The accuracy of the increased prostate specific antigen level (greater than or equal to 20 ng./ml.) in predicting prostate cancer: is biopsy always required?

Mobile Health Solutions for Prostate Cancer Diagnostics-A Systematic Review

Prostate cancer, the most common cause of cancer in men in the UK and one of the most common around the world to date, has no consensus on screening. Multiple large-scale trials from around the world have produced conflicting outcomes in cancer-specific and overall mortality. A main part of the issue is the PSA test, which has a high degree of variability, making it challenging to set PSA thresholds, as well as limited specificity. Prostate cancer has a predisposition in men from black backgrounds, and outcomes are worse in men of lower socioeconomic groups. Mobile targeted case finding, focusing on high-risk groups, may be a solution to help those that most need it. The aim of this systematic review was to review the evidence for mobile testing for prostate cancer. A review of all mobile screening studies for prostate cancer was performed in accordance with the Cochrane guidelines and the PRISMA statement. Of the 629 unique studies screened, 6 were found to be eligible for the review. The studies dated from 1973 to 2017 and came from four different continents, with around 30,275 men being screened for prostate cancer. Detection rates varied from 0.6% in the earliest study to 8.2% in the latest study. The challenge of early diagnosis of potentially lethal prostate cancer remains an issue for developed and low- and middle-income countries alike. Although further studies are needed, mobile screening of a targeted population with streamlined investigation and referral pathways combined with raising awareness in those communities may help make the case for screening for prostate cancer.

SUVmax/ADC Ratio as a Molecular Imaging Biomarker for Diagnosis of Biopsy-Naïve Primary Prostate Cancer

Background:

Gallium-68-prostate-specific membrane antigen (⁶⁸Ga-PSMA) positron emission tomography/computed tomography (PET/CT) has recently been shown to be very high accuracy in biopsy-naïve prostate cancer (PCa) detection and can potentially improve the low specificity noted with diffusion-weighted magnetic resonance imaging (DW-MRI), especially in instances of prostate inflammation. We aimed to compare the diagnostic accuracy of DW-MRI and PSMA PET/CT using apparent diffusion coefficient (ADC) and maximum standardized uptake (SUV_max) values in the diagnosis of PCa.

Patients and Methods:

A retrospective study comparing and analyzing the diagnostic accuracy of prebiopsy DW-MRI and ⁶⁸Ga-PSMA PET/CTs done in patients with suspected PCa (raised prostate specific antigen [PSA] and/or positive digital rectal examination) from January 2019 to December 2020. The standard of reference was transrectal ultrasound-guided biopsies.

Results:

Sixty-seven patients were included in the study, mean age: 70 years (range 49–84), mean PSA: 23.2 ng/ml (range 2.97–45.6). Biopsy was positive for PCa in 56% (n = 38) and negative in 43% (n = 29). Of the benign results, benign hyperplasia was noted in 75% (n = 22) and prostatitis in 25% (n = 7). Of the PCa, 55% (n = 21) of were high International Society of Urological Pathology (ISUP) grade (4–5) and 45% (n = 17) low/intermediate ISUP grade (1–3). Overall the sensitivity/specificity/Accuracy for prediction of PCa of MRI using prostate imaging and reporting data system version 2 criteria and PSMA PET/CT using PCa molecular imaging standardized evaluation criteria was 92.1%/65.5%/80.5% and 76.3%/96.5%/85.1% respectively. Mean apparent diffusion co-efficient (mean ADC) value of benign lesions and PCa was 1.135 × 10^-3 mm²/s and 0.723 × 10^-3 mm²/s, respectively (P = 0.00001). Mean SUV_max and ADC of benign and PCa lesions was 4.01 and 16.4 (P = 0.000246). Mean SUV_max/ADC ratio of benign and malignant lesions was 3.8 × 103 versus 25.21 × 103 (P < 0.000026). Inverse correlation was noted between ADC and SUV_max values (R = −0.609), inverse correlation noted between ADC and Gleason's score (R = −0.198), and positive correlation of SUV_max and SUV_max/ADC with Gleason's score (R = 0.438 and R = 0.448). Receiver operating characteristic curve analysis revealed a SUV_max cutoff 6.03 (sensitivity/specificity - 76%/90%, area under the curve (AUC) - 0.935, Youden index (YI) - 0.66), ADC cutoff of 0.817 × 10⁻³ mm²/s (sensitivity/specificity – 79%/86%, AUC – 0.890, YI - 0.65), and SUV_max/ADC ratio cutoff of 7.43 × 103 (sensitivity/specificity – 87%/98%, AUC - 0.966, YI - 0.85) for PCa diagnosis.

Conclusion:

For diagnosis of biopsy-naïve PCas, the combination of diffusion-weighted MRI and PSMA PET/CT (i.e., SUV_max/ADC ratio) shows better diagnostic accuracy than either used alone and the combination of PET and MRI is especially useful when distinguishing cancer from prostatitis.

Biparametric Magnetic Resonance Imaging-Derived Nomogram to Detect Clinically Significant Prostate Cancer by Targeted Biopsy for Index Lesion

BACKGROUND

Currently, it is necessary to investigate how to combine biparametric magnetic resonance imaging (bpMRI) with various clinical parameters for the detection of clinically significant prostate cancer (csPCa).

PURPOSE

To develop a multivariate prebiopsy nomogram using clinical and bpMRI parameters for estimating the probability of csPCa.

STUDY TYPE

Retrospective, single-center study.

SUBJECTS

Two hundred and twenty-six patients who underwent targeted biopsy (TBx) for the MRI-suspected index lesion because of clinical suspicions of PCa.

FIELD STRENGTH/SEQUENCE

A 3 T MRI including turbo spin-echo T₂ -weighted and diffusion-weighted single-shot echo-planar imaging sequences.

ASSESSMENT

Prebiopsy clinical and bpMRI parameters were patient age, biopsy history (biopsy-naïve or repeated biopsy status), prostate-specific antigen density (PSAD), Prostate Imaging-Reporting and Data System version 2.1 (PI-RADSv2.1), and apparent diffusion coefficient ratio (ADCR). ADCR was defined as mean ADC of the index lesion divided by mean ADC of the contralateral prostatic region. A multivariate prebiopsy nomogram for csPCa (i.e. Gleason sum ≥7) was developed. Area under the curve (AUC) of each parameter and prebiopsy nomogram was assessed. Five-fold cross-validation was performed for robust estimation of performance of the prebiopsy nomogram.

STATISTICAL TESTS

Logistic regression, receiver-operating curve, and 5-fold cross-validation. P-value < 0.05 was considered statistically significant.

RESULTS

Proportion of csPCa was 31.9% (72/226). The AUCs of age, biopsy-naïve status, PSAD, PI-RADSv2.1, ADCR, and prebiopsy nomogram were 0.657 (95% confidence interval [CI], 0.580-0.733), 0.593 (95% CI, 0.525-0.660), 0.762 (95% CI, 0.697-0.826), 0.824 (95% CI, 0.770-0.878), 0.829 (95% CI, 0.769-0.888), and 0.906 (95% CI, 0.863-0.948), respectively: AUC of nomogram was significantly different than that of individual parameter. In the 5-fold cross-validation, the mean AUC of the prebiopsy nomogram for csPCa was 0.888 (95% CI, 0.786-0.983).

DATA CONCLUSIONS

This multivariate prebiopsy nomogram using clinical and bpMRI parameters may help estimate the probability of csPCa in patients undergoing TBx. ADCR seems to enhance the role of bpMRI in detecting csPCa.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Prostate cancer incidence and diagnosis in men with PSA levels >20 ng/ml: is it possible to decrease the number of biopsy cores?

OBJECTIVES

To define if less number of cores would be sufficient to diagnose prostate cancer (PCa) in men with PSA levels >20 ng/ml and to reveal the cancer detection rates in this population.

METHODS

The data of the men who had 12-core prostate biopsy with a PSA value >20 ng/mg were reviewed. We recorded age, prostate volume, PSA level, and pathology report findings. Patients grouped according to PSA levels and compared for PCa detection rates, and several parameters. We created 16 prostate biopsy scenarios (S1-S16) and applied these to our database to find out the best biopsy protocol to detect PCa.

RESULTS

A total of 336 patients with a mean age of 70.5 (47-91) years were included. Mean PSA level was 190.6 (20-5474) ng/ml. PCa detection rates were 55.3%, 81.0%, and 97.7% in patients with PSA levels 20-49.99, 50-99.99, and ≥100 ng/ml, respectively. PSA level was correlated to clinically more important digital rectal examination findings. We selected 2 cores in S1-S6, 4 cores in S7-S12, and 6 cores in S13-S16. We calculated the sensitivity of each scenario and found that all scenarios in PSA Group 3 had a sensitivity >95%. In Group 2, S8, S10, S13, and S14 and in Group 1, only S14 had sensitivity >95%.

CONCLUSIONS

It is not necessary to take 10-12 core biopsy samples in men with PSA levels >20 ng/ml. We recommend taking 2, 4, and 6 samples for patients with PSA levels ≥100 ng/ml, 50-99.99 ng/ml, and 20-49.99 ng/ml, respectively.

Prevalence and correlates of non-tissue prostate cancer diagnosis in the United States

BACKGROUND

Given the potential complications of prostate biopsies, it is sometimes reasonable in selected patients to make a non-tissue diagnosis of prostate cancer. Little is known about prevalence and factors associated with non-tissue prostate cancer diagnoses in the United States.

METHODS

We identified 40 to 99-year-old prostate cancer patients with prostate specific antigen (PSA) ≥20 ng/ml from the 2010-2015 National Cancer Database. Associations were examined between non-tissue prostate cancer diagnosis and age, race, clinical T (cT) and M (cM) categories, PSA, and Charlson-Deyo Comorbidity Index (CCI) with multivariable analyses.

RESULTS

Among 62,635 patients, 6.2% had a non-tissue diagnosis. The proportion of patients with non-tissue diagnoses increased with advanced age (from 0.9% in ages 40-49 to 44.0% in ages 90-99) and disease stage (cT and cM) and higher CCI and PSA level. Demographic and clinical characteristics statistically significantly associated (all P < .001) with non-tissue diagnosis in adjusted analyses were older age (OR = 24.24, 90 to 99 vs. 60 to 69 years), and higher cT (OR = 4.83; T4 vs. T1), cM (OR = 5.25, M1C vs. M0), CCI (OR = 2.07; 3+ vs. 0), and PSA levels (OR = 3.19, >97.9 ng/ml vs.20 to 39 ng/ml), as well as hormonal therapy (OR = 0.51, with vs. without).

CONCLUSIONS

Non-tissue diagnosis of prostate cancer, while rare, is not outside normal clinical practice and is strongly associated with advanced patient age, higher clinical stage, multiple comorbidities, and very high PSA levels.

Life-threatening hemorrhage from acquired hemophilia A as a presenting manifestation of prostate cancer

Acquired factor VIII deficiency (acquired hemophilia A) is a rare condition characterized by the acquisition of autoantibodies that affect the clotting activity of factor VIII (fVIII). The most common manifestation in affected patients is a hemorrhagic diathesis. This disorder is associated with autoimmune diseases, pregnancy, postpartum period, drugs, and malignancy. Management of this condition begins with attempts to arrest an acute bleed based on the site and severity of bleeding and inhibitor titer. The next priority is eradication of the fVIII antibodies using immunosuppressive therapies. We report the case of a 66-year-old male who presented with spontaneous right thigh hematoma with prolonged activated partial prothrombin time and normal prothrombin time. Mixing studies confirmed the presence of an inhibitor. Further investigation for the underlying etiology of acquired hemophilia A leads to diagnosis of prostate cancer. Treatment consisted of bypassing agents including activated factor VII and activated prothrombin plasma concentrate to arrest the bleeding. Steroids and cyclophosphamide were added to suppress the fVIII inhibitors. Concomitant treatment of locally advanced prostate cancer with chemotherapy confirmed the eradication of the inhibitors. To our knowledge, this is the first reported case of prostate cancer diagnosed and treated simultaneously with acquired hemophilia A resulting in favorable patient outcome.

Interval estimation of small tail probabilities - applications in food safety

Often in food safety and bio-surveillance it is desirable to estimate the probability that a contaminant or a function thereof exceeds an unsafe high threshold. The probability or chance in question is very small. To estimate such a probability, we need information about large values. In many cases, the data do not contain information about exceedingly large contamination levels, which ostensibly renders the problem insolvable. A solution is suggested whereby more information about small tail probabilities are obtained by combining the real data with computer-generated data repeatedly. This method provides short yet reliable interval estimates based on moderately large samples. An illustration is provided in terms of lead exposure data. Copyright © 2016 John Wiley & Sons, Ltd.

The Practicality of Targeted Prostate Biopsy Procedures on the Dominant Side of the Tumor Determined by Magnetic Resonance Imaging in Elderly Patients with High Serum Levels of Prostate-Specific Antigen

PURPOSE

To examine the possibility of reducing the number of cores per prostate biopsy in elderly patients with high levels of prostate-specific antigen (PSA) without significantly lowering the detection rate of prostate cancer.

MATERIALS AND METHODS

Two hundreds sixteen men with PSA levels >20 ng/mL who underwent prostate biopsies from May 2009 to April 2013 were retrospectively reviewed. With the help of magnetic resonance imaging (MRI), the laterality of the dominant tumor burden in patients was determined. The results of targeted biopsies were compared with those of conventional biopsy procedures.

RESULTS

The mean age and PSA level were 79.5 years and 81.3 ng/mL, respectively, and the overall diagnostic rate of sextant biopsies was 81.9% (177/216). MRI was able to show the tumor burden in 189 of the 216 patients. The detection rate of transrectal ultrasonography (TRUS)-guided targeted biopsies was 87.3% (165/189). Detection rates were comparable with conventional biopsies (81.9% [177/216]) (p=0.23). Of the 177 men in whom the results of the sextant biopsy were positive, 12 men (6.8%) with PSA levels <29 ng/mL did not have any cancer cells according to targeted biopsies. However, all other patients were diagnosed with prostate cancer using the abovementioned techniques.

CONCLUSIONS

We believe that TRUS-guided targeted biopsies of the prostate in elderly men with high PSA levels could reduce the number of unnecessary cores per biopsy. However, a risk of detection loss remains. Therefore, we recommend that at least a sextant biopsy should be performed, even in elderly patients, in order to detect prostate cancer.

Metabolic syndrome in castration-resistant prostate cancer patients treated with abiraterone

BACKGROUND

Metabolic syndrome (MS) has not yet been studied in castration-resistant prostate cancer (CRPC) men treated with novel hormonal therapies. The study aims to assess the impact of MS on outcome from time starting abiraterone.

PATIENTS AND METHODS

We retrospectively evaluated a consecutive series of metastatic CRPC patients treated with abiraterone after docetaxel failure. MS, as defined by modified Adult Treatment Panel (ATP) III criteria, was assessed at the time of initiation of abiraterone, during treatment and follow-up.

RESULTS

Sixty-seven of 178 patients evaluated (37.6%) met MS criteria at baseline, before abiraterone initiation, whereas for 11 (9.9%) without MS before treatment with abiraterone this occurred during treatment. Median PFS was equal to 4.7 months for patients with MS versus 9 months for those without MS. Patients with MS had an increased risk of 71% of progression or death for all causes than patients without MS (HR = 1.7, 95% CI [1.2-2.4], P = 0.03). Median OS was 14.7 months and 22.3 months in patients with and without MS, respectively. After adjusting for covariates, MS resulted not significantly associated to OS (HR = 1.42, 95% CI [0.91-2.22], P = 0.073).

CONCLUSIONS

The presence of MS is a significant risk factor for shorter PFS in CRPC patients treated with abiraterone, even if it does not show a significant impact on OS. A prospective evaluation is warranted.

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

OBJECTIVE

We aimed to build a nomogram allowing to predict the probability of prostate cancer (PC) after an initial 21-core biopsy and with readily available clinical data.

METHODS

1,490 screened men who underwent an initial 21-core biopsy protocol were included. A multivariate logistic regression was realized including age, prostate volume, prostate-specific antigen (PSA) level, digital rectal examination (DRE) and transrectal ultrasonography (TRUS). Receiver-operating characteristic estimates were used to quantify accuracy of each model.

RESULTS

PC was detected in 41.3% of the patients. Median PSA, age and prostate volume were 6.2 ng/ml (range 0.2-50), 64.6 years (range 33-87) and 40 ml (range 10-270), respectively. Abnormal TRUS findings were detected in 14.7% of patients. Age, PSA level, prostate volume, DRE and TRUS were significantly associated with PC (all p ≤ 0.004) in univariable logistic regression analysis. In multivariate logistic regression analysis, significant associations were found for age, PSA level, prostate volume and DRE. Predictive accuracy estimate of this model was equal to 0.70. TRUS was not an independent predictor of PC.

CONCLUSIONS

We constructed the first prebiopsy predictive nomogram based on an extended 21-core biopsy procedure with age, PSA level, DRE and prostate volume which are readily available clinical data to urologists.

Defining prostate cancer risk before prostate biopsy

Prostate cancer is the most commonly diagnosed cancer in men. At present, patients are selected for prostate biopsy on the basis of age, serum prostate specific antigen (PSA), and prostatic digital rectal examination (DRE) findings. However, due to limitations in the use of PSA and DRE, many patients undergo unnecessary prostate biopsy. A further problem arises as many patients are diagnosed and treated for indolent disease. This review of the literature highlights the strengths and weaknesses of existing methods of prebiopsy risk stratification and evaluates promising serum, urine, and radiologic prostate cancer biomarkers, which may improve risk stratification for prostate biopsy in the future.

The prognostic value of transrectal ultrasound guided biopsy in patients over 70 years old with a prostate specific Antigen (PSA) level ≤ 15 ng/ml and normal digital rectal examination: a 10-year prospective follow-up study of 427 consecutive patients

INTRODUCTION

As a urologist, it is common to review a patient above the age of 70 being referred to a prostate assessments clinic with an elevated PSA. We evaluate the prognosis of these patients clinically as there is no international consensus on the exact PSA cutoff level or a single international guideline as to when these patients should be offered a prostate biopsy.

PATIENTS AND METHODS

On receiving ethic committee approval, we recruited 427 consecutive patients aged 70 years and above referred with a PSA of ≥ 4 ng/ml, from January 1996 to December 2000, into our study. All patients were assessed, examined with a digital rectal examination (DRE) of the prostate, and a subsequent prostate biopsy. We followed up on their histologic diagnosis for up to 10 years and analyzed their outcome. The main outcome measures were disease-free survival and overall survival, stratified according to the PSA level (≤ 15 vs. >15 ng/ml) and DRE findings (normal vs. sbnormal).

RESULTS

There was a statistically significant difference in the overall survival (P value < 0.011) and disease specific survival (P value < 0.0001) of cancer patients with a PSA was >15 ng/ml and an abnormal DRE. However, in patients with a PSA ≤ 15 ng/ml and normal DRE, the incidence of cancer was low and they had no disease-specific or overall survival benefit.

CONCLUSIONS

A policy of deferring prostate biopsy in patients with a PSA ≤ 15 ng/ml and normal DRE (Group A) would significantly decrease the need of unnecessary prostate biopsies. Within this group, patients did not have any survival advantage compared with those without cancer. We conclude that up to 20% of the prostate biopsies performed in this age group could have been avoided.

Is prostate biopsy essential to diagnose prostate cancer in the older patient with extremely high prostate-specific antigen?

Purpose

The results of all prostate biopsies may be positive and suggestive of adenocarcinoma in patients with prostate-specific antigen (PSA) values higher than 100 ng/ml. We considered that the prostate cancer in patients with high PSA might be advanced disease and therefore that the treatment strategy should not be changed according to pathological reports. Thus, we assessed the role of prostate biopsy when diagnosing prostate cancer in patients with extremely high PSA levels.

Materials and Methods

We reviewed the records of 1,150 cases undergoing prostate biopsies. Patients with urinary tract infection and acute urinary retention were excluded. According to the pre-biopsy PSA level, patients were divided into 6 groups (group A, 4 to 20 ng/ml; B, 20 to 40 ng/ml; C, 40 to 60 ng/ml; D, 60 to 80 ng/ml; E: 80 to 100 ng/ml; and F, above 100 ng/ml).

Results

The calculated positive predictive value (PPV) for prostate cancer was 22% in group A, 54% in group B, 73% in group C, 75% in group D, 89% in group E, and 100% in group F, respectively. Pathological diagnosis was adenocarcinoma in all patients in group F (n=56). Among them, 38 patients (67.9%) had lymph node metastasis or extra-prostatic disease or both and 43 patients (76.8%) had bony metastasis. In group F, all cases were advanced prostate cancer (stage III or IV). All of them received hormonal therapy following diagnosis.

Conclusions

We suggest the possibility for biopsy-free diagnosis of prostate cancer in patients with extremely high levels of serum PSA and evidence of advanced disease in imaging studies, especially in older patients with comorbid medical problems.

A comparative performance analysis of total prostate-specific antigen, percentage free prostate-specific antigen, prostate-specific antigen velocity and urinary prostate cancer gene 3 in the first, second and third repeat prostate biopsy

Study Type - Diagnosis (exploratory cohort) Level of Evidence 2b What's known on the subject? and What does the study add? Risk factor assessment in the repeat biopsy setting is affected by a decreasing diagnostic accuracy of each single risk factor (e.g. DRE, tPSA, %fPSA, complexed PSA, PSA density or PSAV] with increasing number of prostate biopsy sessions. PCA3 shows impressive diagnostic performance in the initial and early repeat biopsy settings. In a head-to-head comparison we demonstrate the concept that the number of previous repeat biopsy session strongly influences performance characteristics of biopsy risk factors, including PCA3. While the novel diagnostic marker would have avoided a considerable number of unnecessary biopsies in the first repeat biopsy scenario, its effects dissipated at second and ≥ third repeat biopsies.

OBJECTIVE

To compare the performance characteristics of prostate cancer risk factors such as total prostate-specific antigen (tPSA), percentage free PSA (%fPSA), PSA velocity (PSAV) and urinary prostate cancer gene 3 (PCA3) at first, second and ≥ third repeat biopsy session.

PATIENTS AND METHODS

Patients (n= 127) aged ≤70 years, with suspicious digital rectal examination (DRE) and/or persistently elevated age-specific total PSA levels (2.5-6.5 ng/mL) and/or suspicious prior histology (atypical small acinar proliferations [ASAPs]≥ two cores affected by high-grade prostatic intra-epithelial neoplasia [HGPIN]) undergoing either a first, second, or ≥ third repeat biopsy were investigated using a 12- or 24-core biopsy scheme. PSAV (≥ three values collected over ≥12 months) was calculated using the log-slope method. PCA3 scores were assessed using the Progensa assay®. After stratification according to the number of previous biopsies (first, second and ≥ third), calculation of specificity, positive and negative predictive values (PPV, NPV) and the proportion of avoided unnecessary repeat biopsies (PAB) compared with tPSA at fixed sensitivity thresholds (75, 85 and 95%) were performed. Finally, accuracy estimates (area under the curve [AUC]) were quantified for each repeat biopsy scenario.

RESULTS

At repeat biopsy, overall prostate cancer (PCa) detection was 34.6%. At first repeat biopsy, PCA3 predicted PCa best (AUC = 0.80) and would have avoided 72.2% of repeat biopsies (75% sensitivity) compared with tPSA. At second repeat biopsy, %fPSA demonstrated the highest accuracy (AUC = 0.82) and would have avoided 66.7% of repeat biopsies (75% sensitivity) compared with tPSA. At ≥ third repeat biopsy, again %fPSA demonstrated the highest accuracy (AUC = 0.70) and would have avoided 45.0% of repeat biopsies (75% sensitivity) compared with tPSA. The main limitation of our study resides in its small sample size.

CONCLUSIONS

The findings of the present study promote the concept that the number of previous repeat biopsy sessions strongly influences the performance characteristics of biopsy risk factors. Total PSA was no significant risk factor in the entire analysis. By contrast, %fPSA performed best at second and ≥ third repeat biopsy. PSAV's diagnostic potential was reserved to patients at second and ≥ third repeat biopsy. Finally, PCA3 demonstrated the highest diagnostic accuracy and potential to reduce unnecessary biopsies at first repeat biopsy. However, this advantage dissipated at second and ≥ third repeat biopsy.

Abdominal and back pain in a 65-year-old patient with metastatic prostate cancer

OBJECTIVE

Prostate cancer remains the second leading cause of cancer-related deaths, and African American men are affected with this disease disproportionately in terms of incidence and mortality. The purpose of this article is to present a case report that illustrates the importance of a careful evaluation, including a comprehensive historical review and appropriate physical and laboratory assessment, of a patient with back pain and seemingly unrelated symptoms.

CLINICAL FEATURES

A 65-year-old African American man presented to a chiropractic clinic after experiencing lower back pain for 1 month. The digital rectal examination was unremarkable, but the serum prostate-specific antigen was markedly elevated. A suspicion of metastatic prostate cancer resulted in subsequent referral, further diagnostic evaluation, and palliation.

INTERVENTION AND OUTCOME

The patient was referred for medical evaluation and palliation of his condition. Spinal decompression surgery of the thoracic spine was initiated, resulting in weakness and paresthesia in the lower limbs bilaterally. The patient died because of the complications associated with the medical interventions and the disease about 12 months after the referral.

CONCLUSION

Chiropractic physicians should maintain a high degree of suspicion for catastrophic causes of back-related complaints, such as metastatic prostate cancer. The Prostate Cancer Prevention Trial Risk Calculator, a research validated instrument, should be used in the assessment of prostate cancer risk. Performance of the digital rectal examination and of the prostate-specific antigen determination remains integral in the clinical assessment of the health status in aging men, with or without back pain.

Prostate cancer gene 3 (PCA3): development and internal validation of a novel biopsy nomogram

BACKGROUND

Urinary prostate cancer gene 3 (PCA3) represents a promising novel marker of prostate cancer detection.

OBJECTIVE

To test whether urinary PCA3 assay improves prostate cancer (PCa) risk assessment and to construct a decision-making aid in a multi-institutional cohort with pre-prostate biopsy data.

DESIGN, SETTING, AND PARTICIPANTS

PCA3 assay cut-off threshold analyses were followed by logistic regression models which used established predictors to assess PCa-risk at biopsy in a large multi-institutional data set of 809 men at risk of harboring PCa.

MEASUREMENTS

Regression coefficients were used to construct four sets of nomograms. Predictive accuracy (PA) estimates of biopsy outcome predictions were quantified using the area under the curve of the receiver operator characteristic analysis in models with and without PCA3. Bootstrap resamples were used for internal validation and to reduce overfit bias. The extent of overestimation or underestimation of the observed PCa rate at biopsy was explored graphically using nonparametric loss-calibration plots. Differences in PA were tested using the Mantel-Haenszel test. Finally, nomogram-derived probability cut-offs were tested to assess the ability to identify patients with or without PCa.

RESULTS AND LIMITATIONS

PCA3 was identified as a statistically independent risk factor of PCa at biopsy. Addition of a PCA3 assay improved bootstrap-corrected multivariate PA of the base model between 2% and 5%. The highest increment in PA resulted from a PCA3 assay cut-off threshold of 17, where a 5% gain in PA (from 0.68 to 0.73, p=0.04) was recorded. Nomogram probability-derived risk cut-off analyses further corroborate the superiority of the PCA3 nomogram over the base model.

CONCLUSIONS

PCA3 fulfills the criteria for a novel marker capable of increasing PA of multivariate biopsy models. This novel PCA3-based nomogram better identifies men at risk of harboring PCa and assists in deciding whether further evaluation is necessary.

Prostate cancer diagnosis: should patients with prostate specific antigen >10ng/mL have stratified prostate biopsy protocols?

BACKGROUND

Trans-rectal ultrasound (TRUS) guided systematic prostate biopsy is a standard tool in prostate cancer (CaP) diagnosis. Extended biopsy techniques using 10-12 cores are the norm. Controversy exists on extended TRUS biopsy in men with PSA>10ng/mL. We evaluated cancer detection rates on an individual core basis, to stratify prostate biopsy protocols based on PSA levels.

PATIENTS AND METHODS

Over a five-year period, 1036 patients underwent TRUS guided prostate biopsy for raised serum PSA (>2.5ng/mL). 436 patients had PSA>10ng/mL. Patients with PSA<50ng/mL underwent a 12-core TRUS guided prostate biopsy including six peripheral biopsies. The six peripheral biopsies were directed laterally towards the base, mid-zone and apices. Remainder were standard para-sagittal sextant biopsies. Patients were stratified into three groups (PSA 10-20ng/mL, 20-50ng/mL and >50ng/mL).

RESULTS

Mean age of 436 patients with PSA>10ng/mL was 70.3years. 270 (62%) men had cancer. Cancer detection rates for different PSA levels were 46% (10-20ng/mL), 76% (20-50ng/mL) and 93% (>50ng/mL). Higher PSA levels and advanced clinical stage were associated with increased cancer detection rates. All patients with clinical T3 and T4 disease had biopsy diagnosed CaP.

CONCLUSION

TRUS guided prostate biopsy in patients with PSA>10ng/mL did not require 12 cores to diagnose CaP. CaP diagnosis required 8 cores in men with PSA 10-20ng/mL. These cores were right and left peripheral basal and apical, and right and left para-sagittal basal and apical biopsy. Only 6 cores were necessary to diagnose CaP in men with PSA>20ng/mL which were right and left peripheral basal and apical, and para-sagittal apical biopsies. We suggest limited TRUS prostate biopsy protocols for men with PSA>10ng/mL.

Differences in the rate of lymph node invasion in men with clinically localized prostate cancer might be related to the continent of origin

OBJECTIVE

To test whether the rate of lymph node invasion (LNI) differs between patients treated with radical prostatectomy (RP) at a European or a North American centre.

PATIENTS AND METHODS

In all, 1385 men had RP with bilateral lymphadenectomy for clinically localized prostate cancer (587 from Dallas, Texas and 798 from Milan, Italy). Univariate and multivariate analyses focused on the association between the continent of origin and the rate of LNI, after controlling for prostate-specific antigen (PSA) level, clinical stage, biopsy Gleason sum and the number of examined and removed lymph nodes.

RESULTS

European men had higher PSA levels (9.1 vs 7.8 ng/mL), a higher proportion of palpable cancers (44.5 vs 32.8%), more nodes removed (mean 14.9 vs 7.8) and a higher rate of LNI (9.0% vs 1.2%; all differences P < 0.001). In multivariate analyses that controlled for PSA level and clinical variables, European men had an 8.9-fold higher risk of LNI (P < 0.001) than their counterparts from the USA. Among preoperative variables, the continent of origin was the third most informative predictor of LNI (67.5%), after biopsy Gleason sum (74.3%) and the number of examined lymph nodes (71.0%), and improved the ability to predict LNI by 4.7%.

CONCLUSION

Men treated at a European centre had a 7.3-8.9-fold higher rate of LNI, despite adjusting for all clinical and pathological variables. It remains to be shown what predisposes European men to a higher rate of LNI.

Accuracy of a high prostate-specific antigen level for prostate cancer diagnosis upon initial biopsy in Korean men

PURPOSE

This study aimed to evaluate the cancer detection rate in a Korean population with prostate-specific antigen (PSA) levels greater than or equal to 20.0 ng/mL.

MATERIALS AND METHODS

A total of 174 men 50 to 79 years old (median 69) included in the study. The median prostate volume of the patients was 44.8 mL (range 14.1 to 210.0) and their serum PSA ranged from 20.0 to 9725.0 ng/mL (median 44.8).

RESULTS

Of 174 men 141 (81.0%) were diagnosed with prostate cancer on initial biopsy. In the total number of patients, the positive predictive value (PPV) was 62.9% for PSA 20 to 29.9, 72.7% for PSA 30 to 39.9 and 100% for PSA 40 to 49.9 ng/mL. In patients with an abnormal digital rectal examination (DRE), the values for these PSA ranges increased to 89.5%, 91.7% and 100%, respectively. The PPV was 81.0% for PSA cutoff of 20, 89.2% for a cutoff of 30, 95.4% for a cutoff of 40, and 94.7% for a cutoff of 50 ng/mL. In conjunction with an abnormal DRE, the values for these PSA cutoffs increased to 95.9%, 98.1%, 100%, and 100%, respectively.

CONCLUSION

Our data suggest the ability to predict the presence of prostate cancer reliably on initial biopsy when PSA threshold is greater than or equal to 50 ng/mL. This PSA threshold may be lowered to 40 ng/mL in the presence of an abnormal DRE. In Korean men with high PSA, the detection rate of prostate cancer on biopsy appears to be comparable to that for American men.

Development and external validation of an extended repeat biopsy nomogram

PURPOSE

We hypothesized that the outcome of repeat biopsy could be accurately predicted. We tested this hypothesis in a contemporary cohort from 3 centers.

MATERIALS AND METHODS

The principal cohort of 1,082 men from Hamburg, Germany was used for nomogram development as well as for internal 200 bootstrap validation in 721 and external validation in 361. Two additional external validation cohorts, including 87 men from Milan, Italy and 142 from Seattle, Washington, were also used. Predictors of prostate cancer on repeat biopsy were patient age, digital rectal examination, prostate specific antigen, percent free prostate specific antigen, number of previous negative biopsy sessions and sampling density. Multivariate logistic regression models were used to develop the nomograms.

RESULTS

The mean number of previous negative biopsies was 1.5 (range 1 to 6) and the mean number of cores at final repeat biopsy was 11.1 (range 10 to 24). Of the men 370 (30.2%) had prostate cancer. On multivariate analyses all predictors were statistically significant (p < or =0.028). After internal validation the nomogram was 76% accurate. External validation showed 74% (Hamburg), 78% (Milan) and 68% (Seattle) accuracy.

CONCLUSIONS

Relative to the previous nomograms (10 predictors or 71% accuracy) our tool relies on fewer variables (6) and shows superior accuracy in European men. Accuracy in American men is substantially lower. Racial, clinical and biochemical differences may explain the observed discrepancy in predictive accuracy.

Highly elevated PSA and dietary PhIP intake in a prospective clinic-based study among African Americans

African-American men die from prostate cancer (PC) nearly twice as often as white US men and consume about twice as much of the predominant US dietary heterocyclic amine, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), a genotoxic rat-prostate carcinogen found primarily in well-cooked chicken and beef. To investigate the hypothesis that PhIP exposure increases PC risk, an ongoing prospective clinic-based study compared PC screening outcomes with survey-based estimates of dietary PhIP intake among 40-70-year-old African-American men with no prior PC in Oakland, CA. They completed food-frequency and meat-cooking/consumption questionnaires and had a prostate-specific antigen (PSA) test and digital-rectal exam. Results for 392 men indicated a 17 (+/-17) ng/kg day mean (+/-1 s.d.) daily intake of PhIP, about twice that of white US men of similar age. PhIP intake was attributable mostly to chicken (61%) and positively associated (R(2)=0.32, P<0.0001) with saturated fat intake. An odds ratio (95% confidence interval) of 31 (3.1-690) for highly elevated PSA > or =20 ng/ml was observed in the highest 15% vs lowest 50% of estimated daily PhIP intake (> or =30 vs < or =10 ng/kg day) among men 50+ years old (P=0.0002 for trend) and remained significant after adjustment for self-reported family history of (brother or father) PC, saturated fat intake and total energy intake. PSA measures were higher in African-American men with positive family history (P=0.007 all men, P<0.0001 highest PSA quartile). These preliminary results are consistent with a positive association between PhIP intake and highly elevated PSA, supporting the hypothesis that dietary intervention may help reduce PC risk.

Critical Assessment of Ideal Nodal Yield at Pelvic Lymphadenectomy to Accurately Diagnose Prostate Cancer Nodal Metastasis in Patients Undergoing Radical Retropubic Prostatectomy

OBJECTIVES

To study the relation between the number of removed and examined lymph nodes at pelvic lymph node dissection and the rate of lymph node invasion (LNI).

METHODS

A total of 858 patients aged 45 to 85 years were predominantly treated with extended pelvic lymph node dissection before radical retropubic prostatectomy. The pretreatment prostate-specific antigen level was 0.24 to 49.9 ng/mL (median 5.8). Most lesions were Stage T1c (55.2%) or T2 (40.7%), with a biopsy Gleason sum of 6 or less (62.2%) or 7 (25.1%). Receiver operating characteristic curve coordinates were used to determine the probability of finding LNI according to the number of removed and examined lymph nodes. Moreover, the association between the number of removed lymph nodes and LNI was tested in univariate and multivariate logistic regression models.

RESULTS

From 2 to 40 nodes (mean 15, median 14) were removed and examined, and 88 patients (10.3%) had LNI. The LNI rate increased with the number of removed nodes (P <0.001): 2 to 10 nodes removed, 5.6% LNI rate; 10 to 14 nodes removed, 8.6% LNI rate; 15 to 19 removed, 10.2% LNI rate; and 20 to 40 removed, 17.6% LNI rate. On multivariate analysis, the number of examined nodes predicted for LNI (P <0.001), after accounting for prostate-specific antigen level, clinical stage, and biopsy Gleason sum. The receiver operating characteristic coordinate plot indicated that the removal of 28 nodes yielded a 90% ability to detect LNI. Conversely, the assessment of 10 or fewer nodes was associated with a virtually zero probability of finding LNI.

CONCLUSIONS

We have provided a critical assessment of the concept that the nodal yield at pelvic lymph node dissection is closely associated with the rate of LNI.

Nuclear localization of nuclear factor-kappaB p65 in primary prostate tumors is highly predictive of pelvic lymph node metastases

PURPOSE

Lymph node invasion (LNI) is associated with increased risk of prostate cancer progression. Unfortunately, pelvic lymph node dissections are fraught with a high rate of false-negative findings, emphasizing the need for highly accurate markers of LNI. Because nuclear factor-kappaB (NF-kappaB) is a candidate marker of prostate cancer progression, we tested the association between nuclear localization of NF-kappaB in radical prostatectomy specimens and the presence of LNI.

EXPERIMENTAL DESIGN

NF-kappaB expression in radical prostatectomy specimens was assessed with a monoclonal NF-kappaB p65 antibody, in 20 patients with LNI and in 31 controls with no LNI and no biochemical relapse 5 years after radical prostatectomy. Univariate and multivariate logistic regression models were used. The accuracy of multivariate predictions with and without NF-kappaB was quantified with the area under the receiver operating characteristics curve and 200 bootstrap resamples were used to reduce overfit bias.

RESULTS

Univariate regression models showed a 7% increase in the odds of observing LNI for each 1% increase in NF-kappaB nuclear staining (odds ratio, 1.07; P = 0.003). In multivariate models, each 1% increase in NF-kappaB was associated with an 8% increase in the odds of LNI (odds ratio, 1.08; P = 0.03) and its statistical significance was only surpassed by the presence of seminal vesicle invasion (P = 0.003). Addition of NF-kappaB to all other predictors increased the accuracy of LNI prediction by 2.3% (from 84.8% to 87.1%; P < 0.001).

CONCLUSION

This is the first study that shows that the extent of nuclear localization of NF-kappaB in primary prostate tumors is highly accurately capable of predicting the probability of locoregional spread of prostate cancer.

Validation of a nomogram predicting the probability of lymph node invasion based on the extent of pelvic lymphadenectomy in patients with clinically localized prostate cancer

OBJECTIVE

To develop a multivariate nomogram to predict the rate of lymph node invasion (LNI) in patients with clinically localized prostate cancer according to the extent of extended pelvic lymphadenectomy (PLND), which is associated with significantly higher rate of LNI.

PATIENTS AND METHODS

The study comprised 781 consecutive patients (median age 66.6 years, range 45-85) treated with PLND and radical retropubic prostatectomy (RRP) for clinically localized prostate cancer. Their median (range) prostate-specific antigen (PSA) level was 7 (1.03-49.91) ng/mL, and their clinical stages were T1c in 433 (55.4%), T2 in 328 (42%) and T3 in 20 (2.6%). Biopsy Gleason sums were <or= 6 in 514 (65.8%), 7 in 204 (26.1%) and 8-10 in 63 (8.1%). Multivariate logistic regression models were used to test the association between predictors including PSA level, biopsy Gleason sum, clinical stage, number of nodes removed and the rate of LNI. Finally, regression coefficients were used to develop a nomogram, which was internally validated with 200 bootstrap re-samples.

RESULTS

The median (range) number of lymph nodes removed was 14 (2-40); LNI was detected in 71 patients (9.1%). The univariate predictive accuracy for total PSA level, clinical stage, biopsy Gleason sum and number of total nodes removed and examined was 64.2%, 59.8%, 74% and 62.9%, respectively. Except for PSA (P = 0.2), all variables were statistically significant multivariate predictors of LNI at RRP (P <or= 0.001). A nomogram based on clinical stage, PSA level, biopsy Gleason sum and the number of total lymph nodes removed was 78.6% accurate, and 1.8% more accurate than a nomogram without the number of removed lymph nodes.

CONCLUSIONS

The extent of PLND is directly related to the probability of LNI. The risk of LNI increases linearly, and is proportional to the number of nodes removed and examined. The effect of the increased probability of LNI is weighted more heavily in men with more advanced clinical stage and grade.

Validation of a Nomogram Predicting the Probability of Lymph Node Invasion among Patients Undergoing Radical Prostatectomy and an Extended Pelvic Lymphadenectomy

INTRODUCTION

Our goal was to develop and internally validate a nomogram for prediction of lymph node invasion (LNI) in patients with clinically localized prostate cancer undergoing extended pelvic lymphadenectomy (ePLND).

METHODS

602 consecutive patients (mean age 65.8 years) underwent an ePLND, where 10 or more nodes were removed. PSA was 1.1-49.9 (median 7.2). Clinical stages were: T1c in 55.6%, T2 in 41.4% and T3 in 3%. Biopsy Gleason sums were: 6 or less in 66%, 7 in 25.4%, 8-10 in 8.6%. Multivariate logistic regression models tested the association between all of the above predictors and LNI. Regression-based coefficients were used to develop a nomogram predicting LNI and 200 bootstrap resamples were used for internal validation.

RESULTS

Mean number of lymph nodes removed was 17.1 (range 10-40). LNI was detected in 66 patients (11.0%). Univariate predictive accuracy for total PSA, clinical stage and biopsy Gleason sum was 63%, 58% and 73%, respectively. A nomogram based on clinical stage, PSA and Biopsy Gleason sum demonstrated bootstrap-corrected predictive accuracy of 76%.

CONCLUSIONS

A nomogram based on pre-treatment PSA, clinical stage and biopsy Gleason sum can highly accurately predict LNI at ePLND.

Development and validation of a nomogram predicting the outcome of prostate biopsy based on patient age, digital rectal examination and serum prostate specific antigen

PURPOSE

We developed and validated a nomogram which predicts presence of prostate cancer (PCa) on needle biopsy.

MATERIALS AND METHODS

We used 3 cohorts of men who were evaluated with sextant biopsy of the prostate and whose presenting prostate specific antigen (PSA) was not greater than 50 ng/ml. Data from 4,193 men from Montreal, Canada were used to develop a nomogram based on age, digital rectal examination (DRE) and serum PSA. External validation was performed on 1,762 men from Hamburg, Germany. Data from these men were subsequently used to develop a second nomogram in which percent free PSA (%fPSA) was added as a predictor. External validation was performed using 514 men from Montreal. Both nomograms were based on multivariate logistic regression models. Predictive accuracy was evaluated with areas under the receiver operating characteristic curve and graphically with loess smoothing plots.

RESULTS

PCa was detected in 1,477 (35.2%) men from Montreal, 739 (41.9%) men from Hamburg and 189 (36.8%) men from Montreal. In all models all predictors were significant at 0.05. Using age, DRE and PSA external validation AUC was 0.69. Using age, DRE, PSA and %fPSA external validation AUC was 0.77.

CONCLUSIONS

A nomogram based on age, DRE, PSA and %fPSA can highly accurately predict the outcome of prostate biopsy in men at risk for PCa.

Is quadrant biopsy sufficient in men likely to have advanced prostate cancer? Comparison with extended biopsy

We hypothesized that quadrant prostate biopsy (QPB) provides sufficient first-line pathological evaluation of patients with presumed advanced prostate cancer (PC). The aim of this study was to investigate whether the reduction of core number in first-line PB from 6-12 to 4 in patients with presumed advanced PC leads to loss of clinically relevant information. We retrospectively studied 113 men that underwent PB, classified in two groups: "H" (high) and "L" (low likelihood of having advanced PC), according to PSA, digital rectal and transrectal ultrasound findings. Pathological results of 6-12-core PB and QPB were retrospectively compared for the presence of malignancy, percentage of positive cores, Gleason score (GS), and the presence of high-grade prostatic intraepithelial neoplasia (HGPIN). PC detection rate was not impaired in group H but dropped significantly in group L, and the percentage of positive cores was not significantly changed in group H (p=0.39), but decreased in group L (p=0.04), due to sampling scheme reduction. No HGPIN was missed with QPB in group H, while 2 HGPINs were missed in group L. No significant change in GS in either group was observed (p=0.12, p=0.13) due to reduction to QPB. We conclude that in patients with presumed advanced PC, reduction of the number of cores in PB may be an acceptable diagnostic strategy, but further studies are needed to analyze the impact of PB scheme reduction on other relevant pathological information obtained from PB.

Impact of training level of urology residents on the detection of prostate cancer on TRUS biopsy

The objective of this study is to evaluate the performance of urology residents at each training level in detecting prostate cancer with transrectal ultrasound-guided (TRUS) biopsy. The inclusion criteria were: (1) prostate-specific antigen (PSA) 4-10 ng/ml; and (2) 10-12 cores per biopsy session. Data from repeat biopsy sessions were excluded. Overall prostate cancer detection rate for 170 patients was 39.4%. PSA, digital rectal examination (DRE), and prostate volume were predictors of cancer detection. There were no significant differences in overall cancer detection rates, PSA, DRE, or prostate volume between resident levels. In conclusion, urology residents at all levels of training perform equally well at detecting cancer using TRUS prostate biopsy technology.