Merkel cell polyomavirus is prevalent in a subset of small cell lung cancer: a study of 31 patients

Merkel cell carcinoma (MCC) and small cell lung cancer (SCLC) share quite distinct similarities such as almost undistinguishable histological presentation ( fig 1a,b ) and highly aggressive biological behaviour with high rates of metastasis and poor survival rates. 1 2 While tobacco smoking and genetic susceptibility have been identified as risk factors for SCLC, 3 4 sun exposure and immunosuppression are the main risk factors for MCC. 1 In January 2008, a new virus, called Merkel cell polyomavirus (MCPyV), was desribed by Feng et al as a likely causative agent of MCC, proving monoclonal MCPyV-genome integration in 8 of 10 MCCs. 5 Since then these findings have been reproduced by several groups. 6 7 Because SCLC and MCC share obvious similarities in histological presentation, Wetzels et al recently published the first report looking for MCPyV prevalence in SCLC. 8 They investigated a small cohort of 10 patients with SCLC, finding no prevalence for MCPyV.