Early Diagnosis of Lung Cancer of the Italian Pulmonary Screening Network (RISP): Comparative Analysis for the Use of Low Dose Computed Tomography and Promotion of Primary Prevention Interventions in Subjects at High Risk for Lung Cancer

Tobacco smoking is the most relevant cause of avoidable death in all high-income countries, including the European Union and Italy. Smoking increases the risk of dying from emphysema by 10 times, doubles that of having a stroke, and increases two to four times that of being affected by a heart attack. In addition, the carcinogenic substances contained in tobacco smoke are responsible for about 90% of lung cancers, but also for most cancers of the oral cavity, larynx and bladder. Therefore, the main causes of death attributable to tobacco smoke are cancers, cardiovascular and respiratory diseases. Lung cancer is a serious and far-reaching health problem with reduced survival after 5 years. Seventy per cent of lung cancers are at an advanced clinical stage and difficult to treat when the first symptoms occur, and a certain diagnosis is made. Lung cancer mainly affects people over the age of 50, with a peak incidence around 70-75 years. Over a third of deaths attributed to smoking are between 35 and 69 years of age. For long time it was not possible to have a certain diagnosis by diagnostic tests. Only at the end of the '90s, it became clear that computed tomography allows lung cancer to be detected at an early stage (stage I), before symptoms occur.

Large-scale randomized clinical trials (RCTs) have shown that early detection of lung cancer by CT can reduce lung cancer mortality between 20% and 39%, according to the duration of the intervention. In particular, LDCT screening has been shown to significantly reduce lung cancer mortality by 8-26% for men and 26-61% in women. International lung cancer screening guidelines, currently adopted in the United States, recommend repeating LDCT at annual intervals. However, annual chest LDCT screening has heavy economic impact and can induce radiation-related damage.

Recent studies have shown that the first LDCT screening exam provides information on individual risk thus allowing the personalization of the screening interval. In particular, there are indications that screening interval can be extended safely for low-risk individuals. For example, several studies show that individuals with a negative baseline exam have a substantially lower risk than those with a positive baseline exam. A randomized prospective assessment of risk-based screening intervals therefore has the potential to improve efficiency and reduce the economic-health impact of lung cancer screening. In fact, a personalized screening protocol has a less serious economic impact, both at the instrumental level and in terms of the commitment of the radiological staff.

In this context, the RISP network aims to promote a nationwide early diagnosis program with LDCT that reduces mortality from lung cancer, and at the same time, brings benefit in primary prevention of smoking-related diseases, such as chronic obstructive pulmonary diseases (COPD) and other cardiovascular diseases. RISP will start lung screening in a gradual and controlled way, through a network of reference centers with multidisciplinary clinical competence that provide adequate coverage of the territory, and meanwhile a level of quality fitting to the standards currently achieved in the screening of other cancers (breast, cervix, colon). A systematic screening program will also increase the percentage of lung cancer patients eligible for early-stage surgical resection from the current 25% (without screening) to 50-60%.

At baseline- each volunteer will undergo: