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Background:: To assess the utility of urinary prostate cancer antigen 3 (PCA3) as both a one-time and longitudinal measure in men on active surveillance (AS). Methods:: The Johns Hopkins AS program monitors men with favorable-risk prostate cancer with serial PSA, digital rectal examination (DRE), prostate magnetic resonance imaging and prostate biopsy. Since 2007, post-DRE urinary specimens have also been routinely obtained. Men with multiple PCA3 measures obtained over ⩾3 years of monitoring were included. Utility of first PCA3 score (fPCA3), subsequent PCA3 (sPCA3) and change in PCA3 were assessed for prediction of Gleason grade reclassification (GR, Gleason score >6) during follow-up. Results:: In total, 260 men met study criteria. Median time from enrollment to fPCA3 was 2 years (interquartile range (IQR) 1–3) and from fPCA3 to sPCA3 was 5 years (IQR 4–6). During median follow-up of 6 years (IQR 5–8), 28 men (11%) underwent GR. Men with GR had higher median fPCA3 (48.0 vs 24.5, P=0.007) and sPCA3 (63.5 vs 36.0, P=0.002) than those without GR, while longitudinal change in PCA3 did not differ by GR status (log-normalized rate 0.07 vs 0.06, P=0.53). In a multivariable model including age, risk classification and PSA density, fPCA3 remained significantly associated with GR (log(fPCA3) odds ratio=1.77, P=0.04). Conclusions:: PCA3 scores obtained during AS were higher in men who underwent GR, but the rate of change in PCA3 over time did not differ by GR status. PCA3 was a significant predictor of GR in a multivariable model including conventional risk factors, suggesting that PCA3 provides incremental prognostic information in the AS setting.

Background:: To evaluate the relationship between PSA testing history and high-risk disease among older men diagnosed with prostate cancer. Methods:: Records from 1993 to 2014 were reviewed for men who underwent radiotherapy for prostate cancer at age 75 years or older. Patients were classified into one of four groups based on PSA-testing history: (1) no PSA testing; (2) incomplete/ineffective PSA testing; (3) PSA testing; or (4) cannot be determined. Outcomes of interest were National Comprehensive Cancer Network (NCCN) risk group (that is, low, intermediate or high risk) and biopsy grade at diagnosis. Multivariable logistic regression was used to determine the association between PSA testing history and high-risk cancer. Results:: PSA-testing history was available in 274 (94.5%) of 290 subjects meeting study criteria. In total, 148 men (54.0%) underwent PSA testing with follow-up biopsy, 72 (26.3%) underwent PSA testing without appropriate follow-up, and 54 men (19.7%) did not undergo PSA testing. Patients who underwent PSA testing were significantly less likely to be diagnosed with NCCN high-risk cancer (23.0% vs 51.6%, P<0.001). On multivariable analysis, men with no/incomplete PSA testing had more than three-fold increased odds of high-risk disease at diagnosis (odds ratio 3.39, 95% confidence interval 1.96–5.87, P<0.001) as compared to the tested population. Conclusions:: Older men who underwent no PSA testing or incomplete testing were significantly more likely to be diagnosed with high-risk prostate cancer than those who were previously screened. It is reasonable to consider screening in healthy older men likely to benefit from early detection and treatment.

Background:: The Prostate Health Index (phi) outperforms PSA and other PSA derivatives for the diagnosis of prostate cancer (PCa). The impact of phi testing in the real-world clinical setting has not been previously assessed. Methods:: In a single, large, academic center, phi was tested in 345 patients presenting for diagnostic evaluation for PCa. Findings on prostate biopsy (including Grade Group (GG), defined as GG1: Gleason score (GS) 6, GG2: GS 3+4=7, GG3: GS 4+3=7, GG4: GS 8 and GG5: GS 9–10), magnetic resonance imaging (MRI) and radical prostatectomy (RP) were prospectively recorded. Biopsy rates and outcomes were compared with a contemporary cohort that did not undergo phi testing (n=1318). Results:: Overall, 39% of men with phi testing underwent prostate biopsy. No men with phi<19.6 were diagnosed with PCa, and only three men with phi<27 had cancer of GG⩾2. Phi was superior to PSA for the prediction of any PCa (area under the receiver operating characteristic curve (AUC) 0.72 vs 0.47) and GG⩾2 PCa (AUC 0.77 vs 0.53) on prostate biopsy. Among men undergoing MRI and phi, no men with phi<27 and PI-RADS⩽3 had GG⩾2 cancer. For those men proceeding to RP, increasing phi was associated with higher pathologic GG (P=0.002) and stage (P=0.001). Compared with patients who did not undergo phi testing, the use of phi was associated with a 9% reduction in the rate of prostate biopsy (39% vs 48%; P<0.001). Importantly, the reduction in biopsy among the phi population was secondary to decreased incidence of negative (8%) and GG1 (1%) biopsies, whereas the proportion of biopsies detecting GG⩾2 cancers remained unchanged. Conclusions:: In this large, real-time clinical experience, phi outperformed PSA alone, was associated with high-grade PCa, and provided complementary information to MRI. Incorporation of phi into clinical practice reduced the rate of unnecessary biopsies without changing the frequency of detection of higher-grade cancers.

Background:: B7-H3 (CD276), part of the B7 superfamily of immune checkpoint molecules, has been shown to have an immunomodulatory role. Its regulation, receptor and mechanism of action remain unclear. B7-H3 protein expression correlates with prostate cancer outcomes, and humanized monoclonal antibodies (that is, enoblituzumab) are currently being investigated for therapeutic use. Here we used genomic expression data to examine the relationship between B7-H3mRNA expression and prostate cancer. Methods:: Prostatectomy tissue from 2781 patients were profiled using the Affymetrix HuEx 1.0 ST microarray. Pairwise comparisons were used to identify significant associations between B7-H3 expression and clinicopathologic variables, and survival analyses were used to evaluate the prognostic significance of B7-H3. Pearson’s correlation analyses were performed to assess the relationship of B7-H3expression with molecular subtypes and individual transcripts. Androgen receptor (AR) occupancy at the B7-H3locus was determined using chromatin immunoprecipitation (ChIP), and androgen-dependent expression changes in B7-H3was evaluated by quantitative reverse transcription PCR in LNCaP cell lines. Oncomine was queried to evaluate B7-H3expression in metastatic disease. Results:: B7-H3mRNA expression was positively associated with higher Gleason score (P<0.001), tumor stage (P<0.001), and castrate resistant metastatic disease (P<0.0001). High B7-H3expression correlated with the development of metastasis and prostate cancer specific mortality, but this was not significant on multi-variable analysis. B7-H3expression correlated with ERG-positive disease (r=0.99) and ARexpression (r=0.36). ChIP revealed an AR-binding site upstream of B7-H3, and the presence of androgens decreased B7-H3expression in LNCaP suggesting potential direct AR regulation. Gene set enrichment analysis demonstrated an association of B7-H3with androgen signaling as well as immune regulatory pathways. Conclusions:: Higher B7-H3expression correlates with Gleason grade, prostate cancer stage and poor oncologic outcomes in prostatectomy cohorts. B7-H3expression appears to be related to androgen signaling as well as the immune reactome.

Background:To date, there have been no published trials examining the impact of salvage radiation therapy (SRT) in the post-operative setting for prostate cancer (PCa). We conducted a retrospective, comparative study of post-operative radiation following radical prostatectomy (RP) for men with pT3 disease or positive margins (adverse pathological features, APF).Methods:422 PCa men treated at four institutions with RP and having APF were analyzed with a primary end point of metastasis. Adjuvant radiation treatment (ART, n=111), minimal residual disease (MRD) SRT (n=70) and SRT (n=83) were defined by PSA levels of <0.2, 0.2–0.49 and ⩾0.5 ng ml−1, respectively, before radiation therapy (RT) initiation. Remaining 157 men who did not receive additional therapy before metastasis formed the no RT arm. Clinical–genomic risk was assessed by Cancer of the Prostate Risk Assessment Post-Surgical (CAPRA-S) and Decipher. Cox regression was used to evaluate the impact of treatment on outcome.Results:During the study follow-up, 37 men developed metastasis with a median follow-up of 8 years. Both CAPRA-S and Decipher had independent predictive value on multivariable analysis for metastasis (P<0.05). Adjusting for clinical–genomic risk, SRT and no RT had hazard ratios of 4.31 (95% confidence interval, 1.20–15.47) and 5.42 (95% confidence interval, 1.59–18.44) for metastasis compared with ART, respectively. No significant difference was observed between MRD-SRT and ART (P=0.28). Men with low-to-intermediate CAPRA-S and low Decipher value have a low rate of metastatic events regardless of treatment selection. In contrast, men with high CAPRA-S and Decipher benefit from ART, however the cumulative incidence of metastasis remains high.Conclusions:The decision as to the timing and need for additional local therapy following RP is nuanced and requires providers and patients to balance risks of morbidity with improved oncological outcomes. Post-RP treatment can be safely avoided for men who are low risk by clinical–genomic risk, whereas those at high risk should favor enrollment in clinical trials.