[Oncological disease: dimensions of the phenomenon and the role of ionising radiation]

La malattia oncologica: dimensioni del fenomeno e ruolo delle radiazioni ionizzanti

Age is an extremely important factor in cancer development, since the incidence of cancer increases significantly with age. Because of aging of the Italian population, although the incidence is kept constant, the number of cancer diagnosis is inevitably going to increase over time only to increasing age. Survival after the diagnosis of cancer is one of the main indicators that allow to evaluate the effectiveness of the health system against the cancer disease. The 5-year survival after diagnosis is a widely used indicator. If we consider the relative survival data after 5 years of diagnosis, for cancer cases diagnosed in subsequent three-year periods, from 1990-1992 to 2005-2007, it shows that the 5-year survival has increased significantly over time for both men and women. Many so-called patients "long-term survivors "are of working age and should return to work. This aims to ensure both the mental and social well-being of the worker, both industrial production. For the oncogenic risk assessment by ionizing radiation, the ICRP Publication 60 has referred to the mortality and cancer data collected from 1950 to 1985 by the RERF, Japan-US bi-national institution with headquarters in Hiroshima that leads the research program called Life Span study (LSS), that is the study of the long-term effects on survivors of the bomb A. For the thyroid, instead, reference is made to the data from medical irradiations, as well as for liver and bone, using in this case adapted data relating to exposure to alpha rays (thorium and radio). The interpretation model is the traditional one: the linear dose-effect assumptions without a threshold even at small doses (LNT theory) when epidemiological data are not more informative for statistical uncertainty, although we resort to radiobiological studies. In transferring the risk among different populations ICRP in Publication 103 accommodates the idea that for each type of cancer is more suitable, from time to time, the additive or multiplicative model or a combination of the two. To study the oncogenic role of occupational exposure to ionizing radiation in the onset of neoplastic disease, the probability of cause (PC), is a "reasonable way to address the problem of evaluation of the likelihood that previous exposure to ionizing radiation (IR) is responsible for an oncogenic event "(Committee on Radiation Protection and Measurements - NCKP - Statement N. 7 of 30/09/92).