CD151 protein expression predicts the clinical outcome of low-grade primary prostate cancer better than histologic grading: a new prognostic indicator?

OBJECTIVE

CD151 is the first member of the tetraspanin family to be associated as a promoter of human tumor metastasis. However, its biological function and expression phenotype among different tumors has not been well investigated.

METHOD

Tissue specimens from 76 primary prostate cancers and 30 benign prostate hyperplasia (BPH) controls were obtained from the Department of Anatomical Pathology at the Austin and Repatriation Medical Centre (now Austin Health) from 1984 to 1993. We used quantitative immunohistochemical analysis to measure CD151 protein expression. Analyses of differences among BPH and prostate cancer groups were done with one-way ANOVA and Newman-Keuls test. The Kaplan-Meier method and the log-rank test were used to estimate the overall survival.

RESULTS

CD151 expression was found to be significantly higher in prostate cancer specimens compared with BPH specimens (P < 0.001). Poorly differentiated cancers expressed the strongest staining, whereas well-differentiated cancers expressed the weakest staining for CD151 (P < 0.001). The overall survival rate for cases in which CD151 expression was reduced was significantly higher than for cases in which CD151 expression was increased (P = 0.039) especially in well and moderately differentiated cancers (P = 0.014). This effect was independent of the patients' age or preoperative prostate-specific antigen values and superior in the predictive ability of the Gleason score.

CONCLUSIONS

CD151 has an increasing expression pattern in prostate cancer progression, and higher levels of CD151 are associated with poorer prognosis. CD151 had better predicting value for the clinical outcome of prostate cancer patients than does the traditional histologic grading method (Gleason grading).