Prediction of the risk of harboring prostate cancer by a prebiopsy nomogram based on extended biopsy protocol

A Nomogram Based on a TRUS Five-Grade Scoring System for the Prediction of Prostate Cancer and High Grade Prostate Cancer at Initial TRUS-Guided Biopsy

Purpose: To evaluate the efficacy of transrectal ultrasound five-grade scoring system (TRUS-5) in predicting prostate cancer (PCa) and high grade PCa (HGPCa), compared with TRUS two-grade scoring system (TRUS-2), and establish a TRUS-5 based nomogram for the prediction of PCa and HGPCa at initial biopsy (IPBx).

Methods: Data were collected from 862 men who underwent initial TRUS-guided 12-core prostate biopsy. Age, prostate-specific antigen (PSA), percent free PSA, digital rectal examination (DRE), prostate volume (PV), PSA density (PSAD) and TRUS findings were included in the analysis. For TRUS-5, the probability of PCa was quantified on a scale from 1 (benign) to 5 (malignant). TRUS-2 used the grades “normal” and “suspicious”. After univariate and multivariate logistic regression analyses, nomogram models were developed and internally validated based on independent predictors to predict the probability of PCa and HGPCa.

Results: Overall PCa was detected in 42% (362/862) with 26.22% (226/862) showing HGPCa. TRUS-5 significantly outperformed TRUS-2 for the risk prediction of PCa and HGPCa (area under the receiver operating characteristic curve [AUC]: 0.787 vs. 0.694 for PCa, 0.841 vs. 0.713 for HGPCa, P<0.05). The TRUS-5 based nomogram showed higher AUCs (0.905 for PCa, 0.903 for HGPCa) than PSA alone, clinical base model, the TRUS-2 based model, and other predictive models (P<0.05).

Conclusions: TRUS-5 represents a better imaging predictor than TRUS-2 for PCa and HGPCa. Our TRUS-5 based nomogram models performed well for the prediction of PCa and HGPCa at IPBx, which may help to make the decision to biopsy.

The role of biomarkers in the assessment of prostate cancer risk prior to prostate biopsy: which markers matter and how should they be used?

Prostate cancer (PCa) screening has been substantially influenced by the clinical implementation of serum prostate-specific antigen (PSA). In this context, improvement of early PCa detection and stage migration as well as reduced PCa mortality were achieved, and up-to-date PSA represents the gold standard biomarker of PCa diagnosis together with clinical findings. Nonetheless, PSA shows weakness in discriminating between malign and benign prostatic disease or indolent and aggressive cancers. As a result, the expansion of PSA screening is extensively debated with regard to overdetection and ultimately overtreatment, keeping in mind that PCa is still the third leading cause of cancer-specific mortality in the Western male population. Consequently, today's task is to increase the accuracy of PCa detection and furthermore to allow stratification for indolent PCa that might permit active surveillance and to filter out aggressive cancers necessitating treatment. Thus, novel biomarkers, especially in combination with approved clinical risk factors (e.g., age or family history of PCa), within multivariable prediction models carry the potential to improve many aspects of PCa diagnosis and to enable risk classification in clinical practice. Multivariable models lead to superior accuracy for PCa prediction instead of the use of a single risk factor. The aim of this article was to present an overview of known risk factors for PCa together with new promising blood- and urine-based biomarkers and their application within risk models that may allow risk stratification for PCa prior to prostate biopsy. Risk models may optimize PCa detection and classification with regard to improved PCa risk assessment and avoidance of unnecessary prostate biopsies.

Evaluating the use of prostate-specific antigen as an instrument for early detection of prostate cancer beyond urologists: results of a representative cross-sectional questionnaire study of general practitioners and internal specialists

OBJECTIVES

The aim of this cross-sectional study was to evaluate the value of prostate-specific antigen (PSA) testing as a tool for early detection of prostate cancer (PCa) applied by general practitioners (GPs) and internal specialists (ISs) as well as to assess criteria leading to the application of PSA-based early PCa detection.

METHODS

Between May and December 2012, a questionnaire containing 16 items was sent to 600 GPs and ISs in the federal state Brandenburg and in Berlin (Germany). The independent influence of several criteria on the decision of GPs and ISs to apply PSA-based early PCa detection was assessed by multivariate logistic regression analysis (MLRA).

RESULTS

392 evaluable questionnaires were collected (return rate 65%). 81% of the physicians declared that they apply PSA testing for early PCa detection; of these, 58 and 15% would screen patients until the age of 80 and 90 years, respectively. In case of a pathological PSA level, 77% would immediately refer the patient to a urologist, while 13% would re-assess elevated PSA levels after 3-12 months. Based on MLRA, the following criteria were independently associated with a positive attitude towards PSA-based early PCa detection: specialisation (application of early detection more frequent for GPs and hospital-based ISs) (OR 3.12; p < 0.001), physicians who use exclusively GP or IS education (OR 3.95; p = 0.002), and physicians who recommend yearly PSA assessment after the age of 50 (OR 6.85; p < 0.001).

CONCLUSIONS

GPs and ISs frequently apply PSA-based early PCa detection. In doing so, 13% would initiate specific referral to a urologist in case of pathological PSA values too late. Improvement of this situation could possibly result from specific educational activities for non-urological physicians active in fields of urological core capabilities, which should be guided by joint boards of the national associations of urology and general medicine.