RESUMEN
Objective: To define a predictor of prostate cancer in BPH patients with an intermediate PSA [4.1-10 ng/ml] and a negative initial sextant biopsy
Patients and Methods: During 1999, 193 BPH patients with an intermediate PSA [4.1-10 ng/ml] underwent TRUS and sextant biopsy. The patients whose initial biopsies were negative for prostate cancer were re-evaluated by serum PSA every 6 months. A total of 76 patients were subjected to an extended 11-core biopsy in view of: [1] PSA velocity >/= 1 ng/ml/year, [2] a PSA rise to > 10 ng/ml and [3] suspicious biopsy findings [atypical adenomatous hyperplasia or high-grade prostatic intraepithelial neoplasia]. Overall, 160 patients were subjected either to TURP [n=127] or open prostatectomy [n=33]
Results: On initial sextant biopsy, prostate cancer was diagnosed in 22 out of 193 patients [11.4%]. The specificity of the sextant biopsy was 91.8% and its positive predictive value [PPV] was 61.1%. A repeat 11-core biopsy revealed prostate cancer in 11 out of 76 patients [14.5%]. The specificity of the 11-core biopsy was 95.4% and its PPV was 78.6%. Three cancers out of 160 [2%] were discovered on definitive pathology. The PSA velocity cut-off point at 1.4 ng/ml/year and the PSA density cut-off point at 0.12 were optimal for the prediction of cancer using receiver operating characteristic curves. The multivariate analysis [stepwise logistic regression] revealed that PSA density [p=0.011], PSA velocity [p=0.002] and age [p=0.021] were the most significant predictors of cancer when the data were inserted as a continuous format. The sensitivity, specificity and overall accuracy of the model were 80%, 98.7% and 95.9%, respectively. When the data were re-inserted as a coded format, PSA velocity and PSA density were the only predictors. All the analyzed risk factors [age, PSA, DRE, prostate echogenicity and PSA/TZ index] were excluded from the model
Conclusion: PSA velocity and PSA density were the most significant predictors of prostate cancer in BPH patients with an intermediate PSA [4.1-10 ng/ml] and a negative initial sextant biopsy