Human Papillomavirus (HPV) and Merkel Cell Polyomavirus (MCPyV) in Non Small Cell Lung Cancer

Certain types of human papillomavirus (HPV) induce cancers, especially cervical cancers in women. A meta-analysis of the literature suggests that HPV is also associated with 20%-25% of non small cell lung carcinoma (NSCLC). Merkel cell Polyomavirus (MCPyV) causes most Merkel cell carcinomas in immunocompromised hosts, and is associated with some squamous carcinomas of skin in immunocompetent individuals. Since both oncogenic viruses appear to involve the tonsils and, therefore, have clear access to the lungs, we examined that the possible association of HPV and MCPyV infections with lung cancers, especially, NSCLC. DNAs were extracted from 51 frozen tissues from 30 lung cancer patients, and examined for the presence of HPV and MCPyV by PCR and DNA sequencing analysis. Clinical data was correlated with the viral status. HPVs were only detected in 5 adenocarcinomas (16.7% of all lung cancers examined). Three were positive for HPV-16, 1 for HPV-11 and 1 had an unknown HPV type DNA. None was identified in benign tissue. MCPyV DNA was detected in 5 NSCLCs (16.7%). Three of the 5 were identified in squamous carcinomas, 1 in adenocarcinoma, and 1 in an unspecified NSCLC. Two additional samples were positive for MCPyV DNA within benign adjacent lung tissue only. In one adenocarcinoma, HPV-11 was identified in an adenocarcinoma, and MCPyV DNA was detected in the adjacent "benign" tissue. HPV and MCPyV were directly associated with 33.3% of NSCLC. Further studies are necessary to determine if polyomavirus and papillomavirus are necessary risk factors for some cases of NSCLC.