Prostate cancer and the PCP: the screening dilemma

The 4Kscore blood test accurately identifies men with aggressive prostate cancer prior to prostate biopsy with or without DRE information

INTRODUCTION

The 4Kscore Test is a prebiopsy blood test that incorporates four prostate protein biomarkers along with patient clinical information to determine a man's risk for high-grade, aggressive (Gleason ≥7) prostate cancer. However, some men likely to benefit from the test may be seen in primary care settings where the digital rectal examination (DRE) information is not always obtained. In this study, we assessed the clinical validity of the 4Kscore Test when the DRE information was not included in the algorithm.

METHODS

The Prospective 4Kscore Validation Study enrolled 1012 men scheduled for prostate biopsy across 26 urology practices in the United States. The 4Kscore was calculated for each patient with and without DRE information. The primary outcome was Gleason ≥7 prostate cancer on prostate biopsy. The contribution of DRE to the predictive accuracy of the test was evaluated by area under the receiver operating curve (AUC-ROC), risk calibration and clinical consequences.

RESULTS

High-grade, aggressive prostate cancer was found in 231 (23%) of the 1012 patients. Both versions of the 4Kscore Test, with and without DRE, showed excellent discrimination (AUC=0.821 with DRE and AUC=0.818 without DRE input) and excellent calibration. No clinically significant difference was found between the two versions of the 4Kscore.

CONCLUSIONS

The 4Kscore Test algorithm, whether DRE findings are available or not, performs well in predicting a man's risk of high-grade, aggressive prostate cancer. Patients who are suspected of having aggressive prostate cancer can safely have their risk better defined by 4Kscore even if a DRE has not been performed recently.

Clarifying the PSA grey zone: The management of patients with a borderline PSA

INTRODUCTION

Prostate specific antigen is a marker for prostate cancer and a key diagnostic tool, yet when to refer patients with a borderline PSA is currently unclear. This review describes how to assess a patient with borderline PSA and provides an algorithm for management.

METHODS

Current literature on reference values, factors affecting PSA, indications for referral, non-invasive investigations and the role of MRI were reviewed. Medline and EMBASE were searched using MeSH terms.

RESULTS

The literature suggests that a PSA of over 1.5 ng/mL should be used as a cut-off to consider further testing for all age groups. There is strong evidence to show that adjuncts are useful when interpreting PSA results, most notably percentage free PSA and proPSA. Considerable weighting should also be given to the ERSPC risk calculator when deciding when to refer. Multi-parametric MRI is valuable in closely examining suspicious lesions to reduce the number of negative biopsies. MRI fusion biopsy (TRUS, transrectal ultrasonography or transperineal) should be considered over standard TRUS biopsy to detect more clinically significant disease.

CONCLUSIONS

Management of borderline PSA is not straightforward. A cut-off of 1.5 ng/mL should be used in conjunction with digital rectal exam, risk calculation and PSA adjuncts. Imaging and biopsy should utilise mpMRI to achieve improved diagnosis of clinically significant prostate cancer, with fewer unnecessary investigations.