Cancer incidence in children and young adults living in industrially contaminated sites: From the Italian experience to the development of an international surveillance system

BACKGROUND: this paper is based upon work from COST Action ICSHNet. Children's environmental health is on the 2030 Agenda for Sustainable Development. The incidence of childhood cancer is increasing worldwide and in Europe. Yet, the aetiology of most childhood cancers, including the role of environmental carcinogens, is still largely unknown. Contaminated areas, especially of industrial origin, are of high concern due to complex mix of hazardous pollutants and their potential health impacts on human populations, notably in children. OBJECTIVES: to describe cancer risk in children and young adults (YA) residing in national priority contaminated sites (NPCSs) in Italy and to provide a suitable framework for a development of cancer surveillance in industrially contaminated sites (ICSs) in Europe. METHODS: this study is based on a collaborative work of the Italian Institute of Health (ISS) and the Italian Association of Cancer Registries (AIRTUM), in the context of the SENTIERI project (Epidemiological study of residents in National Priority Contaminated Sites). Incidence rates were standardised according to the European standard population. The number of observed cases was compared to the expected cases derived from the age-, sex-, and cancer-specific incidence rates of the national pool of AIRTUM registries for the period 2006-2013. Standardized incidence ratios (SIRs) and 90% confidence intervals (CIs) were computed. The study reports the cancer profile in all combined 28 NPCSs covered by 22 cancer registries. RESULTS: 1,050 cases of malignant tumours (MTs) were recorded among 3,161,786 person-years in people aged 0-29 years in 28 NPCSs (SIR: 1.03; 90%CI 0.98-1.09), with an age-standardised incidence rate of 317 per million. Excess risks were observed for: MT of the central nervous system in the age-group <1 year (SIR: 3.2; 90%CI 1.4-6.3); soft tissue sarcoma in the age-group 0-14 years (SIR: 1.6; 90%CI 1.1-2.3); acute myeloid leukaemia in the age-group 0-14 years (SIR: 1.7; 90%CI 1.1-2.4); non-Hodgkin lymphoma in the age-group 20-24 years (SIR 1.5; 90%CI 1.1-2.1), and germ cell tumours of male gonads in the age-group 20-29 years (SIR: 1.33; 90%CI 1.1-1.5). A deficit of cases was observed for Hodgkin lymphomas in the age-group 20-29 years (SIR 0.8; 90%CI 0.6-1.0). DISCUSSION: this study, which is based on standardized methods and accredited information sources, supports the hypothesis that living in an NPCS increases the risk of some cancer types in children and young adults. Further work will concern groups of NPCSs characterised by common sources of contamination/key carcinogenic pollutants. In fact, in a novel project proposal we aim to monitor the cancer profile in children living in ICSs in Europe. The new project, based on the SENTIERI-AIRTUM methodology, will build on the networking activities of the COST Action on Industrially Contaminated Sites and Health Networking (IC-SHNet) and childhood cancer studies coordinated by the International Agency for research on Cancer (IARC).