Androgen receptor, Ki67, and p53 expression in radical prostatectomy specimens predict treatment failure in Japanese population.

OBJECTIVES

To evaluate multiple known prognostic markers in localized prostate cancer using tissue microarrays in Japanese patients. Molecular studies have suggested that ethnicity influences prostate tumor biology.

METHODS

Specimens were studied from 52 patients who underwent radical surgery at our institution between 1997 and 2001 without neoadjuvant hormonal therapy and with three or more available and complete cancer spots. Ki67, p53, and androgen receptor antigen expression were examined. Immunohistochemical scores were compared with outcomes of chemical relapse as monitored using prostate-specific antigen.

RESULTS

Pathologic tumor classification (P = 0.047), World Health Organization score (P = 0.026), World Health Organization histologic grade (P = 0.026), and surgical margin status (P = 0.018) were significant conventional clinicopathologic variables for predicting biochemical failure. The tissue microarray Gleason sum (P = 0.038), tissue microarray primary Gleason grade (P = 0.013), Ki67 labeling index (P < 0.0001), p53 (P = 0.0097), and androgen receptor (P = 0.0113) antigen expression also were significant. Moreover, surgical margin status and Ki67 labeling index were independently associated with treatment failure.

CONCLUSIONS

Especially together, the Ki67 labeling index and p53 and androgen receptor expression in localized prostate cancer often predicted postoperative progression in Japanese patients.