The impact of intraoperative manipulation of the prostate on total and free prostate-specific antigen

Prostate-specific antigen kinetics contributes to decision making for biopsy referral: the predictive implication for PSA retest in patients with elevated PSA levels

Background

It is common to repeat prostate-specific antigen (PSA) measurements for men with PSA elevation before prostate biopsy. In this scenario, they may have considerable psychological distress in fear of the presence of cancer until retests. We assessed possible clinical factors causing transient PSA rise and explored the parameters predictive of subsequent PSA change.

Methods

As interfering conditions, the history of ejaculation, bicycling, and any types of infections were assessed using the questionnaire. The pattern of PSA change was compared in association with the various clinical factors. Predictive significance of PSA kinetics such as coefficient of variation (CV) and PSA velocity (PSAV) for PSA values at retest was evaluated.

Results

The rate of reversion to the normal range was 38.3% at retest. The rate of 12.8% of men showed a large increase by ≥20%, whereas 38.2% of men showed a large decline by ≥20% from the baseline. Men with younger age (≤60 years), small prostate (<20 cc), and prior history of ejaculation or infections showed significantly larger PSA decrease than their counterparts. Those with large CV or PSAV before the baseline more frequently showed PSA decrease below the age-specific cutoff or decline by ≥10% from the baseline at retest. These parameters associated with PSA kinetics had independent predictive values for relevant PSA change at retest.

Conclusions

Ejaculation and any types of infections should be avoided before PSA tests. Men with large PSA fluctuation before the baseline are likely to show a significant PSA decrease at retest. This predictive information may help both physicians to determine whether to proceed to an immediate biopsy and patients to reduce their psychological burden.

Effects of cycling and rowing on serum concentrations of prostate-specific antigen: A randomized study of 101 male subjects

OBJECTIVE

To determine the effects if cycling and rowing on serum prostate-specific antigen (PSA) levels.

METHODS

Male volunteers (n = 101), aged 20-80 (mean, 49.9) years were randomized to exercise at the first or second study visit. They performed 1 h of either cycling or rowing on a stationary machine. To determine exercise-induced effects on the PSA level, serum total PSA (tPSA) and free PSA (fPSA) concentrations were evaluated before and after exercise and another sampling was performed at the second study visit. Pre-exercise and postexercise tPSA and fPSA concentrations were compared using the Wilcoxon matched-pairs test. The results were analyzed using the Mann-Whitney U-test.

RESULTS

A significant (p < 0.001) average increase in tPSA after exercise (1.14 ± 1.11 ng/ml to 1.24 ± 1.26 ng/ml [mean, +8.8%]) was observed after both cycling and rowing, without significant differences between the sports (p = 0.54). The exercise-induced increase in PSA concentration affected participants aged ≥50 years (difference, 0.16 ± 0.37; p < 0.001), but not those aged <50 years (difference, 0.01 ± 0.06; p = 0.23). The effect size was clinically irrelevant in all except two outliers, in whom a distinct increase of PSA level by averages of 1.80 ng/ml (+55%) for tPSA and 1.25 ng/ml (+227%) for fPSA following cycling was observed.

CONCLUSION

Rowing and cycling generally do not have a clinically relevant effect on PSA levels. However, outliers exist. Our findings do not support abstaining from exercise during the days approaching PSA sampling.

Is it Possible to Provide a Prognosis after Radical Prostatectomy for Prostate Cancer by Means of a Psa Regression Model?

Background

For over 15 years, studies have been done to evaluate the elimination kinetics of the prostate-specific antigen (PSA) after radical prostatectomy. Even though evaluation of PSA regression in the two-compartment model has become established, no clear data are currently available as to whether a statement can be made with regard to tumor prognosis from a computation of the PSA half-life (PSA-HL). This study focuses on the determination of the PSA-HL in the two-compartment model and on its correlation with the biochemical recurrence-free survival. In addition, a computer program is being developed to simplify the determination of PSA-HL.

Material and methods

Seventy-seven prospective patients were examined who subsequently had a radical prostatectomy at our facility without neoadjuvant or adjuvant hormone deprivation. In addition to preoperative measurement of the PSA value (d0), PSA determinations were carried out postoperatively on days 5, 10 and 60, and at four-monthly intervals thereafter (mean follow-up: 16 months). By means of the computer program developed for this purpose, CTK. TumW, the PSA half-lives for the first (d0–d5, PSA-HL1) and second (d5–d10, PSA-HL2) compartments were subsequently determined and their effect on biochemical recurrence-free survival was assessed.

Results

PSA-HL1 and PSA-HL2 were 1.89 (± 0.03) and 3.39 (± 0.14) days, respectively. Whilst PSA-HL1 did not permit any prognostic statement, the median PSA-HL in the second compartment between patients with and without disease progression differed significantly (4.44 versus 3.12 days; p<0.001). Discrimination analysis produced a cutoff of 3.8 days for the second compartment; patients with a PSA-HL2 ≥3.8 days had a significantly worse biochemical recurrence-free survival after 18 months than the other patients (27% versus 93%; p<0.001).

Conclusion

The PSA regression kinetics after radical prostatectomy follows a two-compartment model in which the prognostic value of the PSA-HL1 is limited. When a cutoff of 3.8 days is used, evaluation of the PSA-HL in compartment 2 (d5–10) appears to permit a prognostic statement. Due to the limited postsurgical follow-up, the disease process was only assessed as biochemical recurrence-free survival, and a longer follow-up will be necessary to generate data on progression-free survival.

Influence of Long-Distance Bicycle Riding on Serum/Urinary Biomarkers of Prostate Cancer

Herein, we present a study focused on the determination of the influence of long-distance (53 km) bicycle riding on levels of chosen biochemical urinary and serum prostate cancer (PCa) biomarkers total prostate-specific antigen (tPSA), free PSA (fPSA) and sarcosine. Fourteen healthy participants with no evidence of prostate diseases, in the age range from 49-57 years with a median of 52 years, underwent physical exercise (mean race time of 150 ± 20 min, elevation increase of 472 m) and pre- and post-ride blood/urine sampling. It was found that bicycle riding resulted in elevated serum uric acid (p = 0.001, median 271.76 vs. 308.44 µmol/L pre- and post-ride, respectively), lactate (p = 0.01, median 2.98 vs. 4.8 mmol/L) and C-reactive protein (p = 0.01, 0.0-0.01 mg/L). It is noteworthy that our work supports the studies demonstrating an increased PSA after mechanical manipulation of the prostate. The subjects exhibited either significantly higher post-ride tPSA (p = 0.002, median 0.69 vs. 1.1 ng/mL pre- and post-ride, respectively) and fPSA (p = 0.028, median 0.25 vs. 0.35 ng/mL). Contrary to that, sarcosine levels were not significantly affected by physical exercise (p = 0.20, median 1.64 vs. 1.92 µmol/mL for serum sarcosine, and p = 0.15, median 0.02 µmol/mmol of creatinine vs. 0.01 µmol/mmol of creatinine for urinary sarcosine). Taken together, our pilot study provides the first evidence that the potential biomarker of PCa-sarcosine does not have a drawback by means of a bicycle riding-induced false positivity, as was shown in the case of PSA.

National Academy of Clinical Biochemistry Laboratory Medicine Practice Guidelines for Use of Tumor Markers in Testicular, Prostate, Colorectal, Breast, and Ovarian Cancers

Background: Updated National Academy of Clinical Biochemistry (NACB) Laboratory Medicine Practice Guidelines for the use of tumor markers in the clinic have been developed.

Methods: Published reports relevant to use of tumor markers for 5 cancer sites—testicular, prostate, colorectal, breast, and ovarian—were critically reviewed.

Results: For testicular cancer, α-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase are recommended for diagnosis/case finding, staging, prognosis determination, recurrence detection, and therapy monitoring. α-Fetoprotein is also recommended for differential diagnosis of nonseminomatous and seminomatous germ cell tumors. Prostate-specific antigen (PSA) is not recommended for prostate cancer screening, but may be used for detecting disease recurrence and monitoring therapy. Free PSA measurement data are useful for distinguishing malignant from benign prostatic disease when total PSA is &lt;10 μg/L. In colorectal cancer, carcinoembryonic antigen is recommended (with some caveats) for prognosis determination, postoperative surveillance, and therapy monitoring in advanced disease. Fecal occult blood testing may be used for screening asymptomatic adults 50 years or older. For breast cancer, estrogen and progesterone receptors are mandatory for predicting response to hormone therapy, human epidermal growth factor receptor-2 measurement is mandatory for predicting response to trastuzumab, and urokinase plasminogen activator/plasminogen activator inhibitor 1 may be used for determining prognosis in lymph node–negative patients. CA15-3/BR27–29 or carcinoembryonic antigen may be used for therapy monitoring in advanced disease. CA125 is recommended (with transvaginal ultrasound) for early detection of ovarian cancer in women at high risk for this disease. CA125 is also recommended for differential diagnosis of suspicious pelvic masses in postmenopausal women, as well as for detection of recurrence, monitoring of therapy, and determination of prognosis in women with ovarian cancer.

Conclusions: Implementation of these recommendations should encourage optimal use of tumor markers.

[Significance of the PSA-concentration for the detection of prostate cancer]

Prostate cancer among adult males is the most common neoplasm in western countries. Prostate specific antigen (PSA) is now a well established tumor marker that aids in the early detection of localized prostate cancer. Increased PSA concentrations are found in the serum of patients with benign prostatic hyperplasia or patients with prostate cancer, respectively. Therefore, in general the specificity of this test is low. The diagnostic value of PSA can be improved in consideration of clinical data, patients age, the measurement of free or complexed PSA, and the measurement of PSA velocity, respectively. Furthermore, there is a high variability between commercial PSA assays. Finally, the pre-analytical laboratory procedures have a high impact on the PSA measurement.

Effect of prostatic massage on serum complexed prostate-specific antigen levels

OBJECTIVES

To evaluate the effects of prostatic massage on the serum complexed PSA (cPSA) concentration in various prostatic diseases.

METHODS

A total of 51 men who presented to our outpatient clinic for the first time with symptoms of lower urinary outflow obstruction were included in this study. Blood samples were obtained from each patient before and 30 minutes after prostatic massage. Total PSA (tPSA), free PSA (fPSA), and cPSA levels were measured using a chemiluminescent enzyme immunoassay.

RESULTS

After prostatic massage, the tPSA and fPSA levels and fPSA/tPSA ratio increased significantly (P < 0.0001), and the increase in cPSA was minimal but statistically significant (P = 0.047). In patients with prostate cancer, no significant increase occurred in the mean forms of PSA (tPSA, cPSA, and fPSA/tPSA ratio), except for fPSA, after prostatic massage. We observed a greater increase in all PSA forms in the chronic prostatitis group.

CONCLUSIONS

In this study, prostatic massage increased serum cPSA concentration, but to a lesser extent than tPSA and fPSA.

PSA elevation during prostate cryosurgery and subsequent decline

PURPOSE

To determine the immediate effect of prostate cryosurgery on PSA and the subsequent decline.

METHODS AND MATERIALS

PSA level was measured in 14 patients who underwent cryosurgery for prostate cancer. Blood samples were taken immediately before and after cryosurgery and 1, 2, 4, 6 weeks and 3 months postoperatively. A confidence interval for the elevation from baseline to maximal PSA was calculated. PSA decline was assessed in patients with a nadir PSA < or =0.5 ng/mL. Patients with a postoperative nadir PSA >0.5 ng/mL were considered to harbor viable cancer and were excluded from the decline analysis. The observed PSA levels during the postoperative period were compared with the expected levels that were calculated according to the maximal PSA level and a serum half-life of 2.5 days. Student t-test was used to compare expected and observed PSA levels.

RESULTS

PSA increased from an average of 9.23 ng/mL preoperatively to a maximum average of 155 ng/mL (maximal PSA ranges: 18.9-490.5 ng/mL). The 95% CI for the increase in PSA from baseline level was 63.4 to 224.14. PSA nadir < or =0.5 ng/mL was achieved in 10 patients. The observed PSA decline course was slower than expected according to its half-life. Average observed and expected PSA levels at 2,4 and 6 weeks after cryosurgery were 10.4 versus 3.57 ng/mL (P = 0.005), 0.65 versus 0.07 (P = 0.007) and 0.09 versus 0.001 (P = 0.03), respectively.

CONCLUSION

PSA levels increase steeply following cryosurgery, and decline slower than expected according to the serum half-life.