No evidence for a role of Merkel cell polyomavirus in small cell lung cancer among Iranian subjects

Merkel cell polyomavirus (MCPyV), as a new member of polyomaviruses, has recently been discovered as a possible etiologic factor for human cancer. It was first detected in Merkel cell carcinoma (MCC). Small cell lung cancer (SCLC) is a malignant lung tumor which shares histopathological and genetic features with MCC, as both are of neuroendocrine origin. In this study, we investigated the presence of MCPyV DNA in SCLC specimens by real-time PCR. Our null hypothesis was that MCPyV is an etiologic factor in SCLC, as previously seen in MCC. Formalin-fixed and paraffin-embedded (FFPE) specimens were obtained from 50 patients, who underwent bronchoscopic biopsy and were diagnosed with SCLC between March 2010 and March 2012. Similarly, we obtained bronchoscopic biopsy specimens from 29 patients, who were diagnosed with non-small cell lung cancer (NSCLC). All samples were obtained at a single center (Masih Daneshvari Hospital, Tehran, Iran). Real-time PCR was done to detect the presence of MCPyV DNA. After excluding one specimen from the SCLC group due to loss of tumor tissue, we did not detect MCPyV DNA in samples from patients with either SCLC (the mean age 58.9 years, male/female ratio: 7.3/1) or NSCLC. Our results suggest that MCPyV does not play a role in the pathogenesis of SCLC, which is in accord with the results from other prior investigations.