[Prognostic significances of natural killer cells and dendritic cells infiltrations in esophageal squamous cell carcinoma]

Abstract

Background & objective: Natural killer (NK) cell and dendritic cell (DC) play important roles in anti-tumor immunity. Heat shock protein (HSP) is also involved in anti-tumor immune mechanisms. This study was to explore prognostic significances of NK cells and DCs infiltrations in esophageal squamous cell carcinoma (ESCC), and their relationships with expressions of HSP27 and HSP70.

Methods: NK cells, and DCs infiltrations were detected by SP immunohistochemistry in 101 specimens of ESCC. Among the relevant 101 patients, 38 were classified into long-term survival group (>/=5 years), and 63 into short-term survival group (</=1 year) according to follow-up data. The 2 groups were matched in all pathologic and clinical features but post-esophagectomy survival time. Infiltrations of NK cells and DCs in ESCC were compared between the 2 groups. Relationships of NK cells and DCs infiltrations to expressions of HSP27 and HSP70 were statistically analyzed.

Results: Immunohistochemical results showed that the mean number of NK cells in the 101 specimens of ESCC was 31.4+/-19.7 per high-power field (x400, HPF), that in long-term survival group was much higher than that in short-term survival group [(41.9+/-21.7)/HPF vs. (25.0+/-15.4)/HPF, P < 0.001]. The mean number of DCs in the 101 specimens of ESCC was (14.8+/-21.7)/HPF; there was no significant difference between long-term and short-term survival groups [(15.2+/-8.6)/HPF vs. (14.5+/-7.4)/HPF, P > 0.05, t test]. NK cells and DCs infiltrations in ESCC had no significant correlation with clinicopathologic features, such as length of tumor, depth of invasion, histological grade, and lymph node metastasis, etc. (P > 0.05). Binary logistic regression analysis indicated that infiltration of NK cells was of prognostic significance for ESCC (P=0.001), while DCs was not (P=0.842). Infiltration of NK cells was positively correlated with infiltration of DCs (r=0.266, P=0.007). Both infiltrations of NK cells and DCs were positively correlated with expression of HSP27 (P=0.017, P=0.018), while no such correlation with expression of HSP70 was found (P > 0.05).

Conclusions: Infiltration of NK cells is an independent prognostic factor of ESCC, and might be a prognostic biomarker of ESCC. Infiltration of DCs has no correlation with prognosis of ESCC. Infiltrations of NK cells and DCs may have internal correlation with the expression of HSP27.