8. Risk Factors
The most important risk factor for lung cancer is smoking, primarily active smoking, but there is objective
evidence that passive smoking is also important. Smoking is the cause of 80–90% of lung cancer cases, and the lifetime risk of developing lung cancer among male smokers is about 17%, among smoking women is about 12%, and among non-smokers is about 1.5% [36,78].
The literature emphasizes the higher risk of lung cancer in people with long-term exposure to compounds such as radon, asbestos, polycyclic aromatic hydrocarbons, arsenic, beryllium, cadmium, silicone, vinyl chloride, nickel and chromium compounds and diesel engine exhaust [79,80].
The compounds mentioned above are characterized by a high genotoxic potential, which contributes to the formation of numerous oxidative and nitrative damages.
In addition, multidirectional activation of signal transduction pathways is observed, as well as the production of the “cross-talk” phenomenon, which leads to an increase in uncontrolled cellular proliferation [81].
Exposure of the lung area to ionizing radiation applied for other cancers (e.g., early Hodgkin lymphoma or breast cancer) as well as environmental pollution also increases the risk of lung cancer [36].
The occurrence of lung cancer in first-degree relatives is associated with a higher risk of developing the disease than in the general population [82,83].
Lung cancer is most often caused by smoking, but in some patients, it is associated with genetic predisposition, according to a study published by the American Society of Clinical Oncology (ASCO).
American specialists have shown that the same predisposition can cause other types of cancer in patients with lung cancer, such as pancreatic cancer, ovarian cancer in women and prostate cancer in men.
They warn that the patient’s closest relatives may also be at greater risk of cancer.
Experts from the American Society of Clinical Oncology point out that most lung cancers can be associated with cigarette smoking, as well as other environmental factors, such as exposure to asbestos, but in the case of thousands of patients, the development of this disease is driven by inherited genetic factors.
Until now, it seemed that adverse genetic changes conducive to lung cancer could be caused by adverse environmental factors, as well as improper lifestyle, including, above all, smoking. However, some people have inherited genetic changes that predispose them more to this cancer.
Research by American specialists shows that the detection of inherited genetic changes (pathogenic germline variants—PGV) is therefore of great importance in predicting the risk of lung cancer.
It has been established that it occurs in a fairly large group, 15% of patients with lung cancer. This is also important information for the closest relatives of these patients.
Early detection of genetic predisposition allows one to reduce the risk of this disease, as well as detect it early, when even more effective treatment is possible [84].
The study included 7788 patients with lung cancer, among whom 1161 patients were found to have inherited genetic changes in 81 known cancer mutations so far.
Approximately 95.1% of patients with these lesions could be treated with available therapies or could be covered by early detection of the disease ,(84)
Fig 6 Risk factors
Smoking
Smoking is the cause of 90% of lung cancer cases in men and 80% in women. Smokers have a 30 times higher risk of death from lung cancer than non-smokers. Cigarette smoke hides over 7000 chemical compounds, including over 70 compounds considered carcinogenic.
Secondhand smoke is also associated with a higher risk of lung cancer compared to people who are not exposed to tobacco smoke. It is estimated that about 20–50% of “non-smokers” who suffer from lung cancer are passive smokers [85].
Alcohol
alcohol Studies indicate that people who abused alcohol were more likely to develop lung cancer.
Researchers do not provide exact data but estimate that it may be related to another factor: smoking. Studies show that people are more likely to reach for cigarettes when they drink.
Researchers at the University of Liverpool studied 125,249 British drinkers and 47,967 Americans. As many as six genes have been identified that, in their opinion, are associated with excessive alcohol consumption and, consequently, with lung cancer [86].
Genetic predisposition
genetic predisposition The role of genetic factors is still quite poorly understood. The high incidence of lung cancer
in some families is associated with a genetically determined tendency to overactivate carcinogenic compounds contained in tobacco smoke or to remove these compounds from the body too slowly. A tendency to slowly repair DNA damage in respiratory epithelial cells after the action of carcinogens is also inherited. To sum up, it can be stated that the hereditary condition is primarily a special susceptibility to the carcinogenic effects of tobacco. This inheritance is the result of the presence of polymorphisms (population variants) in many genes, and there are currently no reliable genetic tests to determine the high risk of developing lung cancer.
Research by American specialists shows that the detection of inherited genetic changes (pathogenic germline variants—PGV) is of great importance in predicting the risk of lung cancer. It has been established that it occurs in a fairly large group, i.e., 15% of patients with lung cancer [84].
Occupational factors
occupational factors Exposure to many occupational factors has consequences in the form of the development of lung diseases, including lung cancer. The most important occupational carcinogens include asbestos, silica, heavy metals and polycyclic aromatic hydrocarbons [87]. All forms of asbestos (chrysotile and amphiboles, including crocidolite, amosite and tremolite) are carcinogenic, although the potency of chrysotile is less than that of other types, likely due to its more effective removal from the lungs. In many underdeveloped countries, occupational exposure to asbestos remains widespread [87,88].
Elevated risk of lung cancer has been reported in several industries and occupations associated with exposure to polycyclic aromatic hydrocarbons, such as aluminum production, coal gasification, coke production, iron and steel foundries, tar distillation, roofing and chimney cleaning. It has also been suggested that people employed in several other industries have increased risk of lung cancer, including shale oil mining, wood impregnation, roofing and carbon electrode manufacturing [88].
Environmental factors
environmental factors Air pollution data show that lung cancer incidence increases by 30–50% in areas with high levels of ambient air pollution compared to areas with lower levels [89,90].
Many studies carried out so far clearly show that the risk of developing lung cancer is much higher in highly urbanized, industrialized regions with a developed transport network, in particular based on the use of internal combustion engines [37].
age The risk of developing lung cancer also increases with age.
The majority of lung cancers occur after the age of 50
(96% of cases in men and 95% of cases in women), with about 50% of cases in both sexes occurring in the population over 65 years of age. The risk of developing lung cancer peaks in men in the eighth decade of life and in women at the turn of the sixth and seventh decades of life [25].
Ref
Int J Mol Sci. 2025 Feb 26;26(5):2049. doi: 10.3390/ijms26052049
Lung Cancer—Epidemiology, Pathogenesis, Treatment and
Molecular Aspect of literature
Beata Smolarz 1,*, Honorata Ł
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