[Correlation of heat shock protein 70 expression in nasopharyngeal carcinoma to immunoglobin A against viral capsid antigen of Epstein-Barr virus in sera and its clinical significance].

Background & Objective: Overexpression of heat shock protein (HSP)70 is expressed in many tumors, but the correlation of its overexpression in nasopharyngeal carcinoma (NPC) to immunoglobin A against viral capsid antigen of Epstein-Barr virus (EBV) in sera and its clinical significance are still unclear. This study was to determine the expression of HSP70 in NPC, and to analyze its correlations to EBV IgA/VCA titer and prognosis.

Methods: The expression of HSP70 in 38 specimens of stage II-III NPC was determined by SP immunohistochemistry; the content of HSP70 in the 38 specimens was detected by ELISA; the EBV IgA/VCA titer in sera of the 38 patients was detected by immunoenzymatic (IE) method.

Results: The positive rate of HSP70 in the 38 NPC samples was 60.5%. HSP70 expression was positively correlated to EBV IgA/VCA titer (r=0.690, P=0.001), but not to sex, age, and clinical stage (P>0.05). The 5-year survival rates of HSP70-positive group and HSP70-negative group were 65.2% and 80.0%. The 5-year tumor-free survival rates of HSP70-positive group and HSP70-negative group were 40.0% and 78.6% (P=0.04).

Conclusion: HSP70 expression in stage II-III NPC tissues is positively correlated to EBV IgA/VCA titer. The prognosis of HSP70-positive NPC patients is poor.