Human papillomavirus and lung cancinogenesis: an overview

Lung cancer is the most common cause of cancer deaths worldwide. Although tobacco smoking is considered to be the main risk factor and the most well-established risk factor for lung cancer, a number of patients who do not smoke have developed this disease. This number varies between 15 % to over one-half of lung cancer cases, and the deaths from lung cancer in non-smokers are increasing every year. There are many other agents that are thought to be etiological, including diesel exhaust exposure, metals, radiation, radon, hormonal factors, cooking oil, air pollution and infectious diseases, such as human papillomavirus (HPV). Studies in various parts of the world have detected HPV DNA at different rates in lung tumors. However, the role of HPV in lung cancer is still unclear. Thus, in this review, we investigated some molecular mechanisms of HPV protein activity in host cells, the entry of HPV into lung tissue and the possible route used by the virus to reach the lung cells.