title: Clinicopathological significance of Fas and Fas ligand expressions in esophageal cancer.
abstract: Esophageal carcinomas have recently been shown to express Fas ligand (FasL) and down-regulate Fas to escape from host immune surveillance. However, the prognostic importance of Fas/FasL and their correlation with clinicopathological characteristics are yet to be delineated in this highly malignant carcinoma. Specimens from 106 esophageal squamous cell carcinoma patients were used for immuno-histochemical evaluation of Fas, FasL, and CD8 expressions. Fifty-two (49%) and 34 (32%) patients were positive for FasL and Fas, respectively. There were no associations between FasL expression and clinicopathological characteristics except lymph vessel invasion. Strong FasL expression correlated with significant (P < 0.001) decrease in tumor nest CD81 cells. However, neither FasL nor CD81 had any impact on patient survival. Strong Fas expression was correlated with depth of invasion (40.3% in pT1, T2 versus 20.5% in pT3, T4; P5 0.0308), histological differentiation (45.7% in well versus 25.4% in nonwell; P < 0.05), and lymph node metastasis (22.6% in positive versus 45.5% in negative; P < 0.01). Fas expression was one of the independent favorable prognosticators for patients' survival (risk ratio, 3.26; P < 0.01) in esophageal SCC. Fas expression was an independent prognosticator for recurrencefree survival, whereas FasL expression did not influence the survival in esophageal squamous cell carcinoma. Down-regulation of tumor Fas may be the hallmark of immune privilege for the tumor, thus causing the patients' poorer outcome. Tumor FasL may counterattack the host immune cells to such an extent that the prognosis is not affected.
authors.affiliation: Department of Cardio-Thoracic Surgery, The First People's Hospital of Yancheng Yancheng 224006, Jiangsu Province, China.
authors.forename: Guang-Zhou
authors.initials: GZ
authors.lastname: Wu
authors.affiliation: The Third People's Hospital of Dalian Dalian 116000, China.
authors.forename: Chun-Xia
authors.initials: CX
authors.lastname: Pan
authors.affiliation: Department of Cardio-Thoracic Surgery, The First Affiliated Hospital of Soochow University Suzhou 215006, Jiangsu Province, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Jiang
authors.affiliation: Department of Cardio-Thoracic Surgery, The First Affiliated Hospital of Soochow University Suzhou 215006, Jiangsu Province, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Thoracic Surgery, The Tumor Hospital of Henan Zhengzhou 450008, Henan Province, P. R. China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Cardio-Thoracic Surgery, The First Affiliated Hospital of Soochow University Suzhou 215006, Jiangsu Province, China.
authors.forename: Shi-Ying
authors.initials: SY
authors.lastname: Zheng
keywords: Esophageal carcinoma; Fas ligand (FasL); counterattack; immune privilege