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

Can multiparametric magnetic resonance of the prostate avoid biopsies in patients with elevated PSA and surgical indication for benign prostatic enlargement?

INTRODUCTION

To evaluate the clinical dilemma of men with surgical indication due to benign prostatic enlargement (BPE) and concomitant elevated PSA, we analysed if multiparametric magnetic resonance imaging (mpMRI) could safely prescind the prostate biopsy.

METHODS

Forty men with surgical indication due to BPE and concomitantly elevated PSA levels were prospectively enrolled and retrospectively analysed. All patients underwent 1.5 Tesla mpMRI prior to TRUS-guided biopsies. In cases where mpMRI was PIRADS 3 with focal lesions, PIRADS 4 or PIRADS 5, additional fragments were obtained with the fusion guided technique. Biopsy histopathological results were used as the standard of reference. Two scenarios were evaluated: scenario 1, considering mpMRI PIRADS 1 and 2 as negative; and scenario 2, considering PIRADS 1, 2 and 3 as negative. Clinically significant prostate cancer (CsPCa) was defined as ISUP ≥ 2.

RESULTS

Median age was 68 years, median PSA was 9.41 (6.40-19.54) and median prostatic volume was 116.5 cc (IQR 86.5-155). Scenario 1 mpMRI sensitivity, specificity, PPV, NPV and accuracy for any prostate cancer on prostate biopsy was 76.9%, 63%, 50%, 85% and 67.5%. For csPCa, they were 87.5%, 59.4%, 35%, 95% and 65%, respectively, for the same measures. Scenario 2 the sensitivity, specificity, PPV, NPV and accuracy of mpMRI for any prostate cancer on prostate biopsy was 53.8%, 96.3%, 87.5%, 81.3% and 82.5%. For csPCa, they were 75%, 93.8%, 75%, 93.8% and 90%, respectively, for the same measures.

CONCLUSION

Prostate mpMRI may prevent unnecessary biopsies in patients with elevated PSA and surgical indications due to BPE, given its high negative predictive value.

Usefulness of Total PSA Value in Prostate Diseases Diagnosis

Introduction:

Analysis of total value of prostate specific antigen (PSAT), with the unavoidable digital rectal examination (DRE) is the basis of prostate cancer detection.

Aim:

The aim of this study was to determine the specificity and sensitivity of the total value of PSAT in the diagnosis of prostate cancer. The aim was also to determine the significance of PSAT in diagnosis of benign prostate hyperplasia, precancerous conditions and inflammatory and atrophic changes of the prostate.

Material and methods:

Data were collected from the “Register of PH biopsy” of Clinic of Urology, CCU Sarajevo.

Results:

Analysis of correlation between the diagnosis and the PSAT value shows statistically significant negative correlation (r =-0,186; p = 0.006) in the sense that the value of the PSAT is highest in cancer patients, and the lowest in patients with benign prostatic hyperplasia. PSAT increases with age (r = 0.152; p = 0.025). For prostate cancer optimal sensitivity and specificity for PSAT value occurs at cut off value of> 8.6 ng /mL. Values lower than 2 ng/mL and higher than 10 ng/mL are most specific, and PPV increases with increasing value of PSAT. PSAT at values of <2 ng/mL and > 10 ng/mL are at high levels of specificity, and value > 10 ng / mL is also of high sensitivity in the detection of prostate cancer, and in this moment these values represent the optimal mode for the subsequent treatment.

Conclusion:

PSAT has a relative significance in the detection of prostate cancer, and should not be used as a guideline without DRE.

Prostate-specific antigen adjusted for the transition zone volume as a second screening test: a prospective study of 248 cases

AIM

This study was conducted to verify the effectiveness of prostate-specific antigen adjusted for the transition zone volume (PSATZ), and its availability as a second screening test for prostate cancer detection.

MATERIALS AND METHODS

Total prostate-specific antigen (PSA) and free PSA was measured in male patients who visited our outpatient department for voiding difficulty or screening for prostate cancer. Patients who had an intermediate PSA level between 4.0 and 10.0 ng/mL, with an apparently normal prostate on a digital rectal examination, were enrolled. PSATZ, free-to-total PSA ratio (F/T ratio) and PSA density (PSAD) were calculated and statistical comparisons between biopsy-positive (cancer) and biopsy-negative patients (benign) were conducted.

RESULTS

Of 248 patients, 51 (20.6%) had prostate cancer and 197 (79.4%) had benign prostatic hyperplasia (BPH) on pathologic examination. Mean PSA, PSAD, F/T ratio and PSATZ were 7.48 +/- 1.77 ng/mL, 0.23 +/- 0.09 ng/mL per mL, 0.14 +/- 0.08 and 0.71 +/- 0.44 ng/mL per mL in patients with prostate cancer and 6.59 +/- 1.60 ng/mL, 0.16 +/- 0.07 ng/mL per mL, 0.21 +/- 0.11 and 0.36 +/- 0.30 ng/mL per mL in patients with benign, respectively. Receiver operating characteristics (ROC) curve analysis demonstrated that PSATZ predicted the biopsy outcome better than F/T ratio. With a cut-off value of 0.37 ng/mL per mL, PSATZ had a sensitivity of 74.5% and a specificity of 72.6% for predicting prostate cancer. The maximal cut-off value that preserves 100% of sensitivity was 0.2, and at this cut-off value, 16.1% of unnecessary biopsies could be reduced.

CONCLUSIONS

Prostate-specific antigen adjusted for the transition zone volume may be more useful than other strategies in detecting prostate cancer in patients with intermediate PSA levels of 4.0-10.0 ng/mL. It can be used as a second screening test to reduce unnecessary biopsy.

[MRI and staging evaluation of prostate cancer]

MRI can assess local and locoregional spread of a newly diagnosed prostate cancer by detecting extracapsular extension (ECE), seminal vesicle invasion (SVI) and lymph node invasion. Endorectal MRI remains the only accurate means to assess local extension. Pelvic MRI with surface coils and the use of superparamagnetic particules provide the sensitivity and the specificity which have never been obtained by the sole measurement of node size of the lymphatic chains draining the prostate gland. With the endorectal coil, only direct signs of extracapsular extension have been maintained and indirect signs have been discarded, giving their too low specificity. Early SVI can only be consistently detected if result of TRUS guided biopsies show involvement of the prostate base. With the pelvic phased array coil, superparamagnetic particules show that metastatic lymph nodes have a specific MR signal which can be detected in normal size nodes. Indications of imaging relies on results of parametrers available before MR imaging. More important than PSA level and Gleason score on biopsies is the so called quantitative histology, represented by the number of sextants involved by tumor and the amount of cancer (measured in mm of tumor) present on biopsies which determine a risk of extraprostatic spread. Of the risk of extraprostatic spread depends indication of MR, which is most probably unnecessary in patients at low risk (<20%) of extraprostatic extension.

Current usefulness of free/total PSA ratio in the diagnosis of prostate cancer at an early stage

The aim of our study was to evaluate five different free/total PSA (f/t PSA) kits for the diagnosis of early stage prostate cancer. We compared the PSA density and the f/t PSA ratio to differentiate between benign prostatic hyperplasia (BPH) and prostate cancer. This prospective study included a total of 120 patients with suspected prostate cancer (PSA between 4 and 15 ng/ml) observed over a period of 30 months. All patients had a blood test as well as a prostate biopsy prior to inclusion. Serum immunoassay total-PSA (t PSA) and free-PSA (f PSA) were carried out using five different assay kits: IMX Abbott (A), Kryptor Brahms (B), Immulite DPC (D), IRMA Immunotech (I) and IRMA DiaSorin (S). The results were compared to determine sensitivity, specificity, threshold values, and to differentiate between BPH and cancer. No difference was found between assay reproducibility and variation in the assays, however, only a slight variation was observed in the mean t PSA values, whereas a significant difference was found with f/t PSA. Receiver operating curves were generated for t-PSA and f/t PSA. The area under the curves did not show any significant differences for either t PSA or f/t PSA. A low comparative variability between the five kits tested for tPSA was observed, which suggest that the f/t PSA ratio has no current usefulness in the initial diagnosis of prostate cancer, particularly in patients with larger prostates. Furthermore, no prognostic value was found for surgically positive margins in radical prostatectomy.

Influence of asymptomatic histologic prostatitis on serum prostate-specific antigen: a prospective study

OBJECTIVES

To determine the influence of asymptomatic inflammatory processes of the prostate on serum prostate-specific antigen (PSA) levels.

METHODS

A total of 51 patients with no evidence of prostate cancer or clinical prostatitis were prospectively studied. All subjects underwent 10 to 12 sector transrectal-ultrasound guided needle biopsies of the prostate. Serum PSA was measured 10 minutes before the biopsies. The fragments were stained and histologically analyzed. Two different classifications were used. One divided patients according to the number of specimens with inflammatory processes: 20% or less (group 1), more than 20% to 50% or less (group 2), and greater than 50% (group 3). Any kind of inflammatory process was considered positive. The second was the presence or absence of foreign body-type giant cells. Pearson's nonparametric test was used in the statistical analysis, with P <0.05 considered statistically significant.

RESULTS

The number of specimens with an inflammatory process was statistically significant (P = 0.02), with a median PSA level of 4.96 ng/mL in group 1 patients, 7.40 ng/mL in group 2, and 8.03 ng/mL in group 3 patients. The presence of foreign body-type giant cells in the histologic analysis was not statistically significant, with a median PSA level of 10.21 ng/mL compared with 5.89 ng/mL in the group without these cells.

CONCLUSIONS

The extension of the inflammatory process, as evaluated by the number of specimens involved, was directly related to elevations of serum PSA levels in asymptomatic patients. We could not find a statistically significant relationship between the presence of foreign body-type giant cells and serum PSA levels.

[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.

Evaluación del antígeno especifico prostático (PSA) ajustado al volumen de la zona transicional en la detección del cáncer de próstata

OBJECTIVE

To investigate if PSA adjusted to transition zone (PSA-TZ) can be considered as a predictor parameter of cancer with better specificity or not than PSA, PSA density (PSAD) or PSA free/total ratio.

MATERIAL AND METHODS

Data of 706 patients with sextant prostatic biopsies are analyzed in prospective way because of prostatic cancer suspicion. Range of PSA was between 4 to 20 ng/ml. Determination of PSA-TZ was calculated by dividing the PSA value by the volume of the transition zone of the prostate applying the ellipsoid formula and comparison of obtained results in detection of cancer was performed by ROC curves analysis for each one of PSA-related parameters.

RESULTS

Of the total group of patients, in 199 cases (28.2%) prostatic cancer was detected. Analysis by ROC curves demonstrated than PSA-TZ and PSAD were better predictors of cancer than PSA free/total ratio and PSA (p < 0.0001). The cutoff value of PSA-TZ of 0.18 ng/ml/cc was considered as the best, obtaining a 95% sensitivity and a 27% specificity. For this sensitivity, PSA, PSAD and PSA free/total ratio only obtained 5, 9 and 16% specificity respectively. Areas under curve (AUC) obtained for PSA, PSA free/total ratio, PSAD and PSA-TZ were 0.539, 0.612, 0.694 and 0.722 respectively.

CONCLUSIONS

PSA-TZ in the studied population was a parameter with better diagnostic specificity than PSA, PSAD and PSA free/total ratio for the same 95% sensitivity. This would justify its utility in clinical paractice reducing the number of unnecesary biopsies.

Antibiotic prophylaxis in prostate biopsy: a comparative randomized clinical assay between ciprofloxacin, norfloxacin and chloramphenicol

OBJECTIVE

To compare, prospectively, 4 different schemes of antibiotic prophylaxis previously to transrectal prostate biopsy.

MATERIALS AND METHODS

257 patients were randomized in 4 groups: Group I: single dose of ciprofloxacin 2 hours before the procedure; Group II: ciprofloxacin 3 days; Group III: chloramphenicol 3 days; and Group IV: norfloxacin 3 days. The complication rate was assessed in a blind way on the third and on the thirtieth days through a questionnaire. Groups were compared by the qui-square method and, in small samples, by the Fisher method, with statistical significance of 95%.

RESULTS

Complications index throughout the sample differed between the 4 groups of patients under study, being 3.1% for group I, 2.1%for group II, 18.3% for group III and 10.5% for group IV. Schemes employing ciprofloxacin were statistically superior to those that used norfloxacin or chloramphenicol (p < 0.05). There was no difference between a single dose and 3 days of ciprofloxacin (p > 0.05).

CONCLUSION

Schemes using ciprofloxacin presented better results in prophylaxis previously to prostate biopsy. We recommend using a single dose of ciprofloxacin due to its posologic ease and low cost, associated with a therapeutic response equivalent to 3-day regimens.

[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.