Background Molecular studies have tried to address the unmet need for prognostic biomarkers in prostate cancer (PCa). Some gene expression tests improve upon clinical factors for prediction of outcomes, but additional tools for accurate prediction of tumor aggressiveness are needed. Methods Based on a previously published panel of 23 gene transcripts that distinguished patients with metastatic progression, we constructed a prediction model using independent training and testing datasets. Using the validated messenger RNAs and Gleason score (GS), we performed model selection in the training set to define a final locked model to classify patients who developed metastatic‐lethal events from those who remained recurrence‐free. In an independent testing dataset, we compared our locked model to established clinical prognostic factors and utilized Kaplan‐Meier curves and receiver operating characteristic analyses to evaluate the model's performance. Results Thirteen of 23 previously identified gene transcripts that stratified patients with aggressive PCa were validated in the training dataset. These biomarkers plus GS were used to develop a four‐gene (CST2, FBLN1, TNFRSF19, and ZNF704) transcript (4GT) score that was significantly higher in patients who progressed to metastatic‐lethal events compared to those without recurrence in the testing dataset (P = 5.7 × 10−11). The 4GT score provided higher prediction accuracy (area under the ROC curve [AUC] = 0.76; 95% confidence interval [CI] = 0.69‐0.83; partial area under the ROC curve [pAUC] = 0.008) than GS alone (AUC = 0.63; 95% CI = 0.56‐0.70; pAUC = 0.002), and it improved risk stratification in subgroups defined by a combination of clinicopathological features (ie, Cancer of the Prostate Risk Assessment‐Surgery). Conclusion Our validated 4GT score has prognostic value for metastatic‐lethal progression in men treated for localized PCa and warrants further evaluation for its clinical utility.

4656 Background: Gleason Sum (GS) predicts clinically significant prostate cancer (CAP) and prostate specific antigen (PSA) survival in men undergoing prostatectomy for CAP. BPH can also elevate PSA. Objective: evaluate prostate gland volume (PV) and American Urologic Symptom Score (AUASS) in men undergoing prostate needle biopsy (PNB) to detect CAP. Analysis endpoints: 1) CAP and 2) GS ≥7. Methods: From 1/2000–7/2005, 1,078 men undergoing PNB were prospectively examined. Urinary voiding symptoms were measured by AUASS. All men were examined by 1 surgeon: DRE and Transrectal Ultrasound (TRUS) were given levels of suspicion (LOS) from 1 = low suspicion (smooth DRE, homogeneous TRUS) to 5 = high suspicion (hard DRE, hypoechoic lesion). LOS ≥3 was abnormal. Prebiopsy parameters: PSA, DRE, age, race, biopsy history, prostate volume (PV), TRUS lesion, and AUASS. All men had 10-core biopsy. 1) Predictors for CAP were evaluated by Univariate (UVA) and multivariate (MVA) analysis (logistic regression) for 1,078 men. 2) Predictors for GS≥7 were evaluated in men with no prior biopsy (NOPB). Results: Median PSA = 5.4 ng/ml (mean 10.4), 38% and 52% had abnormal TRUS & DRE respectively. Mean patient age = 64 years. Mean AUASS = 10.4. Positive biopsy rate = 38%. AUASS: 47% had low symptoms scores (<7), 39% had moderate scores (8–19), and 14% had severe scores (20–35). UVA & MVA (N = 1,078) showed that PSA was not an independent predictor of CAP (p = 0.18), but abnormal DRE, age, low AUASS, no prior biopsy (NOPB), race (AA), abnormal TRUS, and low PV were all independent predictors (p < 0.03). Subset MVA analysis of men in PSA range of 2.5–10 (N = 738), demonstrated that low AUASS (p = 0.05) & low PV (p = 0.00001) were predictors of CAP, while DRE, NOPB, and age were also independent predictors. MVA of men with NOPB (N = 790), indicated that low PV, PSA, DRE, and Age were independent predictors for CAP (p < 0.0001). The multivariate risk of having GS ≥7 on biopsy was independently associate with both low PV (p = 0.001) and abnormal DRE (p = 0.001). The relationship between PV and GS ≥7 showed that for every 1 cc increase in gland volume the risk of GS ≥7 CAP decreases by 2.2%. Conclusions: Men with smaller prostates are more likely to have cancer and are more likely to have significant disease. No significant financial relationships to disclose.

No abstract

62% pursued AS. Use of AS varied across VAMCs (range:31%-84%). AS increased with age, and decreased with higher GS and NCCN risk group. Characteristics were similar among the 97 Veterans prospectively enrolled, including NCCN risk (VL: 24%, L: 38%, INT: 38%). A wide range of GPS results were observed (4-48).The GPS provided a refined risk group in 5% of VL, 27% of L, and 9% of INT. ConClusions: Both groups of patients had characteristics representative of low risk PCa in the VA. Chart review confirmed variation in use of AS. Analysis of 97 tested Veterans showed refined risk estimates after GPS. Results presented at the meeting will demonstrate the ability of the GPS assay to identify men with low risk PCa for AS or immediate therapy using individualized biological information.