Ferrandiz-Pulido, C.Gomez-Tomas, A.Llombart, B.Mendoza, D.Marcoval, J.Piaserico, S.Baykal, C.Bouwes-Bavinck, J.N.Racz, E.Kanitakis, J.Harwood, C.A.Cetkovska, P.Geusau, A.Del Marmol, VMasferrer, E.Cano, C.OrteRicar, J.de Oliveira, W.R.Salido-Vallejo, R.Ducroux, E.Gkini, M.A.Lopez-Guerrero, J.A.Kutzner, H.Kempf, W.Seckin, D.2022-12-152022-12-1520220926-9959https://ddd.uab.cat/pub/artpub/2022/264417/264417.pdfhttp://hdl.handle.net/11727/8309Background The proportion of Merkel cell carcinomas (MCCs) in solid-organ transplant recipients (SOTR) harbouring Merkel cell polyomavirus (MCPyV) is unknown, as are factors affecting their outcomes. Objective To describe clinicopathological features of MCC in SOTR, investigate the tumoral MCPyV-status and identify factors associated with tumour outcomes. Methods Retrospective, international, cohort-study. MCPyV-status was investigated by immunohistochemistry and polymerase chain reaction. Results A total of 30 SOTR and 44 consecutive immunocompetent patients with MCC were enrolled. SOTR were younger at diagnosis (69 vs. 78 years, P < 0.001). Thirty-three percent of SOTR MCCs were MCPyV-positive vs. 91% of immunocompetent MCCs (P = 0.001). Solid-organ transplantation was associated with an increased cumulative incidence of progression (SHR: 3.35 [1.57-7.14], P = 0.002), MCC-specific mortality (SHR: 2.55 [1.07-6.06], P = 0.034) and overall mortality (HR: 3.26 [1.54-6.9], P = 0.002). MCPyV-positivity and switching to an mTOR inhibitor (mTORi) after MCC diagnosis were associated with an increased incidence of progression (SHR: 4.3 [1.5-13], P = 0.008 and SHR: 3.6 [1.1-12], P = 0.032 respectively) in SOTR. Limitations Retrospective design and heterogeneity of SOTR cohort. Conclusions MCPyV appears to play a less prominent role in the aetiopathogenesis of MCC in SOTR. SOTR have a worse prognosis than their immunocompetent counterparts and switching to an mTORi after the diagnosis of MCC does not improve progression.enginfo:eu-repo/semantics/openAccessPOLYOMAVIRUS INFECTIONSURVIVALASSOCIATIONRECURRENCECANCERTUMORLIVERHEARTarticle3611199120010008105796000012-s2.0-85131727639