%0 Journal Article %T PD-1 (PDCD1) promoter methylation in Merkel cell carcinoma: prognostic relevance and relationship with clinico-pathological parameters %J - %D 2019 %R https://doi.org/10.1038/s41379-019-0261-5 %X Merkel cell carcinoma is an aggressive neuroendocrine skin tumor, for which several non-conclusive prognostic factors of adverse clinical behavior have been reported. As promoter methylation of the immune checkpoint receptor CD279/PD-1/PDCD1(mPDCD1) has been shown to be a prognostic factor in different cancers, we investigated its role in Merkel cell carcinoma. mPDCD1was assessed retrospectively in a cohort of 69 Merkel cell carcinoma patients from the University of Bologna, University of Turin and University of Insubria. Kaplan-Meier curves and log-rank tests were calculated for all variables. To assess the influence of mPDCD1, the Cox proportional hazards model and different Royston-Parmar models were evaluated. High PDCD1 methylation (mPDCD1high) was associated with a higher overall mortality at both the univariate analysis (log rank test: ¦Ö2£¿=£¿5.17, p£¿=£¿0.023; permutation test: p£¿=£¿0.023) and the multivariate analysis (HR£¿=£¿2.111, p£¿=£¿0.042). The other variables associated with a higher overall mortality at the multivariate analysis were clinical stage III-IV (HR£¿=£¿2.357, p£¿=£¿0.008), size£¿>£¿2£¿cm (HR£¿=£¿2.248, p£¿=£¿0.031) and Merkel cell polyomavirus (HR£¿=£¿0.397, p£¿=£¿0.015). Further, mPDCD1high was strongly associated with older age (81 vs 76 years, p£¿=£¿0.042), absence of immune cells (92.6%, p£¿<£¿0.001), no expression of PD-L1 by immune cells (70.4%, p£¿=£¿0.041) and by both immune and tumor cells (70.4%, p£¿=£¿0.001). mPDCD1 is a valid prognostic parameter in patients affected by Merkel cell carcinoma. In addition, it could provide an estimate of the global PD-1/PD-L1 expression with potentially relevant implications from a therapeutic point of view %U https://www.nature.com/articles/s41379-019-0261-5