The effect of isolated soy protein on plasma biomarkers in elderly men with elevated serum prostate specific antigen

PURPOSE: We performed a randomized double-blind crossover pilot study in elderly men with elevated prostate specific antigen (PSA) on the effects of the daily consumption of 2 soy beverages, each containing 20 gm. of isolated soy protein, on the isoflavone concentration in blood and urine, and on the 3 serum biomarkers cholesterol, PSA and the soluble p105 component of the p185erbB-2 proto-oncogene. MATERIALS AND METHODS: A total of 34 men supplemented their diet by consuming 1 of 2 soy protein beverages assigned randomly twice daily for a 6-week period. In a second 6-week period they consumed the other soy protein beverage. The beverage ISP+ provided 42 mg. of genistein and 27 mg. of daidzein daily, whereas the other beverage, ISP-, provided only 2.1 and 1.3 mg. of these isoflavones daily, respectively. Blood and 24-hour urine samples were obtained before the study, at 2-week intervals during the study and 2 weeks after study completion. RESULTS: ISP+ and to a lesser extent ISP- substantially increased the serum concentration and urinary output of the isoflavones and their metabolites. Serum cholesterol was significantly decreased by ISP+ irrespective of the order in which the 2 soy beverages were administered and in apparent correlation with the total isoflavone concentration. There was no significant effect of the soy beverages on serum PSA and p105erbB-2 values. CONCLUSIONS: This study reveals that short-term exposure of elderly men with elevated serum PSA values to soy protein containing isoflavones decreases serum cholesterol but not the serum biomarkers PSA and p105erbB-2.     

Combined tests of prostate specific antigen and testosterone will improve diagnosis and monitoring the progression of prostate cancer

Prostate-specific antigen (PSA) testing has been widely used to screen men for prostate cancer (PCa) and to monitor PCa progression. However, more studies have shown that around 15% of men with low or normal PSA levels have PCa. In this study, we aimed to investigate the relationship of androgen and PSA levels and to better understand the reason that some PCa patients have low serum PSA values. The in vitro data demonstrated that cultured LNCaP cells ceased to produce PSA after androgen withdrawal and resumed PSA production after androgen was re-added. The in vivo experiment results showed that 48% of PCa xenografts carrying mice have serum PSA level lower than 4 ng ml⁻¹. The serum PSA levels increased significantly with rises in testosterone (T) levels 1 week after T pellet implantation. These data indicated that the androgen is a key factor controlling the production of PSA. Low serum PSA levels in mice with PCa xenografts are associated with low serum T levels. Raising serum T levels in tumor caring mice will also significantly increase serum PSA level. This may have clinical implications when screening PSA in men, who have occult PCa.     

Mass screening of prostate cancer in a Chinese population：the relationship between pathological features of prostate cancer and serum prostate specific antigen

Aim: To investigate the pathological features of the prostate biopsy through mass screening for prostate cancer in a Chinese cohort and their association with serum prostate specific antigen (PSA). Methods: A total of 12027 Chinese men in Changchun were screened for prostate cancer by means of the serum total prostate specific antigen tPSA test (by Elisa assay). Transrectal ultrasound-guided systematic six-sextant biopsies were performed on those whose serum tPSA value was > 4.0 ng/mL and those who had obstructive symptoms (despite their tPSA value) and were subject to subsequent pathological analysis with the aid of the statistic software SPSS 10.0 (SPSS. Inc., Chicago. USA). Results: Of the 12027 cases, 158 (including 137 patients whose serum tPSA values were 4.0 ng/mL and 21 patients [serum tPSA < 4.0 ng/mL] who had obstructive symptoms) undertook prostate biopsy. Of the 158 biopsies, 41 cases of prostatic carcinoma were found (25.9 %, 41/158). The moderately differentiated carcinoma and poorly differentiated carcinoma accounted for 61% and 34%, respectively. A significant linear positive correlation between the serum tPSA and the Gleason scores in the 41 cases of prostatic carcinoma (r = 0.312, P < 0.01) was established. A significant linear positive correlation between the serum tPSA value of the 41 prostatic carcinoma and the positive counts of carcinoma in sextant biopsies was established (r = 0.406, P < 0.01), indicating a significant linear relationship between serum tPSA and the size of tumor. Conclusion: This study was the first to conduct mass screening for prostate cancer by testing for serum tPSA values and the first to investigate the pathological features of prostate cancer in a cohort of Chinese men. Our results reveal that the moderately differentiated carcinoma is the most common type of prostate cancer. This study also has shown that the serum tPSA value in prostate cancer is associated with the Gleason score and the size of tumor.     

血清PSA、f-PSAR与前列腺重量相关性研究

目的：探讨前列腺增生症（ＢＰＨ）人群中前列腺重量（ＰＷ）与血清前列划抗原（ＰＳＡ）、血清液离前腺特异抗原百分率（ｆ－ＰＳＡＲ）的相关性,方法：术前测定１４６例ＢＰＨ患者血清ＰＳＡ〈其中５１例测定了血清游离前列腺特异抗原值,对血清ＰＳＡ〉１０μｇ／Ｌ患者行前列腺穿刺活检以排除前列腺癌,术后对前列腺手术标本进行称重,并按〈２５ｇ,２５￣５０ｇ、５１￣７５ｇ、〉７５ｇ分为４组,均经病理证实为ＢＰＨ,对忾     

Linkage between polymorphisms in the prostate specific antigen ARE1 gene region,prostate cancer risk,and circulating tumor cells

BACKGROUND: The prostate specific antigen (PSA) gene has a polymorphic androgen response element (ARE) sequence with two alleles, A and G. PSA A-allele carriers have higher serum PSA levels in healthy men (HM). METHODS: We analysed DNA samples from 278 (556 alleles) unrelated individuals, 127 HM and 151 prostate cancer (PC) patients, for PSA ARE1 genotypes. RESULTS: The analysis of the frequencies from the 556 alleles indicates a significant overrepresentation of A-allele in the PC group under the age of 67 compared with the HM group (63.3% vs. 48.8%; P = 0.009). We found that men carrying two A-alleles have increased risk for PC onset under the age of 67 (odds ratio [OR] = 2.92; 95% confidence interval [CI], 1.10-7.86; P = 0.013). Multivariate logistic regression analysis confirmed this association (OR = 1.82; 95% CI, 1.03-3.22; P = 0.037). Furthermore, the homozygosity for the A-allele was associated with higher serum PSA levels (P = 0.027) and with the presence of circulating tumor cells in the blood of PC patients (P = 0.018). CONCLUSION: Our results indicate that polymorphism in the PSA gene promoter may be an important biomarker for prostate cancer risk, especially for an earlier onset of PC.     

Problems with prostate specific antigen screening for prostate cancer in the primary healthcare setting in South Africa

OBJECTIVES: To assess the feasibility of detecting early-stage prostate cancer in the primary healthcare setting, and to investigate whether there is a higher incidence of prostate cancer in Black African men. PATIENTS AND METHODS: The study was a collaboration with registrars in the authors' institutions and primary healthcare centres serving mainly a Black African or mixed ancestry (Coloured) population in the semi-urban Cape Town metropolitan area of South Africa. Men aged 50-70 years attending the clinics were counselled about prostate cancer and invited to have a digital rectal examination (DRE), serum prostate-specific antigen (PSA) assay and transrectal ultrasonography-guided sextant prostate biopsy if the DRE was clinically suspicious of malignancy or the serum PSA was > or = 4.0 ng/mL. An American Urological Association Symptom Index (AUA-SI) was obtained, and urine analysed using dipsticks. RESULTS: From May 2000 to November 2001, 660 men were assessed (mean age 59.4 years, range 30-82); 60.6% were Black African, 37.3% mixed (Coloured), 1.8% White (Caucasian) and 0.2% Asian (Indian). The mean (range) AUA-SI was 5.98 (0-35) in the whole group; the DRE was recorded as clinically suspicious of malignancy in 3.2%. The mean PSA was 20.39 (0.04-10 000) ng/mL in the whole group, but when two outliers (1865 and 10 000 ng/mL) were disregarded, it was 2.4 ng/mL. In Black patients the mean PSA was 31.8 (0.04-10 000) ng/mL, and without the outliers, 2.1 ng/mL; in Coloured patients it was 2.94 (0.05-50) ng/mL. The PSA was > or = 4.0 ng/mL in 9.6% of the whole group, in 7.8% of Black and in 13% of Coloured patients. Prostate biopsies were taken in 21 patients (3.2% of the whole group and a third of those with a PSA of > or = 4.0 ng/mL); in Black patients, biopsies were taken in 1.5% and 19.4%, respectively, and in Coloured patients in 6.1% and 46.9%, respectively. The prostate biopsy showed cancer in 43% of the whole group, in a third of Black and in 47% of Coloured patients; prostate cancer was detected in 1.4%, 0.5% and 2.8%, respectively. CONCLUSIONS: That prostate biopsies were obtained in only 19% of Black and in only 47% of Coloured men with a serum PSA of > or = 4.0 ng/mL is of concern. This indicates that there is a significant problem in getting men with an elevated serum PSA level to undergo a prostate biopsy in the primary healthcare setting in South Africa.     

The role of transperineal template prostate biopsies in restaging men with prostate cancer managed by active surveillance

Study Type – Diagnostic (exploratory cohort) Level of Evidence 3b What's known on the subject? and What does the study add? The optimal method of active surveillance in prostate cancer remains unknown. This study is one of the first to report on the role of transperineal template prostate biopsies in active surveillance. It demonstrates that around one third of men are reclassified with more significant prostate cancer at an early stage in their management. This is a higher proportion than reported in contemporary cancers using standard transrectal biopsies for restaging.

OBJECTIVE

• ? To evaluate the role of transperineal template prostate biopsies in men on active surveillance.

PATIENTS AND METHODS

• ? In all, 101 men on active surveillance for prostate cancer underwent restaging transperineal template prostate biopsies at a single centre.
• ? Criteria for active surveillance were ≤75 years, Gleason ≤3+3, prostate‐specific antigen (PSA) ≤15 ng/mL, clinical stage T1–2a and ≤50% ultrasound‐guided transrectal biopsy cores positive for cancer with ≤10 mm of disease in a single core.
• ? The number of men with an increase in disease volume or Gleason grade on transperineal template biopsy and the number of men who later underwent radical treatment were assessed.
• ? The role of PSA and PSA kinetics were studied.

RESULTS

• ? In all, 34% of men had more significant prostate cancer on restaging transperineal template biopsies compared with their transrectal biopsies.
• ? Of these men, 44% had disease predominantly in the anterior part of the gland, an area often under‐sampled by transrectal biopsies.
• ? In the group of men who had their restaging transperineal template biopsies within 6 months of commencing active surveillance 38% had more significant disease.
• ? There was no correlation with PSA velocity or PSA doubling time.
• ? In total, 33% of men stopped active surveillance and had radical treatment.

CONCLUSIONS

• ? Around one‐third of men had more significant prostate cancer on transperineal template biopsies.
• ? This probably reflects under‐sampling by initial transrectal biopsies rather than disease progression.

     

Polarity of prostate specific membrane antigen,prostate stem cell antigen,and prostate specific antigen in prostate tissue and in a cultured epithelial cell line

BACKGROUND: Madin-Darby canine kidney (MDCK) cells are immortalized epithelial cells that have been used extensively as a model system to study intracellular molecular trafficking, polarized expression, and secretion of proteins in various epithelia. In order to determine if MDCK cells might serve as a model to study molecular events within prostate epithelial cells, we have evaluated the polarized distribution of three prostate restricted proteins, PSMA, PSCA, and PSA, in situ, and in MDCK cells. METHODS: Using immunofluorescence, confocal microscopy, cell surface biotinylation, antibody internalization, and biochemical assays we evaluated surface expression and secretion of three prostate restricted proteins expressed in MDCK cells. We compared these patterns of expression to results observed within prostatic epithelium. RESULTS: We demonstrate that PSMA is localized primarily to the apical plasma membrane in both the prostatic epithelium and transfected MDCK cells, whereas PSCA is expressed in a non-polarized fashion. We also show that PSA is secreted predominantly from the apical surface of transfected MDCK cells, consistent with in vivo observations. CONCLUSIONS: Similar patterns of localization among MDCK and prostatic epithelial cells suggest that the mechanisms of polarized sorting within these cell types are conserved. Thus, MDCK cells offer a useful model system to study mechanisms of targeting of these proteins within the prostate.     

Pretreatment prostate specific antigen (PSA) and 2-year PSA dynamics: Early predictors of prostate cancer prognosis with external radiation therapy

IntroductionThe dynamics of prostate specific antigen (PSA) in patients who have prostate cancer and receive radiotherapy is a very interesting but complicated topic. We tried to plot the sequential changes of PSA with and without hormone therapy and tried to find out the predictors for the high-risk patients for prostate cancer recurrence.MethodsWe reviewed the medical records of 164 prostate cancer patients who underwent intensity-modulated radiation therapy (IMRT) as the primary treatment. We recorded the patients' age, initial PSA, cancer grading at diagnostic biopsies (Gleason's score), clinical stage, the IMRT dosage, neoadjuvant, concomitant, and prolonged hormone therapy, follow-up PSA levels, biochemical progression, and distant metastasis.ResultsOf the 84 patients undergoing radiotherapy for prostate cancer with complete data for analysis, the biochemical failure-free survival (BFFS) rate was 88.09%. The patients with an initial PSA of less than 10 ng/mL had the best BFFS. Of the patients receiving neoadjuvant hormone therapy (NHT), serum PSA levels were significantly higher in those with biochemical failure than those without biochemical failure in the 3 months after radiation therapy. As for the patients free of biochemical failure, the mean PSA fell below 1 ng/mL immediately after IMRT for the NHT(+) group and at 9 months after IMRT for the NHT(–) group.ConclusionFor the patients with localized prostate cancer who underwent IMRT, initial PSA could predict clinical stage, 1-year BFFS, and 2-year BFFS. The follow-up PSA, as early as 3 months, was of clinical predictive value.     

Prostate specific antigen nadir determined using ultra-sensitive prostate specific antigen as a predictor of biochemical progression after radical prostatectomy in Japanese males

OBJECTIVES: We examined whether the prostate specific antigen (PSA) nadir is a good predictor of biochemical failure after radical prostatectomy. METHODS: We retrospectively reviewed clinico-pathological data in 257 patients who underwent radical prostatectomy. Twenty-nine patients of whom PSA nadir did not reach 0.1 ng/mL and three patients in whom second line therapy was started before biochemical failure were excluded, and 225 patients were subject to this study. We evaluated the changes in PSA value at very low (from less than 0.01-0.10 ng/mL) levels using an ultra-sensitive PSA assay after radical prostatectomy. Biochemical failure was defined as three consecutive elevations of PSA to above 0.1 ng/mL. RESULTS: Biochemical failure-free survival was attained by 89.9% of patients at 1 year, 83.0% at 2 years, and 81.0% at 5 years. PSA nadir more than 0.01 ng/mL was strongly associated with biochemical failure after radical prostatectomy (P < 0.0001). Mean time to reach PSA nadir was 3.1 months. Preoperative PSA > 20 ng/mL (P = 0.0013), clinical T stage = T2 (P = 0.0462), Gleason score 8-10 (P = 0.0243) were also independent predictors of biochemical progression. CONCLUSIONS: Prostate specific antigen nadir determined by ultra-sensitive PSA assay is an important parameter that is objective, reliable, and easily measured, and useful for predicting the subgroups of patients both most likely and unlikely to exhibit biochemical progression.     

Early diagnosis of prostate cancer using free／total prostate specific antigen ratio： a population based screening data

Aim: To evaluate the use of free/total prostate specific antig enratio (fPSA/tPSA ratio) in improving the early diagnosis of prostate cancer. Methods: The fPSA/tPSA ratio in the serum was analyzed in 187 men with tPSA ranging between 4.0 and 20.0μg/L. Allof them underwent ultrasound guided sextant prostatic biopsy.The results were calculated by SPSS 10.0 software.     

Ability of PSA-positive circulating macrophages to detect prostate cancer

BACKGROUND: Prostate-specific antigen (PSA) is a widely used serum marker for prostate cancer, but has a poor specificity for early detection at levels below 10 ng/ml, because it can also result from benign conditions. Our aim was to determine the frequencies of circulating PSA+ macrophages in a blinded study and to examine the suitability of this new method for differentiating between benign and malignant prostate disease. METHODS: Between October 2002 and February 2003, 126 patients undergoing transrectal biopsy were enrolled in this study. Peripheral blood macrophages were stained for intracellular content of PSA in all patients. Ten patients' peripheral blood mononulear cells (PBMCs) were also supplementarily stained for cytokeratin (CK) and epithelial membrane antigen (EMA). Macrophages were analysed by flow cytometry. Patients were grouped according to their biopsy histology and bone scan results. FINDINGS: Based on histological data, patients were classified as having no evidence of malignancy (NEM) (n = 59), prostatitis (n = 20), or localised prostate cancer (n = 37). Significantly higher levels of circulating PSA+ macrophages were found in prostate cancer compared to benign conditions. Calculating a 2% cut-off level enabled the detection of localised prostate cancer with 89% sensitivity and 80% specificity. In a subset of patients (65%) with a serum PSA below 4 ng/ml and confirmed prostate cancer, the percentage of PSA+ macrophages was significantly higher compared to NEM and prostatitis. Macrophages of ten patients tested with prostate cancer contained significantly higher amounts of PSA, EMA, and CK compared to ten with NEM. INTERPRETATION: Intracellular PSA in combination with CK and EMA can be found in permeabilized blood macrophages, indicating phagocytosis of complete cancer cells. This study further suggests, that this new method might be suitable for differentiating between prostate cancer and benign conditions especially in patients with low serum PSA.     

Interpreting a rising prostate‐specific antigen after brachytherapy for prostate cancer

The aim of the present study was to review the English language literature on the topic of prostate‐specific antigen bounce after brachytherapy and present a summary of the current knowledge. Although ultimately prostate‐specific antigen is a reliable measure of success after prostate brachytherapy, it can be very misleading in the first 3 years because of the frequency with which temporary benign rises in prostate‐specific antigen occur. We have reviewed the English language literature on the topic of prostate‐specific antigen bounce under the following headings: prostate neoplasms, brachytherapy, biochemical definition of prostate‐specific antigen failure, “benign prostate‐specific antigen bounce” and “prostate‐specific antigen spike”. We included brachytherapy delivered as either low dose rate or high dose rate, and either as monotherapy or as a boost combined with external beam radiotherapy. A benign self‐limited rise in prostate‐specific antigen after prostate brachytherapy is seen in an average of 35% of patients, but increases in frequency with younger age. In patients aged less than 55 years, it is observed in up to 68%. Other factors, such as sexual activity, dose, prostate volume and the use of high dose rate versus low dose rate have been implicated in affecting the frequency of the benign bounce. Benign increases in prostate‐specific antigen are frequent after prostate brachytherapy. It is important to recognize and correctly diagnose this phenomenon in order to avoid unnecessary salvage treatment.     

The role of human glandular kallikrein 2 for prediction of pathologically organ confined prostate cancer

BACKGROUND: In recent studies serum levels of human glandular kallikrein 2 (hK2) demonstrated significant differences in pathologically organ-confined versus non-organ-confined prostate cancer (PCa). In this study we investigated whether hK2 adds independent information when considered together with traditionally used parameters to predict organ confined (pT2a/b) PCa. METHODS: Serum levels of hK2, total and free prostate-specific antigens (PSA) were obtained one day before radical prostatectomy in 245 consecutive men. These were included with clinical stage and biopsy Gleason grade into univariate analysis and multivariate logistic regression models. RESULTS: pT2a/b PCa was found in n = 148 patients. In univariate analysis all preoperative parameters demonstrated significant association with the presence of pT2a/b PCa. Using multivariate logistic regression model hK2 (P = 0.022), clinical stage (P < 0.0001), and Gleason grade (P < 0.0001) were independent predictors of pT2a/b PCa whereas PSA (P = 0.3) was not. In bootstrap corrected logistic regression based nomograms the addition of hK2 density marginally enhanced predictive accuracy when PSA, PSA density, clinical stage, and Gleason grade were considered (AUC = 0.879 without hK2 density and 0.883 with hK2 density). CONCLUSIONS: hK2 and hK2 density could independently predict pT2a/b PCa. However, improvement in predictive accuracy was marginal when nomograms based on traditional variables were complemented with this serum marker.