Extended use of Prostate Health Index and percentage of [-2]pro-prostate-specific antigen in Chinese men with prostate specific antigen 10-20 ng/mL and normal digital rectal examination

A prospective evaluation of the effect of finasteride on prostate health index (phi)

PURPOSE

5-alpha reductase inhibitor (5ARI) reduces prostate-specific antigen (PSA) by half but its effect on prostate health index (phi) is unknown. This study aims to investigate this effect and to enable accurate interpretation of phi in men with elevated PSA and on 5ARI.

METHODS

This is a prospective study evaluating the effect of finasteride on PSA, free PSA (fPSA), [ - 2]proPSA (p2PSA) and phi at 6 and 12 moths in men with PSA 4-20 ng/mL, no prior 5ARI use, and one negative prostate biopsy within 6 months before recruitment. The 5ARI Finasteride (5 mg/day) for 1 year was offered if International Prostatic Symptom Score (IPSS) was ≥ 8 at baseline. 5ARI group included patients taking finasteride, while control group included patients not on finasteride. The blood results were compared with t-test between baseline and different time points in each group and between groups at 1 year.

RESULTS

164 men fit the inclusion criteria and 150 were analyzed. In 5ARI group (n = 100) at 1 year, mean PSA reduced by 51.4% from 8.9(± SD 3.7) to 4.4(± SD 2.8)ng/mL (paired t-test, p < 0.001), fPSA reduced by 52.4% from 1.6(± 0.6) to 0.8(± 0.4)ng/mL (p < 0.001), p2PSA reduced by 55.3% from 18.4(± 8.8) to 8.3(± 5.6)pg/mL (p < 0.001), and phi reduced by 34.2% from 33.7(± 11.9) to 22.4(± 12.5) (p < 0.001). PSA and phi values in the control group remained static over 1 year and significantly higher than those in 5ARI group.

CONCLUSION

This study demonstrated p2PSA and phi are reduced by about 55% and 34% in men on 5ARI. A conversion factor of division by 0.66 is needed for phi in men on finasteride to allow the interpretation and use of phi in men on 5ARI.

Prostate health index (PHI) as a reliable biomarker for prostate cancer: a systematic review and meta-analysis

OBJECTIVES

Prostate cancer (PCa) represents the second most common solid cancer in men worldwide. In the last decades, the prostate health index (PHI) emerged as a reliable biomarker for detecting PCa and differentiating between non-aggressive and aggressive forms. However, before introducing it in clinical practice, more evidence is required. Thus, we performed a systematic review and meta-analysis for assessing the diagnostic performance of PHI for PCa and for detecting clinically significant PCa (csPCa).

METHODS

Relevant publications were identified by a systematic literature search on PubMed and Web of Science from inception to January 11, 2022.

RESULTS

Sixty studies, including 14,255 individuals, met the inclusion criteria for our meta-analysis. The pooled sensitivity and specificity of PHI for PCa detection was 0.791 (95%CI 0.739-0.834) and 0.625 (95%CI 0.560-0.686), respectively. The pooled sensitivity and specificity of PHI for csPCa detection was 0.874 (95%CI 0.803-0.923) and 0.569 (95%CI 0.458-0.674), respectively. Additionally, the diagnostic odds ratio was 6.302 and 9.206, respectively, for PCa and csPCa detection, suggesting moderate to good effectiveness of PHI as a diagnostic test.

CONCLUSIONS

PHI has a high accuracy for detecting PCa and discriminating between aggressive and non-aggressive PCa. Thus, it could be useful as a biomarker in predicting patients harbouring more aggressive cancer and guiding biopsy decisions.

Reclassification prediction of first-year protocol biopsy on active surveillance of prostate cancer by p2PSA-related parameters: from PRIAS-JAPAN

BACKGROUND

There is no useful predictive marker for reclassification on active surveillance. Thus, we aimed to investigate thresholds of [-2] proPSA (p2PSA)-related parameters to predict reclassification of the first-year protocol biopsy (1-year PBx) and evaluate the influence of clinical decision-making.

METHODS

This was an observational, prospective cohort study conducted at 19 Japanese institutes. The inclusion criteria included clinical stage T1c/T2, prostate-specific antigen (PSA) levels ≤10 ng/mL, PSA density <0.2 ng/ml/cc, one or two positive biopsy cores, and Gleason score (GS) ≤6 (GS ≦7 for patients aged ≥70 years) at diagnostic biopsy. All participants were required to receive a blood-sampling test on a protocol visit at inclusion and at the 1-year PBx. PSA and PSA isoforms (free PSA, p2PSA) were measured, and parameters (%free PSA, %p2PSA, phi) were calculated. Multivariable logistic regression models were used to predict the reclassification risk. To assess the predictive power and thresholds for reclassification, we plotted Receiver Operating Characteristic (ROC) curves. Decision curve analysis (DCA) was used to evaluate the variables that yielded a net clinical benefit.

RESULTS

A total of 135 patients were included, and 36 patients were reclassified on the 1-year PBx. Multivariate analyses showed that %p2PSA and phi at inclusion and p2PSA, %p2PSA, and phi before the 1-year PBx were significant predictors of reclassification at the 1-year PBx. The ROC analysis showed an optimal cutoff point, sensitivity, and specificity of %p2PSA and phi before the 1-year PBx of 1.64, 86%, 49% and 35.92, 89%, 47%, respectively. The DCA showed that phi before the 1-year PBx had the highest net benefit. The study limitation was its single-arm observational design.

CONCLUSIONS

%p2PSA and phi before the 1-year PBx had a good prediction power. phi is the most useful indicator for clinical decision-making on active surveillance.

TRIAL REGISTRATION

This study is registered atthe Japan Trial Register with ID UMIN000009876 ( https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000011573 ).

Diagnostic accuracy of [-2]proPSA versus Gleason score and Prostate Health Index versus Gleason score for the determination of aggressive prostate cancer: a systematic review

OBJECTIVE

The objective of this review was to determine the diagnostic accuracy of [-2]proPSA (p2PSA) and the Prostate Health Index compared to the Gleason score in determining the aggressiveness of prostate cancer.

INTRODUCTION

Prostate cancer is the most commonly diagnosed cancer in men. However, the utility of currently available biomarkers for determining the aggressive form of the disease remains unknown. This review sought to determine the diagnostic accuracy of two new biomarkers in determining the aggressive form of prostate cancer.

INCLUSION CRITERIA

Diagnostic accuracy studies that enrolled men of any age and any prostate specific antigen (PSA) level with histologically confirmed prostate cancer in which Prostate Health Index and p2PSA were assessed in comparison to Gleason score for the determination of aggressive prostate cancer were considered for inclusion. There was no time limitation on study inclusion.

METHODS

A three-step search strategy was utilized to identify both published and unpublished studies in the English language in the following sources: PubMed, Cochrane Central Register of Controlled Trials, CINAHL, Web of Science, Google Scholar, MedNar, and SIGLE. Databases were searched from inception to January 2019. Study selection, critical appraisal, data extraction, and data synthesis were done according to the approach recommended by JBI.

RESULTS

A total of 12 studies (n = 8462) that recruited men with aggressive prostate cancer were considered in this review. The majority of included subjects had a total PSA level of 2 to 10ng/mL. The sensitivity of the Prostate Health Index ranged from 67% to 97% while specificity ranged from 6% to 64%. At a Prostate Health Index threshold of 25 and below (three studies, n = 3222), pooled sensitivity was 97% (95% confidence interval [CI], 95% to 98%) and specificity was 10% (95% CI, 6% to 16%). At a Prostate Health Index threshold of between 26 and 35 (six studies, n = 6030), pooled sensitivity was 87% (95% CI, 8% to 91%) and specificity was 45% (95% CI, 39% to 50%). At a Prostate Health Index threshold of 36 and above (five studies, n = 1476), pooled sensitivity was 72% (95% CI, 64% to 79%) and specificity was 74% (95% CI, 68% to 80%). Only one study assessed p2PSA. Sensitivity ranged from 80% to 95%, and specificity ranged from 9.9% to 27.9% with increasing threshold values from 7.9 to 10.9ng/mL.

CONCLUSIONS

Overall, both Prostate Health Index and p2PSA have acceptable accuracy for the determination of the likelihood of aggressive prostate cancer. However, the inverse relationship between sensitivity and specificity makes it difficult to determine an optimum cut-off value for positivity. Further research is warranted to determine their utility in the management of prostate cancer.

Preanalytical stability of [-2]proPSA in whole blood stored at room temperature before separation of serum and plasma: implications to Phi determination

Background [-2]proPSA seems to outperform free/total prostate-specific antigen (PSA) ratio in prostate cancer diagnosis. However, [-2]proPSA stability remains an underestimated issue. We examined [-2]proPSA stability over time in whole blood before separation of serum and plasma and its implications for prostate health index (Phi) determination. Total PSA (tPSA) and free PSA (fPSA) stabilities were also assessed. Methods Blood was drawn from 26 patients and separated in two tubes for plasma (K2EDTA and K2EDTA plus protease inhibitors - P100) and one for serum (clot activator plus gel separator). Tubes were stored at room temperature before centrifugation 1, 3 and 5 h for serum and EDTA plasma or 1 and 5 h for P100 plasma. To investigate the influence of gel separator on markers' stability, blood was collected from 10 patients in three types of tubes to obtain serum: tubes with clot activator plus gel separator, with silica particles or glass tubes. Biomarkers were assayed with chemiluminescent immunoassays. Results [-2]proPSA and Phi levels significantly and progressively increased over time in serum (+4.81% and +8.2% at 3 h; +12.03% and +14.91% at 5 h, respectively, vs. 1 h; p<0.001). Conversely, [-2]proPSA levels did not change in plasma (EDTA or P100). tPSA levels did not change over time in serum or plasma, whereas fPSA decreased in serum. All markers were higher in plasma than in serum at any time point. This difference did not seem to be attributable to the use of gel for serum preparation. Conclusions EDTA prevented spurious in vitro modifications in PSA-related isoforms, confirming that a stabilized blood sample is a prerequisite for [-2]proPSA measurement and Phi determination.

Prospective performance of the Prostate Health Index in prostate cancer detection in the first prostate biopsy of men with a total prostatic specific antigen of 4-10 ng/mL and negative digital rectal examination

Background

The disadvantage of using total serum prostatic specific antigen (PSA) test for detection of prostate cancer is that it has a low specificity. The low specificity of total PSA (tPSA) test leads to unnecessary prostate biopsies. In this prospective study, we assessed the serum tPSA, free PSA, p2PSA, and the Prostate Health Index (PHI) in the detection of prostate cancer in men with a tPSA of 4–10 ng/mL and a negative digital rectal examination (DRE).

Materials and methods

101 male outpatients with a serum PSA of 4–10 ng/mL and nonsuspicious DRE for prostate cancer who underwent first transrectal ultrasound with a prostate biopsy were recruited. A blood sample to enable tPSA, free PSA, and p2PSA levels to be calculated was drawn before the prostate biopsy. The diagnosis and detection of high-grade cancer are correlated with the blood sample.

Results

Sixteen patients were positive for prostate cancer. All had significantly higher serum 2pPSA and PHI levels than patients with no cancer. A PHI level at 90% sensitivity (cutoff of 34.14) demonstrated a higher area under the receiver operating characteristic curve and more specificity in diagnosis and detection of high-grade prostate cancer than other tests.

Conclusions

The PHI in men with a PSA level of 4–10 ng/mL with negative DRE increased specificity in the detection of prostate cancer. This test is useful in discriminating between patients with or without cancer and also enables the detection of high-grade cancer avoiding unnecessary biopsies.