treatment. In this paper time trends of morbidity, survival and mortality for colorectal cancer during the period 1970-1990 are estimated and analysed.
Methods: Mortality trends were obtained from official death certificates. Relative survival rates were computed from population-based cancer registries. Incidence and prevalence rates were estimated from mortality and survival data.
Results: Incidence rates were increasing during the period considered, with a lower rate of increase for the youngest birth cohorts. Relative survival rates of both colon and rectum cancers were higher for women, and for younger age groups, and were positively associated with period of diagnosis. No significant survival difference among the cancer registries used was found. A total of about 155,000 prevalent cases, 40% of which had been diagnosed > or = 7 years before, were estimated in the Italian population for the year 1990. Mortality rates were slightly increasing for men and stable for women. Projections of colorectal cancer trends to the year 2000 indicate major expected rises in both incidence and prevalence.
Conclusion: Colorectal cancer represents a problem of growing impact for health services in Italy. This conclusion can probably be extended to many developed countries.