Serum Prostate Specific Antigen Levels after Transurethral Resection of Prostate: A Longitudinal Characterization in Men with Benign Prostatic Hyperplasia

Initial Postoperative Prostate Specific Antigen and PSA Velocity Are Important Indicators of Underlying Malignancy After Simple Prostatectomy

Background: There is a paucity of guidelines for prostate-specific antigen (PSA) monitoring after simple prostatectomy (SP) despite these patients remaining at risk for prostate cancer (PCa). Our objective was to determine if PSA kinetics can be a potential indicator of PCa after SP. Methods: A retrospective review was performed of all simple prostatectomies at our institution from 2014 to 2022. All patients who met criteria were included in the study. Relevant clinical variables were collected preoperatively, including PSA value, prostate size, and voiding symptoms. Surgical and urinary function outcomes were analyzed. Results: A total of 92 patients were divided into two groups based on malignancy status. Sixty-eight patients did not have PCa, while 24 patients had known PCa before surgery (14) or were diagnosed as having incidental PCa from the pathological specimen (10). Patients with benign prostates had an initial postoperative PSA value of 0.76 ng/mL compared with 1.68 ng/mL for those with cancer (p < 0.01). PSA velocity for the first 24 months after surgery was 0.042 ± 1.61 ng/(mL·year) for the benign cohort compared with 1.29 ± 1.02 ng/(mL·year) for the malignant cohort (p = 0.01). Voiding improvements were noted by objective (postvoid residual and flow rate) and subjective (American Urological Association symptom score and quality of life score) measures in both groups. Conclusions: PSA interpretation and monitoring after SP have not been well established. Our study indicates that initial postoperative PSA value and PSA velocity are important indicators of underlying malignancy in patients after SP. Further efforts are needed to establish threshold values and formal guidelines.

The Diagnostic Value of PI-RADS v2.1 in Patients with a History of Transurethral Resection of the Prostate (TURP)

To explore the diagnostic value of the Prostate Imaging−Reporting and Data System version 2.1 (PI-RADS v2.1) for clinically significant prostate cancer (CSPCa) in patients with a history of transurethral resection of the prostate (TURP), we conducted a retrospective study of 102 patients who underwent systematic prostate biopsies with TURP history. ROC analyses and logistic regression analyses were performed to demonstrate the diagnostic value of PI-RADS v2.1 and other clinical characteristics, including PSA and free/total PSA (F/T PSA). Of 102 patients, 43 were diagnosed with CSPCa. In ROC analysis, PSA, F/T PSA, and PI-RADS v2.1 demonstrated significant diagnostic value in detecting CSPCa in our cohort (AUC 0.710 (95%CI 0.608−0.812), AUC 0.768 (95%CI 0.676−0.860), AUC 0.777 (95%CI 0.688−0.867), respectively). Further, PI-RADS v2.1 scores of the peripheral and transitional zones were analyzed separately. In ROC analysis, PI-RADS v2.1 remained valuable in identifying peripheral-zone CSPCa (AUC 0.780 (95%CI 0.665−0.854; p < 0.001)) while having limited capability in distinguishing transitional zone lesions (AUC 0.533 (95%CI 0.410−0.557; p = 0.594)). PSA and F/T PSA retain significant diagnostic value for CSPCa in patients with TURP history. PI-RADS v2.1 is reliable for detecting peripheral-zone CSPCa but has limited diagnostic value when assessing transitional zone lesions.

Are all procedures for benign prostatic hyperplasia created equal? A systematic review on post-procedural PSA dynamics and its correlation with relief of bladder outlet obstruction

PURPOSE

To evaluate and provide a comprehensive literature review of Prostate specific antigen (PSA) dynamics after various surgical procedures for benign prostatic hyperplasia (BPH).

METHODS

A thorough PubMed database search was performed over last 30 years including terms "PSA" and various surgical procedures for BPH. PSA nadir after various procedure was evaluated. The post-operative improvement in International Prostate Symptom Score, maximum void rates and post-void residue after surgeries were recorded. An indirect correlation was made between PSA nadir and outcome of various BPH surgical procedures.

RESULTS

Enucleation procedures like simple prostatectomy and endoscopic enucleation of prostate (EEP) produced maximum drop in PSA level after surgery and were associated with the highest improvement in post-operative parameters. The PSA nadir following resection techniques like transurethral resection of prostate and Holmium laser resection of prostate and vaporization technique was variable and less robust when compared to EEP. Newer techniques like Aquablation, Rezum, Urolift, Prostate artery embolization and Temporary implantable nitinol devices (iTIND) produce relatively less reduction in PSA and lesser percentile improvement in post-operative parameters.

CONCLUSIONS

Various surgical procedures for BPH result in varying PSA nadirs level. Enucleation procedures and simple prostatectomy produce the most drastic and sustained decrease in PSA. There is a possible indirect evidence suggesting that the level of PSA nadir corresponds closely with the degree of post-operative improvement and durability of the procedure. Establishing the new PSA nadir at 3-6 months after the procedure is recommended as a part of routine surveillance for prostate cancer in eligible patients.

Impact of perioperative factors on nadir serum prostate‐specific antigen levels after holmium laser enucleation of prostate

Objective

To investigate the relationship of preoperative prostate size, urinary retention, positive urine culture, and histopathological evidence of prostatitis or incidental prostate cancer on baseline and 3‐month nadir prostate‐specific antigen (PSA) value after Holmium laser enucleation of prostate (HoLEP).

Patients and methods

Data from 90 patients who underwent a HoLEP by En‐bloc technique were analyzed. PSA values at baseline and at 3‐month follow‐up, preoperative urinary retention and urine culture status, weight of resected tissue, and histopathological evidence of prostatitis or prostate cancer were recorded. We performed univariable and multivariable gamma‐regression analyses to determine the impact of the aforementioned perioperative variables on preoperative PSA, 3‐month postoperative PSA, and change in PSA.

Results

Serum PSA reduced significantly at 3 months from 6.3 ± 5.9 ng/mL to 0.6 ± 0.6 ng/mL. On both univariable and multivariable analysis, 3‐month nadir level was independent of all preoperative factors examined, except preoperative urinary retention status. Although patients with smaller prostate (resected tissue weight <40 g) had less percentile reduction in PSA when compared with those with larger prostate (resected tissue weight >80 g) (77.67% vs 89.06%; P < .001), patients from both these groups noted a similar PSA nadir level after 3 months (0.54 vs 0.56 ng/dL). The drop in PSA level after HoLEP remained stable up to 1‐year follow‐up.

Conclusions

PSA nadir 3 months after HoLEP remains relatively consistent across patients, regardless of preoperative prostate size, PSA value, urine culture status, and histopathological evidence of prostatitis or incidental prostate cancer.

[First 25 cases of photo-selective vaporization of the prostate (PVP) with 120-watt high performance system for benign prostatic hyperplasia]

PURPOSE

We examined the safety and efficacy of photo-selective vaporization of the prostate (PVP) using a 120-W high-performance system (HPS) for benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

We prospectively reviewed the records of 25 patients who had undergone PVP using a 120-W HPS in our institution. Patients were evaluated pre-operatively, and at 2 weeks and 1, 3, and 6 months postoperatively.

RESULT

The mean age was 73.6 years, and the mean estimated preoperative prostate volume was 51.5 ml. Laser vaporization was performed successfully in all 25 patients. The operating time was 104 +/- 29 minutes. The mean decrease in hemoglobin was 0.6 g/dl on post-operative day 1. The International Prostate Symptom Score (IPSS), QOL score, maximum flow rate, and residual urine volume were significantly improved 2 weeks after the procedure. There were no serious complications during the peri-operative period, and no patients were transfused.

CONCLUSION

PVP using a 120-W HPS was shown to be an effective, safe procedure for patients with BPH and lower urinary tract symptoms.

Changes in S-PSA after transurethral resection of prostate and its correlation to postoperative outcome

PURPOSE

Although different factors may affect prostate-specific antigen (PSA) reduction after transurethral resection of prostate, an approximate 70 % decrease from baseline is expected. We hereby undertook a prospective study to analyze changes in serum PSA (S-PSA) after transurethral resection of the prostate (TURP) and its correlation with the residual prostatic weight and clinical symptom score improvement.

METHODS

Seventy patients who underwent TURP for bladder outlet obstruction were included in the study. Patient's evaluation included history, International Prostate Symptom Score (IPSS), S-PSA, Qmax, post-void residual urine and prostate size. On follow-up, trans-rectal ultrasonography, S-PSA and IPSS score were calculated. Patients were analyzed in three groups based on the amount of tissue resected: less than 40, 40-60 and more than 60 % tissue resected.

RESULTS

Preoperative prostate size, IPSS, Qmax and S-PSA were 62.56 ml, 23.84, 11.68 ml/sec and 3.3 ng/ml. There was a significant decrease in the IPSS score, prostate size and S-PSA levels after TURP in all the three groups. There was a significant positive correlation of the amount of tissue resected with change in S-PSA levels, change in IPSS score and postoperative IPSS score. Reduction in IPSS score significantly correlated with patient's satisfaction.

CONCLUSIONS

The amount of tissue resected in TURP has a direct bearing on the S-PSA levels, change in symptom score and residual prostate volume. It is the percentage change in IPSS score and not the absolute value of IPSS, which has a direct bearing with the patient satisfaction and with the amount of tissue resected. Percentage fall in S-PSA by 70 % was found to be predictor of more than 60 % resection.

Association of symptomatic benign prostatic hyperplasia and prostate cancer: results from the prostate cancer prevention trial

This study examined the association between symptomatic benign prostatic hyperplasia (BPH) and prostate cancer risk in 5,068 placebo-arm participants enrolled in the Prostate Cancer Prevention Trial (1993-2003). These data include 1,225 men whose cancer was detected during the 7-year trial--556 detected for cause (following abnormal prostate-specific antigen or digital rectal examination) and 669 detected not for cause (without indication), as well as 3,843 men who had biopsy-proven absence of prostate cancer at the trial end. Symptomatic BPH was assessed hierarchically as self-report of surgical or medical treatment, moderately severe symptoms (International Prostate Symptom Score >14), or physician diagnosis, and analyses were completed by BPH status at baseline (prevalent) or BPH prior to cancer diagnosis or study end (prevalent plus incident). Controlled for age, race, and body mass index, neither prevalent (risk ratio = 1.03, 95% confidence interval: 0.92, 1.14) nor prevalent plus incident (risk ratio = 0.96, 95% confidence interval: 0.87, 1.06) symptomatic BPH was associated with prostate cancer risk. This lack of association was consistent across subgroups defined by type of BPH-defining event (treatment, symptoms, or physician diagnosis), prompt for prostate cancer diagnosis, and prostate cancer grade. This study provides the strongest evidence to date that BPH does not increase the risk of prostate cancer.

[Clinical evaluation of transurethral enucleation with bipolar (TUEB)]

OBJECTIVE

Transurethral enucleation with bipolar (TUEB) is an established procedure for treating patients with benign prostatic hyperplasia (BPH). In this study, the usefulness of TUEB was evaluated by comparing the preoperative and postoperative results.

MATERIALS AND METHODS

A total of 45 patients with symptomatic BPH underwent TUEB at our hospital between February 2008 and August 2009. All the patients were assessed using the International prostate symptom score (IPSS), quality of life (QOL) index, overactive bladder symptom score (OABSS), maximum urinary flow rate (Qmax), post void urine residue (PVR), serum prostate specific antigen (PSA) measurement, and estimated prostate weight. Total operative time, enucleation time, enucleated tissue weight, changes in levels of hemoglobin, hematocrit and serum sodium, duration of urethral catheterization, and complications were also investigated. IPSS, QOL index, Qmax, and PVR were reassessed 1, 3, 6 and 12 months after surgery. PSA reduction rate was also assessed 3 months after surgery.

RESULTS

The average age was 71.6 years (60-84 years), estimated prostate weight 53.2 g (11.8-105.6 g), total operative time 125.5 minutes (76-212 min.), enucleation time 96.1 min (56-169 min), enucleated tissue weight 32.3 g (6-82 g), and duration of urethral catheterization 2.5 days (2-7 days). Blood transfusion was not required and hyponatremia was not observed in any patients. IPSS, QOL index, OABSS, PVR, and Qmax were significantly improved 1 month after surgery. As complications, re-catheterisation was reported in 2 patients (4.4%), bladder tanponade in 1 (2.2%), and urinary incontinence requiring at least 1 pad 6 months after surgery in 1 (5.9%). Postoperative PSA declined by 89.8% 3 months after surgery.

CONCLUSIONS

TUEB was a safe and effective treatment procedure for patients with BPH.

Changes in Serum Prostate-Specific Antigen Levels after Potassium-Titanyl-Phosphate (KTP) Laser Vaporization of the Prostate

Purpose

The prostate-specific antigen (PSA) level decreases after transurethral resection of the prostate (TURP). However, changes in the PSA level after potassium-titanyl-phosphate (KTP) laser vaporization of the prostate are not well known. The aim of this study was to investigate the effect of KTP laser vaporization of the prostate on PSA levels in patients with benign prostatic hyperplasia (BPH).

Materials and Methods

Serum PSA levels were checked before and 1, 3, 6, and 12 months after the procedure in patients who underwent KTP laser vaporization between October 2004 and August 2008. Patients with prostate cancer, a history of urinary retention, or prostatitis during the follow-up period were excluded. The results for 278 patients were studied.

Results

The mean age of the patients was 69.0±6.7 years (range, 50-91 years) and the mean preoperative PSA level was 2.72±2.93 ng/ml. The PSA level tended to be increased at 1 month after the operation (3.18±3.23 ng/ml, p=0.032) but decreased within 3 months and became stabilized after 6 months at 1.79±1.82 ng/ml (p<0.001).

Conclusions

PSA levels may increase after KTP laser vaporization for a certain period of time, but eventually decrease and become stabilized after 6 months. Therefore, it may be appropriate to wait up to 3 months if the PSA level rises after the procedure, and further investigation should be considered if the PSA level still remains high after 6 months.

Postoperative PSA and PSA velocity identify presence of prostate cancer after various surgical interventions for benign prostatic hyperplasia

OBJECTIVES

To determine whether prostate-specific antigen (PSA) values can distinguish those with prostate cancer (CaP) from those with histologic benign prostatic hyperplasia (BPH) only after surgical intervention. Prostatic adenoma inevitably remains after BPH surgery; therefore, patients remain at risk of developing CaP. Although the PSA level can be used for CaP screening in this population, it might be influenced by the efficacies of different BPH procedures.

METHODS

We performed a review of patients who had undergone transurethral resection of the prostate (TURP; n = 343), holmium laser resection of the prostate (HoLRP; n = 54), or open prostatectomy (OP; n = 68). The PSA and PSA velocity values were collected at regular intervals both pre- and postoperatively for all patients. Only patients with histologic BPH and those with incidental CaP who underwent a watchful waiting strategy were included.

RESULTS

The average preoperative PSA values were significantly different between the TURP, HoLRP, and OP groups. Only 1 patient had incidental CaP in the HoLRP group. No differences were present between the preoperative PSA values for patients with histologic BPH and those with incidental CaP undergoing a watchful waiting strategy (P > .05). However, the postoperative PSA values were increased in the patients with CaP (watchful waiting compared with the patient with BPH only (2.4 vs 1.7 ng/mL TURP and 4.1 vs 1.1 ng/mL OP). Similarly, patients with incidental CaP had a significantly elevated postoperative mean PSA velocity compared with patients without CaP (0.38 vs 0.06 ng/mL/y TURP and 0.47 vs -0.13 ng/mL/y OP; P < .05).

CONCLUSIONS

Postoperative PSA and PSA velocity measurements can be used to distinguish patients with CaP from those with histologic BPH only.

Advantages of prostate-specific antigen (PSA) clearance model over simple PSA half-life computation to describe PSA decrease after prostate adenomectomy

OBJECTIVES

A population kinetic approach based on PSA clearance (CL(PSA)) may be a more rational strategy to characterize prostate-specific antigen (PSA) decrease profile after prostate surgery than the commonly used method (half-life from mono/bi-exponential models).

METHODS

We used 182 post-adenomectomy PSA concentrations from 56 benign prostatic hyperplasia patients to build, with NONMEM software, a multi-exponential and a CL(PSA) model for comparison.

RESULTS

The best multi-exponential model was PSA(t)=4.96e(-)(0.269t)+3.10e(-)(0.16t)+0.746e(+)(0.0002t) with a stable median residual PSA at 0.64 ng/mL. The best model parametrized with clearance was CL(PSA)=0.0229()(AGE/69)(3.78). Akaike information criteria and standard errors favored the CL(PSA) model. Median peripheral zone and transitional zone productions were 0.034 ng/mL/cm(3) and 0.136 ng/mL/g. A threshold at 2 ng/mL on day 90 allowed for a diagnostic of biochemical relapse diagnostic.

CONCLUSIONS

The population CL(PSA) model was superior to the multi-exponential approach for investigating individual post-adenomectomy PSA decreases.

The effect of dutasteride on the peripheral and transition zones of the prostate and the value of the transition zone index in predicting treatment response

PURPOSE

We determined the effects of dutasteride on transition and peripheral zone volume, and the clinical value of the transition zone index in men with benign prostatic hyperplasia.

MATERIALS AND METHODS

A total of 2,802 men 50 years or older with diagnosed benign prostatic hyperplasia, American Urological Association symptom index score 12 or greater, total prostate volume 30 cc or greater, prostate specific antigen 1.5 ng/ml or greater and 10 ng/ml or less, and peak urinary flow rate 15 ml per second or less were randomized to receive 0.5 mg dutasteride daily or placebo for 2 years. Total prostate and transition zone volume was measured with transrectal ultrasound at baseline and 4 times during the 2-year period. Peripheral zone volume (total prostate volume minus transition zone volume) and the transition zone index (transition zone volume/total prostate volume) were calculated. Patients were stratified into tertiles according to baseline total prostate and transition zone volume, and the transition zone index.

RESULTS

At 24 months dutasteride significantly decreased total prostate volume from baseline (p <0.0001). There were similar decreases in transition and peripheral zone volume (approximately 25%). In men receiving placebo high baseline total prostate and transition zone volume, and transition zone index were associated with poor 2-year outcomes, ie a low peak urinary flow rate, high American Urological Association symptom index scores, and an increased frequency of acute urinary retention and benign prostatic hyperplasia related surgery. Improvements in outcomes with dutasteride vs placebo were greatest in men with the highest baseline total prostate and transition zone volume, and transition zone index. In men with low (30 to less than 42 cc) and intermediate (42 to less than 58 cc) baseline total prostate volume the benefits of dutasteride therapy were only significant in the intermediate (0.4 to less than 0.55) and high (0.55 to less than 1.0) transition zone index tertiles.

CONCLUSIONS

Total prostate and transition zone volume, and the transition zone index are directly related to benign prostatic hyperplasia progression. The transition zone index may add value to transition zone volume alone for predicting outcomes. Dutasteride decreased transition and peripheral zone volume equally, supporting a known therapeutic role in benign prostatic hyperplasia and a possible preventive role in prostate cancer.

PSA velocity in conservatively managed BPH: can it predict the need for BPH-related invasive therapy?

OBJECTIVE

To study the value of PSA velocity (PSAV) to predict benign prostatic hyperplasia (BPH) progression in patients managed with alpha(1)-blockers or watchful waiting (WW).

METHODS

Nine hundred and forty two BPH patients treated with alpha(1)-blocker or WW were reviewed. PSAV was defined as: (PSA(t)-PSA(b))/(t/12); where PSA(t) = PSA at time of follow-up (t, in months), PSA(b) = PSA at baseline. PSA(t) was taken from the 1 year follow-up visit or, if not present, from the next available visit with a maximum of 24 months.

RESULTS

Five hundred and ninety five patients (234 alpha(1)-blocker, 361 WW) were included in the analyses. PSAV range was -5.24 to 43.06 ng/ml/year in alpha(1)-blocker patients and -6.11 to 19.55 ng/ml/year in WW patients (median: 0.01 ng/ml/year). PSAV was stratified into tertiles (Stable/Decrease/Increase). There were no significant differences in retreatment-free survival and the risk of BPH-related invasive therapy between the tertiles in both treatment groups.

CONCLUSIONS

PSAV did not predict BPH progression in either alpha(1)-blocker treated patients or WW group.

Changes in serum prostate-specific antigen following prostatectomy in patients with benign prostate hyperplasia

PURPOSE

To investigate how prostatectomy for patients with benign prostate hyperplasia (BPH) affected the serum prostate-specific antigen (PSA) levels.

METHODS

In 193 patients who underwent prostatectomy for BPH, serum PSA levels were measured before and three months after the operation. The total prostate weight measured by transrectal ultrasonography (TRUS) and the weight of the surgical specimen were examined in relation to the pretreatment PSA value and the changes in PSA levels after the operation.

RESULTS

The transition zone volume measured by TRUS could well estimate the weight of the surgical specimen in patients who underwent subcapsular prostatectomy and transurethral resection of the prostate. The concentration of preoperative serum PSA showed a significant correlation with the prostatic volume and with the transition zone volume. Removal of 1 g of BPH tissue reduced serum PSA levels by an average of 0.18 ng/mL. The change in serum PSA levels after the prostatectomy correlated with the total prostatic gland volume and with the transition zone volume.

CONCLUSIONS

The elevated PSA levels in patients with BPH were caused by the enlargement of the transition zone. After the resection of the adenoma, PSA levels should be expected to decrease to the normal range.

Human Kallikrein 2 (hK2) and prostate-specific antigen (PSA): two closely related, but distinct, kallikreins in the prostate

Recent studies on human kallikrein 2 (hK2) have revealed striking similarities and significant differences with the closely related kallikrein PSA. Both PSA and hK2 are primarily localized to the prostate and share close structural similarities. Although both kallikreins are produced by the same secretory epithelial cells in the prostate, hK2 is associated more with prostate tumors than PSA and is highly expressed in poorly differentiated cancer cells. The potent trypsin-like activity of hK2 contrasts with the weak chymotrypsin-like activity of PSA. The inactive precursor form of PSA, proPSA, is converted rapidly to active PSA by hK2, suggesting an important in vivo regulatory function by hK2 on PSA activity. The high homology between hK2 and PSA results in significant cross-reactivity to hK2 by polyclonal and some monoclonal antibodies to PSA. Future studies on both PSA and hK2 need to take into account this potential for cross-reactivity. Specific monoclonal antibodies to hK2 have now demonstrated that serum levels of hK2, like PSA, are correlated with prostate cancer. The production of hK2 protein in active protease form and specific monoclonal antibodies to the hK2 antigen will allow extensive future studies delineating the physiological and clinical utility of this new prostate antigen.

Biologic variability of prostate-specific antigen and its usefulness as a marker for prostate cancer: effects of finasteride. Finasteride PSA Study Group

OBJECTIVES

The effects of finasteride on prostate-specific antigen (PSA) variability and usefulness in prostate cancer detection were examined.

METHODS

Percent change and crossover of PSA levels between the low (1.0 to 3.9 ng/mL) and high (4.0 to 10.0 ng/mL) ranges were evaluated in 72 men with benign prostatic hyperplasia (BPH) and 77 men with both BPH and prostate cancer (PCa) treated with finasteride or placebo for 6 months. Patients with PCa were studied as a model for evaluating the effects on PSA levels in patients with BPH and latent PCa. As recommended on the product label, PSA levels for finasteride-treated patients were doubled for interpretation.

RESULTS

In patients with BPH, most placebo- and finasteride-treated patients with low PSA levels at baseline had subsequent PSA levels below 4.0 ng/mL throughout the study. Among patients with high baseline PSA levels, only 1 of 17 finasteride-treated patients, compared with 8 of 13 placebo-treated patients, crossed into the low range. In the BPH/PCa study, most placebo-treated patients maintained PSA levels in the same range (15 of 19 less than 4.0 ng/mL; 14 of 16 greater than 4.0 ng/mL). Almost one third of finasteride-treated patients with low PSA levels at baseline crossed into the high range (8 of 22), whereas most patients with high PSA levels at baseline were not masked with treatment, with PSA levels remaining high (12 of 15).

CONCLUSIONS

PSA levels cross between the low and high PSA ranges in both finasteride- and placebo-treated patients with BPH and those with both BPH and PCa. Doubling the PSA levels in finasteride-treated patients allows appropriate interpretation of PSA values and does not mask the detection of PCa.

Interpretation of free prostate specific antigen clinical research studies for the detection of prostate cancer

PURPOSE

We reviewed the use of percent free prostate specific antigen (PSA) to enhance specificity of PSA testing and aid in the discrimination of benign and malignant prostate disease. We present proposed percent free PSA cut points and probability factors, and discuss factors that are believed to affect study outcomes and conclusions.

MATERIALS AND METHODS

We reviewed the literature with respect to PSA and free PSA with particular emphasis on clinical use of percent free PSA and factors that may affect study outcomes.

RESULTS

Percent free PSA may increase the specificity of PSA testing without sacrificing the cancer detection rate. Differences in study designs and subject populations may account for the confusion in the current literature. Specific factors that may influence study outcomes include sample size, PSA range, age, race, digital rectal examination findings, prostate size, tumor size and pathology, as well as treatment history, sample collection and storage conditions, and the particular assays used to determine free and total PSA values.

CONCLUSIONS

The use of percent free PSA to enhance the specificity of prostate cancer screening is thought to provide useful information to aid in the differentiation of benign and malignant prostate diseases. There is evidence to suggest a benefit cost advantage to a tailored biopsy approach based on percent free PSA. However, statistically valid multisite clinical trials that take into account influencing factors are needed to set assay specific cut points and probability determinations.

Biologic variability of prostate-specific antigen and its usefulness as a marker for prostate cancer: effects of finasteride. The Finasteride PSA Study Group

OBJECTIVES

The effects of finasteride on prostate-specific antigen (PSA) variability and usefulness in prostate cancer detection were examined.

METHODS

Percent change and crossover of PSA levels between the low (1.0 to 3.9 ng/mL) and high (4.0 to 10.0 ng/mL) ranges were evaluated in 72 men with benign prostatic hyperplasia (BPH) and 77 men with both BPH and prostate cancer (PCa) treated with finasteride or placebo for 6 months. Patients with PCa were studied as a model for evaluating the effects on PSA levels in patients with BPH and latent PCa. As recommended on the product label, PSA levels for finasteride-treated patients were doubled for interpretation.

RESULTS

In patients with BPH, most placebo- and finasteride-treated patients with low PSA levels at baseline had subsequent PSA levels below 4.0 ng/mL throughout the study. Among patients with high baseline PSA levels, only 1 of 17 finasteride-treated patients compared with 8 of 13 placebo-treated patients crossed into the low range. In the BPH/PCa study, most placebo-treated patients maintained PSA levels in the same range (15 of 19 less than 4.0 ng/mL; 14 of 16 greater than 4.0 ng/mL). Almost one third of finasteride-treated patients with low PSA levels at baseline crossed into the high range (8 of 22), whereas most patients with high PSA levels at baseline were not masked with treatment, with PSA levels remaining high (12 of 15).

CONCLUSIONS

PSA levels cross between the low and high PSA ranges in both finasteride- and placebo-treated patients with BPH and those with both BPH and PCa. Doubling the PSA levels in finasteride-treated patients allows appropriate interpretation of PSA values and does not mask the detection of PCa.