Estimating the sensitivity of a prostate cancer screening programme for different PSA cut-off levels: A UK case study

PSA screening for prostate cancer in the United States: 30 years of controversy

In 1994, the United States approved the Prostate-Specific Antigen (PSA) test as a screening tool for prostate cancer. It did so despite the test's inherent weakness: not being prostate cancer specific. Subsequent randomized trials yielded conflicting results as to its benefits. Medical guideline organizations are concerned that PSA screening results in the diagnosis and treatment of clinically indolent prostate cancer. Nevertheless, PSA screening is prevalent in North America and Europe with PSA screening increasing in other regions. We provide a critical review of the major factors that led to the prevalence of PSA screening in the United States despite the debate about its benefits. Public advocacy in favor of the test and failure of the medical community to appreciate its inherent weakness led to widespread adoption. These factors persist today. Other countries need to carefully analyze the utility of the PSA test before adopting it.

Development of a multigenomic liquid biopsy (PROSTest) for prostate cancer in whole blood

INTRODUCTION

We describe the development of a molecular assay from publicly available tumor tissue mRNA databases using machine learning and present preliminary evidence of functionality as a diagnostic and monitoring tool for prostate cancer (PCa) in whole blood.

MATERIALS AND METHODS

We assessed 1055 PCas (public microarray data sets) to identify putative mRNA biomarkers. Specificity was confirmed against 32 different solid and hematological cancers from The Cancer Genome Atlas (n = 10,990). This defined a 27-gene panel which was validated by qPCR in 50 histologically confirmed PCa surgical specimens and matched blood. An ensemble classifier (Random Forest, Support Vector Machines, XGBoost) was trained in age-matched PCas (n = 294), and in 72 controls and 64 BPH. Classifier performance was validated in two independent sets (n = 263 PCas; n = 99 controls). We assessed the panel as a postoperative disease monitor in a radical prostatectomy cohort (RPC: n = 47).

RESULTS

A PCa-specific 27-gene panel was identified. Matched blood and tumor gene expression levels were concordant (r = 0.72, p < 0.0001). The ensemble classifier ("PROSTest") was scaled 0%-100% and the industry-standard operating point of ≥50% used to define a PCa. Using this, the PROSTest exhibited an 85% sensitivity and 95% specificity for PCa versus controls. In two independent sets, the metrics were 92%-95% sensitivity and 100% specificity. In the RPCs (n = 47), PROSTest scores decreased from 72% ± 7% to 33% ± 16% (p < 0.0001, Mann-Whitney test). PROSTest was 26% ± 8% in 37 with normal postoperative PSA levels (<0.1 ng/mL). In 10 with elevated postoperative PSA, PROSTest was 60% ± 4%.

CONCLUSION

A 27-gene whole blood signature for PCa is concordant with tissue mRNA levels. Measuring blood expression provides a minimally invasive genomic tool that may facilitate prostate cancer management.

Current advances of liquid biopsies in prostate cancer: Molecular biomarkers

Prostate cancer (PCa) incidence is increasing and endangers men's lives. Early detection of PCa could improve overall survival (OS) by preventing metastasis. The prostate-specific antigen (PSA) test is a popular screening method. Several advisory groups, however, warn against using the PSA test due to its high false positive rate, unsupported outcome, and limited benefit. The number of disease-related biopsies performed annually far outweighs the number of diagnoses. Thus, there is an urgent need to develop accurate diagnostic biomarkers to detect PCa and distinguish between aggressive and indolent cancers. Recently, non-coding RNA (ncRNA), circulating tumor DNA (ctDNA)/ctRNA, exosomes, and metabolomic biomarkers in the liquid biopsies (LBs) of patients with PCa showed significant differences and clinical benefits in diagnosis, prognosis, and monitoring response to therapy. The analysis of urinary exosomal ncRNA presented a substantial correlation among Exos-miR-375 downregulation, clinical T stage, and bone metastases of PCa. Furthermore, the expression of miR-532-5p in urine samples was a vital predictive biomarker of PCa progression. Thus, this review focuses on promising molecular and metabolomic biomarkers in LBs from patients with PCa. We thoroughly addressed the most recent clinical findings of LB biomarker use in diagnosing and monitoring PCa in early and advanced stages.

Prostate cancer incidence in men with prostate-specific antigen below 3 ng/mL: The Finnish Randomized Study of Screening for Prostate Cancer

Prostate-specific antigen (PSA)-based screening for prostate cancer (PCa) can reduce PCa mortality, but also involves overdetection of low-risk disease with potential adverse effects. We evaluated PCa incidence among men with PSA below 3 ng/mL and no PCa diagnosis at the first screening round of the Finnish Randomized Study of Screening for PCa. Follow-up started at the first screening attendance and ended at PCa diagnosis, emigration, death or the common closing date (December 2016), whichever came first. Cox regression analysis was used to estimate hazard ratios and their confidence intervals (CI). Among men with PSA <3 ng/mL, cumulative PCa incidence was 9.1% after 17.6 years median follow-up. Cumulative incidence was 3.6% among men with baseline PSA 0 to 0.99 ng/mL, 11.5% in those with PSA 1.0 to 1.99 ng/mL and 25.7% among men with PSA 2 to 2.99 ng/mL (hazard ratio 9.0, 95% CI: 7.9-10.2 for the latter). The differences by PSA level were most striking for low-risk disease based on Gleason score and EAU risk group. PSA values <1 ng/mL indicate a very low 20-year risk, while at PSA 2 to 2.99 ng/mL risks are materially higher, with 4- to 5-fold risk for aggressive disease. Using risk-stratification and appropriate rescreening intervals will reduce screening intensity and overdetection. Using cumulative incidence of clinically significant PCa (csPCa) as the criterion, rescreening intervals could range from approximately 3 years for men with initial PSA 2 to 2.99 ng/mL, 6 years for men with PSA 1 to 1.99 ng/mL to 10 years for men with PSA <1 ng/mL.

Outcome of Patients With Elevated Prostate-Specific Antigen and Lower Urinary Tract Symptoms Receiving Holmium Laser Enucleation of the Prostate

Purpose

This study investigated functional outcomes in lower urinary tract symptoms (LUTS), the incidence of incidental prostate cancer (PCa), and changes in prostate-specific antigen (PSA) levels after holmium laser enucleation of the prostate (HoLEP) in patients with elevated PSA and benign prostatic hyperplasia (BPH).

Methods

A retrospective review of a prospectively designed protocol for patients who underwent HoLEP at our institution from January 2010 to May 2020 was conducted. Patients were classified into low-PSA (<3.0 ng/mL) and high-PSA (≥3.0 ng/mL) groups at baseline. Follow-up for PSA was performed at the sixth postoperative month. Baseline and postoperative clinical parameters, functional parameters, PCa incidence, and postoperative changes in PSA were compared between the low- and high-PSA groups.

Results

The baseline PSA of 1,296 patients (mean age, 69.7±6.8 years) was 4.0±4.1 ng/mL, with 712 patients (55.0%) in the low-PSA group (1.6±0.8 ng/mL), and 584 patients (45.0%) in the high-PSA group (6.9±4.7 ng/mL). Incidental PCa was detected in 82 patients (6.3%), with a similar incidence in the low-PSA (41 patients, 5.9%) and high-PSA (41 patients, 7.0%) groups (P>0.05). At 6 months postoperatively, both groups showed significant improvements in the maximum flow rate, postvoid residual volume, and all domains of the International Prostate Symptom Score (P<0.05). At postoperative 6 months, the PSA level significantly decreased by 66.6%±23.6% in all patients (54.3%±23.9% in the low-PSA group; 79.6%±14.7% in the high-PSA group) (P<0.05), and the PSA levels of 1,264 patients (97.6%) had normalized.

Conclusions

In patients with elevated PSA presenting with LUTS/BPH, our study demonstrated significant improvements in functional parameters and decreased PSA after HoLEP. The incidental PCa detection rate did not show a statistically significant difference between the low- and high-PSA groups. Timely surgery for LUTS/BPH without delay due to PSA monitoring should be considered.

Predictive value of neutrophil-to-lymphocyte ratio in diagnosis of early prostate cancer among men who underwent robotic transperineal prostate biopsy

To evaluate the predicted value of neutrophil-to-lymphocyte ratio (NLR) in the diagnosis of early prostate cancer by using standardized Full blood count (FBC) performed within 4 weeks before biopsy and histology results from transperineal prostate biopsy (RTPB).Patients who underwent RTPB under general anesthesia (GA), at Urology Department, Singapore General Hospital between September 2006 and Febuary 2016 were retrospectively reviewed.NLR was calculated using full blood count (FBC) that was done as a pre-admission test before GA within 4 weeks before the biopsy. Statistical analyses were done to establish the correlation of NLR and different clinical parameters such as biopsy histology, pre-biopsy PSA, and prostate volume.A total of 652 patients who underwent RTPB for diagnostic purposes with a valid PSA level were included in this study. There was total of 409 (62.7%) benign histology and 243 (37.3%) prostate cancer. There was no significant difference in median NLR between the benign and prostate cancer group (2.00 vs 1.99; P = .29).In the subgroups analysis, there was also no significant difference of median NLR value in clinical significant cancer (defined as Gleason 3 + 4 and above) and benign histology group (NLR 2.00 vs 2.01, P = .41), as well as prostate cancer and benign group according to different pre-biopsy PSA levels: PSA (ug/l) < 4, 4 to 10, 10 to 20, and >20, respectively. (Median NLR 1.34 vs 1.76; 1.97 vs 1.97; 1.97 vs 2.18; 2.18 vs 1.98, P > .05). NLR is neither associated with prostate cancer using logestic regression model nor a strong predictor of the Gleason grade group and D'Amico risk stratification group using ordinal regression model. (P > .05)There was no statistically significant difference of NLR between the benign and prostate cancer group as a whole or in the subgroup analyses for patients who underwent robotic transperineal prostate biopsy. NLR may have a limited role in predicting early-stage prostate cancer.

A Comprehensive Review of Pharmaceutical and Surgical Interventions of Prostate Cancer

As the second most common cause of death amongst men in the United States, prostate cancer is a type of cancer that is known to develop and originate in the prostate gland. The main function of the prostate gland is to produce seminal fluid in which the sperm bathes. The seminal fluids are necessary for allowing the sperm to move easily through the urethra and also allows successful fertilization by providing an alkaline environment for the sperm in the acidic nature of the vagina. The seminal vesicles are two smaller glands that are attached to either side of the prostate gland and in radical prostatectomies, can get removed. In the event that the seminal vesicles are removed during a radical prostatectomy, the individual is unable to produce any seminal fluids and thus, becoming infertile. Prostate cancer is most commonly seen in patients over the age of 66 years, however, in the presence of predisposing risk factors, may occur as early as in the late 40s. Certain risk factors may speed the presentation of prostate cancer in individuals and thus, mandatory screening is recommended around the age of 45. If no risk factors are present, screening is recommended to begin after the age of 50 years. Screening for prostate cancer is focused on looking for prostate-specific antigen (PSA) in a blood test, though this may not be the most reliable method. The method of diagnosis stems from further testing done following an abnormal PSA test. A digital rectal examination and ultrasonography may also be used to assist with the diagnosis of prostate cancer. Though there are several different types of pharmaceutical interventions currently present in the eradication of prostate cancer, with androgen deprivation therapy being the most commonly used, surgical interventions may be utilized to completely resect cancer from an individual. Different radical prostatectomies are used; the appropriate approach utilized is dependent on the extensiveness of cancer and the type of cancer that is present.

Serum lipids might improve prostate-specific antigen sensitivity in patients undergoing transrectal ultrasonography-guided biopsy for suspected prostate cancer: A pilot study

Objectives: To investigate the potential use of body mass index (BMI) and serum lipids in improving prostate-specific antigen (PSA) sensitivity in patients undergoing biopsy for suspicion of prostate cancer, as there is an established relationship between metabolic syndrome, obesity and serum lipids with prostate cancer.

Patients and methods: A pilot study was conducted in a tertiary referral centre between June 2016 and August 2017 of patients undergoing transrectal ultrasonography (TRUS)-guided biopsy. After the result of TRUS-biopsy, the first 50 patients diagnosed with prostate cancer (study group) and those with no prostate cancer (control group) were enrolled. BMI, serum PSA level, fasting blood sugar and lipid profile (e.g. cholesterol, triglycerides, low-density lipoprotein [LDL] and high-density lipoprotein [HDL]), were compared between the groups.

Results: Higher BMI, cholesterol, LDL and lower HDL together with PSA were significantly associated with a positive biopsy. On multivariate analysis, LDL (odds ratio [OR] 5.3, 95% confidence interval [CI] 1.2–24.9; P = 0.03) and total PSA level (OR 12.9, 95% CI 4.7–35; P < 0.001) were independent predictors of a positive biopsy. A combination of LDL <80 mg/dL and PSA level <26 ng/mL threshold values determined by receiver operating characteristic curve analysis, had a sensitivity and specificity of 94% and 28%, respectively; whilst, the negative (NPV) and positive predictive values were 82.4% and 56.6%, respectively. The sensitivity and NPV of the combination was significantly higher than that of PSA level alone (94% vs 72% and 82.4% vs 75%, respectively; P < 0.001).

Conclusions: Serum lipids might have a role in the diagnosis of prostate cancer and could be used as an adjunct to PSA measurement to improve sensitivity and avoid unnecessary biopsies.

Abbreviations: AUC: area under the curve; BMI: body mass index; FBS: fasting blood sugar; HDL: high-density lipoprotein; LDL: low-density lipoprotein; LOX-1: lectin-like oxidised LDL receptor-1; OR: odds ratio; ROC: receiver operating characteristic; RP: radical prostatectomy; TG: triglyceride