Combined c-Myc and caveolin-1 expression in human prostate carcinoma predicts prostate carcinoma progression

BACKGROUND. Over-expression of the oncogene c-Myc has been implicated in the development and progression of human prostate carcinoma. However, previous assessments of c-Myc expression have not revealed its potential for predicting prostate carcinoma progression. Caveolin-1 is associated with prostate carcinoma progression and is a downstream target gene of c-Myc. The observation that caveolin-1 can suppress c-Myc-induced apoptosis suggested the potential for cooperation between c-Myc and caveolin-1 in malignant progression. In this study, the authors evaluated the prognostic potential of combined c-Myc and caveolin- 1 expression in human prostate carcinoma progression. METHODS. Inummostaining with c-Myc and caveolin-1 -specific antibodies was performed on paraffin sections from 104 radical prostatectomy specimens from men with lymph node negative prostate carcinoma. Combined c-Myc and caveolin- I immunostaining scores were related with the clinical and pathologic features and the probability of prostate -specific antigen recurrence after surgery. RESULTS. The combination of c-Myc and caveolin-1 immunopositivity correlated positively with Gleason score (p = 0.219; P = 0.0253) and positive surgical margin (p = 0.333; P = 0.0006). The combination of positive c-Myc and caveolin-1 in patients with clinically confined prostate carcinoma was a significant prognostic marker for the time to disease progression after surgery in both univariate analysis (P = 0.0039; hazard ratio, 3.035) and multivariate analysis (P = 0.0114; hazard ratio, 2.916). CONCLUSIONS. The coexpression of c-Myc and caveolin-1 showed potential as a useful prognostic marker for human prostate carcinoma. The current results suggest interactions between c-Myc and caveolin-1 in the progression of human prostate carcinoma. Cancer 2005;103:1186-94. (C) 2005 American Cancer Society.