Mark J. Sarno

B7-H4 Is a Novel Membrane-Bound Protein and a Candidate Serum and Tissue Biomarker for Ovarian Cancer

Using cDNA database mining strategies and real-time quantitative reverse transcription-PCR, we identified B7-H4 as a novel gene that is overexpressed in ovarian and breast cancer tissues when compared with normal tissues. The gene encodes a protein of 282 amino acids with a signal sequence, an immunoglobulin domain, and a COOH-terminal hydrophobic transmembrane domain. Immunohistochemistry experiments show plasma membrane staining in serous ovarian and breast cancer, confirming the tissue specificity and cell surface localization. We have developed a sensitive dual monoclonal antibody sandwich ELISA to analyze the level of B7-H4 protein in >2,500 serum samples, ascites fluids, and tissue lysates. High levels of B7-H4 protein were detected in ovarian cancer tissue lysates when compared with normal tissues. B7-H4 was present at low levels in all sera but showed an elevated level in serum samples from ovarian cancer patients when compared with healthy controls or women with benign gynecologic diseases. The median B7-H4 concentration in endometrioid and serous histotypes was higher than in mucinous histotypes, consistent with results of immunohistochemical staining. The multivariate logistic regression analysis of B7-H4 and CA125 measured in the same sample set resulted in an area under the curve (AUC) of 0.86 for all stages and 0.86 for stage I/II patients, which was significantly higher than the AUC for either marker alone. In early-stage patients, the sensitivity at 97% specificity increased from 52% for CA125 alone to 65% when used in combination with B7-H4. We conclude that B7-H4 is a promising new biomarker for ovarian carcinoma.

PCA3 Molecular Urine Test for Predicting Repeat Prostate Biopsy Outcome in Populations at Risk: Validation in the Placebo Arm of the Dutasteride REDUCE Trial

PURPOSE We determined the performance of PCA3 alone and in the presence of other covariates as an indicator of contemporaneous and future prostate biopsy results in a population with previous negative biopsy and increased serum prostate specific antigen. MATERIALS AND METHODS Urine PCA3 scores were determined before year 2 and year 4 biopsies from patients in the placebo arm of the REDUCE trial, a prostate cancer risk reduction study evaluating men with moderately increased serum prostate specific antigen results and negative biopsy at baseline. PCA3, serum prostate specific antigen and percent free prostate specific antigen results were correlated with biopsy outcome via univariate logistic regression and ROC analyses. Multivariate logistic regression was also performed including these biomarkers together with prostate volume, age and family history. RESULTS PCA3 scores were measurable from 1,072 of 1,140 subjects (94% informative rate). PCA3 scores were associated with positive biopsy rate (p <0.0001) and correlated with biopsy Gleason score (p = 0.0017). PCA3 AUC of 0.693 was greater than serum prostate specific antigen (0.612, p = 0.0077 vs PCA3). The multivariate logistic regression model yielded an AUC of 0.753 and exclusion of PCA3 from the model decreased AUC to 0.717 (p = 0.0009). PCA3 at year 2 was a significant predictor of year 4 biopsy outcome (AUC 0.634, p = 0.0002), whereas serum prostate specific antigen and free prostate specific antigen were not predictive (p = 0.3281 and 0.6782, respectively). CONCLUSIONS PCA3 clinical performance was validated in the largest repeat biopsy study to date. Increased PCA3 scores indicated increased risk of contemporaneous cancers and predicted future biopsy outcomes. Use of PCA3 in combination with serum prostate specific antigen and other risk factors significantly increased diagnostic accuracy.

Lipoprotein-Associated Phospholipase A2 Is an Independent Predictor of Incident Coronary Heart Disease in an Apparently Healthy Older Population: The Rancho Bernardo Study

OBJECTIVES Lipoprotein-associated phospholipase A2 (Lp-PLA2) levels predict incident coronary heart disease (CHD) in adults without known CHD, independent of heart disease risk factors. We examined whether the independent association was apparent in older adults. BACKGROUND Serum levels of Lp-PLA2, an enzyme that hydrolyzes oxidized phospholipids to yield potentially proatherogenic particles, have been associated with CHD and may help predict cardiovascular risk. METHODS Participants were 1,077 community-dwelling men and women, median age 72 years, who had no known CHD at baseline (1984 to 1987) when blood samples and risk factor data were collected. Participants were followed for CHD events for a mean of 16 years, through 2002. Cox proportional hazards regression models were used to examine the association of serum Lp-PLA2 with incident CHD (myocardial infarction, angina, or coronary revascularization). RESULTS The Lp-PLA2 levels positively correlated with age (r = 0.09), body mass index (r = 0.11), low-density lipoprotein (r = 0.37), triglycerides (r = 0.25), and C-reactive protein (r = 0.10), and negatively correlated with high-density lipoprotein (r = -0.27) (all p < 0.05). During follow-up, 228 participants had incident CHD events. Lipoprotein-associated phospholipase A2 levels in the second, third, and fourth quartiles predicted an increased risk of CHD compared with the lowest quartile (hazard ratios 1.66, 1.80, and 1.89, respectively; p < 0.05 for each). This association persisted after adjusting for C-reactive protein and other CHD risk factors. CONCLUSIONS Elevated Lp-PLA2 levels predict CHD events in apparently healthy older adults, independent of CHD risk factors.

Nucleic Acid Detection Immunoassay for Prostate-Specific Antigen Based on Immuno-PCR Methodology

BACKGROUND Serum prostate-specific antigen (PSA) concentrations after radical prostatectomy typically become undetectable with the use of current immunometric assay methods. Despite modern surgical techniques, 15%-30% of prostate cancer patients undergoing radical prostatectomy develop a biochemical recurrence during follow-up. Unfortunately, poor analytical sensitivity of standard PSA assays delays biochemical recurrence detection, and because of day-to-day assay imprecision ultrasensitive PSA assays cannot assess PSA kinetics. We developed an immuno-PCR assay for total PSA that has a limit of quantification >10 times lower than current ultrasensitive assays. METHODS The 2-site immunometric assay for total PSA employed 2 monoclonal antibodies, one conjugated to a double-stranded DNA label and the other bound to paramagnetic microparticles. After several washing steps, quantification cycles were determined and values were converted to PSA concentrations. We characterized analytical performance and compared accuracy with a commercially available total PSA assay. RESULTS The limit of quantification was 0.65 ng/L and the assay was linear in the range of 0.25-152.0 ng/L. Total imprecision estimates at PSA concentrations of 3.8, 24.1, and 69.1 ng/L were <15.2%, <9.4%, and <10.6%, respectively. Recovery of supplemented PSA ranged from 87.5% to 119.2% (mean 100.3%). Dilution recovery ranged from 96.4% to 115.3% (mean 102.3%). There was no high-dose hook effect up to 50 000 ng/L of PSA. Comparison with the commercial PSA assay showed a regression slope of 1.06 and a correlation coefficient of 0.996. CONCLUSIONS The analytical characteristics of the assay support the use of this assay for the accurate and precise measurement of serum PSA, even at sub-nanogram-per-liter concentrations.

Prostate cancer gene 3 score predicts prostate biopsy outcome in men receiving dutasteride for prevention of prostate cancer: results from the REDUCE trial.

OBJECTIVES To examine the ability of the urinary prostate cancer gene 3 (PCA3) assay to predict biopsy-detected cancers in men receiving dutasteride in the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) study cohort. METHODS Urine and serum samples from 930 men in the active arm were acquired at years 2 and 4 of the biopsy visits. In addition to univariate logistic regression and receiver operating characteristic analysis, multivariate analysis for association with biopsy outcome was performed for PCA3 score in the presence of serum prostate-specific antigen (PSA), age, prostate volume, and family history of prostate cancer. RESULTS At year 2, the univariate PCA3 score area under the receiver operating characteristic curve (AUC) was 0.668 versus 0.603 for PSA. At year 4, the PCA3 assay significantly predicted the biopsy outcome (AUC 0.628, 95% confidence interval 0.556-0.700), and the PSA level was not predictive (AUC 0.556, 95% confidence interval 0.469-0.642). The year 2 multivariate model yielded an AUC of 0.712. Removing the PCA3 score decreased the AUC to 0.660 (P = .0166 vs the full model). The median PCA3 scores in the dutasteride arm were not different from those in the 1072 men in the placebo arm (16.2 and 17.2 at year 2, P = .1755; and 18.8 and 18.1 at year 4, P = .2340, respectively). However, the PSA values were reduced >50% in the dutasteride arm at both visits (both P < .0001 vs placebo). At a PCA3 score cutoff of 35, the sensitivity and specificity were equivalent between the 2 arms. CONCLUSIONS In the present study, the PCA3 assay outperformed PSA for cancer detection in men undergoing dutasteride treatment and improved the diagnostic accuracy when combined with the PSA level and other clinical variables. In addition, no adjustment in PCA3 score was needed to yield equivalent clinical performance between the dutasteride and placebo arms. These findings are particularly important in light of the potential role of dutasteride for prostate cancer chemoprevention.

NADiA ProsVue prostate-specific antigen slope is an independent prognostic marker for identifying men at reduced risk of clinical recurrence of prostate cancer after radical prostatectomy.

OBJECTIVE To validate the hypothesis that men displaying serum prostate-specific antigen (PSA) slopes ≤ 2.0 pg/mL/mo after prostatectomy, measured using a new immuno-polymerase chain reaction diagnostic test (NADiA ProsVue), have a reduced risk of clinical recurrence as determined by positive biopsy, imaging findings, or death from prostate cancer. MATERIALS AND METHODS From 4 clinical sites, we selected a cohort of 304 men who had been followed up for 17.6 years after prostatectomy for clinical recurrence. We assessed the prognostic value of a PSA slope cutpoint of 2.0 pg/mL/mo against established risk factors to identify men at low risk of clinical recurrence using uni- and multivariate Cox proportional hazards regression and Kaplan-Meier analyses. RESULTS The univariate hazard ratio of a PSA slope >2.0 pg/mL/mo was 18.3 (95% confidence interval 10.6-31.8) compared with a slope ≤ 2.0 pg/mL/mo (P <.0001). The median disease-free survival interval was 4.8 years vs >10 years in the 2 groups (P <.0001). The multivariate hazard ratio for PSA slope with the covariates of preprostatectomy PSA, pathologic stage, and Gleason score was 9.8 (95% confidence interval 5.4-17.8), an 89.8% risk reduction for men with PSA slopes ≤ 2.0 pg/mL/mo (P <.0001). The Gleason score (<7 vs ≥ 7) was the only other significant predictor (hazard ratio 5.4, 95% confidence interval 2.1-13.8, P = .0004). CONCLUSION Clinical recurrence after radical prostatectomy is difficult to predict using established risk factors. We have demonstrated that a NADiA ProsVue PSA slope of ≤ 2.0 pg/mL/mo after prostatectomy is prognostic for a reduced risk of prostate cancer recurrence and adds predictive power to the established risk factors.

NADiA ProsVue Prostate-specific Antigen Slope, CAPRA-S, and Prostate Cancer–specific Survival After Radical Prostatectomy

OBJECTIVE To assess whether NADiA ProsVue prostate-specific antigen slope, a prognostic biomarker for identifying men at a reduced risk of clinically recurrent prostate cancer after radical prostatectomy, is prognostic for prostate cancer--specific mortality (PCSM) and other outcomes. MATERIALS AND METHODS We examined long-term outcome in the cohort of 304 men selected for the ProsVue 510(k) clinical trial. We assessed the prognostic value of a ProsVue result ≤ 2.0 pg/mL/mo and pathologic risk stratified by the Cancer of the Prostate Risk Assessment Postsurgical nomogram for a reduced risk of prostate cancer--specific survival. We also assessed its value for predicting clinical outcome in men given salvage treatment for biochemical recurrence. Efficacy was assessed using univariate and multivariate Cox regression and the Kaplan-Meier analyses. RESULTS Median (interquartile range) overall survival for the groups of men with a ProsVue slope result ≤ 2.0 and >2.0 pg/mL/mo were 11.0 (9.4-12.9) and 9.2 (4.9-11.6) years, respectively. The ProsVue univariate hazard ratio (95% confidence interval) for PCSM was 20.6 (6.8-62.7), with P <.0001 for a ProsVue result >2.0 pg/mL/mo vs a result ≤ 2.0 pg/mL/mo. The multivariate hazard ratio of ProsVue adjusted by Cancer of the Prostate Risk Assessment Postsurgical nomogram remained significant (16.7 [4.7-58.6]; P <.0001). The inverse of the hazard ratio translates to a 94.0% risk reduction for PCSM for men with a ProsVue result ≤ 2.0 pg/mL/mo. Salvage treatment for biochemical recurrence did not significantly reduce the hazard of clinical recurrence or PCSM; however, this is based on only 18 events. CONCLUSION A NADiA ProsVue slope result ≤ 2.0 pg/mL/mo was prognostic for a reduced risk of PCSM in men after radical prostatectomy.

Impact of NADiA ProsVue PSA slope on secondary treatment decisions after radical prostatectomy

BACKGROUND:Selecting appropriate candidates for postprostatectomy radiotherapy is challenging, because adverse pathological features cannot accurately predict clinical recurrence. Biomarkers that identify residual disease activity may assist clinicians when counseling patients on the risks, benefits and costs of secondary treatment. NADiA ProsVue PSA slope results ⩽2.0 pg ml−1 month−1 are predictive of a reduced risk of clinical recurrence; however, its clinical utility has not yet been studied.METHODS:We prospectively enrolled men treated by radical prostatectomy in a multicenter, institutional review board-approved clinical trial. At postsurgical follow-up, investigators (N=17) stratified men into low-, intermediate- or high-risk groups for prostate cancer recurrence based on clinicopathological findings and other factors. Investigators documented their initial treatment plan for each subject and serially collected three serum samples for ProsVue testing. After the ProsVue result was reported, investigators recorded whether or not the initial treatment plan was changed. The proportion of cases referred for secondary treatment before and after ProsVue was reported, and the significance of the difference determined.RESULTS:Complete assessments were reported for 225 men, 128 (56.9%) of whom were stratified into intermediate- and high-risk groups. Investigators reported that they would have referred 41/128 (32.0%) at-risk men for secondary treatment. However, after results were known, they referred only 15/128 (11.7%) men. The difference in proportions (−20.3%, 95% confidence interval (CI) −29.9 to −10.3%) is significant (P<0.0001). Odds of a referral was significantly reduced after results were reported (odds ratio 0.28, 95% CI 0.15–0.54, P<0.0001).CONCLUSIONS:Knowledge of a ProsVue result had significant impact on the final treatment plan. A ProsVue result ⩽2.0 pg ml−1 month−1 significantly reduced the proportion of men at risk of recurrence who otherwise would have been referred for secondary treatment.

Reflex PCA3 Messenger Ribonucleic Acid Testing: Validation of Postbiopsy Urine Samples and Correlation With Prostate Biopsy Findings in ∼2000 Patients

OBJECTIVE To validate post-transrectal ultrasonography (TRUS) prostate biopsy (bx) urine samples for PCA3 messenger ribonucleic acid testing, including correlation of PCA3 score with concurrent bx findings. METHODS From July 2008 to July 2010, 2015 patients had urine collected immediately after a TRUS-guided prostate bx. Excluded were men with history of prostate carcinoma (CaP), <6 or ≥24 bx cores, and/or prostate-specific antigen (PSA) level ≥50 ng/mL, resulting in 1909 included men. PCA3 and PSA messenger ribonucleic acid were quantitated using transcription-mediated amplification. A PCA3 score of ≥35 was considered positive. RESULTS Mean and median ages were 66 years. Mean and median PSA levels were 6.7 and 5.1 ng/mL, respectively. Bxs were benign in 970 (50.8%), CaP in 726 (38%), high-grade prostatic intraepithelial neoplasia (HGPIN) in 124 (6.5%), and atypical in 89 (4.7%). PCA3 test was informative in 1887 (98.8%) patients. Means ± standard deviations (median) of PCA3 scores for benign, HGPIN, atypical, and CaP were 22.3 ± 27.9 (12.8), 37.6 ± 43.2 (24.1), 35.7 ± 36.2 (25.7), and 46.9 ± 48.1 (31.6; P <.05 benign vs CaP, benign vs HGPIN and atypical, HGPIN and atypical vs CaP). Sensitivity and specificity of PCA3 for CaP were 46.3% and 78.7%, respectively. CaP risk increased with progressively higher PCA3 score ranges from 14.8% for PCA3 <5 to 66.7% for PCA3 >100. Area under the curve (AUC) for the PCA3 receiver operating characteristics was not significantly different in men without prior bx (AUC = 0.716) compared with men with at least 1 prior nonpositive bx (AUC = 0.702). CONCLUSION Post-TRUS bx urine is a valid sample for PCA3 testing. Patients with a negative bx and a positive PCA3 test may have a higher likelihood of unsampled CaP.