ABSTRACT
OBJECTIVE: The aim of this retrospective study was to evaluate the programmed cell death 1 (PD‑1) expression in esophageal squamous cell carcinoma (ESCC) and association with clinical characteristics. MATERIALS AND METHODS: From January 2009 to December 2014, 88 patients with ESCC were retrospectively included in this study. Eighty‑eight cancer tissues, 35 paraneoplastic atypical hyperplasia tissues (PAHTs), and 30 relative normal esophageal tissues (RNETs) were collected and tested for expression of PD‑1 by immunohistochemistry assay. The PD‑1 expression and clinical characteristics of the ESCC patients were evaluated. The prognosis of the ESCC patients was compared between the PD‑1 positive and negative patients. RESULTS: The PD‑1 positive rate was 51.2% (45/88), 22.9% (8/35), and 6.7% (2/30) for the cancer tissue, PAHT, and RNET, respectively, with statistical difference (P < 0.05); The PD‑1 expression was significantly associated with lymph node metastasis (P < 0.05) and pathology grade (P < 0.05). The median overall survival was 29.8 months and 32.1 months for the PD‑1 positive and negative groups without statistical difference (hazard ratio = 1.00, 95% confidence interval = 0.58–1.71, P < 0.05). CONCLUSION: PD‑1 may play a key role in the process of carcinogenesis of ESCC but not associated with prognosis and overall survival.