Faculty Bibliography

Study Type - Prognostic (cohort) Level of Evidence 2b What's known on the subject? and What does the study add? Previous studies have attempted to characterize the normal biological variability in PSA among men without prostate cancer. These reports suggest that PSA variability is unrelated to age, but there are conflicting data on its association with the baseline PSA level. There are limited published data regarding the effects of prostate volume on PSA variability. A prior study assessing whether prostate volume changes would confound the use of PSA velocity in clinical practice reported that prostate volume changes were not significantly related to PSA changes. This study did not directly address the effect of baseline prostate volume on serial PSA variability. The objective of the current study was to further examine the relationship between prostate volume and PSA variability. Our hypothesis was that larger baseline prostate volume would be associated with increased PSA variability in men without known prostate cancer and in those with suspected small-volume disease. The results of the study suggest that baseline PSA, not prostate volume, is the primary driver of PSA variability in these populations. OBJECTIVE: * To clarify the relationship between serial prostate-specific antigen (PSA) variability and prostate volume in both cancer-free participants from the Baltimore Longitudinal Study of Aging (BLSA) and patients with low-risk prostate cancer from the Johns Hopkins Active Surveillance Program (AS). MATERIALS AND METHODS: * In all, 287 men from the BLSA and 131 patients from the AS were included in the analysis, all with at least two PSA measurements and concurrent prostate volume measurements. * PSA variability was calculated in ng/mL per year, and a linear mixed-effects model was used to determine the relative effects of prostate volume, baseline PSA and age on PSA change over time. RESULTS: * In a model with prostate volume, age and baseline PSA, there was no significant relationship between prostate volume and PSA variability (BLSA, P= 0.57; AS, P= 0.49). * Only baseline PSA showed a significant relationship to PSA yearly variability (PSAYV) (P < 0.001). Specifically, a one unit higher baseline PSA (ng/mL) corresponded on average to 0.09 and 0.06 ng/mL per year higher PSAYV in the BLSA and AS populations, respectively. CONCLUSIONS: * The results of the present study suggest that the primary driver of PSA variability is the baseline PSA level, rather than prostate volume. * Clinicians might consider the baseline PSA level to help predict the expected variability in serial PSA measurements.

The reported incidence of prostate cancer has risen since the implementation of screening. It is felt that the introduction of widespread prostate-specific antigen testing is responsible for most patients with prostate cancer now being diagnosed with asymptomatic, clinically localised disease. Diagnosis at this stage is associated with significantly improved treatment outcomes and longer life expectancy. Although there is evidence that screening has reduced prostate cancer mortality, there is a risk of over-diagnosis and over-treatment of early state prostate cancers, including clinically insignificant and indolent cancers. Active surveillance and focal therapy have been advocated as potential management options for some patients. However, these approaches face several challenges. Biopsy sampling errors together with less than optimal imaging of tumours can lead to difficulties in selecting suitable low-risk patients for these options. To overcome these challenges, novel approaches to the staging and monitoring of patients with early prostate cancer are being developed. These include new imaging techniques, such as multi-parametric magnetic resonance imaging, and the development of new biomarkers and biopsy-based methods. These techniques aim to assess the potential of a specific tumour to be aggressive, and to improve patient outcomes. The aim of the present paper is to summarise presentations and debates at the third annual Interactive Genitourinary Cancer Conference concerning the use of population-based screening methods and the roles of active surveillance and focal therapy as prostate cancer treatments. The application of novel imaging biopsy-based methods and biomarkers in early-stage prostate cancer will also be explored.

BACKGROUND: The European Randomized Study of Screening for Prostate Cancer (ERSPC) risk calculators (RCs) are validated tools for prostate cancer (PCa) risk assessment and include prostate volume (PV) data from transrectal ultrasound (TRUS). OBJECTIVE: Develop and validate an RC based on digital rectal examination (DRE) that circumvents the need for TRUS but still includes information on PV. DESIGN, SETTING, AND PARTICIPANTS: For development of the DRE-based RC, we studied the original ERSPC Rotterdam RC population including 3624 men (885 PCa cases) and 2896 men (547 PCa cases) detected at first and repeat screening 4 yr later, respectively. A validation cohort consisted of 322 men, screened in 2010-2011 as participants in ERSPC Rotterdam. MEASUREMENTS: Data on TRUS-assessed PV in the development cohorts were re-coded into three categories (25, 40, and 60 cm3) to assess the loss of information by categorization of volume information. New RCs including PSA, DRE, and PV categories (DRE-based RC) were developed for men with and without a previous negative biopsy to predict overall and clinically significant PCa (high-grade [HG] PCa) defined as T stage>T2b and/or Gleason score>/=7. Predictive accuracy was quantified by the area under the receiver operating curve. We compared performance with the Prostate Cancer Prevention Trial (PCPT) RC in the validation study. RESULTS AND LIMITATIONS: Areas under the curve (AUC) of prostate-specific antigen (PSA) alone, PSA and DRE, the DRE-based RC, and the original ERSPC RC to predict PCa at initial biopsy were 0.69, 0.73, 0.77, and 0.79, respectively. The corresponding AUCs for predicting HG PCa were higher (0.74, 0.82, 0.85, and 0.86). Similar results were seen in men previously biopsied and in the validation cohort. The DRE-based RC outperformed the PCPT RC (AUC 0.69 vs 0.59; p=0.0001) and a model based on PSA and DRE only (AUC 0.69 vs 0.63; p=0.0075) in the relatively small validation cohort. Further validation is required. CONCLUSIONS: An RC should contain volume estimates based either on TRUS or DRE. Replacing TRUS measurements by DRE estimates may enhance implementation in the daily practice of urologists and general practitioners.

Many malignancies have been linked to specific environmental exposures. Several environmental and occupational factors have been studied for an association to prostate cancer (CaP) risk. These include Agent Orange exposure, farming and pesticides, sunlight/ultraviolet radiation, as well as trace minerals used in tire and battery manufacturing. This manuscript reviews the literature on these environmental exposures and CaP.

OBJECTIVE: * To determine whether the prostate-specific antigen velocity (PSAV) risk count (i.e. the number of times PSAV exceeds a specific threshold) could increase the specificity of screening for prostate cancer and potentially life-threatening tumours. PATIENTS AND METHODS: * From 1989 to 2001, we calculated two serial PSAV measurements in 18 214 prostate cancer screening-study participants, of whom 1125 (6.2%) were diagnosed with prostate cancer. * The PSAV risk count was determined as the number of PSAV measurements of >0.4 ng/mL/year (0, 1, or 2). * We used receiver operating characteristic (ROC) and reclassification analyses to examine the ability of PSAV risk count to predict screen-detected and high-grade prostate cancer. RESULTS: * The PSAV was >0.4 ng/mL/year twice (risk count 2) in 40% of prostate cancer cases compared with only 4% of those with no cancer (P < 0.001). * After adjusting for age and PSA level, a PSAV risk count of 2 was associated with an 8.2-fold increased risk of prostate cancer (95% confidence interval 7.0-9.6, P < 0.001) and 5.4-fold increased risk of Gleason score 8-10 prostate cancer on biopsy. * Compared with a model with age and PSA level, the addition of the PSAV risk count significantly improved discrimination (area under the ROC curve 0.625 vs 0.725, P= 0.031) and reclassified individuals for the risk of high-grade prostate cancer (net reclassification, P < 0.001). CONCLUSIONS: * Sustained rises in PSA indicate a significantly greater risk of prostate cancer, particularly high-grade disease. * Compared with men with a risk count of 0.4 ng/mL/year (risk count 2) had an 8-fold increased risk of prostate cancer and 5.4-fold increased risk of Gleason 8-10 disease on biopsy, adjusting for age and PSA level. * Compared to PSA alone, PSAV risk count may be useful in reducing unnecessary biopsies and the diagnosis of low-risk prostate cancer.