Reference range of prostate-specific antigen after transurethral resection of the prostate

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.

Endoscopic enucleation for prostate larger than 60 mL: comparison between holmium laser enucleation and plasmakinetic enucleation

PURPOSE

To compare perioperative and functional outcomes of two different energy sources, holmium laser and bipolar current for endoscopic enucleation of prostate larger than 60 mL.

METHODS

A prospective, monocentric, comparative, non-randomized study was conducted including all patients treated for prostate larger than 60 mL, measured by transrectal ultrasound. Patients were assigned to each group based on the surgeons' practice. Perioperative data were collected (preoperative characteristics, operating, catheterization and hospitalization times, hemoglobin loss, complications) and functional outcomes (IPSS, IPSS Quality of Life (QoL), PSA) at 3 months and 1 year.

RESULTS

100 patients were included in each group from October 2015 to March 2018. No differences between HoLEP and plasma groups were observed at baseline, except for mean IPSS score, IPSS QoL score and preoperative PVR that were significantly higher in the HoLEP group. Operating time (142.1 vs 122.4 min; p = 0.01), catheterization time (59.6 vs 44.4 h; p = 0.01) and hospitalization time (2.5 vs 1.8 days; p = 0.02) were significantly shorter in the plasma group. Complication and transfusion rate were no significantly different between HoLEP and plasma. No significant differences were observed concerning functional outcomes at 3 months and 1 year. The urinary incontinence rate was higher 21.1% vs 6.4% (p < 0.01) at 3 months in HoLEP group, but no difference was observed at 1 year.

CONCLUSION

Holmium and plasma are both safe and effective for endoscopic treatment for prostate larger than 60 mL. Operating, catheterization and hospitalization times were significantly shorter in the plasma group. The complication rate and functional outcomes were not significantly different.

Bipolar Plasma Enucleation of the Prostate (B-TUEP) in Benign Prostate Hypertrophy Treatment: 3-Year Results

OBJECTIVE

To investigate numerous endoscopic techniques that have been described for the treatment of benign prostate enlargement. Plasma-button enucleation of the prostate (B-TUEP) is a successful treatment option because the large surface creates a fast enucleation process, vaporization, and concomitant hemostasis. The aim of this study was to evaluate the efficacy of bipolar button electrode transurethral adenoma enucleation (B-TUEP) in saline solution. The second end point was to determine the change of International Prostate Symptom Score (IPSS), post-void residual urine, International Index of Erectile Function, transrectal ultrasound gland volume evaluation, and prostate-specific antigen.

MATERIALS AND METHODS

Between July 2011 and March 2012, 50 consecutive patients underwent B-TUEP in our facility, all performed by a single surgeon (R.G.). All patients were preoperatively assessed with maximum urinary flow rate, single-question quality of life assessment, IPSS and the International Index of Erectile Function questionnaires, transrectal ultrasound gland volume evaluation, prostate-specific antigen, and post-void residual urine.

RESULTS

We observed a significant improvement at 12, 24, and 36 months in terms of maximum urinary flow rate (22.3 ± 4.74 mL/s, 23.2 ± 0.30 mL/s, and 23.6 ± 1.26 mL/s, respectively, P <.01) and quality of life (5.28 ± 0.97, 5.69 ± 0.90, and 5.73 ± 0.87). IPSS and IEEF scores improved significantly (P <.05). Gland volume evaluation and post-void residue decreased (P <.001). The prostate-specific postoperative antigen levels were 0.76 ± 0.61 ng/mL, 0.7 ± 0.51 ng/mL, and 0.62 ± 0.18 ng/mL, at 12, 24, and 36 months, respectively. Two patients (4%) had persistent bladder outlet obstruction requiring reoperation.

CONCLUSION

After 3-year follow-up, B-TUEP represents an effective, durable, and safe form of surgical intervention. B-TUEP is an alternative treatment for symptomatic benign prostate enlargement.

Transurethral Enucleation with Bipolar for Benign Prostatic Hyperplasia: 2-Year Outcomes and the Learning Curve of a Single Surgeon's Experience of 603 Consecutive Patients

BACKGROUND

To investigate perioperative outcomes, the learning curve, and 2-year follow-up after transurethral enucleation with bipolar (TUEB) for patients with benign prostatic hyperplasia (BPH).

METHODS

From December 2011 to October 2016, 603 consecutive patients underwent TUEB for BPH, performed by a single surgeon. Patients were preoperatively assessed by using the International Prostate Symptom Score (IPSS), quality-of-life score (QOLs), serum prostate-specific antigen (PSA), and uroflowmetry evaluation. Intra- and post-operative outcomes were also evaluated. Early and late complications were postoperatively recorded. Patients were evaluated at 3, 12, and 24 months of follow-up by using IPSS, QOLs, and uroflowmetry evaluations. TUEB efficiency was defined as prostatic specimen weight (grams) per operative time (minute) (g/min). Differences were compared by using Student's t-test for continuous values.

RESULTS

Mean age of patients was 69.6 ± 0.26 years, and estimated prostate volume was 54.7 ± 0.90 cc. Mean operative time was 57.5 ± 1.1 minutes, and mean prostatic specimen weight was 30.5 ± 0.68 g. Overall TUEB efficiency was 0.54 ± 0.01 g/min, and it improved markedly when the experience level exceeded 50 cases. Only three patients required hospital stay (0.49%). PSA level reduction before and after operation was 82.6% ± 0.70%. Significant improvement occurred in maximum flow rate (26.7 ± 1.3 mL/s, p < 0.0001), average flow rate (15.5 ± 0.45 mL/s, p < 0.0001), IPSS (3.8 ± 0.19, p < 0.0001), and QOLs (1.0 ± 0.06, p < 0.0001) at the 2-year follow-up compared with preoperative baseline values. No patients required transfusion after TUEB.

CONCLUSIONS

TUEB represents an effective and a safe surgical procedure. The relief from bladder outlet obstruction also proved to be durable after the 2-year follow-up.

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.

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.

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.

Diagnosis of prostate cancer

The contemporary challenge of prostate cancer diagnosis has been changed in the past decade from the endeavor to increase detection to that of detecting only those tumors that are clinically significant. Better interpretation of the role of prostate-specific antigen (PSA) and its kinetics as a diagnostic tool, the adoption of extended prostate biopsy schemes, and perhaps implementation of new transrectal ultrasound (TRUS) technologies promote the achievement of this clinical mission. This chapter reviews these issues as well as the change in practice of patient preparation for TRUS-biopsy and analgesia during it, the role of repeat and saturation prostate biopsies, and the interpretation of an incidental prostate cancer finding. Currently, the lifetime risk of a diagnosis of prostate cancer for North American men is 16%, compared to the lifetime risk of death from prostate cancer, which is 3% (Carter 2004). The advent of prostate-specific antigen (PSA) screening and transrectal ultrasonography (TRUS) has significantly impacted the detection of prostate cancer over the last 20 years. The mean age at diagnosis has decreased (Hankey et al. 1999; Stamey et al. 2004) and the most common stage at diagnosis is now localized disease (Newcomer et al. 1997; Stamey et al. 2004). The goal of prostate cancer screening is to detect only those men at risk for death from the disease at an early curable phase. The ambiguous natural history of this most common malignancy in men, being latent with questionable life-threatening potential in a large number of cases on the one hand, with only a relatively small number (though not negligible) of highly malignant cases on the other, propels many doubts about whether this is possible. This was famously phrased more than 20 years ago by Whitmore who asked: "Is cure possible for those in whom it is necessary; and is it necessary for those in whom it is possible?" This is probably even more relevant nowadays. During the past decade two factors influenced significantly the increased detection rate of prostate cancer in general and that of clinically insignificant prostate cancers in particular: the widespread use of serum PSA as a screening tool to a large extent and to a lesser though significant extent the application of extended multiple core biopsy schemes (Master et al. 2005). In fact, 75% of men in the United States aged 50 years and older have been screened with the PSA test (Sirovich et al. 2003). Outside of the screening context, which is dealt with in depth in Chap. 5, clinical suspicion of prostate cancer is raised usually by abnormal digital rectal examination (DRE) and/or by abnormal levels of serum PSA. Final diagnosis is achieved only based on positive prostate biopsies.

Change in Serum Prostate Specific Antigen Concentration after Holmium Laser Enucleation of the Prostate: A Marker for Completeness of Adenoma Resection?

BACKGROUND AND PURPOSE

Holmium laser enucleation of the prostate (HoLEP) is a well-established technique for the treatment of benign prostatic hyperplasia (BPH). To date, changes in serum prostate specific antigen (PSA) after HoLEP have not been published. We hypothesized that HoLEP produces a diminution in PSA similar to that produced by the gold-standard therapies for BPH. To test this hypothesis, we have examined PSA data before and after HoLEP from two institutions performing high volumes of this procedure.

PATIENTS AND METHODS

Between August 1998 and September 2004, 509 HoLEPs were performed at two institutions for which complete PSA data were available. Preoperative demographic and transrectal ultrasonography (TRUS) volume measurements were recorded; postoperative pathology and TRUS volume were obtained. Change in PSA as a function of the weight of prostate resected and the relation of preoperative TRUS volume to PSA was determined.

RESULTS

The average weight of adenoma resected was 49.8 g (range 5-300 g) in the McGill group and 90.4 g (range 7.9-312 g) in the Methodist Hospital group. The mean decrease in PSA was 81.7% in the McGill group (range 6.0-1.1 ng/mL; P < 0.0001) and 86.0% in the Methodist Hospital group (range 8.6-1.2 ng/mL; P < 0.0001). Log transformed preoperative PSA correlated well with TRUS volume (r = 0.45), as did the weight of adenoma resected with absolute change in PSA (r = 0.38). The TRUS volume decreased significantly, from 111.9 cc to 26.5 cc, in the Methodist Hospital group (P < 0.0001).

CONCLUSION

The HoLEP procedure produces a significant diminution in PSA that correlates well with the weight of adenoma resected. Measurement of PSA may be a useful tool for the objective assessment of ablative therapies for BPH, as the reduction in PSA corresponds well with the amount of adenoma removed.

Detection of prostate cancer and changes in prostate-specific antigen (PSA) six months after surgery for benign prostatic hyperplasia in patients with elevated PSA

OBJECTIVE

To evaluate early postoperative results of patients with elevated prostate-specific antigen (PSA) levels who underwent surgery due to benign prostatic hyperplasia (BPH).

PATIENTS AND METHODS

64 patients who had lower urinary tract symptoms (LUTS), normal digital rectal examinations (DRE), elevated PSA levels and prostate biopsies reported as being benign pathologically in specimens obtained by transrectal ultrasound (TRUS)-guided biopsies, were included in the study. Patients were assessed in accordance with PSA density, free/total PSA ratio and uroflowmetric studies. Patients had no cancer pre- and postoperatively (according to operative specimens). Six months postoperatively, 32 patients were accepted for re-evaluation for all PSA parameters, routine tests and prostatic biopsies.

RESULTS

64 patients with a mean age of 66.8 (SD 6.72) were included in the study. Total PSA average value was 14.38 (SD 7.49) ng/ml. Free PSA average value was 2.11 (SD 1.43) ng/ml. Average PSA density and free/total PSA ratio were 25.19 SD (14.12) ng/ml/cm(3) and 14.53% (SD 5.35%) respectively. 56 patients had BPH, 7 had chronic prostatitis and 1 had prostatic intraepithelial neoplasia (PIN) preoperatively with biopsies. Re-biopsy of the patient with PIN was reported as BPH. In pathologic examination with resected tissues postoperatively, 49 patients had BPH, 14 had chronic prostatitis and 1 had PIN. In the sixth month, average values of free/total PSA were 0.45 (SD 0.26) and 3.71 (SD 4.96) ng/ml respectively. Average PSA density and free/total PSA ratio were 12.41 (SD 13.8) ng/ml/cm(3) and 19.59% (SD 10.33%) respectively. There were significant decreases in PSA densities (p < 0.001) and increases in free/total PSA ratios (p = 0.004). Seven patients still had elevated PSA levels 6 months postoperatively. Three of 7 patients were reported as chronic prostatitis. One of them was indicated as prostatic carcinoma who was reported as PIN preoperatively. All other patients were stated as BPH at re-biopsies.

CONCLUSION

If pretreatment biopsies are negative and operative specimens are also benign in patients with high PSA values, these patients can be followed up like usual BPH patients, but long-term follow-up is still unclear.

Holmium laser enucleation of prostate (HoLEP): the Methodist Hospital experience with greater than 75 gram enucleations

PURPOSE

Holmium laser enucleation of the prostate (HoLEP) effectively removes obstructive prostate tissue in minimally invasive fashion. We present our large enucleation outcomes (greater than 75 gm retrieved). We examined post-procedural prostate specific antigen (PSA) and transrectal ultrasound (TRUS) volume changes to assess tissue removal completeness.

MATERIALS AND METHODS

We retrospectively reviewed HoLEPs performed from April 1, 1999 through September 30, 2002 to identify all enucleations greater than 75 gm. Demographic, laboratory, operative and pathological data were obtained. Patients were surveyed to document longer term complications.

RESULTS

The cohort of 108 patients had a mean age and specimen weight of 71.5 years (range 53 to 90) and 120.6 gm (range 75.3 to 376), respectively. Average procedural time and hospital stay were 166.8 minutes (range 75 to 473) and 1.2 days (range 0 to 4), respectively. No deaths or episodes of transurethral resection syndrome occurred. Postoperative complications included transfusion in 2 cases, a clot retention episode in 3, capsular perforation in 2, morcellator blade malfunction in 4, minor bladder mucosal injury in 1 and bladder neck contracture in 1. American Urological Association symptom scores reassessed in 53 patients without chronic retention an average +/- SD of 10.6 +/- 7.1 months postoperatively showed a mean decrease from 20.3 +/- 6.4 to 4.7 +/- 3.8. PSA in 48 patients a mean of 5.0 +/- 4.1 months postoperatively had decreased an average of 91.7%. In 10 patients TRUS data revealed a mean post-procedural volume decrease of 85.9%.

CONCLUSIONS

HoLEP can be performed on extremely large prostates with minimal risk or need for secondary interventions. Most patients are discharged home after an overnight stay. Postoperative decreases in PSA and TRUS volumes support the completeness of enucleation that can be achieved.

Changes of serum prostate-specific antigen following high energy thick loop prostatectomy

We evaluated the effect of the high electrocuting energy used with the thick loop, in transurethral vaporization resection of the prostate (TUVRP), on serum prostate-specific antigen (PSA). Forty-eight patients with benign protatic hyperplasia (BPH) were included in this prospective single arm sequential study. All patients had TUVRP using the 'Wing' thick resection electrode (Richard Wolf, Germany). Serum PSA was measured before, 1 day and 6 weeks in the morning post TUVRP. PSA values were correlated to preoperative prostate size and to prostatic resection weight. Serum PSA values (mean +/- SD) were 6.29+/-4.4 ng/ml, 14.9+/-11.1 and 2.3+/-1.9 before, 1 day and 6 weeks post TUVRP respectively. The mean increase in the PSA at 1 day over baseline value was 2.72, this was statistically significant (p < or = 0.0001). The PSA level returned to less than pre TUVRP value in all but 3 patients by 6 weeks. The PSA value 1 day post TUVRP correlated well with the pre PSA level, prostate size and prostatic resection weight (r = 0.58, r = 0.38 and r = 0.44 respectively) however, the PSA level at 6 weeks correlated only to pre TUVRP values (r = 0.53). We conclude that that serum PSA is not reliable within 6 weeks of TUVRP. The reversible increase in serum PSA value is similar to other forms of prostatectomy which, suggests that the increased level of electrosurgical energy that is used in TUVRP does not have an added adverse effect on the PSA levels.

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.

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.

The effects of prostatic manipulation on prostate-specific antigen levels

Serum PSA determinations are an important part of the urologic evaluation for prostate cancer. DRE, TRUS, cystoscopy, and ejaculation have minimal effects on serum PSA levels. Prostatic massage, needle biopsy, TURP, and prostatitis can cause significant elevations of serum PSA (Table 1). These factors should be kept in mind for interpretation of PSA values.