Lung cancer is increasingly affecting non-smokers as well, with up to 70 percent of cases among non-smokers being women[1]. Smoking causes 80 to 90 percent of all cases, while 10 to 15 percent is due to environmental factors such as PM2.5 air pollution, which, according to the WHO, leads to more than 300,000 deaths annually[1][4]. In Slovakia, 3,000 cases are diagnosed annually and approximately 2,000 people die, which means a death every four hours[5][7]. The disease is often asymptomatic in the early stages, and up to three quarters of cases are detected late in the inoperable stage[5]. With early detection, the five-year survival rate rises from 22 to 55 percent, and the chance of survival reaches up to 75 percent[1][5]. Secondhand smoke can cause 15 to 35 percent of cases in nonsmokers[3]. Experts are calling for wider screening of non-smokers as the patient profile is changing to younger individuals, non-smokers and women with adenocarcinoma[1][2]. Air pollution is the second most common cause of death from this cancer after smoking[4].