Prostate specific antigen and gleason grade: an immunohistochemical study of prostate cancer

Blood Prostate-specific Antigen by Volume of Benign, Gleason Pattern 3 and 4 Prostate Tissue

OBJECTIVE

To evaluate how blood levels of prostate-specific antigen (PSA) relate to prostate volume of benign tissue, Gleason pattern 3 (GP3) and Gleason pattern 4 (GP4) cancer.

METHODS

The cohort included 2209 consecutive men undergoing radical prostatectomy at 2 academic institutions with pT2N0, Grade Group 1-4 prostate cancer and an undetectable postoperative PSA. Volume of benign, GP3, and GP4 were estimated. The primary analysis evaluated the association between PSA and volume of each type of tissue using multivariable linear regression. R2, a measure of explained variation, was calculated using a multivariable model.

RESULTS

Estimated contribution to PSA was 0.04/0.06 ng/mL/cc for benign, 0.08/0.14 ng/mL/cc for GP3, and 0.62/0.80 ng/ml/cc for GP4 for the 2 independent cohorts, respectively. GP4 was associated with 6 to 8-fold more PSA per cc compared to GP3 and 15-fold higher compared to benign tissue. We did not observe a difference between PSA per cc for GP3 vs. benign tissue (P = 0.2). R2 decreased only slightly when removing age (0.006/0.018), volume of benign tissue (0.051/0.054) or GP3 (0.014/0.023) from the model. When GP4 was removed, R2 decreased 0.051/0.310. PSA density (PSA divided by prostate volume) was associated with volume of GP4 but not GP3, after adjustment for benign volume.

CONCLUSION

Gleason pattern 4 cancer contributes considerably more to PSA and PSA density per unit volume compared to GP3 and benign tissue. Contributions from GP3 and benign are similar. Further research should examine the utility of determining clinical management recommendations by absolute volume of GP4 rather than the ratio of GP3 to GP4.

Understanding and targeting prostate cancer cell heterogeneity and plasticity

Prostate cancer (PCa) is a prevalent malignancy that occurs primarily in old males. Prostate tumors in different patients manifest significant inter-patient heterogeneity with respect to histo-morphological presentations and molecular architecture. An individual patient tumor also harbors genetically distinct clones in which PCa cells display intra-tumor heterogeneity in molecular features and phenotypic marker expression. This inherent PCa cell heterogeneity, e.g., in the expression of androgen receptor (AR), constitutes a barrier to the long-term therapeutic efficacy of AR-targeting therapies. Furthermore, tumor progression as well as therapeutic treatments induce PCa cell plasticity such that AR-positive PCa cells may turn into AR-negative cells and prostate tumors may switch lineage identity from adenocarcinomas to neuroendocrine-like tumors. This induced PCa cell plasticity similarly confers resistance to AR-targeting and other therapies. In this review, I first discuss PCa from the perspective of an abnormal organ development and deregulated cellular differentiation, and discuss the luminal progenitor cells as the likely cells of origin for PCa. I then focus on intrinsic PCa cell heterogeneity in treatment-naïve tumors with the presence of prostate cancer stem cells (PCSCs). I further elaborate on PCa cell plasticity induced by genetic alterations and therapeutic interventions, and present potential strategies to therapeutically tackle PCa cell heterogeneity and plasticity. My discussions will make it clear that, to achieve enduring clinical efficacy, both intrinsic PCa cell heterogeneity and induced PCa cell plasticity need to be targeted with novel combinatorial approaches.

Trends in the use of active surveillance and treatments in Medicare beneficiaries diagnosed with localized prostate cancer

BACKGROUND

The treatment for men diagnosed with localized prostate cancer has changed over time given the increased attention to the harms associated with over-diagnosis and the development of protocols for active surveillance.

METHODS

We examined trends in the treatment of men diagnosed with localized prostate cancer between 2004 and 2015, using the most recently available data from Surveillance, Epidemiology, and End Results Program (SEER)-Medicare. Patients were stratified by Gleason score, age, and race groups.

RESULTS

The use of active surveillance increased from 22% in 2004-2005 to 50% in 2014-2015 for patients with a Gleason score of 6 or below and increased from 9% in 2004-2005 to 13% in 2014-2015 for patients with a Gleason score of 7 or above. Patients with a Gleason score of 7 or above had increased use of intensity-modulated radiation therapy and prostatectomy, especially among patients aged 75 years and older. Among patients with a Gleason score of 6 or below non-Hispanic black men were less likely to undergo active surveillance than non-Hispanic white men.

CONCLUSIONS

There has been a large increase in the use of active surveillance among men with a Gleason score of 6 or below. However, non-Hispanic black men with a Gleason score of 6 or below are less likely to receive active surveillance.

Diagnostic utility of immunohistochemical marker prostein for evaluation of primary and metastatic prostatic carcinomas

Context

The diagnosis of prostatic adenocarcinoma on histopathology depends on architectural and cytomorphological features supported by immunohistochemistry (IHC). Though all the prostate markers show excellent specificity, the sensitivity and percentage positivity vary.

Aims

In this study, we aim to study the expression of prostein in normal, benign, and malignant (primary and metastatic) lesions with particular emphasis on its utility in the differential diagnosis of poorly differentiated and metastatic prostatic adenocarcinoma along with a standard panel of IHC markers.

Settings and Design

This was both a prospective and retrospective as well as descriptive and observational study.

Subjects and Methods

All samples from patients with clinically suspected carcinoma prostate from both primary and metastatic sites from June 2015 to May 2016 were included in the study. Samples with difficulty in diagnosis on hematoxylin and eosin staining were subjected to a panel of IHC markers along with prostein.

Statistical Analysis Used

Receiver operating curve analysis and Chi-square test.

Results

Prostein showed a 100% sensitivity and specificity to identify normal prostatic epithelium, benign and premalignant lesions, and prostatic adenocarcinoma. Prostein showed a specificity of 100% in differentiating prostatic carcinoma from poorly differentiated urothelial carcinoma and in differentiating metastatic prostatic carcinoma from adenocarcinoma of nonprostatic origin.

Conclusions

Prostein is a new and promising prostate-specific marker that showed slightly more sensitivity and specificity than prostate-specific antigen. Thus, adding prostein to the IHC panel will greatly improve the detection of poorly differentiated primary and metastatic lesions of the prostate.

Analysis of the expression and association of retinoblastoma binding protein 6 with the JNK signaling pathway in prostate cancers

This study aims to investigate the expression of retinoblastoma binding protein 6 (RBBP6) in prostate cancer (PCa) and its association with the c-Jun N-terminal kinase (JNK) pathway. Immunohistochemistry was used to detect RBBP6 and JNK1/2 expression in PCa and benign prostatic hyperplasia tissues. RBBP6 expression in PCa cells (LNCap, PC3, and DU145) and noncancerous prostate epithelial cells (RWPE-1) was determined by quantitative real-time polymerase chain reaction and western blot analysis. PC3 and DU145 cells were transfected with RBBP6 small interfering RNAs (siRNAs) to examine the biological characteristics. Anisomycin (a JNK activator) with/without RBBP6 siRNA was used to treat PC3 cells for further investigating the ramification of the RBBP6-mediated JNK pathway in PCa. PCa tissues and cells showed higher RBBP6 and JNK1/2 expression. RBBP6 was positively correlated with JNK1/2 in PCa tissues. Besides, RBBP6 expression was correlated to clinical tumor stage, lymph node metastasis, Gleason grade, preoperative prostate-specific antigen level, as well as prognosis of PCa. RBBP6 siRNA reduced cell proliferation, arrested cells at G2/M, and promoted cell apoptosis, and suppressed JNK pathway. In addition, migration and invasion decreased after the RBBP6 siRNA transfection with downregulated matrix metallopeptidase-2 (MMP-2) and MMP-9. Anisomycin promoted the proliferation, invasion, and migration of PC3 cells and inhibited PC3 cell apoptosis, which could be reversed by RBBP6 siRNA. RBBP6 expression was upregulated in PCa tissues and positively correlated with expression level of JNK1/2. With inhibition of RBBP6 expression, the proliferation, invasion, and migration of PCa cells decreased dramatically, while PC3 cell apoptosis increased appreciably, accompanied by the suppression of the JNK pathway.

Prognostic significance of the presence of tertiary Gleason grade 5 in robot-assisted radical prostatectomy specimens in Japanese patients with clinically localized prostate cancer

BACKGROUND

The aim of this study was to study the prognostic significance of tertiary Gleason grade (TGG) 5 in patients with clinically localized prostate cancer treated with robot-assisted radical prostatectomy (RARP).

METHODS

A total of 600 Japanese patients who underwent RARP for clinical stage T1-3N0M0 prostate cancer were evaluated. TGG5 was evaluated according to the International Society of Urological Pathology criterion. Cox hazard regression was used to evaluate the prognostic significance of prostate-specific antigen and pathological features in RARP specimens.

RESULTS

Of the 600 RARP specimens, 92 (15%) had TGG5. TGG5 component was found in 30 (10%) of 287 cases with Gleason score (GS) 3 + 4, 55 (37%) of 149 cases with GS 4 + 3 and 7 (17%) of 40 cases with GS 4 + 4. There were no significant differences in pathological stage and surgical margin status between GS 3 + 4 with and without TGG5, as well as between GS 4 + 4 with and without TGG5. Of the 600 patients, 92 (15%) patients had biochemical recurrence (BCR) after surgery, with a median follow-up period of 42 (3-104) months. There were no differences in 5-year BCR-free survival rates between patients with GS 3 + 4 with and without TGG5 (92 vs. 100%, P = 0.16), as well as between patients with GS 4 + 3 with and without TGG5 (79 vs. 71%, P = 0.30). Similarly, there were no differences in 3-year BCRFS rates between patients with GS 4 + 4 with and without TGG5 (80 vs. 71%, P = 0.38).

CONCLUSIONS

In our population, the presence of TGG5 in RARP specimens had no strong impact on pathological and prognostic outcomes.

Understanding PSA and its derivatives in prediction of tumor volume: Addressing health disparities in prostate cancer risk stratification

Objectives

To address health disparities in risk stratification of U.S. Hispanic/Latino men by characterizing influences of prostate weight, body mass index, and race/ethnicity on the correlation of PSA derivatives with Gleason score 6 (Grade Group 1) tumor volume in a diverse cohort.

Results

Using published PSA density and PSA mass density cutoff values, men with higher body mass indices and prostate weights were less likely to have a tumor volume <0.5 cm³. Variability across race/ethnicity was found in the univariable analysis for all PSA derivatives when predicting for tumor volume. In receiver operator characteristic analysis, area under the curve values for all PSA derivatives varied across race/ethnicity with lower optimal cutoff values for Hispanic/Latino (PSA=2.79, PSA density=0.06, PSA mass=0.37, PSA mass density=0.011) and Non-Hispanic Black (PSA=3.75, PSA density=0.07, PSA mass=0.46, PSA mass density=0.008) compared to Non-Hispanic White men (PSA=4.20, PSA density=0.11 PSA mass=0.53, PSA mass density=0.014).

Materials and Methods

We retrospectively analyzed 589 patients with low-risk prostate cancer at radical prostatectomy. Pre-operative PSA, patient height, body weight, and prostate weight were used to calculate all PSA derivatives. Receiver operating characteristic curves were constructed for each PSA derivative per racial/ethnic group to establish optimal cutoff values predicting for tumor volume ≥0.5 cm³.

Conclusions

Increasing prostate weight and body mass index negatively influence PSA derivatives for predicting tumor volume. PSA derivatives’ ability to predict tumor volume varies significantly across race/ethnicity. Hispanic/Latino and Non-Hispanic Black men have lower optimal cutoff values for all PSA derivatives, which may impact risk assessment for prostate cancer.

Androgen Receptor Pathway-Independent Prostate Cancer Is Sustained through FGF Signaling

Androgen receptor (AR) signaling is a distinctive feature of prostate carcinoma (PC) and represents the major therapeutic target for treating metastatic prostate cancer (mPC). Though highly effective, AR antagonism can produce tumors that bypass a functional requirement for AR, often through neuroendocrine (NE) transdifferentiation. Through the molecular assessment of mPCs over two decades, we find a phenotypic shift has occurred in mPC with the emergence of an AR-null NE-null phenotype. These "double-negative" PCs are notable for elevated FGF and MAPK pathway activity, which can bypass AR dependence. Pharmacological inhibitors of MAPK or FGFR repressed the growth of double-negative PCs in vitro and in vivo. Our results indicate that FGF/MAPK blockade may be particularly efficacious against mPCs with an AR-null phenotype.

Systematic dissection of phenotypic, functional, and tumorigenic heterogeneity of human prostate cancer cells

Human cancers are heterogeneous containing stem-like cancer cells operationally defined as cancer stem cells (CSCs) that possess great tumor-initiating and long-term tumor-propagating properties. In this study, we systematically dissect the phenotypic, functional and tumorigenic heterogeneity in human prostate cancer (PCa) using xenograft models and >70 patient tumor samples. In the first part, we further investigate the PSA^−/lo PCa cell population, which we have recently shown to harbor self-renewing long-term tumor-propagating cells and present several novel findings. We show that discordant AR and PSA expression in both untreated and castration-resistant PCa (CRPC) results in AR⁺PSA⁺, AR⁺PSA⁻, AR⁻PSA⁻, and AR⁻PSA⁺ subtypes of PCa cells that manifest differential sensitivities to therapeutics. We further demonstrate that castration leads to a great enrichment of PSA^−/lo PCa cells in both xenograft tumors and CRPC samples and systemic androgen levels dynamically regulate the relative abundance of PSA⁺ versus PSA^−/lo PCa cells that impacts the kinetics of tumor growth. We also present evidence that the PSA^−/lo PCa cells possess distinct epigenetic profiles. As the PSA^−/lo PCa cell population is heterogeneous, in the second part, we employ two PSA⁻ (Du145 and PC3) and two PSA⁺ (LAPC9 and LAPC4) PCa models as well as patient tumor cells to further dissect the clonogenic and tumorigenic subsets. We report that different PCa models possess distinct tumorigenic subpopulations that both commonly and uniquely express important signaling pathways that could represent therapeutic targets. Our results have important implications in understanding PCa cell heterogeneity, response to clinical therapeutics, and cellular mechanisms underlying CRPC.

Tumor and Plasma Met Levels in Non-Metastatic Prostate Cancer

Objective

To measure Met protein content in prostate biopsies guided by fused magnetic resonance and ultrasound imaging, and to measure soluble Met (sMet) protein concentration in plasma samples from patients presenting evidence of prostate cancer.

Patients and Methods

345 patients had plasma samples drawn prior to image-guided biopsy of the prostate. Of these, 32% had benign biopsies. Of the 236 that were positive for prostate adenocarcinoma (PCa), 132 treated by total prostatectomy had Gleason scores of 6 (17%), 7, (55%), 8 (16%), or 9–10 (12%). 23% had evidence of local invasion. Plasma samples were also obtained from 80 healthy volunteers. Tissue Met and plasma sMet were measured by two-site immunoassay; values were compared among clinically defined groups using non-parametric statistical tests to determine significant differences or correlations.

Results

PCa tumor Met correlated significantly with plasma sMet, but median values were similar among benign and malignant groups. Median plasma sMet values were also similar among those groups, although both medians were significantly above normal. Median Met content in primary PCa tumors and sMet concentrations were independent of Gleason score, final pathologic stage and age.

Conclusion

Plasma sMet is not predictive of PCa or its severity in patients with organ-confined or locally invasive disease. Quantitative analysis of Met protein content and activation state in PCa tumor biopsy samples was highly feasible and may have value in follow-up to genomic and/or transcriptomic-based screens that show evidence of oncogenically relevant MET gene features that occur at relatively low frequency in non-metastatic PCa.

[Metastatic lymph node collision of a prostatic adenocarcinoma and an urothelial carcinoma and review of the literature]

INTRODUCTION

Tumor collision is the encounter of two tumors from two different topographical sites. Cases of metastatic lymph node collision are exceptional. We report the case of a metastatic lymph node collision of an urothelial carcinoma and a prostatic adenocarcinoma.

OBSERVATION

A 61-year-old man was hospitalized for a right nephroureterectomy with peri-ureteral lymph node dissection. He was followed since 2004 for prostatic adenocarcinoma and treated with radical prostatectomy then radiation therapy 4 years later due to a new increase of PSA. In the follow-up, an urothelial carcinoma of the lower right ureter was discovered in 2014. Histological analysis of a peri-ureteral lymph node showed a double metastasis of urothelial and prostatic origin. The prostatic adenocarcinoma was composed of acinar and ductal subtypes. Immunohistochemical study including CK7, CK20, PSA, GATA3, P63 antibodies confirmed the distinct phenotype of the 2 tumors.

DISCUSSION

Metastatic collision of urothelial carcinoma and prostatic adenocarcinoma has been reported in 4 cases only. Our review of literature shows that prostatic adenocarcinoma always precedes the urothelial carcinoma. Immunohistochemical study, when carried out for distinguishing both tumors, should include CK7, CK20 and PSA. GATA3, androgen receptor and P63 could be added in a second time.

Solitary recurrence of castration-resistant prostate cancer with low or undetectable levels of prostate specific antigen salvaged with local ablative radiation therapy: A case report

Prostate cancer recurrences are usually first detected by increased levels of prostate specific antigen (PSA), and systemic therapy is often initiated if distant metastasis is confirmed. However, low or nearly undetectable levels of PSA in the modern era of ultrasensitive PSA assay may be difficult to interpret in patients with a history of prostate cancer. Deciding whether to initiate additional systemic therapy in limited indolent metastatic disease while balancing the quality of life of the patient and ensuring the oncologic control of the disease may be challenging. In the present study, the case of a biopsy-confirmed solitary spine recurrence of prostate cancer with nearly undetectable but persistent levels of PSA (0.05 ng/ml) is reported. Treatment of the recurrence with local ablative radiotherapy improved the pain experienced by the patient, and reduced his levels of PSA to undetectable limits (<0.05 ng/ml). Repeated imaging analysis, PSA assay and clinical assessment demonstrated durable control of the disease without the requirement for additional systemic treatments. The present case highlighted the importance of initiating appropriate work-up according to the clinical scenario. Local treatment for solitary or oligometastatic recurrence of prostate cancer may enhance the effectiveness of current therapeutic strategies and benefit certain patients.

Treatment of Breast and Prostate Cancer by Hypofractionated Radiotherapy: Potential Risks and Benefits

Breast cancer and prostate cancer are the most common cancers diagnosed in women and men, respectively, in the UK, and radiotherapy is used extensively in the treatment of both. In vitro data suggest that tumours in the breast and prostate have unique properties that make a hypofractionated radiotherapy treatment schedule advantageous in terms of therapeutic index. Many clinical trials of hypofractionated radiotherapy treatment schedules have been completed to establish the extent to which hypofractionation can improve patient outcome. Here we present a concise description of hypofractionation, the mathematical description of converting between conventional and hypofractionated schedules, and the motivation for using hypofractionation in the treatment of breast and prostate cancer. Furthermore, we summarise the results of important recent hypofractionation trials and highlight the limitations of a hypofractionated treatment regimen.

Decreased expression of ferroportin in prostate cancer

The present study examined the expression levels of ferroportin, a transmembrane protein that transports iron from the inside of a cell to the outside, in the prostate cancer PC3, DU145 and LNCAP cell lines, in the normal prostate RWPE2 cell line, and in tissue samples from different differentiation stages of prostatic carcinoma and prostatic hyperplasia. The study also investigated the role of ferroportin protein expression in the diagnosis and prognosis of prostate cancer. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were employed to measure the mRNA and protein expression levels of ferroportin in the PC3, DU145, LNCAP and RWPE2 cells. Immunohistochemistry was used to determine ferroportin protein expression in the prostate cancer and prostatic hyperplasia tissues. Compared with the normal prostate RWPE2 cells, ferroportin protein expression was significantly lower in the prostate cancer PC3, DU145 and LNCAP cells (P<0.05). Compared with the prostatic hyperplasia tissues, ferroportin protein expression was significantly reduced in the prostate cancer tissues (P<0.05). Overall, the expression levels of ferroportin in the prostate cancer tissues were lower than those in the normal prostate tissues, which may provide valuable clinical information for the diagnosis and prediction of disease progression in prostate cancer, and may indicate a potential therapeutic target for treating prostate cancer by regulating iron metabolism.

Evaluation of contemporary prostate and urothelial lineage biomarkers in a consecutive cohort of poorly differentiated bladder neck carcinomas

OBJECTIVES

New immunohistochemical (IHC) markers of urothelial carcinoma (UCa) and prostatic adenocarcinoma (PCa) have emerged in recent years, yet comparative studies to establish markers remain lacking. We aimed to identify an effective but parsimonious approach for poorly differentiated bladder neck lesions, to establish a best practice panel approach in a setting simulating prospective use.

METHODS

We tested the performance of a panel of IHC markers on whole sections of a consecutive cohort of transurethral resection specimens of poorly differentiated, challenging bladder neck resections (n=36).

RESULTS

In the setting of poorly differentiated bladder neck carcinomas, biomarker sensitivities for UCa were as follows: GATA3, 100%; S100P, 88%; p63, 75%; and cytokeratin (CK) 5/6, 56%; specificities of each were 100%. CK7 and CK20 showed sensitivities of 75% and 63%, though these were only 85% and 80% specific. For PCa markers, NKX3.1, p501S, prostate-specific membrane antigen, and androgen receptor (AR) each showed 100% sensitivity, outperforming ERG (35%) and prostate-specific antigen (PSA; 25%). All the prostate histogenesis markers were 100% specific, except for AR, which was positive in 13% of the UCa cases.

CONCLUSIONS

Novel IHC markers show improved diagnostic performance that enables positive and negative support for identifying histogenesis with the use of as few as two markers for this critical therapeutic distinction. PSA underperforms newer markers.

CD57 expression in incidental, clinically manifest, and metastatic carcinoma of the prostate

OBJECTIVES

CD57 is normally found on NK-cells, but little is known about its expression in prostatic tissue.

METHODS

We investigated CD57 expression by immunohistochemistry using tissue microarrays containing 3262 prostate cancers (PCa), lymph node metastases, and benign prostatic tissue. The results were compared with clinical and pathological parameters.

RESULTS

Overall, 87% of PCa showed a moderate or strong expression of CD57. There was no significant difference to corresponding benign prostatic tissue. CD57 was increasingly lost from incidental over clinically manifest cancers to metastases. It correlated significantly with Gleason grade and pT-category, but not with PSA tissue expression. Loss of CD57 expression was an independent risk factor for PSA recurrence after prostatectomy in a multivariate Cox regression analysis. In standard sections, CD57 expression was heterogeneous, especially in large, high-grade PCa.

CONCLUSIONS

There is a peculiar expression of CD57 in PCa and benign prostatic tissue. CD57 loss is associated with tumor dedifferentiation and tumor size. However, the use of this marker for prognostic purposes is hampered by its heterogeneous expression.

PSMA/PSA ratio evaluated by immunohistochemistry may improve diagnosis of prostate cancer

Prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) measured in serum are not fully satisfactory as biomarkers of prostate cancer (PC). Results obtained in this article indicated that PSMA/PSA ratio evaluated by immunohistochemistry in normal prostate (NP), benign prostatic hyperplasia (BPH), and PC at the individual level could be a useful tool for diagnosis and prognosis of PC. PSMA and PSA were equally expressed in NP and the PSMA/PSA ratio was 1.22 ± 0.15. Data also indicated that PSMA/PSA ratio fluctuates in BPH and PC compared to NP. In BPH, the PSMA/PSA ratio was around 0.47 ± 0.02, whereas it's significantly increased in PC, about 4.95 ± 0.83. In parallel, the highest PSMA/PSA ratio was associated with high intratumoral angiogenesis in PC patients with (PSMA+,PSA+) profile.

Diagnostic utility of androgen receptor expression in discriminating poorly differentiated urothelial and prostate carcinoma

AIMS

Pathological separation of poorly differentiated urothelial and prostate carcinoma is difficult, but imperative because of the impact on patient management. Tumour morphology, in conjunction with a panel of immunohistochemistry (IHC), such as prostate-specific antigen (PSA), prostatic acid phosphatase (PSAP), CK7, CK20, p63 and high molecular weight keratins (HMWKs) are usually employed to resolve this issue. Androgen receptor (AR) expression is maintained in high-grade, undifferentiated prostate carcinoma, and thus, could be considered as a potentially useful adjunct to the conventional panel of markers.

METHODS

We performed an institutional review of all cases from 2006 to 2012 in which AR IHC had been performed to determine its diagnostic utility in discriminating between poorly differentiated urothelial and prostate carcinoma. Of the eligible cases (n=40), there were 9 high-grade urothelial carcinomas, 27 prostate carcinomas and 4 with both prostate and bladder tumours. All diagnoses were made by integrating the clinical, radiological, morphological and IHC results.

RESULTS

In all the prostate carcinomas, there was diffuse, intense nuclear staining for AR. The urothelial tumours were either negative, had cytoplasmic staining or showed occasionally weak nuclear staining. The difference was highly significant with p<0.0001 (Mann-Whitney U test).

CONCLUSIONS

We conclude that AR is an important marker as it is best able to distinguish between poorly differentiated urothelial and prostate carcinoma. AR appears superior to PSA and PSAP, which are not consistently expressed in high-grade prostate carcinoma. Also, high-grade urothelial carcinoma may be negative for CK20, p63/HMWK and occasionally CK7. We advocate the inclusion of AR in the panel of markers to differentiate these tumours.

Spondin-2, a secreted extracellular matrix protein, is a novel diagnostic biomarker for prostate cancer

PURPOSE

SPON2 belongs to the F-spondin family of secreted extracellular matrix proteins. It is deregulated in some tumors, including prostate cancer. In this prospective study we assessed the role of serum SPON2 as a biomarker for prostate cancer diagnosis as well as any association between SPON2 levels and clinicopathological features. We also compared the diagnostic performance of this biomarker to that of serum sarcosine, and percent free-to-total and total prostate specific antigen.

MATERIALS AND METHODS

SPON2 was measured using a sandwich enzyme linked immunosorbent assay in serum samples from 286 patients with prostate cancer and 68 with no evidence of malignancy, as confirmed by 10 to 12-core ultrasound guided prostate biopsy. Nonparametric statistical tests and ROC analysis were done to assess the diagnostic performance of SPON2 vs the other biomarkers.

RESULTS

Median serum SPON2 was significantly higher in patients with prostate cancer than in those with no evidence of malignancy (77.5 vs 23.6 ng/ml, p<0.0001). ROC analysis showed a higher predictive value of SPON2 (AUC 0.952) than of serum sarcosine (AUC 0.674), percent free-to-total prostate specific antigen (AUC 0.806) and total prostate specific antigen (AUC 0.561). Moreover, patients with low grade prostate cancer had higher median SPON2 levels (p=0.001). Spearman rank correlation confirmed a negative association with Gleason score (rs=-0.29, p=0.0005).

CONCLUSIONS

We found evidence that SPON2 levels were significantly higher in patients with prostate cancer than in healthy individuals. Moreover, this biomarker had better diagnostic performance than serum sarcosine, and percent free-to-total and total prostate specific antigen. This greater accuracy was also present in a subset of patients with normal prostate specific antigen.

Biomarkers for the diagnosis of new and recurrent prostate cancer

Prostate cancer is the most prevalent cancer in men and can be managed effectively if diagnosed early and monitored. Currently, prostate-specific antigen testing in conjunction with a digital rectal exam has been utilized for screening at-risk men. However, the lack of specificity of prostate-specific antigen as a marker for prostate cancer combined with the asymptomatic and slow-growing nature of prostate tumors has resulted in many men being overdiagnosed and subjected to surgery or treatment with adverse side effects. The focus in the research community currently has been on discovering noninvasive surrogate markers such as proteins, circulating tumor cells and nucleic acids in the blood or urine of patients with prostate cancer. These markers, in combination with prostate-specific antigen, are providing promise that a personalized multiparametric approach to prostate cancer diagnosis and monitoring will aid in managing this disease.

Prostate specific antigen and Gleason score in men with prostate cancer at a private diagnostic radiology centre in Western Jamaica

BACKGROUND

Prostate cancer is the most common malignant tumour in men and the second most common cause of male cancer death. The study examines the clinicopathological features of patients with prostate cancer consecutively diagnosed at a private Diagnostic Radiology Centre in Western Jamaica over a 6-year period.

METHOD

The medical records, including the pathology reports of 423 consecutive patients who had transrectal ultrasonography (TRUS) - guided prostate biopsy between January 2006 and December 2011 were reviewed.

RESULTS

The mean age at diagnosis of the 191 men with prostate adenocarcinoma was 68.5 ± 0.59 years with the majority in the 70 - 79 year age group (43.5%). Moderately differentiated carcinomas (Gleason score of 6) comprised the largest group with 72 cases (37.9%); poorly differentiated cancers with Gleason scores of 8 - 10 comprised 49 cases (25.8%). The PSA levels increased with Gleason score. The mean PSA levels for men with Gleason score of 6 was 50.1 ± 30.0 ng/mL compared with 136.5 ± 59.9 ng/mL in patients with Gleason score of 8 and 140.5 ± 31.8 ng/mL in patients with Gleason score of 9. Perineural invasion was present in 7.85% of the cases overall; high-grade prostatic intraepithelial neoplasia (HGPIN) was present in 4.71% of the biopsies.

CONCLUSION

Although the majority of patients had moderate, and moderate to poor differentiated carcinomas, the number with poorly differentiated carcinoma was high. This is a reflection of the patients' late clinical presentation at the time of diagnosis.

Preoperative insulin-like growth factor-binding protein-3 (IGFBP-3) blood level predicts gleason sum upgrading

BACKGROUND

About 43% of men with low Gleason grade prostate cancer (PCa) at biopsy will be finally diagnosed with high-grade PCa at radical prostatectomy (RP). Gleason sum at RP is a good indicator of biochemical recurrence and poor clinical outcome. Therefore, there is a need to improve clinical evaluation of PCa aggressiveness in order to choice appropriate treatment. To this aim an easy-available tool is represented by circulating biomarkers. Among these, the best candidates are some molecules involved in PCa pathogenesis such as IGFBP-2 and IGFBP-3, IL-6, and its soluble receptor (SIL-6R).

METHODS

In this study, we evaluated the ability of preoperative IGFBP-2, IGFBP-3, IL-6, and SIL-6R serum levels to predict Gleason score upgrade in 52 PCa patients.

RESULTS

We found that IGFBP-3 median levels were significantly lower in patients who showed Gleason upgrading from biopsy to RP (P = 0.024). We also found an association between biopsy T-stage and Gleason Upgrade (P = 0.011). Using multivariate logistic regression model, we demonstrated that the association of IGFBP-3 serum levels together with biopsy T-stage and biopsy Gleason score was useful to calculate a prognostic risk score. ROC curve analysis of risk score showed a good ability to predict GSU (AUC = 0.81; 95% CI 0.69-0.93).

CONCLUSIONS

Our results suggest that preoperative IGFBP-3 circulating levels determination may be useful to predict Gleason score upgrading alone and/or in combination with biopsy T-stage and biopsy Gleason score.

Prostate cancer - a biomarker perspective

Despite early detection and reduced risk of death, prostate cancer still remains the second leading cause of cancer death in American men. There is currently no cure for advanced prostate cancer. The multistage, stochastic and highly heterogeneous nature of prostate cancer, coupled with genetic and epigenetic alterations that occur during disease progression and response to therapy, represent fundamental challenges in our quest to understand and control this complex and prevalent disease. Recent advances in drug development and breakthroughs in omics technologies have renewed our efforts to identify novel biomarkers for prostate cancer prognosis, prediction, and therapeutic response monitoring. In this perspective article, we overview the current status and highlight future prospects of biomarkers for prostate cancer, a disease that affects millions of men worldwide.

Diagnostic utility of p63/P501S double sequential immunohistochemical staining in differentiating urothelial carcinoma from prostate carcinoma

Background

Distinguishing urothelial carcinoma (UC) from prostate carcinoma (PC) is important due to potential therapeutic and prognostic implications. However, this can be a diagnostic challenge when there is limited tissue and in poorly differentiated tumors. We evaluated the diagnostic utility of a dual immunohistochemical stain comprising p63 and P501S (prostein), applied sequentially on a single slide and visualized by double chromogen reaction, in differentiating these two cancers. Thus far, there have been no previous studies assessing the diagnostic utility of p63 and P501S combined together as a dual immunostain in distinguishing between these two cancers.

Methods

p63/P501S dual-color sequential immunohistochemical staining was performed on archival material from 132 patients with high-grade UC and 23 patients with PC, and evaluated for p63 (brown nuclear) and P501S (red cytoplasmic) expression. Both the staining intensity and percentage of positive tumor cells were assessed.

Results

p63 was positive in 119/132 of UC and negative in PC. P501S was positive in 22/23 of PC and negative in UC. The p63+/P501S- immunoprofile had 90% sensitivity and 100% specificity for UC. The p63-/P501S+ immunoprofile had 96% sensitivity and 100% specificity for PC.

Conclusion

Our results indicate that double sequential immunohistochemical staining with p63 and P501S is highly specific and can be a useful tool in distinguishing UC from PC especially when there is limited diagnostic tissue as it can be performed on a single slide.

Hypofractionation for radiotherapy of prostate cancer using a low alfa/beta ratio--possible reasons for concerns? An example of five dimensional radiotherapy

It is very attractive, due to the assumed low alfa/beta ratio of prostate cancer (PC), to construct new treatment schedules for prostate cancer using only a few large fractions of radiation (hypofractionation). This will widen the therapeutic window since the ratio for PC might be lower than that of the organs at risk (OAR). PC is an extremely variable disease and often contains both highly and poorly differentiated cells. It is reasonable to assume that different cells have different patterns of radiosensitivity, i.e. alfa/beta ratios and proliferation. In this study we will simulate the effect on the outcome of the treatment with different fractionations and different ratios.

MATERIAL AND METHODS

In this simulation we use an extension of the Linear Quadratic (LQ)/Biological Effective Dose (BED) formula called the dose volume inhomogeneity corrected BED (DVIC-BED). In the formula the tumour volume is divided in 50 subvolumes (step of 2%) and it is possible to calculate the relative effect of the treatment with different ratios (1.5, 4 and 6.5) in different subvolumes.

RESULTS

The simulations demonstrate that only a small portion (5-10%) of cells with a higher ratio will dramatically change the effect of the treatment. Increasing the total dose can compensate this, but this will on the other hand increase the dose to the OAR and also the risk for severe side effects.

CONCLUSION

These simulations highlight possible reasons for concerns about the use of hypofractionation for pathologically heterogeneous tumours, such as prostate cancer, and also demonstrate the need for testing new treatment schedules using both high and low ratios.

Osteoblasts can stimulate prostate cancer growth and transcriptionally down-regulate PSA expression in cell line models

INTRODUCTION

To investigate the effect of bone environment on cellular proliferation, mature prostate-specific antigen (PSA) production and secretion, and PSA transcriptional regulation of prostate cancer cells.

MATERIALS AND METHODS

Androgen-independent C4-2 prostate cancer cells were co-cultured with various osteoblastic cells in a transwell system. Proliferation was measured via cell counting and MTT assay. Lactate and PSA were determined in the conditioned media (CM). Transcriptional activity of the full-length PSA promoter (6.1 kilobases) and of 3 deletion constructs was determined via luciferase reporter assay upon exposure to CM from various osteoblastic cell lines.

RESULTS

Osteoblastic bone cells and CM, but not control cells (fibroblast) or CM, reproducibly stimulated the proliferation of C4-2 cells. The co-culture system, PSA production by C4-2 cells transiently decreased when in co-culture with osteoblastic, but not with control cells. After abundant prostate cell proliferation, the secreted PSA levels rose exponentially. Addition of CM from osteoblastic cells, but not control cells, consistently decreased (about 3-fold) the transcriptional activity of the PSA promoter in C4-2 cells. Deletion construct analysis of the PSA promoter revealed that the transcriptional down-regulation is dually controlled by elements close to the TATA and upstream androgen responsive (ARE(III)) components.

CONCLUSIONS

The osteoblastic environment stimulates prostate cancer cell proliferation but reduces PSA production initially. The mechanism of PSA down-regulation is transcriptional, most likely in response to soluble factors present in the osteoblastic bone stromal cell CM. Transcriptional down-regulation appears to be mediated by elements near both the TATA box and the ARE(III) component.

Are predictive models for cancer volume clinically useful in localized prostate cancer?

OBJECTIVES

To evaluate the correlation between preoperatively predicted and pathologically measured prostate cancer volumes and to investigate the clinical use of preoperatively predicted cancer volume in predicting pathological stage.

METHODS

Correlations between pathological findings and various preoperative parameters, including the cancer volumes as predicted by using two methods (Vca and estimated PCvol), were analyzed in 196 patients who underwent radical prostatectomy for clinically localized prostate cancer.

RESULTS

Pathologically measured prostate cancer volume was significantly correlated with the Vca and estimated PCvol, but the correlation coefficients were respectively only 0.46 and 0.35. Prostate-specific antigen (PSA), PSA density (PSAD), primary Gleason score, Vca, Vca fraction (Vcafx), and estimated PCvol were significantly higher in 82 patients with extraprostatic cancer than in 114 patients with organ-confined cancer. Magnetic resonance imaging (MRI) findings were significantly correlated with pathological stage. Multivariate logistic regression analysis indicated that the Vcafx and MRI findings were significant predictors of extraprostatic cancer, but receiver operating characteristic analysis revealed that the combination of Vcafx and MRI findings had no advantage over the combination of Gleason score, PSAD, and MRI findings.

CONCLUSIONS

Vca and estimated PCvol are significantly correlated with the pathologically measured cancer volume but their ability to accurately predict cancer volume is limited. Vcafx and MRI findings were statistically significant predictors of extraprostatic cancer but their combination was not superior to the combination of Gleason score, PSAD, and MRI findings.

The effect of Gleason score on the predictive value of prostate-specific antigen doubling time

OBJECTIVE

To evaluate the influence of the pathological Gleason score on the predictive value of the prostate-specific antigen (PSA) doubling time (DT), as this variable predicts a patient's risk of disease progression both before and after definitive therapy for prostate cancer, and there is an inverse correlation between the Gleason score and PSA production.

PATIENTS AND METHODS

We evaluated all men treated with radical prostatectomy (RP) between 1990 and 1999 who did not receive neoadjuvant or adjuvant therapy. We identified 2296 patients who had multiple PSA values available before RP, and 1323 who had biochemical recurrence after RP and had at least two PSA values available before starting secondary therapy. Systemic progression and cancer-specific survival (CSS) rates were estimated using the Kaplan-Meier method and Cox proportional hazard regression models.

RESULTS

A PSA DT of <18 vs >18 months predicted a lower 10-year systemic progression-free survival for patients with tumours having a pathological Gleason score of <7 (98% vs 99%, P = 0.005), 7 (82% vs 91%, P = 0.003) and 8-10 (57% vs 73%, P = 0.042). A PSA DT after RP of <12 months was significantly associated with a lower 10-year systemic progression-free survival for patients with tumours having a Gleason score of <7 (77% vs 94%, P < 0.001) and 7 (61% vs 86%, P < 0.001), but not 8-10 (61% vs 75%, P = 0.11). The ability of PSA DT before and after RP to predict systemic progression and CSS decreased with increasing Gleason score.

CONCLUSIONS

The PSA DT remains associated with outcome both before and after RP across increasing pathological Gleason scores, although the predictive ability of PSA DT is diminished in Gleason 8-10 cancers.

Urine analysis and protein networking identify met as a marker of metastatic prostate cancer

PURPOSE

Metastatic prostate cancer is a major cause of death of men in the United States. Expression of met, a receptor tyrosine kinase, has been associated with progression of prostate cancer.

EXPERIMENTAL DESIGN

To investigate met as a biomarker of disease progression, urinary met was evaluated via ELISA in men with localized (n = 75) and metastatic (n = 81) prostate cancer. Boxplot analysis was used to compare the distribution of met values between each group. We estimated a receiver operating characteristic curve and the associated area under the curve to summarize the diagnostic accuracy of met for distinguishing between localized and metastatic disease. Protein-protein interaction networking via yeast two-hybrid technology supplemented by Ingenuity Pathway Analysis and Human Interactome was used to elucidate proteins and pathways related to met that may contribute to progression of disease.

RESULTS

Met distribution was significantly different between the metastatic group and the group with localized prostate cancer and people with no evidence of cancer (P < 0.0001). The area under the curve for localized and metastatic disease was 0.90, with a 95% confidence interval of 0.84 to 0.95. Yeast two-hybrid technology, Ingenuity Pathway Analysis, and Human Interactome identified 89 proteins that interact with met, of which 40 have previously been associated with metastatic prostate cancer.

CONCLUSION

Urinary met may provide a noninvasive biomarker indicative of metastatic prostate cancer and may be a central regulator of multiple pathways involved in prostate cancer progression.

Predictive value of prostate-specific antigen expression in prostate cancer: a tissue microarray study

OBJECTIVES

To evaluate the prognostic potential of prostate-specific antigen (PSA) expression in tumor specimens in a large cohort of prostate cancers treated by prostatectomy. Although serum PSA measurement has been established as a diagnostic and prognostic tool in prostate cancer, no larger studies have been done of the prognostic potential of this parameter.

METHODS

We used a tissue microarray containing samples of 3261 prostatectomy specimens. PSA expression was scored after immunohistochemical staining on a scale from 0 (absent) to 3 (strong) by an investigator unaware of all other variables. The results were correlated with the pre- and postoperative clinical and pathologic parameters and follow-up data.

RESULTS

Of 2556 eligible tumors, PSA expression was strong in 48.0%, moderate in 36.7%, weak in 12.2%, and absent in 3.1%. The loss of PSA expression correlated significantly with a greater Gleason score, the presence of extraprostatic extension, and a peripheral zone prostate cancer location. It was also significantly associated with PSA recurrence after prostatectomy on univariate analysis but not on multivariate analysis containing the pathologic parameters of the prostatectomy specimens. In the subsets of patients with a preoperative PSA value <6 ng/mL or biopsy Gleason score of 3 + 4, the loss of PSA expression in tissue microarray spots was significantly associated with nonorgan-confined disease.

CONCLUSIONS

The results of our study have shown that the loss of PSA expression in tissue samples of prostate cancer is associated with adverse pathologic features and clinical outcome but is not an independent prognostic factor for PSA recurrence after prostatectomy. However, in the biopsy scenario and in subgroups of patients, it might be a useful parameter for predicting extraprostatic tumor extension.

Percentage of tumor in prostatectomy specimens: a study of American Veterans

In this study, I have estimated the percentage of tumor by visual estimate in 447 prostatectomy specimens from American Veterans Affairs patients and related this measurement to overall survival. Although percentage of tumor was significantly related to the serum prostate-specific antigen level, tumor stage, and Gleason score-that is, it was not statistically independent from these-it was more closely associated with overall survival than any of them. Altogether, 2 variables available at the time of the prostatectomy related to survival: patient age (P = .0032; Cox proportional hazards model analysis) and percentage of tumor (P = .0013; Cox model). Patient age undoubtedly reflects the combination of comorbidities and general expected length of life. Percentage of tumor, by contrast, seems to efficiently reflect any undue hazard for early death due to prostate cancer. The results suggest that percentage of tumor is a useful prognostic variable for understanding risk of early death after prostatectomy.

A 6-year analysis of the clinicopathological profile of patients with prostate cancer at the University Hospital of the West Indies, Jamaica

OBJECTIVE To document the clinicopathological characteristics of prostate cancer in a public hospital-based population in Jamaica, over a 6-year period, and examine any trends in these characteristics over time, as prostate cancer is the leading cause of cancer in Jamaican men, but there are few published reports documenting the clinicopathological profile of this disease in the Jamaican population. PATIENTS AND METHODS All patients consecutively diagnosed with prostate cancer by transrectal ultrasonography-guided biopsy at the University Hospital of the West Indies, from January 2000 to December 2005, were identified at time of diagnosis, and relevant clinical and pathological data collected from the accompanying histopathology request forms. RESULTS There were 529 cases of prostate cancer diagnosed over the 6 years. The mean (sd) age was 70.66 (8.74) years, with 137 patients aged 70-74 years. A serum prostate-specific antigen (PSA) level was obtained for 490 (92.6%) patients. Of these, an accurate PSA value was available for 456 (86.2%) patients and a 'minimum level' recorded for the remaining 34, all of whom had a PSA level of >100 ng/mL. Of the patients with available PSA information, only 91 (18.5%) had a level of < or =10.0 ng/mL. By contrast, 155 (31.6%) patients had levels of >100 ng/mL. The median (range, interquartile range) serum PSA level for those patients with accurate values was 30.7 (1-14 260, 11.7-109) ng/mL. Histologically, moderately and poorly differentiated cancers accounted for 198 (37.5%) and 160 (30.2%) cases, respectively. Correlation of the variables under investigation confirmed that there was a statistically significant positive and moderate correlation between serum PSA level and Gleason score (Spearman r 0.49; P < 0.001). Statistical analysis of all other variables, including the number of cases of prostate cancer diagnosed annually, showed no significant differences. CONCLUSION Compared with many countries, including some in the Caribbean, prostate cancer in Jamaican men is diagnosed when they are older and these patients have significantly higher PSA levels at diagnosis, suggesting more advanced disease. Despite increasing public awareness of prostate cancer, it appears that there has been no significant change in the profile of patients with prostate cancer, at the time of diagnosis, over the last 6 years, findings consistent with the absence of an organized screening programme for prostate cancer in Jamaica.

Emerging Biomarkers for the Diagnosis and Prognosis of Prostate Cancer

Background: Early detection of prostate cancer (CaP), the most prevalent cancer and the second-leading cause of death in men, has proved difficult, and current detection methods are inadequate. Prostate-specific antigen (PSA) testing is a significant advance for early diagnosis of patients with CaP.

Content: PSA is produced almost exclusively in the prostate, and abnormalities of this organ are frequently associated with increased serum concentrations. Because of PSA’s lack of specificity for CaP, however, many patients undergo unnecessary biopsies or treatments for benign or latent tumors, respectively. Thus, a more specific method of CaP detection is required to augment or replace screening with PSA. The focus recently has been on creating cost-effective assays for circulating protein biomarkers in the blood, but because of the heterogeneity of CaP, it has become clear that this effort will be a formidable challenge. Each marker will require proper validation to ensure clinical utility. Although much work has been done on variations of the PSA test (i.e., velocity, density, free vs bound, proisoforms) with limited usefulness, there are many emerging markers at various stages of development that show some promise for CaP diagnosis. These markers include kallikrein-related peptidase 2 (KLK2), early prostate cancer antigen (EPCA), PCA3, hepsin, prostate stem cell antigen, and α-methylacyl-CoA racemase (AMACR). We review biomarkers under investigation for the early diagnosis and management of prostate cancer.

Summary: It is hoped that the use of panels of markers can improve CaP diagnosis and prognosis and help predict the therapeutic response in CaP patients.

Blood biomarkers for prostate cancer detection and prognosis

Prostate cancer is the most non-cutaneous malignancy diagnosed in men in the USA. The discovery of prostate-specific antigen (PSA) revolutionized prostate cancer diagnosis and management in the 1990s. Despite its remarkable performance as a marker for prostate cancer, PSA is not prostate cancer specific. PSA can be released by normal as well as hyperplastic prostate cells, which undermines the specificity of PSA for prostate cancer diagnosis. Hence, there is a need for new biomarkers that can detect prostate cancer and, in addition, distinguish indolent from biologically aggressive cancers. Moreover, the emergence of new therapeutic approaches for prostate cancer cannot flourish without a more reliable set of markers to serve as prognosticators, targets and surrogate end points of disease progression and response to treatment. As the most useful clinical biomarkers are likely to be those assayed from blood, there is an increasing interest in profiling blood proteins. With recent advances in biotechnology such as high-throughput molecular analyses, many potential blood biomarkers have been identified and are currently under investigation.

New circulating biomarkers for prostate cancer

The introduction of prostate-specific antigen (PSA) revolutionized prostate cancer (PCa) screening and ushered the PSA era. However, its use as a screening tool remains controversial and changes in the epidemiology of PCa have strongly limited its prognostic role. Therefore, we need novel approaches to improve our ability to detect PCa and foretell the course of the disease. To improve the specificity of total PSA, several approaches based on PSA derivatives have been investigated such as age-specific values, PSA density (PSAD), PSAD of the transition zone, PSA velocity and assessment of various isoforms of PSA. With recent advances in biotechnology such as high-throughput molecular analyses, many potential blood biomarkers have been identified and are currently under investigation. Given the plethora of candidate PCa biomarkers, we have chosen to discuss a select group of candidate blood-based biomarkers including human glandular kallikrein, early prostate cancer antigens, insulin-like growth factor-I (IGF-I) and its binding proteins (IGFBP-2 and IGFBP-3), urokinase plasminogen activation system, transforming growth factor-beta1, interleukin-6, chromogranin A, prostate secretory protein, prostate-specific membrane antigen, PCa-specific autoantibodies and alpha-methylacyl-CoA racemase. While these and other markers have shown promise in early phase studies, no single biomarker is likely to have the appropriate degree of certainty to dictate treatment decisions. Consequently, the future of cancer prognosis may rely on small panels of markers that can accurately predict PCa presence, stage, metastasis, and serve as prognosticators, targets and/or surrogate end points of disease progression and response to therapy.

New blood-based biomarkers for the diagnosis, staging and prognosis of prostate cancer

The introduction of prostate-specific antigen (PSA) has revolutionized the detection and management of patients with prostate cancer. Despite this there has always been a concern among clinicians about the usefulness of total PSA levels as a marker for prostate cancer. We discuss the use of calculated variables and molecular forms of PSA. The precursor forms of PSA have been associated with the presence and biological behaviour of prostate cancer. With recent advances in biotechnology, e.g. high-throughput molecular analyses, many potential blood biomarkers have been identified and are currently under investigation. Given the plethora of candidate biomarkers we discuss a selected group of novel blood-based biomarkers, e.g. human glandular kallikrein, early prostate cancer antigen, insulin-like growth factors, urokinase plasminogen activators, transforming growth factor-beta, interleukin-6, chromogranin A, and prostate secretory protein. While these and other markers have shown promise in early-phase studies, no single biomarker is likely to have the appropriate degree of certainty to dictate treatment decisions. Consequently, the future of cancer prognosis might rely on small panels of markers that can accurately predict cancer presence, stage and metastasis, and serve as prognosticators, targets, and/or surrogate endpoints of disease progression and response to therapy.

Immunohistochemical differentiation of high-grade prostate carcinoma from urothelial carcinoma

The histologic distinction between high-grade prostate cancer and infiltrating high-grade urothelial cancer may be difficult, and has significant implications because each disease may be treated very differently (ie, hormone therapy for prostate cancer and chemotherapy for urothelial cancer). Immunohistochemistry of novel and established prostatic and urothelial markers using tissue microarrays (TMAs) were studied. Prostatic markers studied included: prostate-specific antigen (PSA), prostein (P501s), prostate-specific membrane antigen (PSMA), NKX3.1 (an androgen-related tumor suppressor gene), and proPSA (pPSA) (precursor form of PSA). "Urothelial markers" included high molecular weight cytokeratin (HMWCK), p63, thrombomodulin, and S100P (placental S100). TMAs contained 38 poorly differentiated prostate cancers [Gleason score 8 (n=2), Gleason score 9 (n=18), Gleason score 10 (n=18)] and 35 high-grade invasive urothelial carcinomas from radical prostatectomy and cystectomy specimens, respectively. Each case had 2 to 8 tissue spots (0.6-mm diameter). If all spots for a case showed negative staining, the case was called negative. The sensitivities for labeling prostate cancers were PSA (97.4%), P501S (100%), PSMA (92.1%), NKX3.1 (94.7%), and pPSA (94.7%). Because of PSA's high sensitivity on the TMA, we chose 41 additional poorly differentiated primary (N=36) and metastatic (N=5) prostate carcinomas which showed variable PSA staining at the time of diagnosis and performed immunohistochemistry on routine tissue sections. Compared to PSA, which on average showed 18.8% of cells with moderate to strong positivity, cases stained for P501S, PSMA, and NKX3.1 had on average 42.5%, 53.7%, 52.9% immunoreactivity, respectively. All prostatic markers showed excellent specificity. HMWCK, p63, thrombomodulin, and S100P showed lower sensitivities in labeling high-grade invasive urothelial cancer in the TMAs with 91.4%, 82.9%, 68.6%, and 71.4% staining, respectively. These urothelial markers were relatively specific with only a few prostate cancers showing scattered (<or=2%) weak-moderate positive cells. In summary, PSA can be used as the first screening marker for differentiating high-grade prostate adenocarcinoma from high-grade urothelial carcinoma. Immunohistochemistry for P501S, PSMA, NKX3.1, and pPSA are useful when high-grade prostate cancer is suspected based on the morphology or clinical findings, yet shows negative or equivocal PSA staining. HMWCK and p63 are superior to the novel markers thrombomodulin and S100P.

Ubiquitylation of epsilon-COP by PIRH2 and regulation of the secretion of PSA

Ubiquitylation appears to be involved in the membrane trafficking system including endocytosis, exocytosis, and ER-to-Golgi transport. We found that PIRH2, which was identified as an interacting protein for androgen receptor or p53, interacts with and ubiquitylates the epsilon-subunit of coatmer complex, epsilon-COP. PIRH2 promotes the ubiquitylation of epsilon-COP in vitro and in vivo and consequently promotes the degradation of epsilon-COP. The interaction between PIRH2 and epsilon-COP is affected by the presence of androgen, and PIRH2 in the presence of androgen promotes ubiquitylation of epsilon-COP in vivo. Furthermore, overexpression of the wild type of PIRH2 in prostate cancer cells causes downregulation of the secretion of prostate-specific antigen (PSA), a secretory protein in prostate epithelial cells and one of diagnostic markers for prostate cancer. Our results indicate that PIRH2 functions as a regulator for COP I complex.

Increased expression of tumor-associated trypsin inhibitor, TATI, in prostate cancer and in androgen-independent 22Rv1 cells

OBJECTIVES

Tumor-associated-trypsin inhibitor (TATI) is frequently coexpressed with trypsinogen in tumors. Recently, we found expression of trypsinogens in prostate cancer. We have now studied whether TATI is also expressed in prostate cancer and if TATI expression is associated with Gleason grade, proliferation, and neuroendocrine differentiation.

METHODS

Expression of TATI and prostate-specific antigen (PSA) was studied by immunohistochemistry and in situ hybridization, and that of chromogranin A (CgA) and Ki-67 by immunohistochemistry. Immunofluorometric assays were used to quantify TATI and PSA in serum from prostate cancer patients and in medium of 22Rv1 prostate cancer cells.

RESULTS

TATI expression was weak in benign prostatic epithelium and moderate to strong in prostate cancer and high-grade prostatic intraepithelial neoplasia. There was no correlation between TATI and Ki-67 immunostaining in a tissue microarray of 115 prostate cancer cores, but strong expression of TATI was associated with higher Gleason grade (p=0.002) and CgA immunostaining intensity (p=0.012). Serum TATI was elevated in 44% (29 of 66) of patients with prostate cancer, and the levels correlated with serum PSA (p<0.0001, r=0.306). DU145, PC-3, LNCaP, and 22Rv1 cells contained TATI mRNA as determined by RT-PCR, but only 22Rv1 cells produced detectable TATI protein. The synthetic androgen R1881 decreased secretion of TATI from 22Rv1 cells.

CONCLUSIONS

We demonstrate for the first time that TATI is expressed in the benign and malignant prostate. Increased TATI protein expression is found in high-grade tumors and in 22Rv1 cells in which it is regulated by androgens.

Immunohistochemical Staining of Precursor Forms of Prostate-specific Antigen (proPSA) in Metastatic Prostate Cancer

Precursors of prostate-specific antigen (proPSA) have been previously shown to be more concentrated in prostate cancer tissue. This study characterizes the immunohistochemical staining (IHS) of proPSA forms in metastatic prostate cancer compared with prostate specific antigen (PSA) and prostatic acid phosphatase (PAP). A tissue microarray, consisting of 74 cases of metastatic prostate carcinoma and control tissues, was used. IHS, using monoclonal antibodies against proPSA with a truncated proleader peptide containing 2 amino acids ([-2]pPSA), native ([-5/-7]pPSA), PSA, and PAP, was analyzed. The monoclonal antibodies were specific for both benign and malignant prostatic glandular tissue. IHS with [-5/-7]pPSA showed the least number of cases with negative staining (3%), and the most number of cases with moderate or strong staining (76%). In the 60 cases where all 4 stains could be evaluated, none of them were negative for proPSA and positive for PSA or PAP, and all 7 cases that were negative for both PSA and PAP showed IHS to proPSA. [-5/-7]pPSA (native proPSA) may be a better marker than PSA and PAP in characterizing metastatic prostate adenocarcinoma, with most of the cases showing positivity for the marker. Even cases that were negative for PSA and PAP, were reactive for proPSA. Such enhanced detection is particularly important in poorly differentiated carcinomas involving metastatic sites where prostate carcinoma is a consideration. A panel of markers, including proPSA, should be performed when metastatic prostate carcinoma is in the differential diagnosis.

Poorly differentiated prostate cancer treated with radical prostatectomy: long-term outcome and incidence of pathological downgrading

PURPOSE

Patients with high grade (Gleason score 8 to 10) prostate cancer on biopsy are at high risk for cancer recurrence after local treatment, such as radiation therapy and radical prostatectomy. We examined long-term outcomes in patients with high grade prostate cancer on biopsy who were treated with radical prostatectomy alone. We also investigated the impact on outcomes of changes in the radical prostatectomy Gleason score.

MATERIALS AND METHODS

Of 5,662 patients who underwent radical prostatectomy during 20 years 238 had a biopsy Gleason score of 8 to 10. We analyzed the rate of biochemical recurrence in this subgroup according to the Gleason grade of cancer in the radical prostatectomy specimen.

RESULTS

Ten-year biochemical recurrence-free probability in the cohort was 39%. However, 45% of patients (95% CI 38 to 51%) with Gleason score 8 to 10 cancer on biopsy had a Gleason score of 7 or less in the radical prostatectomy specimen. These patients had a 10-year biochemical recurrence-free probability of 56% compared to 27% in those with a final Gleason score that remained 8 to 10 (p = 0.0004). On multivariate analysis neither prostate specific antigen nor biopsy features, including total number of cores, number of cores with cancer and percent of cancer in the cores, was a significant predictor of downgrading. However, clinical stage and biopsy Gleason score were significant with 58% of cT1c and 51% of biopsy Gleason score 8 cancers downgraded. Almost 65% of cT1c Gleason score 8 cancers were downgraded compared to 11% of cT3 Gleason score 9 cancers.

CONCLUSIONS

Patients diagnosed with poorly differentiated prostate cancer (Gleason score 8 to 10) on biopsy do not uniformly have a poor prognosis. Of the patients 39% remain free of cancer recurrence 10 years after radical prostatectomy. Of these cancers 45% have a lower Gleason score in the radical prostatectomy specimen and a correspondingly more favorable long-term outcome. Predictors of downgrading are lower clinical stage (cT1c) and Gleason score 8 in the biopsy specimen.

Pre-operative percent free PSA predicts clinical outcomes in patients treated with radical prostatectomy with total PSA levels below 10 ng/ml

INTRODUCTION

To evaluate the association of total prostate specific antigen (T-PSA) and percent free PSA (%F-PSA) with prostate cancer outcomes in patients treated with radical prostatectomy (RP).

METHODS

Pre-operative serum levels of T-PSA and F-PSA were prospectively measured in 402 consecutive patients treated with RP for clinically localized prostate cancer who had T-PSA levels below 10 ng/ml.

RESULTS

T-PSA was not associated with any prostate cancer characteristics or outcomes. Lower %F-PSA was significantly associated with higher percent positive biopsy cores, extracapsular extension, seminal vesicle involvement, lympho-vascular invasion, perineural invasion, positive surgical margins, and higher pathologic Gleason sum. When adjusted for the effects of standard pre-operative features, lower %F-PSA significantly predicted non-organ confined disease, seminal vesicle involvement, lympho-vascular invasion, and biochemical progression. %F-PSA did not retain its association with biochemical progression after adjusting for the effects of standard post-operative features. Based on data from 22 patients with biochemical progression, lower %F-PSA was correlated with shorter T-PSA doubling time after biochemical progression (rho = 0.681, p = 0.010). %F-PSA was lower in patients who failed salvage radiation therapy (p = 0.031) and in patients who developed distant cancer metastases compared to patients who did not (p < 0.001).

CONCLUSIONS

Pre-operative T-PSA is not associated with prostate cancer outcomes after RP when levels are below 10 ng/ml. In contrast, pre-operative %F-PSA is associated with adverse pathologic features, biochemical progression, and features of aggressive disease progression in patients treated with RP and T-PSA levels below 10 ng/ml. %F-PSA may improve pre-operative predictive models for predicting clinical outcomes of patients diagnosed with prostate cancer nowadays.