Predictive Variables of the Progression to Androgen Independent Prostate Cancer after Combined Androgen Blockade / 대한비뇨기과학회지

ABSTRACT

PURPOSE: Despite of the effectiveness of androgen deprivation therapy for prostate cancer, it progress to androgen independent prostate cancer (AIPC) after various periods of time. The objective of this study was to analyze the clinical and pathological variables that predict progression to AIPC after combined androgen blockade (CAB). MATERIALS AND METHODS: We retrospectively reviewed the medical records of 343 patients who were treated with CAB for prostate cancer. Binary logistic regression test was used to analyze the independent predictors for the progression to AIPC. The time to AIPC, according to variables, was assessed by the Kaplan-Meier method and the variables were compared using the Log-Rank test. RESULTS: The mean follow-up was 42.1 months (range 12-120). Seventy seven patients (33.3%) experienced progression to AIPC at a median of 20.2 months (range 6-72). On univariate analysis, the percentage of positive prostate biopsies, the Gleason score, the T stage, the extent of bone metastasis, lymph node metastasis, the pretreatment PSA level, the nadir PSA and the PSA level at 3 and 6 months all had a significant relationship with the progression to AIPC. The receiver operating characteristic curve analysis for the nadir PSA showed that the optimal cut-off point to predict progression to AIPC was 0.5ng/ml with an area under curve of 0.769. A multivariate analysis demonstrated that the Gleason score (>7), the nadir PSA (>0.5ng/ml), and the PSA level at 6 months (>4.0ng/ml) were significantly correlated with the progression to AIPC. CONCLUSIONS: This study suggested that Gleason score, the nadir PSA and the PSA level at 6 months were independent variables to predict progression to AIPC after CAB. The PSA level at 6 months may be the most accurate variable to predict progression to AIPC.