Tumor immune systems in esophageal cancer with special reference to heat-shock protein 70 and humoral immunity.

UNLABELLED The objective of this study was to clarify the participation of heat-shock protein 70 (HSP70) and the humoral immune system in antitumor immunity in esophageal cancer. PATIENTS AND METHODS Immunohistochemical staining for HSP 70, and CD4(+) T-, CD8(+) T-, B- and plasma cells was performed on surgical specimens obtained from 125 patients with esophageal cancer. An enzyme-linked immunosorbent assay (ELISA) was then performed to measure serum anti-HSP70 antibodies in the azygos vein. RESULTS The expression of HSP 70 correlated inversely with depth of invasion (p<0.0001), pathological stage (p<0.0001) and blood vessel invasion (p<0.001), and there was a positive correlation between HSP70 and CD4(+) T-, CD8(+) T-, B- and plasma cells. Of these, the B- and plasma cells had the strongest correlation to HSP70 expression. Serum anti-HSP70 antibody levels in the azygos vein correlated with HSP70 expression, and B and plasma cell infiltration. Patients positive for HSP70, and B- and plasma cell infiltration had good prognosis compared to other cases. According to multivariate analyses, simultaneous occurrence of HSP70 expression, and B- and plasma cell infiltration is a stronger prognostic factor than simultaneous occurrence of HSP70 expression, and CD4(+) T- and CD8(+) T-cell infiltration. CONCLUSION It is suggested that the HSP70-humoral immune cell system might play an important role in antitumor effects in patients with esophageal cancer.