The role of human papilloma virus in lung cancer: a review of the evidence.

Papillomaviruses are small nonenveloped DNA viruses that infect squamous epithelial cells. These viruses have been found in many organisms. Human papillomaviruses (HPVs) give rise to a large spectrum of epithelial lesions, mainly benign hyperplasia (eg, warts and papillomas) with low malignant potential. There is a subgroup of HPV, the "high-risk" HPV, which is associated with precancerous and cancerous lesions. A small fraction of people infected with high-risk HPV will develop cancers that usually arise many years after the initial infection (Psyrri and Dimaio, Nat Clin Pract Oncol. 2008;5:24-31). Nonsmall cell lung cancer is a heterogeneous disease. The most common histologic subtypes include squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. Despite different histologies, nonsmall cell lung cancers are often classified together because of similarities in approach and management of the disease. In this article, we reviewed the current literature on lung cancer and HPV. On the basis of this data, we suggested a possible mechanism of carcinogenesis induced by HPV.