Cancer registries are much more than centres for epidemiological research: on top of research into cause they also contribute to research into the effectiveness of health systems, of public health interventions, and into aspects of survivorship, to assess effectiveness of treatment. Some examples of the expanded role of population-based cancer registries in the health care system studies include:

• planning future needs of cancer services using projections of cancer frequency in conjunction with assumed trends in risk factors and interventions
• assessing differences in cancer incidence and mortality to address inequality in prevention and care using assessment of variations in frequency of cancer between and within countries according to ethnic origin, occupation, socioeconomic status, and area of residence
• monitoring the effect of primary prevention campaigns by assessing trends in cancer frequency. Cancer registry data are also used to monitor screening programmes by observing the proportion of patients detected by screening and shifts in stage distribution
• assessing the effectiveness of cancer treatment, which is best monitored by survival trends