Immunohistochemical detection of HSP60-expression in human ovarian cancer.Correlation with survival in a series of 247 patients

Purpose: In a previous pilot study,HSP60 expression at the transcriptional (mRNA) level was shown to be a negative prognostic factor in ovarian cancer . The aim of this study was to determine HSP60-expression by means of immun ohistochemistry and to correlate the results with survival in a large serie s of ovarian carcinoma patients with a closed follow-up. Materials and Meth ods: Slides from routinely processed, paraffin-embedded tumor blocks belong ing to 247 patients with epithelial ovarian carcinoma were studied for the overexpression of HSP60 using the Lk2 monoclonal antibody and the strepatvi din-biotin-peroxidase technique. HSP60-expression was correlated with overa ll survival by means of life-fable analysis and the Kaplan-Meier method. Re sults: 47 tumors (19%) expressed HSP60. Of them, 12/29 (41.4% positivity) w ere stage I tumors, whereas only 35 out of the remaining 218 tumors in more adanced surgical stage (16.1%) showed HSP60 staining. This difference was statistically significant (Fisher s exact test; p 0.004). Even when stratif ying stage for stage the difference between groups still remained statistic ally significant (Chi square test; p = 0.0095). The survival curve analysis showed a significant differerence in favor of those tumors expressing HSP6 0 (median survival 28 vs. 37 months; log- rank test, p = 0.02). Conclusion: Immunohistochemical detection of HSP60-expression in human epithelial ovar ian carcinoma is significantly more frequent in tumors from patients with i nitial stages of the disease. Therefore, HSP60-expression determined by thi s method is associated with a significantly level better prognosis.