[Cancer figures in Italy: an overview].

Background: the description of the geographical distribution and temporal trends of cancer is relevant for prevention and improving the quality of care. This is primarily achieved through the incidence measures derived from population cancer registries (CRs). In recent years, in Italy there has been a prevalence of 'real-time' estimates and projections, although based on rather dated data. Given the significant increase in registration activity and still in absence of a national cancer registry network, the recent publication of Volume 12 of Cancer Incidence in Five Continents (CI5) provides a valuable opportunity to update cancer incidence estimates in Italy and to provide national and macroarea reference estimates.

Objectives: to explore the pattern of cancer in Italy by reviewing and reorganizing the most recent data from cancer registries.

Materials and methods: data from Italian cancer registries included in CI5 for the years 2013-2017 were obtained. Populations were verified, corrected for errors, and normalized to Italian National census reconstruction. The completeness of CR data was assessed using the mortality/incidence ratio applied to potential outlier data. Age-specific rates, Age standardized rates (ASRs), and truncated rates for adults (35-64 years) were calculated for 79 different neoplasms. Analyses were performed for individual CRs and macroareas. Temporal comparisons were made for 23 CRs with data from 2008-2012.

Results: the observed incidence rates show extreme heterogeneity. Among males, the overall ASR ranges from 584 per 100,000 in the province of Reggio Calabria to 809.9 per 100,000 in the province of Sondrio. Among women, ASR is highest in Emilia-Romagna (540.5) and lowest in the province of Avellino (409.9). The gradient with decreasing rates from North to South is clearly visible only for female breast cancer. Higher rates of lung cancer are observed for the city of Naples in both genders. In adult males (35-64 years), ASRs of lung cancer are maximum in the provinces of Caserta and Naples, where they are more than double the ASRs observed in the Veneto Region. In general, a significant decline in male ASRs is observed in Northern Italy compared to the previous five-year period. A significant part of this trend is influenced by lung cancer that is significantly decreasing throughout the Centre-North among men and substantially increasing among women. The database and tables with details of all calculated indicators are provided as supplementary material.

Conclusions: the analysis has shown the importance of a review of real CR data and, in general, working with real data to not only develop specific estimates of cancers in Italy, but also to share reference rates and basic data for further analysis. The present review has also revealed critical issues with data submitted to the IARC. The comparison and verification of data quality through control and audit processes must represent a concrete operational perspective of the national cancer registry network. From the perspective of cancer epidemiology, important indications emerge regarding the distribution of cancers that can fuel aetiological research, as well as the planning of prevention and care activities. The data also show that it is advisable to separate the provinces of Caserta and Naples from the South in estimation and projection models. The comparison and verification of data quality through control and audit processes must represent a concrete operational perspective of the national cancer registry network.