Prospective evaluation of prostate-specific antigen density and systematic biopsies for early detection of prostatic carcinoma

Oncological outcomes in robot-assisted radical prostatectomy: the value of PSA density as a preoperative predictive factor

Background

Pretreatment assessment of patients diagnosed with localized prostate cancer (PCa) is essential for therapeutic decision-making. Currently available staging systems based on prostate-specific antigen (PSA), Gleason score, and clinical stage allow for determining the prognostic characteristics of these patients. Several studies have evaluated the preoperative use of prostate-specific antigen density (PSAD) as a prognostic factor for further risk stratification. To date, the role of PSAD in this setting is still an object of debate.

Objectives

The present analysis aimed to assess the predictive potential of PSAD for adverse oncological outcomes after robot-assisted radical prostatectomy (RARP) and to compare its accuracy to preoperative PSA (pPSA).

Design and methods

We retrospectively reviewed 427 patients diagnosed with localized PCa who underwent RARP at a single institution between January 2015 and January 2020. Generating receiver operator characteristic (ROC) curves, calculating areas under the curves (AUCs), and using a linear regression model, we analyzed the association of PSAD and pPSA with postoperative positive surgical margins (PSM), Gleason score ⩾ 7, persistent PSA, and biochemical recurrence (BCR), with a median follow-up of 47 months.

Results

PSAD showed a significant association with PSM (p < 0.0001), PSA persistence (p < 0.0001), and Gleason ⩾ 7 (p < 0.0001), without being statistically significant in predicting BCR (p = 0.098). The predictive value of PSAD was comparable to pPSA for outcomes of PSA persistence (AUC 0.727 versus 0.771) and Gleason ⩾ 7 (AUC 0.683 versus 0.649).

Conclusion

PSAD is a predictive factor for postoperative oncological outcomes of PSM, Gleason score ⩾ 7, and persistence of PSA. Despite the need for further studies, PSAD could be useful as a prognostic parameter in conjunction with established staging systems.

Clinical value of prostate health index as an indicator for recommending magnetic resonance imaging in patients with gray-zone prostate-specific antigen level

PURPOSE

To evaluate the usefulness of prostate health index (PHI) as an indicator for recommending magnetic resonance imaging (MRI) in patients with prostate-specific antigen (PSA) gray zone level < 10 ng/mL.

METHODS

443 patients who underwent prostate biopsy (PB) after serum PHI test and MRI between April 2019 and December 2022 were enrolled. For patients with visible lesion on MRI with Prostate Imaging Reporting and Data System Score (PI-RADS) ≥ 3, MRI-targeted PB was performed in addition to systematic 12-core PB.

RESULTS

The optimal cutoff value of PHI for predicting PI-RADS ≥ 3 lesions was 39.6, which was significantly associated with overall prostate cancer (OR 3.07, p = 0.018) and clinically significant prostate cancer (csPCa) (OR 4.15, p = 0.006) at MRI-targeted PB cores. When MRI was restricted to patients with PHI ≥ 39.6 alone, 28.7% of unnecessary MRI could be saved at the cost of missing 13.6% of csPCa. When omitting MRI for patients with PHI < 39.6 and PSAD < 0.12 ng/mL2, unnecessary MRI could be reduced by 20.1% with the risk of missing 6.2% of csPCa. With addition of systematic PB, 21.0% of patients with negative MRI-targeted PB were diagnosed as csPCa.

CONCLUSIONS

For patients in PSA gray zone, PHI of 39.6 might be an indicator for MRI and further MRI-targeted PB in additional to PSAD of 0.12 ng/mL2, reducing 20.1% of unnecessary MRI with the minimal risk of missing 6.2% of csPCa. To maximize csPCa detection, combining both MRI-targeted and systematic PB should be also considered.

Prostate-specific Antigen Density Cutoff of 0.15 ng/ml/cc to Propose Prostate Biopsies to Patients with Negative Magnetic Resonance Imaging: Efficient Threshold or Legacy of the Past?

BACKGROUND

A prostate-specific antigen density (PSAd) cutoff of 0.15 ng/ml/cc is a commonly recommended threshold to identify patients with negative prostate magnetic resonance imaging (MRI) who should proceed to a prostate biopsy. We were unable to find any study that explicitly examined the properties of this threshold compared with others.

OBJECTIVE

To investigate whether the 0.15 cutoff is justified for selecting patients at risk of harboring high-grade cancer (Gleason score ≥3 + 4) despite negative MRI.

DESIGN, SETTING, AND PARTICIPANTS

A cohort of 8974 prostate biopsies provided by the Prostate Biopsy Collaborative Group (PBCG) was included in the study.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Locally weighted scatterplot smoothing was used to investigate whether there was a change in the risk of high-grade cancer around this value. We examined whether the use of this cutoff in patients with negative MRI corresponds to a reasonable threshold probability for a biopsy (defined as a 10% risk of high-grade disease). To do so, we applied the negative likelihood ratio of MRI, calculated from eight studies on prostate MRI, to the risk curve derived from the PBCG.

RESULTS AND LIMITATIONS

There was no discontinuity in the risk of high-grade prostate cancer at a PSAd cutoff of 0.15. This cutoff corresponded to a probability of high-grade disease ranging from 2.6% to 10%, depending on MRI accuracy. Using 10% as threshold probability, the corresponding PSAd cutoff varied between 0.15 and 0.38, with the threshold increasing for greater MRI accuracy. Possible limitations include difference between studies on MRI and the use of ultrasound to measure prostate volume.

CONCLUSIONS

The 0.15 cutoff to recommend prostate biopsies in patients with negative MRI is justified only under an extreme scenario of poor MRI properties. We recommend a value of at least ≥0.20. Our results suggest the need for future studies to look at how to best identify patients who need prostate biopsies despite negative MRI, likely by using individualized risk prediction.

PATIENT SUMMARY

In this study, we investigated whether the commonly used prostate-specific antigen density cutoff of 0.15 is justified to identify patients with negative magnetic resonance imaging (MRI) who should proceed to a prostate biopsy. We found that this cutoff is appropriate only in case of very poor MRI quality, and a higher cutoff (≥0.20) should be used for the average MRI.

Diagnostic value of combining PI-RADS v2.1 with PSAD in clinically significant prostate cancer

PURPOSE

To investigate the diagnostic value of the Prostate Imaging Reporting and Data System version 2.1 (PI-RADS v2.1) for clinically significant prostate cancer (CsPCa). We also aimed to combine PI-RADS v2.1 with prostate-specific antigen (PSA) derivatives to improve the predictive value of CsPCa.

METHODS

We retrospectively collected relevant data who underwent standard MRI examinations of the prostate and subjected to a prostate biopsy at Shenzhen People's hospital from November 2014 to November 2019. Included 125 cases of CsPCa and 383 cases of non-CsPCa. All cases were scored using the PI-RADS v2.1. The clinical data collected included age, PSA, free PSA/total PSA, prostate volume and PSA density (PSAD). A univariate analysis was performed to identify statistically significant indicators. Logistic regression was used to analyze the predictive value of the multi-parameter combination on CsPCa.

RESULTS

Except age, the difference in all of indicators between the CsPCa group and non-CsPCa group was statistically significant. The PI-RADS score and PSAD value had the highest diagnostic value. Logistic regression analysis revealed that the PI-RADS score and PSAD value were independent predictors of CsPCa, with a regression model AUC of 0.935. CsPCa detection rates were low when the PI-RADS score ≤ 2 or the PI-RADS score = 3 and the PSAD value ≤ 0.33 ng/ml/ml.

CONCLUSION

Combining the PI-RADS score and PSAD value improved the predictive performance of CsPCa. Patients with a PI-RADS score ≤ 2 or a PI-RADS score = 3 and a PSAD value ≤ 0.33 ng/ml/ml can avoid an unnecessary biopsy.

Prostate cancer biomarkers: a practical review based on different clinical scenarios

Traditionally, diagnosis and staging of prostate cancer (PCa) have been based on prostate-specific antigen (PSA) level, digital rectal examination (DRE), and transrectal ultrasound (TRUS) guided prostate biopsy. Biomarkers have been introduced into clinical practice to reduce the overdiagnosis and overtreatment of low-grade PCa and increase the success of personalized therapies for high-grade and high-stage PCa. The purpose of this review was to describe available PCa biomarkers and examine their use in clinical practice. A nonsystematic literature review was performed using PubMed and Scopus to retrieve papers related to PCa biomarkers. In addition, we manually searched websites of major urological associations for PCa guidelines to evaluate available evidence and recommendations on the role of biomarkers and their potential contribution to PCa decision-making. In addition to PSA and its derivates, thirteen blood, urine, and tissue biomarkers are mentioned in various PCa guidelines. Retrospective studies have shown their utility in three main clinical scenarios: (1) deciding whether to perform a biopsy, (2) distinguishing patients who require active treatment from those who can benefit from active surveillance, and (3) defining a subset of high-risk PCa patients who can benefit from additional therapies after RP. Several validated PCa biomarkers have become commercially available in recent years. Guidelines now recommend offering these tests in situations in which the assay result, when considered in combination with routine clinical factors, is likely to affect management. However, the lack of direct comparisons and the unproven benefits, in terms of long-term survival and cost-effectiveness, prevent these biomarkers from being integrated into routine clinical use.

Peripheral zone PSA density: a predominant variable to improve prostate cancer detection efficiency in men with PSA higher than 4 ng ml-1

To improve the diagnostic efficiency of prostate cancer (PCa) and reduce unnecessary biopsies, we defined and analyzed the diagnostic efficiency of peripheral zone prostate-specific antigen (PSA) density (PZ-PSAD). Patients who underwent systematic 12-core prostate biopsies in Shanghai General Hospital (Shanghai, China) between January 2012 and January 2018 were retrospectively identified (n = 529). Another group of patients with benign prostatic hyperplasia (n = 100) were randomly preselected to obtain the PSA density of the non-PCa cohort (N-PSAD). Prostate volumes and transition zone volumes were measured using multiparameter magnetic resonance imaging (mpMRI) and were combined with PSA and N-PSAD to obtain the PZ-PSAD from a specific algorithm. Receiver operating characteristic (ROC) curve analysis was used to assess the PCa detection efficiency in patients stratified by PSA level, and the area under the ROC curve (AUC) of PZ-PSAD was higher than that of PSA, PSA density (PSAD), and transition zone PSA density (TZ-PSAD). PZ-PSAD could amend the diagnosis for more than half of the patients with inaccurate transrectal ultrasonography (TRUS) and mpMRI results. When TRUS and mpMRI findings were ambiguous to predict PCa (PIRADS score ≤3), PZ-PSAD could increase the positive rate of biopsy from 21.7% to 54.7%, and help 63.8% (150/235) of patients avoid unnecessary prostate biopsy. In patients whose PSA was 4.0–10.0 ng ml⁻¹, 10.1–20.0 ng ml⁻¹, and >20.0 ng ml⁻¹, the ideal PZ-PSAD cut-off value for predicting clinically significant PCa was 0.019 ng ml⁻², 0.297 ng ml⁻², and 1.180 ng ml⁻², respectively (sensitivity >90%). Compared with PSA, PSAD, and TZ-PSAD, the efficiency of PZ-PSAD for predicting PCa is the highest, leading to fewer missed diagnoses and unnecessary biopsies.

The use of prostate specific antigen density to predict clinically significant prostate cancer

The purpose of this study was to assess the predictive value of prostate specific antigen density (PSAD) for detection of clinically significant prostate cancer in men undergoing systematic transrectal ultrasound (TRUS)-guided prostate biopsy. We retrospectively analyzed data of men who underwent TRUS-guided prostate biopsy because of elevated PSA (≤ 20 ng/ml) or abnormal digital rectal examination. Receiver operating characteristic curve analysis to compare PSA and PSAD performance and chi-square automatic interaction detector methodologies were used to identify predictors of clinically significant cancer (Gleason score ≥ 7 or international society of urological pathology grade group ≥ 2). Nine-hundred and ninety-two consecutive men with a median age of 66 years (IQR 61-71) were included in the study. Median PSAD was 0.10 ng/ml² (IQR 0.10-0.22). Prostate adenocarcinoma was diagnosed in 338 men (34%). Clinically significant prostate adenocarcinoma was diagnosed in 167 patients (50% of all cancers and 17% of the whole cohort). The AUC to predict clinically significant prostate cancer was 0.64 for PSA and 0.78 for PSAD (P < 0.001). The highest Youden's index for PSAD was at 0.20 ng/ml² with 70% sensitivity and 79% specificity for the diagnosis of clinically significant cancer. Men with PSAD < 0.09 ng/ml² had only 4% chance of having clinically significant disease. The detection rate of clinically significant prostate cancer in patients with PSAD between 0.09 and 0.19 ng/ml² was significantly higher when prostate volume was less than 33 ml. In conclusion, PSAD was a better predictor than PSA alone of clinically significant prostate cancer in patients undergoing TRUS-guided biopsy. Patients with PSAD below 0.09 ng/ml² were unlikely to harbor clinically significant prostate cancer. Combining PSAD in the gray zone (0.09-0.19) with prostate volume below 33 ml adds diagnostic value of clinically significant prostate cancer.

Prostate Specific Antigen Density as a Predictor of Clinically Significant Prostate Cancer When the Prostate Specific Antigen is in the Diagnostic Gray Zone: Defining the Optimum Cutoff Point Stratified by Race and Body Mass Index

PURPOSE

We assessed the predictive value of prostate specific antigen density to detect clinically significant prostate cancer, defined as prostate cancer grade group 2 or greater, in a series of men undergoing prostate biopsy with prostate specific antigen 4 to 10 ng/ml. We sought to define an optimum cutoff point for prostate specific antigen density and assess how race and body mass index affects prostate specific antigen density performance.

MATERIALS AND METHODS

We analyzed data on 2,162 men, of whom 56% were African American, with serum prostate specific antigen 4 to 10 ng/ml who underwent prostate biopsy. We compared the AUC between prostate specific antigen and prostate specific antigen density to predict clinically significant and any prostate cancer vs no cancer. We calculated the negative predictive value of prostate specific antigen density cutoff points ranging from 0.05 to 0.15 by every 0.01 step. We a priori defined the optimal cutoff point of prostate specific antigen density as a negative predictive value of 95% and tested whether the cutoff was sensitive to body mass index and race by comparing the negative predictive value across strata.

RESULTS

Median prostate specific antigen was 5.6 ng/ml (IQR 4.8-7) and median prostate specific antigen density was 0.15 ng/ml/cc (IQR 0.1-0.22). Prostate specific antigen density improved the performance of prostate specific antigen to detect significant cancer (AUC 0.58 to 0.68) and any cancer (AUC 0.55 to 0.69, each p <0.001). We identified a prostate specific antigen density cutoff point of less than 0.08 ng/ml/cc with a 96% negative predictive value for grade group 2 or greater. This was largely unchanged among different races and body mass indexes.

CONCLUSIONS

Regardless of race or body mass index men with prostate specific antigen density less than 0.08 were unlikely to harbor grade group 2 or greater disease when prostate specific antigen was 4 to 10 ng/ml. If validated, prostate specific antigen density is a simple inexpensive and available tool that can be used to identify men who can likely forego prostate biopsies, thus reducing the over detection and morbidity of unnecessary biopsies.

Differentiating prostate cancer from benign prostatic hyperplasia using PSAD based on machine learning: Single-center retrospective study in China

The incidence of prostate cancer increases annually. Prostate cancer is an underreported and emerging problem in China. We conducted a cross-sectional study of 392 eligible patients from 710 men with prostate cancer or benign prostatic hyperplasia between 2000 and 2003. For total prostate-specific antigen, age, three diameters of prostate, prostate volume and prostate-specific antigen density seven indices, analysis of variance and t test were used to analyze the difference between the groups. A decision tree with pruning was established using the prostate-specific antigen density, age and transversal diameter of the prostate to screen the patient with prostate cancer. According to the established decision tree model, prostate-specific antigen density was the most important factor affecting the occurrence of prostate cancer. In elderly people over the age of 83 years, the transverse diameter of prostate cancer was smaller than that of benign prostatic hyperplasia, with prostate-specific antigen density less than . No additional index was introduced, and the detection rate of prostate cancer was 86.6 %.The specificity was enhanced to 78.1%.

[Evaluation and results of ablative therapies in prostate cancer]

OBJECTIVE

To perform a state of the art about methods of evaluation and present results in ablative therapies for localized prostate cancer.

METHODS

A review of the scientific literature was performed in Medline database (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) using different associations of keywords. Publications obtained were selected based on methodology, language and relevance. After selection, 102 articles were analysed.

RESULTS

Analyse the results of ablative therapies is presently difficult considering the heterogeneity of indications, techniques and follow-up. However, results from the most recent and homogeneous studies are encouraging. Oncologically, postoperative biopsies (the most important criteria) are negative (without any tumor cells in the treated area) in 75 to 95%. Functionally, urinary and sexual pre-operative status is spared (or recovered early) in more than 90% of the patients treated. More and more studies underline also the correlation between the results and the technique used considering the volume of the gland and, moreover, the "index lesion" localization.

CONCLUSION

The post-treatment pathological evaluation by biopsies (targeted with MRI or, perhaps in a near future, with innovative ultrasonography) is the corner stone of oncological evaluation of ablative therapies. Ongoing trials will allow to standardize the follow-up and determine the best indication and the best techniques in order to optimize oncological and functional results for each patient treated.

Re-examining Prostate-specific Antigen (PSA) Density: Defining the Optimal PSA Range and Patients for Using PSA Density to Predict Prostate Cancer Using Extended Template Biopsy

OBJECTIVE

To compare the predictive accuracy of prostate-specific antigen (PSA) density vs PSA across different PSA ranges and by prior biopsy status in a prospective cohort undergoing prostate biopsy.

MATERIALS AND METHODS

Men from a prospective trial underwent an extended template biopsy to evaluate for prostate cancer at 26 sites throughout the United States. The area under the receiver operating curve assessed the predictive accuracy of PSA density vs PSA across 3 PSA ranges (<4 ng/mL, 4-10 ng/mL, >10 ng/mL). We also investigated the effect of varying the PSA density cutoffs on the detection of cancer and assessed the performance of PSA density vs PSA in men with or without a prior negative biopsy.

RESULTS

Among 1290 patients, 585 (45%) and 284 (22%) men had prostate cancer and significant prostate cancer, respectively. PSA density performed better than PSA in detecting any prostate cancer within a PSA of 4-10 ng/mL (area under the receiver operating characteristic curve [AUC]: 0.70 vs 0.53, P < .0001) and within a PSA >10 mg/mL (AUC: 0.84 vs 0.65, P < .0001). PSA density was significantly more predictive than PSA in detecting any prostate cancer in men without (AUC: 0.73 vs 0.67, P < .0001) and with (AUC: 0.69 vs 0.55, P < .0001) a previous biopsy; however, the incremental difference in AUC was higher among men with a previous negative biopsy. Similar inferences were seen for significant cancer across all analyses.

CONCLUSION

As PSA increases, PSA density becomes a better marker for predicting prostate cancer compared with PSA alone. Additionally, PSA density performed better than PSA in men with a prior negative biopsy.

Screening and Detection of Prostate Cancer-Review of Literature and Current Perspective

Screening of prostatic cancer is a matter of debate among uro-oncologist. With many new screening modalities like prostatic health index (PHI), 4K testing the role of screening has increased as one is able to stratify patients with serum prostate specific antigen level in a grey zone of 4-10 ng/ml and normal digital rectal examination into various risk groups, thus avoiding unnecessary biopsy which was the pitfalls of routine screening practice. PHI is better at predicting malignancy while 4K is better at predicting high-grade disease. This in combination with multiparametric MRI especially with prostate imaging reporting and data system score has made screening less difficult and more meaningful for a practising uro-oncologist.

Prostate-specific antigen density values among patients with symptomatic prostatic enlargement in Nigeria

Background

This study aims to estimate the prostate-specific antigen density (PSAD) cutoff level for detecting prostate cancer (CAP) in Nigerian men with “grey zone PSA” (4–10 ng/ml) and normal digital rectal examination findings. We addressed this research question: Is the international PSAD cutoff of 0.15 ideal for detecting CAP in our symptomatic patients with “grey zone PSA?”

Methods

Aim: To estimate the prostate-specific antigen density (PSAD) cutoff level for detecting CAP in Nigerian men with “grey zone PSA” (4–10 ng/ml) and normal digital rectal examination findings.

Design: Prospective.

Setting: A tertiary medical center in Enugu, Nigeria.

Participants: Two hundred and fifty-four men with either benign prostatic hyperplasia (BPH) or CAP were recruited.

Intervention: Patients with PSA above 4 ng/ml or abnormal digital rectal examination or hypoechoic lesion in the prostate were biopsied.

Outcome measures: PSAD and histology report of BPH or CAP.

Results

Ninety-seven patients had CAP while 157 had benign prostatic hyperplasia (BPH). Seventy-two patients had their serum PSA value within the range of 4.0 and 10 ng/ml. PSAD cutoff level to detect CAP was 0.04 (sensitivity 95.88 %; specificity 28.7 %).

Conclusions

The PSAD cutoff level generated for Nigerian men in this study is 0.04 which is relatively different from international consensus. This PSAD cutoff level has a positive correlation with histology and could detect patients with CAP who have “grey zone PSA.”

Correlation of High Body Mass Index With More Advanced Localized Prostate Cancer at Radical Prostatectomy Is Not Reflected in PSA Level and PSA Density but Is Seen in PSA Mass

OBJECTIVES

Prostate cancer screening algorithms and preoperative nomograms do not include patients' body mass index (BMI). We evaluated outcomes at radical prostatectomy (RP) adjusted to BMI.

METHODS

Serum prostate-specific antigen (PSA) levels, PSA mass, PSA density (PSAD), and RP findings were analyzed with respect to BMI in 4,926 men who underwent RP between 2005 and 2014.

RESULTS

In total, 1,001 (20.3%) men were normal weight, 2,547 (51.7%) were overweight, and 1,378 (28%) were obese. Median PSA levels (ng/mL) were normal weight, 5.0; overweight, 5.1; and obese, 5.2 (P = .094). Median PSA mass increased with increasing BMI: 15.9 vs 17.4 vs 19.4 μg (P < .001). Median PSAD was not significantly different: 0.11 vs 0.11 vs 0.11 ng/mL/g (P = .084). Median prostate weight increased with increasing BMI: 44 vs 45 vs 49 g (P < .001). Median prostatectomy tumor volume increased with increasing BMI: 3.9 vs 4.7 vs 5.9 cm(3) (P < .001). Overweight and obese patients had a higher Gleason score and more locally advanced cancer (P < .001). Frequency of positive surgical margins increased with higher BMIs (P < .001). Frequency of lymph node metastasis did not differ significantly (P = .088).

CONCLUSIONS

While BMI correlates with tumor volume, Gleason score, and extent of disease at RP, there is no routinely measured clinical parameter reflecting this. Only PSA mass highlights this correlation. Thus, BMI and potentially PSA mass should be taken into account in predictive algorithms pertaining to prostate cancer and its surgical treatment.

Developing a follow-up strategy for patients with PSA ranging from 4 to 10 ng/ml via a new model to reduce unnecessary prostate biopsies

Objective

The aim of this study was to develop a follow-up strategy based on the new model to reduce unnecessary prostate biopsies in patients with prostate specific antigen (PSA) ranging from 4 to 10 ng/ml.

Methods

A total of 436 patients with PSA ranging from 4 to 10 ng/ml who had undergone transrectal ultrasound (TRUS)-guided prostate biopsy were evaluated during the first stage. Age, PSA, free PSA (fPSA), digital rectal examination (DRE) findings, ultrasonic hypoechoic mass, ultrasonic microcalcifications, prostate volume (PV) and PSA density (PSAD) were considered as predictive factors. A multiple logistic regression analysis involving a backward elimination selection procedure was applied to select independent predictors. After a comprehensive analysis of all results, we developed a new model to assess the risk of prostate cancer and an effective follow-up strategy.

Results

Age, PSA, PV, fPSA, rate of abnormal DRE findings and rate of hypoechoic masses detected by TRUS were included in our model. A significantly greater area under the receiver-operating characteristic curve was obtained in our model when compared with using PSA alone (0.782 vs. 0.566). Patients were grouped according to the value of prostate cancer risk (PCaR). In the second stage of our study, patients with PCaR>0.52 were recommended to undergo biopsies immediately while the rest of the patients continued close follow-up observation. Compared with the first stage, the detection rate of PCa in the second stage was significantly increased (33.0% vs 21.1%, p = 0.012). There was no significant difference between the two stages in distribution of the Gleason score (p = 0.808).

Conclusions

We developed a follow-up strategy based on the new model, which reduced unnecessary prostate biopsies without delaying patients’ diagnoses and treatments.

Role of PSA density in diagnosis of prostate cancer in obese men

PURPOSE

To compare the performance of prostate-specific antigen (PSA) density in the diagnosis of prostate cancer in obese and non-obese Chinese men.

METHODS

The results of transrectal ultrasound-guided (TRUS) prostate biopsies of Chinese men with PSA <20 ng/mL were reviewed. Parameters including age, body mass index (BMI), TRUS prostate volume, and TRUS biopsy results were recorded. The diagnostic yields of PSA density (>0.15 ng/mL as positive) in obese and non-obese men with PSA <20 ng/mL were compared. Obesity was defined as BMI ≥ 27 kg/m(2) according to WHO recommendation for Hong Kong Chinese.

RESULTS

TRUS biopsy, BMI, and PSA density data were available for 854 men (mean age 65.9 ± 7.3). The mean PSA values for the obese and non-obese patients were 7.9 ± 3.7 and 8.2 ± 4.1 ng/mL, respectively (p = 0.416). TRUS volumes in obese and non-obese men were 63.2 ml and 51.6 ml, respectively (t test, p < 0.001), and PSA density was significantly lower in obese men (0.145 vs. 0.188, p < 0.001). For obese men, positive PSA density was associated with four times (41.1 vs. 9.5 %, p < 0.001) the risk of prostate cancer, compared to only twice the risk (18.8 vs. 9.7 %, p = 0.001) in non-obese men. The specificity and area under the curve of PSA density were 74.2 % and 0.731, respectively, for obese men, and 51.4 % and 0.653, respectively, for non-obese men. Among patients with a diagnosis of prostate cancer, the obese patient group had a significantly higher proportion of patients with Gleason 7-10 prostate cancer than the non-obese patient group (48.9 vs. 32.7 %, Chi-square test, p = 0.035), and a trend toward a higher proportion of bilateral lobe involvement.

CONCLUSION

PSA density had better performance in obese men. Positive PSA density in obese men was associated with four times the risk of prostate cancer.

Role of prostate volume in the early detection of prostate cancer in a cohort with slowly increasing prostate specific antigen

PURPOSE

To investigate the relationship between prostate volume and the increased risk for being diagnosed with prostate cancer (PCa) in men with slowly increasing prostate specific antigen (PSA).

MATERIALS AND METHODS

A cohort of 1035 men who visited our hospital's health promotion center and were checked for serum PSA levels more than two times between January 2001 and November 2011 were included. Among them, 116 patients had a change in PSA levels from less than 4 ng/mL to more than 4 ng/mL and underwent transrectal ultrasound guided prostate biopsy. Median age was 55.9 years and 26 (22.4%) had PCa. We compared the initial PSA level, the last PSA level, age, prostate volume, PSA density (PSAD), PSA velocity, and follow-up period between men with and without PCa. The mean follow- up period was 83.7 months.

RESULTS

Significant predictive factors for the detection of prostate cancer identified by univariate analysis were prostate volume, follow-up period and PSAD. In the multivariate analysis, prostate volume (p<0.001, odds ratio: 0.890) was the most significant factor for the detection of prostate cancer. In the receiver operator characteristic curve of prostate volume, area under curve was 0.724. At the cut-off value of 28.8 mL for prostate volume, the sensitivity and specificity were 61.1% and 73.1% respectively.

CONCLUSION

In men with PSA values more than 4 ng/mL during the follow-up period, a small prostate volume was the most important factor in early detection of prostate cancer.

The Prostate Cancer Detection Rate on the Second Prostate Biopsy according to Prostate-Specific Antigen Trend

Purpose

To identify the prostate cancer detection rate on the patients who had second prostate biopsy out of the patients who were reported negative in their first biopsy.

Materials and Methods

From July 2006 to February 2012, prostate biopsy was performed on 843 patients with over 4 ng/ml and on 618 biopsy negative patients PSA was performed from between 6 months and 9 months after biopsy. On 164 patients, second biopsy was performed, and 42 patients were selected. If there was less than 10% change between PSA before the prostate biopsy and PSA measured during 6 to 9 months after the first biopsy it was considered as no change. If above 10% increase, it was considered increase and if above 10% decrease it was considered as decrease.

Results

The cancer detection rate in PSA increase group was 20%, the detection rate in no change in PSA level but still over the normal range group 8.3%, and that in the PSA decrease group was 0%. When comparing prostate cancer group and non-cancer group, it is more probable to have prostate cancer when they are older, prostate volume is smaller and PSA density is higher.

Conclusions

The second biopsy is strongly recommended when PSA level shows no change or increase, age is older, prostate volume is smaller or PSA density is higher.

Development of a real-time clinical decision support system upon the Web MVC-based architecture for prostate cancer treatment

BACKGROUND

A real-time clinical decision support system (RTCDSS) with interactive diagrams enables clinicians to instantly and efficiently track patients' clinical records (PCRs) and improve their quality of clinical care. We propose a RTCDSS to process online clinical informatics from multiple databases for clinical decision making in the treatment of prostate cancer based on Web Model-View-Controller (MVC) architecture, by which the system can easily be adapted to different diseases and applications.

METHODS

We designed a framework upon the Web MVC-based architecture in which the reusable and extractable models can be conveniently adapted to other hospital information systems and which allows for efficient database integration. Then, we determined the clinical variables of the prostate cancer treatment based on participating clinicians' opinions and developed a computational model to determine the pretreatment parameters. Furthermore, the components of the RTCDSS integrated PCRs and decision factors for real-time analysis to provide evidence-based diagrams upon the clinician-oriented interface for visualization of treatment guidance and health risk assessment.

RESULTS

The resulting system can improve quality of clinical treatment by allowing clinicians to concurrently analyze and evaluate the clinical markers of prostate cancer patients with instantaneous clinical data and evidence-based diagrams which can automatically identify pretreatment parameters. Moreover, the proposed RTCDSS can aid interactions between patients and clinicians.

CONCLUSIONS

Our proposed framework supports online clinical informatics, evaluates treatment risks, offers interactive guidance, and provides real-time reference for decision making in the treatment of prostate cancer. The developed clinician-oriented interface can assist clinicians in conveniently presenting evidence-based information to patients and can be readily adapted to an existing hospital information system and be easily applied in other chronic diseases.

Prostate kallikrein markers in diagnosis, risk stratification and prognosis

The kallikrein, prostate-specific antigen (PSA), is one of the world's most frequently used disease biomarkers. After almost two decades of research and clinical experience, the diagnostic and monitoring limitations of PSA are beginning to be understood. Most physicians are aware of PSA's low specificity for cancer among older men with benign prostatic conditions; fewer are aware of recent data, which show that a prior negative biopsy or a prior PSA value below the threshold for biopsy might compromise the predictive accuracy of PSA even further. Furthermore, a subtle increase in serum PSA level during early middle age is strongly correlated with clinically important prostate cancer. We review current and past reports on the prostate kallikreins PSA and hK2 in relation to pathology and epidemiology.

Between-subject variations of transition zone epithelial volume and serum PSA levels in men with benign prostatic hyperplasia

PURPOSE

We verified if the measure of transition zone epithelial volume (TZepiV) could be a valid predictor of serum PSA value in men with benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

Between January 2005 and July 2008, a total of 90 patients undergoing transvesical suprapubic adenomectomy for sintomatic BPH were enrolled. In case of an elevated PSA level (above 4 ng/ml) or abnormal digital rectal examination, systematic multisite biopsies were performed preoperatively to rule out prostate cancer. We have examined PSA levels before and after open surgery, TZ weight as measured by the pathologist and TZepiV by multiplying percentage of epithelium of a single biopsy core with the weight of adenoma. Means, Spearman correlation coefficients and percent change were calculated for all variables and intervals.

RESULTS

The mean serum PSA decreased from 4.8 ng/ml preoperatively to 0.5 ng/ml postoperatively. The mean decrease in PSA was 90% (range 70-99%).The mean weight of enucleated adenoma was 67 gr.(range 18-201) and the TZepiV was 7.7 ml (0.3-28.4). Overall, both TZ volume and TZepiV were correlated to PSA value with TZepiV representing the most predictive variable for PSA (r = 0.54 P = 0.002 vs. r = 0.26 P = 0.02). When we analyzed different ranges of PSA values, only TZepiV was always significantly proportional to PSA.

CONCLUSIONS

Ninety percentage of serum PSA level comes from TZ in range of 0.01-0.17 ng/ml/gr. In presence of equal BPH volumes, the amount of epithelium can be different and it is the main determinant in PSA increase. Thus, TZ epithelial volume could represent a new useful clinical tool able to increase the specificity of PSA in the diagnosis of prostate cancer.

Beyond PSA: utility of novel tumor markers in the setting of elevated PSA

The introduction of prostate-specific antigen (PSA) for prostate cancer screening and detection has been used for over 20 years and has dramatically changed the face of prostate cancer. Although it is a highly sensitive serum test, its routine use has been the subject of continued controversy owing to its limited specificity. Due to this lack of specificity, many have proposed modifications of PSA in an attempt to bolster the performance of this analyte. The human genome project and high throughput gene expression profiling has recently yielded several promising molecular biomarkers for prostate cancer detection beyond PSA or PSA modifications. This review will first highlight several characteristics of an ideal biomarker, then focus on select emerging biomarkers for the detection of prostate cancer.

[Parameters with possible influence in PSA adjusted for transition zone volume]

OBJECTIVE

To evaluate the effect of age, digital rectal examination results and prostatic volume on PSA value adjusted to transition zone (PSA-TZ) in the detection of prostatic cancer.

MATERIAL AND METHODS

Data of 243 patients with serum PSA of 4 to 20 ng/ml who underwent biopsy because of prostatic cancer suspicion are analyzed. In this population, cancer was detected in 62 cases (24.8%). Total prostatic volume and transition zone volume were calculated by transrectal echography applying the ellipsoid formula.

RESULTS

Applying lineal regresion analysis, it was found no correlation between age and PSA-TZ (Pearson coefficient 0.00). By dividing these patients among those with normal rectal examination (84%) and those with suspicious digital rectal examination (16%), cutoff values of PSA-TZ were found to be not different by ROC curves analysis for 95% sensitivity varying specificity only among 24 and 26% between these two groups of patients. Prostatic size (< or = or >40 cc) showed that, for obtaining the same 95% sensitivity in the detection of cancer, PSA-TZ value would require to be modified, being 0.17 in large prostates (> 40 cc) and 0.25 in small prostates (< or =40 cc).

CONCLUSIONS

The utility of PSA-TZ as a potential predictor parameter of prostatic cancer did not need to be modified with respect to age or to data of digital rectal examination. However, for supporting sensivity of its best cutoff value, PSA-TZ would need to be modified with respect to total prostatic volume.

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.

The ratio of prostate-specific antigen (PSA) to prostate volume (PSA density) as a parameter to improve the detection of prostate carcinoma in PSA values in the range of < 4 ng/mL

BACKGROUND

The objective of this study was to evaluate the prostate specific antigen (PSA) density (PSAD) (the quotient of PSA and prostate volume) compared with the percent free PSA (%fPSA) in different total PSA (tPSA) ranges from 2 ng/mL to 20 ng/mL. Possible cut-off levels depending on the tPSA should be established.

METHODS

In total, 1809 men with no pretreatment of the prostate were enrolled between 1996 and 2004. Total and free PSA were measured with the IMMULITE PSA and Free PSA kits (Diagnostic Products, Los Angeles, CA). Prostate volume was determined by transrectal ultrasound. The diagnostic validity of tPSA, %fPSA, and PSAD was evaluated by receiver operation characteristic (ROC) curve analysis.

RESULTS

The PSAD differed significantly (P < 0.0001) between patients with prostate carcinoma and patients with benign prostatic hyperplasia in all analyzed ranges of tPSA and prostate volume. At the 90% and 95% sensitivity levels and regarding the area under the ROC curve (AUC) within the tPSA range of 2-4 ng/mL, The PSAD was significantly better than tPSA and %fPSA. Within the tPSA range of 4-10 ng/mL, the PSAD did not perform better than %fPSA.

CONCLUSIONS

PSAD showed a better performance than %fPSA at tPSA concentrations < 4 ng/mL for detecting prostate carcinoma, with a significantly larger AUC for PSAD (0.739) compared with %fPSA (0.667). PSAD did not perform better than %fPSA when the tPSA range of 4-10 ng/mL was analyzed. Different PSAD cut-off values of 0.05 at tPSA 2-4 ng/mL, 0.1 at tPSA 4-10 ng/mL, and 0.19 at 10-20 ng/mL were necessary to reach 95% sensitivity.

Comparison of prostate-specific antigen adjusted for transition zone volume versus prostate-specific antigen density in predicting prostate cancer by transrectal ultrasonography

OBJECTIVE

Prostate-specific antigen is an excellent tumor marker, but it is not specific for prostate cancer. We evaluated the efficacy of prostate-specific antigen adjusted for transition zone volume calculated by transrectal ultrasonography in predicting prostate cancer in men with intermediate prostate-specific antigen levels of 4.1 to 10.0 ng/mL compared with prostate-specific antigen density.

METHODS

Between June 1998 and December 2001, prostate-specific antigen adjusted for transition zone volume was obtained from 131 patients who underwent ultrasonographically guided biopsies and had prostate-specific antigen of 4.1 to 10.0 ng/mL. Prostate-specific antigen density was calculated by dividing total serum prostate-specific antigen by total prostate volume, and total serum prostate-specific antigen was divided by transition zone volume to yield prostate-specific antigen adjusted for transition zone volume. This was compared with prostate-specific antigen density via receiver operating characteristic curves.

RESULTS

Of 131 patients, 34 (26%) had prostate cancer, and 97 (74%) had benign prostatic hyperplasia on pathologic examination. Total prostate volume was correlated with transition zone volume (P < .001). Mean prostate-specific antigen adjusted for transition zone volume and prostate-specific antigen density were 0.71 +/- 0.25 and 0.27 +/- 0.09 ng x mL(-1) x mL(-1) in patients with prostate cancer and 0.32 +/- 0.09 and 0.16 +/- 0.05 ng x ml(-1) x mL(-1) in patients with benign prostatic hyperplasia. With a cutoff value of 0.35 ng mL(-1) x mL(-1), prostate-specific antigen adjusted for transition zone volume had sensitivity of 82% and specificity of 84%. Receiver operating characteristic curve analysis showed that prostate-specific antigen adjusted for transition zone volume predicted biopsy outcome significantly better than prostate-specific antigen density (P < .05).

CONCLUSIONS

Prostate-specific antigen adjusted for transition zone volume is more accurate than prostate-specific antigen density in distinguishing prostate cancer from benign prostatic hyperplasia in men with intermediate serum prostate-specific antigen of 4.1 to 10.0 ng/mL. Determination of transition zone volume by transrectal ultrasonography may be helpful for predicting the probability of positive biopsy results.

Prostate-specific antigen and screening for prostate cancer

This article discusses prostate-specific antigen (PSA) and screening for prostate cancer. Topics explored include the history of PSA testing, the biology of PSA, clinical uses of PSA testing, improving the accuracy of PSA testing, and controversies in prostate cancer screening.

The incidence of prostate cancer in men with prostate specific antigen greater than 4.0 ng/ml: a randomized study of 6 versus 12 core transperineal prostate biopsy

PURPOSE

The prostate cancer detection rate in patients with elevated prostate specific antigen (PSA) increases with extended needle biopsy protocols. Transperineal biopsy under transrectal ultrasound guidance is rarely reported, although notable cancer diagnoses are obtained with this technique. We describe the results of 6 and 12 core transperineal biopsy.

MATERIALS AND METHODS

A total of 214 patients with PSA greater than 4.0 ng/ml were prospectively randomized to undergo 6 or 12 core transperineal biopsy. Each group of 107 patients was comparable in terms of clinical characteristics. The procedure was performed on an outpatient basis using local anesthesia. Specimens were obtained with a fan technique with 2 puncture sites slightly above the rectum (1 per lobe) under transrectal ultrasound guidance. Cores were taken from all peripheral areas, including the far lateral aspect of the prostate.

RESULTS

The overall cancer detection rate was 38% and 51% for 6 and 12 core biopsy, respectively. In patients with PSA between 4.1 and 10 ng/ml the cancer detection rate was 30% and 49% for 6 and 12 core biopsy, respectively.

CONCLUSIONS

The 12 core transperineal prostate biopsy is superior to 6 core biopsy. The technique provides optimal prostate cancer diagnosis. About half of the patients with PSA greater than 4.0 ng/ml and a slightly lower percent with PSA between 4.1 and 10 ng/ml have prostate cancer.

Repeating the measurement of prostate-specific antigen in symptomatic men can avoid unnecessary prostatic biopsy

OBJECTIVES

To report the 2-year clinical and biochemical follow-up of symptomatic men who had a high prostate-specific-antigen (PSA) level, for whom our policy has been to avoid biopsy in those with a normal repeat PSA, as minimizing negative prostate biopsies is an important goal in managing men with a high PSA, where the decision for biopsy based on one high value may be inappropriate.

PATIENTS AND METHODS

In all, 101 men (median age 72 years, range 47-85) referred to a urology department over 1 year with a PSA level above the age-specific reference range (but < 50 ng/mL) had a repeat PSA measurement. Those with a normal PSA and a normal digital rectal examination (DRE) were not biopsied. Their follow-up included a symptom review, DRE and PSA measurements.

RESULTS

Of the 101 men, 67% presented with LUTS, 11% with symptoms of urinary infection, 8% with haematuria and 9% for screening. In 35 patients the repeat PSA level was normal; in three of these 35 prostate cancer was diagnosed after biopsy because of an abnormal DRE, three were lost to follow-up and one died from unrelated causes. Thus 28 patients were available for review at 2 years. In 23 (82%) the PSA remained within the normal range. In 66 of the 101 men the repeat PSA was abnormal. Cancer was diagnosed in 28 and the remaining 36 with no cancer were managed by PSA review; 30 were reviewed at 2 years and in half of them the PSA level returned to normal.

CONCLUSIONS

In symptomatic men referred with a raised PSA level and who have a normal DRE and normal repeat PSA, prostatic biopsy can be safely avoided.

[Value of prostate-specific antigen density and transitional-zone prostate-specific antigen density in the diagnosis of prostate cancer]

INTRODUCTION

With serum prostate specific antigen (PSA) levels of 4.1 to 10 ng/ml a significant number of patients are unnecessary subjected to biopsy. We try to determine if the calculation of prostate specific antigen density (PSAD) and prostate specific antigen density of the transition zone (PSADTZ) improve the capacity to discriminate between non-malignant disease and prostate cancer.

METHODS

A prospective study including 314 males with PSA levels between 4.1 and 10 ng/ml is reported. Transrectal ultrasonography and prostatic biopsy were performed in all of them and total prostate and transition-zone volumes were calculated. PSA density and PSA density of the transition zone were calculated for each patient. Receiver operating characteristics (ROC) curves for PSA, PSAD and PSADTZ were constructed for all the patients and for those patients with digital rectal examination unsuspicous of malignancy, determining the sensitivity and specificity for several cutoff values.

RESULTS

The area under the curve for both, PSAD and PSADTZ, were greater than for PSA (p < 0.05), without any significant differences between PSADTZ and PSAD. The cutoff value of greatest diagnostic efficiency for PSAD was 0.17 ng/ml/cc (71.4% sensitivity and 55.7% specificity), while it was 0.41 ng/ml/cc for DPSATZ (70% sensitivity and 61.5% specificity). For those cases of normal digital rectal examination, no differences were observed between PSA and PSAD but they were between PSA and PSADTZ. In any event, the area under ROC curves was always less than 0.7, and, in order to avoid a large number of biopsies (high specificity), a large number of cancers are left without diagnosis (low sensitivity).

CONCLUSIONS

We conclude that PSAD and PSADTZ are not excessively useful for adequately discriminating between patients with prostate cancer and those with non-malignant disease, particularly when digital rectal examination is normal.

Prostate specific antigen density. Is there a role for this parameter when screening for prostate cancer?

The objective of this paper is to validate prostate specific antigen (PSA) density (PSAD) routine use to enhance PSA specificity in men with normal digital rectal examination and intermediate PSA values. It is a retrospective study of 235 men from a prostate cancer (PCa) screening program. All of them presented PSA values between 4 and 10 ng/ml, normal digital rectal examination, and a transrectal ultrasound (TRUS) guided biopsy available (PSA>/=4 ng/ml as the sole criterion for biopsy). Multivariate analysis failed to demonstrate higher PSAD values in men with PCa. PSAD cutoff points higher than 0.07 ng/ml per cc were considered as unacceptable, with less than 95% sensitivity. When a cutoff point of 0.15 was considered, as many as 30.6% of the cancers were missed. In conclusion we cannot recommend the use of this parameter for the above mentioned purpose.Prostate Cancer and Prostatic Diseases (2001) 4, 146-149.

Comparative evaluation of total PSA, free/total PSA, and complexed PSA in prostate cancer detection

OBJECTIVES

To compare the performance of prostate-specific antigen (PSA), the free/total PSA (F/T PSA) ratio, and complexed PSA (cPSA) in prostate cancer detection.

METHODS

Five hundred thirty-five patients evaluated at the UROMED prostate cancer detection clinic had total PSA, free PSA, and cPSA measured before undergoing transrectal ultrasonography and sextant prostate biopsies. A direct comparison was performed between the different PSA assays to evaluate their ability to detect prostate cancer.

RESULTS

Of the 535 patients evaluated, 38.1% had prostate cancer detected. The mean age of the entire population was 63.6 years (range 35 to 86). Abnormal digital rectal examination findings were present in 33.4% of the patients. The mean and median values of PSA and cPSA were significantly higher and the F/T PSA ratio was lower in patients with prostate cancer. The F/T PSA ratio performed better than either cPSA or total PSA. A higher specificity was observed with the F/T PSA ratio than with cPSA using either the entire patient population or subsets of patients with PSA levels between 4.0 and 10 ng/mL or 4.0 to 6.0 ng/mL.

CONCLUSIONS

The use of the F/T PSA ratio offers improved prostate cancer detection compared with either cPSA or total PSA.

The value of a single biopsy with 12 transperineal cores for detecting prostate cancer in patients with elevated prostate specific antigen

PURPOSE

Prostate cancer detection on standard sextant biopsy is considered inadequate. Various biopsy protocols have been introduced to improve cancer diagnosis. We report our experience with transperineal 12-core prostate biopsy.

MATERIALS AND METHODS

In a prospective study 650 patients underwent prostate specific antigen (PSA) measurement during a 15-month period, of whom 141 with PSA greater than 4 ng./ml. also underwent transperineal 12-core prostate biopsy using the fan technique. Median PSA was 8 ng./ml. (range 4.1 to 5,000).

RESULTS

Prostate cancer was detected in 72 of the 141 patients (51%), including 44 of the 97 (45%) with PSA between 4.1 and 10 ng./ml. This incidence is higher than previously reported in the literature using other biopsy techniques. Disease was low grade Gleason 2 to 4 in 4 cases (5%), intermediate grade Gleason 5 to 6 in 26 (35%) and high grade Gleason 7 to 10 in the remaining 42 (60%).

CONCLUSIONS

A high cancer detection rate is achieved by 12-core transperineal prostate biopsy. Most tumors represent clinically significant cancer. Further randomized trials are required to confirm these data.

Should prostate-specific antigen or prostate-specific antigen density be used as the determining factor when deciding which prostates should undergo biopsy during prostate ultrasound

Prostate ultrasound has been accepted as the appropriate tool for prostate biopsy guidance to determine the presence of prostate cancer if the prostate-specific antigen (PSA) level is not normal. Prostate-specific antigen density (PSAD) has been used to determine if an increased PSA level may be because of benign enlargement of the gland or possible presence of cancer. The specific "cutoff" for PSA and PSAD to delineate which patients are at highest risk has been controversial. We attempted to assess which PSA level or PSAD level should be used. A retrospective analysis of 600 consecutive men, referred for prostate ultrasound and possible biopsy because of an abnormal DRE result or increased PSA level was undertaken. All had prostate volume determined by biplanar endorectal ultrasound. One hundred sixty-six men had cancer confirmed by biopsy. This latter group was further analyzed and was divided into PSA <4.0, PSA 4 to 10, or PSA >10.0 ng/ml. Groups were divided according to those with PSAD <0.10, <0.12, and <0.15 ng/ml. Correlation with Gleason grade of the tumor was made. Of the 166 men with cancer, 15 had PSA levels <4 ng/ml (all palpable), and 81 had PSA levels between 4.0 and 10.0 ng/ml (48 were not palpable by digital rectal examination [DRE]). There were 38 (22.8%) of 166 men with cancer who had a PSAD <0.15. Using the Gleason scoring system, 30 of 38 men had mid-grade or high-grade cancers. Twenty-one (12.6%) of 166 men with cancer had a PSAD <0.12. Of these, 17 of 21 men had mid-grade or high-grade cancers. Fifteen (9.0%) of 166 men with cancer had a PSAD <0.10. Of these, 13 of 15 had mid-grade or high-grade cancer. If the PSA level is more than 4.0 ng/ml, even if no palpable lesion is discerned by DRE, suspicion for the presence of cancer should be raised. The use of PSAD threshold of 0.15 is not inclusive enough to identify clinically important cancer, and it should not be used. Our data demonstrate that 7.9% of men with cancer had a PSAD <0.15 and mid-grade or high-grade, i.e., clinically important, cancer. Although more negative biopsy results will be obtained, we recommend the use of a lower PSAD "cutoff" than the literature has suggested. We recommend that those men with PSA levels more than 4 ng/ml and a PSAD higher than 0.10 should undergo a prostate biopsy to detect clinically important cancer.

Volume-specific cutoffs are necessary for reproducible application of prostate-specific antigen density of the transition zone in prostate cancer detection

OBJECTIVES

To determine the effect of prostate volume on the specificity of prostate-specific antigen density (PSAD) and PSAD of the transition zone (PSA-TZ) in the detection of prostate cancer.

METHODS

Between February 1994 and April 1998, transrectal ultrasound-guided prostate needle biopsies were performed in 235 men with serum prostate-specific antigen (PSA) levels between 4.0 and 10.0 ng/mL. The PSAD and PSA-TZ specificities were calculated at 95% sensitivity cutoff levels generated from the whole group, as well as from cohorts stratified by transition zone index or prostate volume.

RESULTS

Statistical significance was noted between the benign (n = 176) and prostate cancer (n = 59) groups for all tested PSA parameters. At 95% sensitivity, PSA-TZ carried a specificity of 37.5% compared with 29.6% for PSAD. When applying a single 95% sensitivity cutoff derived from the entire group to individual volume-stratified cohorts, the specificity decreased to 0% in glands less than 30 g in size. A 95% sensitivity PSA-TZ cutoff generated individually for volume-stratified cohorts of glands less than 30, 30 to 40, and 40 to 60 g resulted in more consistent specificity of 28.2%, 35.2%, and 45.7% for each cohort, respectively.

CONCLUSIONS

Unlike whole group-derived cutoffs, the use of volume-specific PSA-TZ cutoffs allows consistently high specificity in all volume-stratified cohorts. The discrepancies in the PSA-TZ and PSAD specificities in published reports are likely due to the application of published cutoffs to populations of differing prostate volumes. The use of volume-specific cutoffs results in reproducible specificity in populations with differing prostate volume distribution, and thereby definitively resolves the differences in PSA-TZ specificity reported in published reports.

The influence of prostate volume on the prostate-specific antigen (PSA) level adjusted for the transition zone volume and free-to-total PSA ratio: a prospective study

OBJECTIVES

To evaluate the influence of prostate volume on the prostate-specific antigen (PSA) level adjusted for the transition zone volume (PSAT) and free-to-total PSA ratio (f/tPSA) in detecting prostate cancer in men with intermediate PSA levels of 4.1-10.0 ng/mL.

PATIENTS AND METHODS

From March 1997 to June 1999, the f/tPSA and PSAT were measured in 105 patients who underwent ultrasound-guided systemic biopsies and had a PSA level of 4.1-10.0 ng/mL, with an apparently normal prostate on a digital rectal examination. The PSAT and f/tPSA were evaluated in all patients and in subgroups of patients with small (< 40 mL) or large (> or = 40 mL) prostates, using receiver operating characteristic (ROC) curves.

RESULTS

Total prostate volume was highly correlated with transition zone volume in all patients and in both subgroups (P < 0.001). In all 105 patients, PSAT had a sensitivity of 82% and its use would have avoided the largest number of unnecessary biopsies (87% specificity) at a threshold value of 0.35 ng. In men with small prostates f/tPSA and PSAT had a high sensitivity and specificity, at threshold values of 0.12 and 0.35 ng, respectively. In large prostates the PSAT was superior to f/tPSA in detecting prostate cancer.

CONCLUSIONS

These results suggest that both f/tPSA and PSAT are useful in detecting prostate cancer in men with small prostates, while PSAT is superior to f/tPSA in detecting prostate cancer in men with large prostates.