Cytoplasmic Expression of P16 is Related to Low Infiltration of CD8+ T cell and Poor Prognosis in Digestive Neuroendocrine Carcinoma

Background and Aims: The aim of this study is to examine the predictive and prognostic value of cytoplasmic P16Ink4A (cP16) and poor infiltration of CD8+ T cell in primary digestive neuroendocrine carcinoma (dNEC). Methods: We retrospectively reviewed 86 cases of NEC and mixed NEC (all cases thereafter refer to NEC), which had primary sites in digestive system. Kaplan-Meier survival curves and log-rank test were used for the survival analysis. Bioinformatics analysis was performed to identify the P16-related pathways. Results: The expression frequency of P16 in dNEC and adjacent tissues was 81.4% and 19.3% respectively (p