Alteration of HLA-F and HLA I antigen expression in the tumor is associated with survival in patients with esophageal squamous cell carcinoma.

Alteration of human leukocyte antigen (HLA) expression, such as decreased HLA I (HLA-A, -B and -C) antigens and elevated nonclassical HLA I antigens (HLA-E, -F and -G), was reported to have an unfavorable prognosis in various cancers. In our study, HLA-F expression in 105 primary esophageal squamous cell carcinoma (ESCC) lesions and 62 case-matched adjacent normal tissues, and HLA I antigens among 68 cases were analyzed by immunohistochemistry. Data revealed that HLA-F expression was observed in 58.1% (61/105) of the ESCC lesions and in 54.8% (34/62) of the normal esophageal tissues. Among the 62 case-matched samples, HLA-F expression (lesion vs. normal tissue) was upregulated, unchanged and downregulated in 13 (21.0%), 6 (9.6%) and 43 (69.4%) cases, respectively. Patients with HLA-F positive had a worse survival than those with HLA-F negative (p = 0.040). Patients with upregulated HLA-F expression (lesion vs. normal tissue) had significantly worse survival than those with HLA-F unchanged and downregulated (p = 0.010). Furthermore, decreased HLA I expression was observed in 41.2% (28/68) patients and was with worse prognosis in comparison to those with preserved HLA I expression (p = 0.001). Multivariate analysis using Cox's proportional hazards model revealed that upregulated HLA-F expression (p = 0.026) and downregulated HLA I expression (p = 0.013) could be an independent unfavorable prognostic factor. In conclusion, our study provided the evidence that alteration of HLA I and HLA-F antigen expression was associated with survival in patients with ESCC.