What's new in screening in 2015?

Value of PHI and PHID in the detection of intermediate- and high-risk prostate cancer

BACKGROUND AND AIMS

PSA testing practice results in a large number of unnecessary prostate biopsies and the overdiagnosis of clinically insignificant prostate cancer (PCa). The aim of our study was to evaluate the value of PHI and PHID for the detection of PCa.

MATERIALS AND METHODS

We measured tPSA, fPSA and p2PSA in 455 patients scheduled for biopsy, including 243 patients with PCa. D'Amico criteria were used to classify these patients in three groups related to risk of progression. Intermediate- and high-risk PCa were considered as aggressive PCa.

RESULTS

The best area under the curve (AUC) value obtained in the detection of aggressive PCa was achieved for PHI and PHID (0.766 and 0.760, respectively). We found a relationship of the performance of by these tests with the calculated prostate volume or the estimated prostate size by digital rectal exam, obtaining the higher AUC in patients with a small prostate. Thus, the AUC for PHI was 0,843 for patients with small calculated prostate volume and 0,817 for patients with small estimated prostate size.

CONCLUSIONS

Our results underline that PHI and PHID outperforms the efficacy obtained with tPSA and %fPSA. Substantial differences in their value in relation to prostate volume were found.

Definition of Outcome-Based Prostate-Specific Antigen (PSA) Thresholds for Advanced Prostate Cancer Risk Prediction

Simple Summary

In this study, we used a well calibrated risk prediction model to define prostate-specific antigen (PSA) thresholds for identifying or excluding advanced prostate cancer (PCa) as an aid to personalize management of the diagnostic workup. PSA concentrations ≤ 4.1 (<65 years old) and ≤3.7 μg/L (≥65 years old) excluded an advanced PCa in patients without glandular inflammation, while PSA > 5.7 (<65) and >6.1 μg/L (≥65) suggested a biopsy referral. In the presence of glandular inflammation, PSA does not provide a valid estimate for risk of advanced cancer since the marker variability is higher and the pre-test probability of PCa is low in this group. The proposed PSA thresholds may allow an individualized approach to the diagnostic workup, assisting patients in making an informed decision. However, patients with asymptomatic prostatitis cannot benefit from the use of this model since they cannot be pre-biopsy identified.

Abstract

We defined prostate-specific antigen (PSA) thresholds from a well calibrated risk prediction model for identifying and excluding advanced prostate cancer (PCa). We retrieved 902 biopsied patients with a pre-biopsy PSA determination (Roche assay). A logistic regression model predictive for PCa including the main effects [i.e., PSA, age, histological evidence of glandular inflammation (GI)] was built after testing the accuracy by calibration plots and Hosmer-Lemeshow test for goodness of fit. PSA thresholds were derived by assuming a diagnostic sensitivity of 95% (rule-out) and 80% (rule-in) for overall and advanced/poorly differentiated PCa. In patients without GI, serum PSA concentrations ≤ 4.1 (<65 years old) and ≤3.7 μg/L (≥65 years old) excluded an advanced PCa (defined as Gleason score ≥ 7 at biopsy), with a negative predictive value of 95.1% [95% confidence interval (CI): 83.0–98.7] and 88.8% (CI: 80.2–93.9), respectively, while PSA > 5.7 (<65) and >6.1 μg/L (≥65) should address biopsy referral. In presence of GI, PSA did not provide a valid estimate for risk of advanced cancer because of its higher variability and the low pre-test probability of PCa. The proposed PSA thresholds may support biopsy decision except for patients with asymptomatic prostatitis who cannot be pre-biopsy identified.

Prostate cancer screening: guidelines review and laboratory issues

Background Prostate-specific antigen (PSA) remains as the most used biomarker in the detection of early prostate cancer (PCa). Clinical practice guidelines (CPGs) are produced to facilitate incorporation of evidence into clinical practice. This is particularly useful when PCa screening remains controversial and guidelines diverge among different medical institutions, although opportunistic screening is not recommended. Methods We performed a systematic review of guidelines about PCa screening using PSA. Guidelines published since 2008 were included in this study. The most updated version of these CPGs was used for the evaluation. Results Twenty-two guidelines were selected for review. In 59% of these guidelines, recommendations were graded according to level of evidence (n = 13), but only 18% of the guidelines provided clear algorithms (n = 4). Each CPG was assessed using a checklist of laboratory issues, including pre-analytical, analytical, and post-analytical factors. We found that laboratory medicine specialists participate in 9% of the guidelines reviewed (n = 2) and laboratory issues were frequently omitted. We remarked that information concerning the consequences of World Health Organization (WHO) standard in PSA testing was considered by only two of 22 CPGs evaluated in this study. Conclusions We concluded that the quality of PCa early detection guidelines could be improved properly considering the laboratory issues in their development.

Detection and Prognosis of Prostate Cancer Using Blood-Based Biomarkers

Prostate cancer (PCa) is second only to lung cancer as a cause of death. Clinical assessment of patients and treatment efficiency therefore depend on the disease being diagnosed as early as possible. However, due to issues regarding the use of prostate-specific antigen (PSA) for screening purposes, PCa management is among the most contentious of healthcare matters. PSA screening is problematic primarily because of diagnosis difficulties and the high rate of false-positive biopsies. Novel PCa biomarkers, such as the Prostate Health Index (PHI) and the 4Kscore, have been proposed in recent times to improve PSA prediction accuracy and have shown higher performance by preventing redundant biopsies. The 4Kscore also shows high precision in determining the risk of developing high-grade PCa, whereas elevated PHI levels suggest that the tumor is aggressive. Some evidence also supports the effectiveness of miRNAs as biomarkers for distinguishing PCa from benign prostatic hyperplasia and for assessing the aggressiveness of the disease. A number of miRNAs that possibly act as tumor inhibitors or oncogenes are impaired in PCa. These new biomarkers are comprehensively reviewed in the present study in terms of their potential use in diagnosing and treating PCa.

Towards personalized prostate cancer screening

The value of the prostate-specific antigen (PSA) in prostate cancer (PCa) screening is controversial. Contradictory results have been reported in the literature as to whether PSA-based screening reduces mortality. Also, some of the studies published are methodologically flawed. However, evidence consistently demonstrates that screening programs results in the identification of patients with indolent prostatic tumors which rate has increased. Controversy is not only about the value of PSA-based screening, but also about the age range for screening, risk groups based on baseline PSA, PSA ranges, or the use of other biomarkers (PHI, 4Kscore). At present, PCa screening in the general population is not recommended by most scientific societies, although it can be used after discussing the risks and benefits with the patient. When discussing the need to perform a screening, the risks of using screening (lack of specificity of PSA, overdiagnosis) must be weighed against the risks of not performing it (increased rate of patients with initial diagnosis of metastasis). In the recent years, a number of authors have advocated the use of personalized screening, which could change the risk/benefit evaluation, thereby making screening necessary on the basis of a set of individual factors.

Prostate cancer screening-when to start and how to screen?

Prostate-specific antigen (PSA) screening reduces prostate cancer (PCa) mortality; however such screening may lead to harm in terms of overdiagnosis and overtreatment. Therefore, upfront shared decision making involving a discussion about pros and cons between a physician and a patient is crucial. Total PSA remains the most commonly used screening tool and is a strong predictor of future life-threatening PCa. Currently there is no strong consensus on the age at which to start PSA screening. Most guidelines recommend PSA screening to start no later than at age 55 and involve well-informed men in good health and a life expectancy of at least 10–15 years. Some suggest to start screening in early midlife for men with familial predisposition and men of African-American descent. Others suggest starting conversations at age 45 for all men. Re-screening intervals can be risk-stratified as guided by the man’s age, general health and PSA-value; longer intervals for those at lower risk and shorter intervals for those at higher risk. Overdiagnosis and unnecessary biopsies can be reduced using reflex tests. Magnetic resonance imaging in the pre-diagnostic setting holds promise in pilot studies and large-scale prospective studies are ongoing.

Improving the evaluation and diagnosis of clinically significant prostate cancer in 2017

PURPOSE OF REVIEW

To provide an overview of the current state of the evidence and highlight recent advances in the evaluation and diagnosis of clinically significant prostate cancer, focusing on biomarkers, risk calculators and multiparametric MRI (mpMRI).

RECENT FINDINGS

In 2017 there are numerous options to improve early detection as compared to a purely prostate-specific antigen (PSA)-based approach. All have strengths and drawbacks. In addition to repeating the PSA and performing clinical work-up (digital rectal examination and estimation of prostate volume), additional tests investigated in the initial biopsy setting are: %free PSA, Prostate Health Index, 4-kallikrein score, SelectMDx, and Michigan Prostate Score and in the repeat setting: %free PSA, Prostate Health Index, 4-kallikrein score, Prostate Cancer Antigen 3, and ConfirmMDx. Risk calculators are available for both biopsy settings and incorporate clinical data with, or without, biomarkers. mpMRI is an important diagnostic adjunct.

SUMMARY

There are numerous tests available that can help increase the specificity of PSA, in the initial and repeat biopsy setting. All coincide with a small decrease in sensitivity of detecting high-grade cancer. Cost effectiveness is crucial. The way forward is a multivariable risk assessment on the basis of readily available clinical data, potentially with the addition of PSA subforms, preferably at low cost. MRI in the prediagnostic setting is promising, but is not ready for 'prime time'.

The effect of the USPSTF PSA screening recommendation on prostate cancer incidence patterns in the USA

Guidelines regarding recommendations for PSA screening for early detection of prostate cancer are conflicting. In 2012, the United States Preventive Services Task Force (USPSTF) assigned a grade of D (recommending against screening) for men aged ≥75 years in 2008 and for men of all ages in 2012. Understanding temporal trends in rates of screening before and after the 2012 recommendation in terms of usage patterns in PSA screening, changes in prostate cancer incidence and biopsy patterns, and how the recommendation has influenced physician's and men's attitudes about PSA screening and subsequent ordering of other screening tests is essential within the scope of prostate cancer screening policy. Since the 2012 recommendation, rates of PSA screening decreased by 3-10% in all age groups and across most geographical regions of the USA. Rates of prostate biopsy and prostate cancer incidence have declined in unison, with a shift towards tumours being of higher grade and stage upon detection. Despite the recommendation, some physicians report ongoing willingness to screen appropriately selected men, and many men report intending to continue to ask for the PSA test from their physician. In the coming years, we expect to have an improved understanding of whether these decreased rates of screening will affect prostate cancer metastasis and mortality.