Diagnostic accuracy of percent free prostate-specific antigen in prostatic pathology and its usefulness in monitoring prostatic cancer patients

Can post-treatment free PSA ratio be used to predict adverse outcomes in recurrent prostate cancer?

OBJECTIVES

To assess whether free PSA ratio (FPSAR) at biochemical recurrence (BCR) can predict metastasis, castrate-resistant prostate cancer (CRPC), and cancer-specific survival (CSS), following therapy for localised disease.

PATIENTS AND METHODS

A single-centre retrospective cohort study (NCT03927287) including a discovery cohort composed of patients with an FPSAR after radical prostatectomy (RP) or radiotherapy (RT) between 2000 and 2017. For validation, an independent Biobank cohort of patients with BCR after RP was tested. Using a defined FPSAR cut-off, the metastasis-free-survival (MFS), CRPC-free survival, and CSS were compared. Multivariable Cox models determined the association between post-treatment FPSAR, metastases, and CRPC.

RESULTS

Overall, 822 patients (305 RP- and 363 RT-treated patients and 154 Biobank patients) were analysed. In the RP cohort, a total of 272/305 (89.1%) and 33/305 (10.9%) had a FPSAR test incidentally and reflexively, respectively. In the RT cohort, 155/363 (42.7%) and 208/263 (57.3%) had a FPSAR test incidentally and reflexively, respectively. However, in the prospective Biobank RP cohort, FPSAR testing was done on all samples of patients diagnosed with BCR. A FPSAR cut-off of 0.10 was determined using receiver operating characteristic analyses in both the RP and RT cohorts. A FPSAR of <0.10 resulted in longer median MFS (14.8 vs 9.3 years and 14.8 vs 13 years, respectively), and longer median CRPC-free survival (median not reached vs 9.9 years and 20.7 vs 13.8 years, respectively). Multivariable analyses showed that a FPSAR of ≥0.10 was associated with increased metastasis in the RP cohort (hazard ratio [HR] 1.915, 95% confidence interval [CI] 1.241-2.955) and RT cohort (HR 1.754, 95% CI 1.112-2.769), and increased CRPC in the RP cohort (HR 2.470, 95% CI 1.493-4.088). Findings were validated in the Biobank cohort.

CONCLUSIONS

A post-treatment FPSAR of ≥0.10 is associated with more aggressive disease, suggesting a potentially novel role for this biomarker.

The role of IGF-1 and the distribution of body fat in decreasing the number of prostate rebiopsies

OBJECTIVE

To assess the usefulness of IGF-1 and internal organ fat measured by bioelectrical impedance audiometry to avoid rebiopsies in patients with persistently high prostate-specific antigen (PSA) levels.

MATERIAL AND METHOD

A prospective study was conducted with 92 patients who underwent prostate rebiopsy due to high PSA levels with negative results in the rectal examination and a lack of preneoplastic lesions. The patients previously had their IGF-1 levels measured and had undergone an impedance audiometry test using the abdominal Fat Analyser AB-140 TANITA system. We calculated the receiver operating characteristic (ROC) curves for the PSA levels, %PSA, internal organ fat and IGF-1 and PSA density.

RESULTS

Twenty-five patients were diagnosed with prostate cancer. These patients had significantly higher PSA, PSAd and IGF-1 values and a tendency towards higher internal organ fat levels and lower %PSA readings (p=.001, p=.003, p=.001, p=.24 and P=0.28, respectively). The ROC curve showed an area under the curve for IGF-1 and PSA of .82 and .81, respectively. Using the cutoff points for 95% sensitivity and using the 3 criteria as an indication of rebiopsy, 74% of the biopsies would have been spared, leaving undiagnosed only 1 patient with clinically significant cancer -Gleason score>7 (4+3)-. The positive and negative predictive values for the set of variables were higher than for each one separately (PPV: 66/NPV: 63). The cost of both determinations was 82 euros.

CONCLUSIONS

Our results suggest that measuring IGF-1 could significantly decrease the number of unnecessary rebiopsies in an inexpensive and safe manner.

MicroRNA Regulating Glutathione S-Transferase P1 in Prostate Cancer

Glutathione S-transferase P1 (GSTP1), an enzyme involved in detoxification process, is frequently inactivated in prostate cancer due to epigenetic modifications. Through in silico analysis we identified a subset of miRNAs that are putative targets in regulating GSTP1. miRNAs are small endogenous non-coding RNA that are critical regulators of various physiologic and pathologic processes and their level of expression may play a precise role in early diagnosis and prognosis of cancer. These small molecules have been detected in a wide variety of human biological specimens including blood, serum, urine, ejaculate and tissues, which could be utilized as clinically useful biomarker in early detection and prognosis of prostate cancer. The chapter summarizes the current knowledge about miRNA involved in GSTP1 regulation in prostate cancer and their potential as useful biomarkers of disease for early detection and prognosis, along with challenges and limitations in this development.

Effect of histological inflammation on total and free serum prostate-specific antigen values in patients without clinically detectable prostate cancer

Purpose

We are often confronted with patients in the "gray zone" (prostate-specific antigen [PSA]<10 ng/mL) whose biopsies reveal no malignancy but only inflammation. We investigated the relationship between histological inflammation and total PSA (tPSA), free PSA (fPSA), and percentage of free PSA (f/tPSA) levels in patients without prostate cancer (PC).

Materials and Methods

We studied 106 men with tPSA<10 ng/mL who had undergone biopsy that was negative for PC and who had no clinical prostatitis. Inflammation observed at biopsies was scored for inflammation type in each biopsy core by use of a four-point scale and was then correlated with tPSA, fPSA, and f/tPSA.

Results

Different patterns of inflammation were found in each set of biopsies. Regression factor analysis was used to form two groups according to inflammation type: more chronic and more acute. Median tPSA, fPSA, and f/tPSA levels in the more chronic and more acute inflammation groups were 6.4 ng/mL, 1.09 ng/mL, and 15%, and 7.3 ng/mL, 0.79 ng/mL, and l2%, respectively. A significant difference was found in fPSA (p=0.003) and f/tPSA (p<0.001), whereas the difference in tPSA was not significant (p=0.200). Total PSA correlated with fPSA (r=0.4, p<0.001) but not with inflammation type (r=0.12, p>0.010). A correlation existed between inflammation type and fPSA (r=-0.31, p=0.001) and f/tPSA (r=-0.43, p<0.001) in that the fPSA and f/tPSA were lower in the group with more acute inflammation.

Conclusions

Subclinical inflammation has a significant influence on fPSA in patients with tPSA<10 ng/mL but without PC or clinical prostatitis. Subclinical inflammation is not characterized by elevated tPSA alone but also by a decreased fPSA, a tendency similar to that in PC.

Interventions to improve decision making and reduce racial and ethnic disparities in the management of prostate cancer: a systematic review

OBJECTIVES

Ethnic minorities are disproportionately impacted by prostate cancer (PCa) and are at risk for not receiving informed decision making (IDM). We conducted a systematic literature review on interventions to improve: (1) IDM about PCa in screening-eligible minority men, and (2) quality of life (QOL) in minority PCa survivors.

DATA SOURCES

MeSH headings for PCa, ethnic minorities, and interventions were searched in MEDLINE, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, CINAHL, and PsycINFO. SUBJECT ELIGIBILITY CRITERIA: We identified U.S.-based, English-language articles (1985 - 2010) on interventions to improve PCa IDM and QOL that included 50% or more minority patients or analyses stratified by race/ethnicity.

STUDY APPRAISAL AND SYNTHESIS METHODS

Articles (n = 19) were evaluated and scored for quality using a Downs and Black (DB) system. Interventions were organized by those enhancing 1) IDM about PCa screening and 2) improving QOL and symptom among PCa survivors. Outcomes were reported by intervention type (educational seminar, printed material, telephone-based, video and web-based).

RESULTS

Fourteen studies evaluated interventions for enhancing IDM about PCa screening and five evaluated programs to improve outcomes for PCa survivors. Knowledge scores were statistically significantly increased in 12 of 13 screening studies that measured knowledge, with ranges of effect varying across intervention types: educational programs (13% - 48% increase), print (11% - 18%), videotape/DVD (16%), and web-based (7% - 20%). In the final screening study, an intervention to improve decision-making about screening increased decisional self-efficacy by 9%. Five cognitive-behavioral interventions improved QOL among minority men being treated for localized PCa through enhancing problem solving and coping skills.

LIMITATIONS

Weak study designs, small sample sizes, selection biases, and variation in follow-up intervals across studies.

CONCLUSIONS

Educational programs were the most effective intervention for improving knowledge among screening-eligible minority men. Cognitive behavioral strategies improved QOL for minority men treated for localized PCa.

Reduction of prostate-specific antigen after tamsulosin treatment in patients with elevated prostate-specific antigen and lower urinary tract symptoms associated with low incidence of prostate cancer at biopsy

OBJECTIVES

To evaluate the effect of tamsulosin on reducing the serum levels of prostate-specific antigen (PSA) in patients with lower urinary tract symptoms and an elevated PSA level.

METHODS

From June 2004 to July 2006, patients with lower urinary tract symptoms, a PSA level of >or=4 ng/mL, and a maximal flow rate of <15 mL/s received tamsulosin 0.4 mg daily for 2 months. They were then scheduled for 12-core prostate biopsy. PSA determination and a uroflow study were performed before biopsy.

RESULTS

A total of 80 patients completed the present study. The mean patient age was 66.3 years, and the mean PSA level was 7.8 +/- 8.4 ng/mL at baseline and 7.1 +/- 9.1 ng/mL after treatment (P < .001). A total of 29 patients (36.25%) were diagnosed with prostate cancer from the biopsy findings. A significant increment in the PSA level was observed in patients with prostate cancer (6.7 versus 7.9 ng/mL; P = .002). A significant decrease in the PSA level was observed in patients with negative biopsy findings (6.9 versus 5.1 ng/mL, P = .000). Of the 38 patients with a decrease in the PSA level, 1 (2.6%) was diagnosed with prostate cancer and 37 (97.4%) with an benign prostatic hyperplasia/prostatitis. Of the 42 patients with no change in the PSA level, 28 (66.7%) had prostate cancer and 14 (33.3%) had negative findings. A change in PSA level after treatment gave a sensitivity of 96.6%, specificity of 72.5%, and diagnostic accuracy of 81% for prostate cancer.

CONCLUSIONS

Treatment with tamsulosin seemed to reduce the PSA levels and identified patients at high risk of prostate cancer.

Aggressiveness of Inflammation in Histological Prostatitis – Correlation with Total and Free Prostate Specific Antigen Levels in Men with Biochemical Criteria for Prostate Biopsy

Background and Aims

Although prostatitis can contribute to the lack of prostate specific antigen (tPSA) specificity, there is disagreement concerning the effect of histological inflammation on free PSA (fPSA). We investigated the correlation between aggressiveness of histological inflammation and tPSA, fPSA and f/tPSA in patients without detectable prostate cancer (PC).

Methods

The study included 106 patients with tPSA <10 ng/mL, without clinical prostatitis and with biopsy negative for PC. The inflammation in prostate biopsies was scored for aggressiveness using the four-point scale reported by Irani. The patients were divided into two groups of less aggressive and more aggressive inflammation and compared by use of regression analysis.

Results

The median tPSA, fPSA and f/tPSA levels were 6.39 ng/mL, 1.1 ng/mL and 16% in the less aggressive inflammation group and 7.3 ng/mL, 0.79 ng/mL and 10.7% in the more aggressive inflammation group, respectively. There was no significant between-group difference in tPSA levels (P=0.16), however, statistically significant between-group differences were recorded in fPSA and f/tPSA levels (P<0.001 both). Spearman's analysis yielded a significant negative correlation of inflammation aggressiveness with fPSA (r=-0.34; P<0.001) and f/tPSA (r=-0.45; P<0.001). Free PSA and f/tPSA were lower in the group with more aggressive inflammation.

Conclusions

Histological inflammation has a high prevalence in cancer-free prostate biopsy specimens and exerts similar effects on fPSA and f/tPSA levels as PC. Our study suggests histological prostatitis to be an important cause of decreased fPSA and f/tPSA values; therefore, when it is identified, antibiotic or anti-inflammatory therapy should be introduced to reduce the percentage of men with a continuing indication for prostate biopsy.

Association of extent and aggressiveness of inflammation with serum PSA levels and PSA density in asymptomatic patients

OBJECTIVES

The relationship between serum prostate-specific antigen (PSA) levels and histologic prostatic inflammation is controversial. Previous studies were performed using either the intensity or extent of inflammation for grading, with a relatively lower number of specimens. In our study, the inflammation was categorized more profoundly, using both the intensity and the extent of inflammation, to determine the influence of prostatic inflammation on serum PSA levels, percent free PSA (%fPSA), and PSA density (PSAD).

METHODS

The study included 115 patients who underwent transrectal ultrasound-guided prostate biopsy. To categorize the inflammation, a grading method that included the intensity and extent of inflammation was used. The extent and aggressiveness of inflammation were analyzed. The patients were divided into groups using five grades for the extent and four grades for the aggressiveness of inflammation. The serum PSA levels, fPSA levels, %fPSA, and PSAD in each group were compared.

RESULTS

The extent of inflammation grade correlated positively with the serum PSA level (r = 0.423, P <0.001) and PSAD (r = 0.319, P = 0.001). However, a negative correlation was found between the extent of inflammation grade and %fPSA (r = -0.268, P = 0.015). The aggressiveness of inflammation grade correlated positively with the serum PSA level (r = 0.386, P <0.001) and PSAD (r = 0.341, P = 0.001) and negatively with %fPSA (r = -0.289, P = 0.03).

CONCLUSIONS

If the elevation of serum PSA is thought to be caused by histologic inflammation, it might prevent unnecessary repeated biopsies.

Epidemiology - identifying the causes and preventability of cancer?

It has been almost 25 years since Doll and Peto performed their landmark analysis of epidemiological data to identify the causes of cancers and possible modes of cancer prevention. Since then, there have been many additional studies of cancer incidence using various epidemiological techniques. These studies revealed expanded opportunities for cancer prevention through approaches that include vaccination, increased physical activity, weight control and avoidance of post-menopausal hormone therapy.

Effect of NIH-IV Prostatitis on Free and Free-to-total PSA

OBJECTIVE

To examine the effect of asymptomatic prostatic inflammation (NIH category IV prostatitis) on total PSA (tPSA), free serum PSA (fPSA) and the ratio of free-to-total prostate specific antigen (%fPSA). The role of free and %fPSA as a diagnostic tool for distinguishing between cancer and non-malignant diseases of the prostate was also investigated.

MATERIAL AND METHODS

In a retrospective study 1090 prostate biopsies performed between January 2000 and September 2003 were evaluated and the levels of serum total and free PSA as well as the f/tPSA ratio were determined in samples obtained immediately before biopsy. 404 patients with full clinical and histological records were included in the study. All patients underwent 6 or 8 core primary prostate needle biopsies.

RESULTS

A total of 404 patients were included in the analysis. 100 prostate cancer (PCa) (24.8%), 137 NIH-IV prostatitis (33.9%) and 143 patients with benign prostatic hyperplasias (BPH) (35.4%) were identified. 24 (5.9%) patients presented with both PCa and prostatitis on histology and were excluded from further analysis. The mean (median) levels of tPSA, fPSA and %fPSA were 11.94 ng/ml (8.0), 1.31 ng/ml (1.07) and 0.15 (0.14) for NIH-IV prostatitis; 11.94 ng/ml (8.35), 1.54 ng/ml and 0.13 (0.11) for prostate cancer; and 8.19 ng/ml (7.0), 1.48 ng/ml (1.03) and 0.18 (0.15) for BPH. No significant difference was found in tPSA levels between PCa and prostatitis (p = 0.32), while the difference in tPSA levels between PCa and BPH was significant (p = 0.007). Free PSA alone had no diagnostic power in distinguishing PCa from prostatitis (p = 0. 37) and BPH (p = 0. 61). By contrast, the f/tPSA ratio showed significant between-group differences (PCa versus prostatitis (p = 0. 011), PCa versus BPH (p = 0.0001).

CONCLUSIONS

Chronic asymptomatic prostatitis NIH category IV has similar effects on total PSA and free PSA levels in serum as PCa. fPSA alone cannot distinguish prostate cancer from non-malignant inflammatory disease of the prostate. The ratio of free-to-total PSA is significantly different in PCa and NIH category IV prostatitis.

Production of serum-free and total prostate-specific antigen due to prostatic intraepithelial neoplasia

OBJECTIVE

High serum total prostate-specific antigen (PSA) levels have proven to be predictive of concurrent cancer but the role of prostatic intraepithelial neoplasia (PIN) in the production of total (t) and free (f) PSA is still the subject of research. In this study we wanted to discover whether variations in serum fPSA and tPSA levels are caused by PIN.

MATERIAL AND METHODS

We reviewed the medical records of 87 patients: in 32 of them the diagnosis of isolated PIN was made from surgical samples (simple prostatectomy, n = 19; radical cystectomy, n = 13); in 30 patients a diagnosis of benign prostatic hyperplasia (BPH) without PIN or prostatic carcinoma was made after simple prostatectomy (n = 20) or radical cystectomy (n = 10); and in 25 patients a clinically significant prostatic cancer was diagnosed and these patients underwent radical prostatectomy. All patients underwent a standard preoperative evaluation, including serum fPSA and tPSA determinations and PSA density.

RESULTS

The frequency of isolated PIN in simple prostatectomy specimens was 6.3%. The mean f/t PSA ratios were 17.66% in the 32 patients with PIN, 19.2% in the 8 patients with low-grade PIN, 17.6% in the 24 patients with high-grade PIN, 24.2% in patients with BPH and 13% in patients who underwent radical prostatectomy.

CONCLUSIONS

We believe that to make a definitive diagnosis of isolated PIN without carcinoma, study of the whole prostate gland is necessary, in order to definitively exclude the presence of concurrent neoplastic foci. Our data show that PIN does not contribute to tPSA levels and density; however, it may be responsible for a slight reduction in the f/t PSA ratio, with a significant reduction in cases with high-grade PIN (17.6%) compared to those with BPH (24.2%).