In Italy, every year, about 400,000 new cases of malignant tumors are recorded with an annual average of deaths from cancer, according to the Italian Oncological Registers, of about 3 deaths per 1,000 people. To date, long-term (spanning at least a decade) and spatially detailed (up to the municipal scale) data have neither been readily accessible nor fully available for public consultation by citizens, scientists, research groups and associations.

For this reason, we decided to publish, with free access [1], the longest available ten-year (2009-2018) database on cancer death rates (SMR), elaborated from data provided by the Italian Institute of Statistics (ISTAT). Our database includes 23 macro-categories of tumors recorded in Italy on a municipal, provincial and regional scale and covers the entire nation. Our goal was to create a complete, ready-to-use and open data source easily accessible by local and national stakeholders and administrators and to provide researchers with data for further studies.

Hence, our effort to collect the most detailed and long-term database of cancer mortality for Italy was intended to provide the scientific community with a reliable statistical base to better investigate the causes related to cancer mortality and address the problem at its origin. Indeed, cancers are a type of disease whose treatments are intrusive and heavy to bear, both physically and emotionally, and involve a bigger number of people than just the person affected. Certainly, it would be more effective to eliminate the causes than repair the damage but the lack of data on tumor incidence and mortality are often difficult to find in a standardized, statistically corrected, and user-friendly repository. All these constraints have, so far, limited the possibilities to weigh comprehensively the factors that trigger cancers and are not evidently associated with tumors. For instance, the relation of cancer with lifestyle factors has been thoroughly studied so that paying attention to correct habits has fortunately become common sense. Of course, this is the result of continuous research and divulgative efforts. On the contrary, the effects of pollution and environmental degradation are not properly consolidated yet. This was true also for other pandemics, of more media visibility than cancer. In fact, last year we showed that the mortality caused by the Sars-Cov-2 virus is strongly linked to the exposure of citizens to the differential distribution of air pollution, and in particular to fine particulate matter (PM2.5) and NO2, in Italian territories [2, 3]. 

In a view of planetary health, so called One Health, in which it is now clear that the quality of life of our species strictly depends on that of the Earth, it is necessary to give priority, not only to the search for a cure for cancer, but above all to reduction and prevention of its causes, such as environmental contamination. This search for causes is an essential action to be implemented in the difficult fight against the onset of cancer, which is a much more hidden pandemic, but with higher mortality [4]. Only if we know how to heal our planet can we avoid getting sick. 

Despite multiple studies and preliminary scientific evidence, governments and institutions have not launched programs aimed at better understanding the environmental factors of cancer. In a recent study, we analyzed the links between cancer mortality, socio-economic factors and sources of environmental pollution in Italy, on a regional and provincial scale, using innovative and sophisticated artificial intelligence methods [5]. Contrary to what was believed, we found that cancer mortality among Italian citizens has neither a random nor spatially well-defined distribution, but exceeds the national average especially when environmental pollution is higher in certain areas of the country despite healthier lifestyle habits. The analysis of as many as 35 environmental sources of pollution (such as industries, pesticides, incinerators, car traffic, etc.) showed that air quality ranks first in importance as regards the association with the average mortality rate for cancer, followed by the sites to be reclaimed, the presence of urban areas and the density of motor vehicles. In addition, other specific environmental sources of pollution have been found to be significant for the mortality of some specific types of cancer.

Our study confirmed the importance of having long-term reliable data on cancer rates of mortality for whole countries, but also at regional, and local communities. On their basis, in fact, we were able, in Italy, to show the relevance of the environment compared to other socio-economic factors and lifestyle, and to determine what potential sources of pollution could cause cancer mortality to exceed the national average, providing a focus on environmental factors that are mostly associated with specific types of tumor [5].

Furthermore, our research provides more support to the idea that random factors (often simplistically associated with luck or misfortune) are not the main triggers of cancer, contrary to what has been suggested so far. In fact, two important results have emerged: the first is that the Italian regions with a relatively high cancer mortality rate are characterized by a relatively high degree of pollution, despite recording a relatively low frequency of factors generally associated with cancer risk (such as overweight and smoking, low income, high meat consumption and low fruit/vegetable consumption); the second is that specific tumors showed a significant spatial association with some specific sources of pollution (which explains more than half of the association between environment and tumors), confirming that, in most cases, exposure to a contaminated environment significantly affects cancer mortality in Italy.

This is, however, not surprising for Italy. In a previous study, we showed that living nearby one of the most polluted cities of the country, Taranto, with numerous industrial activities that impact population health, increases the mortality rate for some specific cancer types in the city and towns of the two provinces located downwind. We found strong evidence that, for most tumor types, mortality decreases with the distance from the main industrial site but we also found that other local causes may be implicated in the excess of mortality in some specific areas besides the potential dispersal of pollutants from the polluted city. Thanks to the help of georeferenced cancer mortality rate, we discovered that the proximity to Taranto cannot, in fact, explain all the anomalies detected in some populations. It is likely that other site-specific sources of heavy pollution are playing a role in worsening the death toll of these towns and this must be taken into serious consideration by environmental policymakers and local authorities. 

Our hope is that, with this new long-term dataset [1], more light could be shed on the geographical distribution of cancer in Italy (and be taken as a useful exercise for other countries) and this could contribute to reducing the sad death toll of our species’ health  main enemy.

References

[1]  Cazzolla Gatti, R., Di Paola, A., Monaco, A., Velichevskaya, A., Amoroso, N., Bellotti, R., 2022. A ten-year (2009-2018) database of cancer mortality rates in Italy. Scientific Data, 9:638. doi: 10.1038/s41597-022-01729-0

[2] Cazzolla Gatti, R., Velichevskaya, A., Tateo, A., Amoroso, N., Monaco, A. (2020). Machine learning reveals that prolonged exposure to air pollution is associated with SARS-CoV-2 mortality and infectivity in Italy. Environmental Pollution, 267, 115471.

[3] Amoroso, N., Cilli, R., Maggipinto, T., Monaco, A., Tangaro, S., Bellotti, R. (2022). Satellite data and machine learning reveal a significant correlation between NO2 and COVID-19 mortality. Environmental Research, 204, 111970.

[4] Cazzolla Gatti, R. (2021). Why we will continue to lose our battle with cancers if we do not stop their triggers from environmental pollution. International journal of environmental research and public health, 18(11), 6107.

[5] Cazzolla Gatti, R., Di Paola, A., Monaco, A., Velichevskaya, A., Amoroso, N., Bellotti, R. (2022). The spatial association between environmental pollution and long-term cancer mortality in Italy. Science of The Total Environment, 158439.

[6] Cazzolla Gatti, R., Velichevskaya, A. (2022). Taranto’s Long Shadow? Cancer Mortality Is Higher for People Living Closer to One of the Most Polluted City of Italy. Sustainability, 14(5), 2662.