Differences in biopsy features between prostate cancers located in the transition and peripheral zone

Prostate cancer lesions in transition zone exhibit a higher propensity for pathological upgrading in radical prostatectomy

BACKGROUND

The varying malignancy and lethality of different grades of prostate cancer (PCa) highlight the importance of accurate diagnosis. This study aims to evaluate the upgrading of transition zone (TZ) prostate cancer biopsies and identify factors to improve TZ biopsy accuracy.

MATERIALS AND METHODS

This retrospective study included 217 patients who underwent laparoscopic radical prostatectomy after 12 + X cores transperineal transrectal ultrasound-magnetic resonance imaging (MRI)-guided targeted prostate biopsy from 2018 to 2021 in our center.

RESULTS

Patients with TZ lesions showed a higher incidence of International Society of Urological Pathology (ISUP) grade upgrading from 1 to higher grade compared to peripheral zone lesions (16.9% vs. 5.0%, p = 0.005). Multivariate analysis confirmed TZ lesions as an independent risk factor (OR: 4.594, 97.5% CI: 1.569-15.238, p = 0.008) for upgrading from 1 to higher. Additionally, the number of positive biopsy cores (OR: 0.586, 97.5% CI: 0.336-0.891, p = 0.029) and anterior TZ lesion location (OR: 10.797, 97.5% CI: 1.503-248.727, p = 0.048) were independent factors for the upgrading in TZ patients.

CONCLUSIONS

This study found that PCa lesions located in the TZ, particularly the anterior TZ, have a higher risk of ISUP grade upgrading. This elevated risk arises from the insufficient distribution of biopsy cores around the TZ lesion. The findings underscore the importance of having an adequate number of biopsy cores around the lesion area to improve the accuracy of ISUP grade assessments.

The Etiology and Pathogenesis of Benign Prostatic Hyperplasia: The Roles of Sex Hormones and Anatomy

Benign prostatic hyperplasia (BPH) mainly causes lower urinary tract symptoms in ageing men, but its exact etiology and pathogenesis have not been established. The objective of this review was to design an update on the advances of human BPH research. We undertook a literature search for identifying studies of the roles of sex hormones (androgens and estrogens) in the onset and development of human BPH using the Pubmed database. In literature, many studies have indicated that ageing and obesity are the factors for preceding the onset of BPH. No evidence for the role of testosterone (T) or dihydrotestosterone (DHT) is found in BPH initiation. Since BPH exclusively occurs in the transitional zone (TZ) surrounding the urethra, it is postulated that years of exposure to uncharacterized urinary toxins could disrupt the homeostasis of the stroma and/or epithelium of this prostatic zone that are typically occurring in ageing men. After cellular damage and subsequent inflammation generated, the intraprostatic DHT produced mainly from T by 5α-reductase promotes BPH development. Further, estrogens could take part in the nodular proliferation of stromal cells in some BPH patients. The confounding of BPH may attenuate the development of prostate tumor in the TZ. In conclusion, evidence in literature suggests that androgens are not etiological factors for BPH, and intraprostatic DHT along with chronic inflammation are mainly responsible for nodular proliferation of stromal and/or epithelial cells in prostatic TZ. The urinary factors for the etiology of BPH and BPH as a prediction of PCa progression still need further investigation.

Apparent differences in prostate zones: susceptibility to prostate cancer, benign prostatic hyperplasia and prostatitis

Men are inevitably plagued by prostate disease throughout their lives. However, the understanding of the pathogenesis of prostate diseases is still limited. In the 1960s, McNeal proposed the theory of prostate zones: the prostate was divided into three main zones: transition zone, central zone, and peripheral zone. Over the past 50 years, significant differences between different prostate zones have been gradually revealed. We summarized the most significant differences in different zones of the prostate. For the first time, we proposed the "apparent difference in prostate zones" concept. This new concept has been proposed to understand the different zones of the prostate better. It also provided new ideas for exploring the susceptibility of lesions in different prostate zones. Despite the reported differences between zones, the treatment of prostate-related diseases remains partition agnostic. Therefore, we also discussed the clinical significance of the "apparent difference in the prostate zone" and emphasized the necessity of prostate zones.

Tale of two zones: investigating the clinical outcomes and research gaps in peripheral and transition zone prostate cancer through a systematic review and meta-analysis

Objective

To assess pathological characteristics, clinical features and outcomes of patients diagnosed with peripheral zone (PZ) and transition zone (TZ) prostate cancer after prostatectomy.

Methods and analysis

We systematically reviewed PubMed, EMBASE and MEDLINE. Primary endpoints were biochemical relapse-free survival (bRFS) and distant metastases rate; secondary endpoints included clinical and pathological features.

Results

Ten retrospective cohort studies were identified, six reported HRs for bRFS between PZ and TZ tumours. Patients with TZ tumours had significantly better bRFS (pooled HR 0.57 (0.47, 0.68)) than those with PZ tumours. Two studies reported a lower proportion of distant metastasis in patients diagnosed with TZ tumours compared with PZ tumours (1.5% vs 4.9% (median follow-up 7.0 years) and 0% vs 5% (median follow-up 7.8 years)). PZ tumours presented higher Gleason group and T staging more frequently, while TZ tumours were associated with higher prostate specific antigen levels at diagnosis.

Conclusion

PZ tumours were associated with poorer prognostic clinical features and outcomes. Despite adjusting for poor prognostic clinical features, PZ tumours consistently showed worse clinical outcomes than TZ tumours. Our systematic review underscores the need for further research comparing PZ and TZ prostate cancer to understand the underlying differences and refine clinical practice.

Differences in the pathogenetic characteristics of prostate cancer in the transitional and peripheral zones and the possible molecular biological mechanisms

Since the theory of modern anatomical partitioning of the prostate was proposed, the differences in the incidence and pathological parameters of prostate cancer between the peripheral zone and transition zone have been gradually revealed. It suggests that there are differences in the pathogenic pathways and molecular biology of prostate cancer between different regions of origin. Over the past decade, advances in sequencing technologies have revealed more about molecules, genomes, and cell types specific to the peripheral and transitional zones. In recent years, the innovation of spatial imaging and multiple-parameter magnetic resonance imaging has provided new technical support for the zonal study of prostate cancer. In this work, we reviewed all the research results and the latest research progress in the study of prostate cancer in the past two decades. We summarized and proposed several vital issues and focused directions for understanding the differences between peripheral and transitional zones in prostate cancer.

Prostate zones and cancer: lost in transition?

Localized prostate cancer shows great clinical, genetic and environmental heterogeneity; however, prostate cancer treatment is currently guided solely by clinical staging, serum PSA levels and histology. Increasingly, the roles of differential genomics, multifocality and spatial distribution in tumorigenesis are being considered to further personalize treatment. The human prostate is divided into three zones based on its histological features: the peripheral zone (PZ), the transition zone (TZ) and the central zone (CZ). Each zone has variable prostate cancer incidence, prognosis and outcomes, with TZ prostate tumours having better clinical outcomes than PZ and CZ tumours. Molecular and cell biological studies can improve understanding of the unique molecular, genomic and zonal cell type features that underlie the differences in tumour progression and aggression between the zones. The unique biology of each zonal tumour type could help to guide individualized treatment and patient risk stratification.

The Value and Evaluability of the PCA3 Urine Assay in Prostate Carcinoma is Independent of the Tumor Localization

INTRODUCTION

The prostate cancer gene 3 (PCA3) test is based on the analysis of tumor cell mRNA in urine. As an exprimated urinary marker, its retrieval is subject to certain physical aspects like palpation pressure and detachment force during the squeezing of cells. Other potential factor of influence may be the distance the cells have to cover until they reach the urethra. Thus, it was investigated whether the localization of the tumors within the prostate with regard to the urethra and the seminal colliculus influences the PCA3 score.

METHODS

Prostatectomy specimens of 55 organ-confined prostate cancer patients were processed according to the Stanford protocol. For each prostatectomy specimen, a three-dimensional reconstruction including the surface of the prostate, the tumor areas and the urethra was created. By model simulating, virtual concentric tubes were placed around the urethra and spherical volumes were virtually positioned around the seminal colliculus at diameters of 8, 16 and 32 mm. Depending on localization, tumor volumes may or may not protrude into the tubes or spherical volumes. For each respective diameter, PCA3 levels were compared between the subgroup with and without protrusion of tumor tissue into the tube or spherical ball.

RESULTS

For none of the diameters, whether in tubes or spherical balls, were patients without intersection volumes-hence showing peripherally located tumors-found to have lower PCA3 levels. No clinical or histopathological parameter correlated with the PCA3 score.

CONCLUSION

The location of the tumor mass in the prostate with respect to the urethra or the seminal colliculus did not to affect the PCA3 score. Hence, the location of the tumor does not limit the validity of the PCA3 score, and even for exclusively peripherall y located tumors, this possible influencing factor did not lead to an artificial modulation of the PCA3 score.

Early channel transurethral resection of the prostate for patients with urinary retention after brachytherapy

OBJECTIVE

It is recommended that transurethral resection of the prostate (TURP) after brachytherapy should not be performed at an early stage after implantation. Herein we report our experiences and the results of channel TURP (cTURP) within six months post-implant for patients with refractory urinary retention.

METHODS

One hundred and ninety patients with localized prostate cancer of clinical stages T1c to T2c were treated by brachytherapy as monotherapy at our institution from February 2009 to July 2013. Nine patients who developed refractory urinary retention and underwent cTURP within six months after brachytherapy were retrospectively reviewed and analyzed.

RESULTS

The median interval between prostate brachytherapy and cTURP was three months (range 1.5 to 5.0 months). There were no intraoperative or postoperative complications and no incontinence resulting from the surgery. All urinary retention was relieved per the American Brachytherapy Society urinary symptom score. With a mean follow-up time of 16 months (range 6 to 26 months) after cTURP, no patient experienced biochemical recurrence. The mean serum prostate-specific antigen (PSA) of the patients who underwent cTURP was 0.42 ng/ml (range 0.08 to 0.83 ng/ml) at the end of their follow-up.

CONCLUSIONS

Early cTURP was found to be safe and effective in relieving urinary retention after brachytherapy and could be performed without compromising its therapeutic efficacy.

Incremental value of transition zone and midline apical biopsy at baseline TRUS-guided biopsy for prostate cancer detection

PURPOSE

To determine the diagnostic yield of transition zone (TZB) and midline apical biopsies (MAB) in baseline transrectal ultrasound (TRUS)-guided biopsies and to establish whether TZB and MAB for the diagnosis of prostate cancer (PCa) add clinical relevant information.

METHODS

We performed baseline 9-core TRUS-guided biopsy in 412 consecutive subjects using sextant biopsies of the PZ (PZB), with an additional TZB on either side and a MAB at the prostatic apex. We determined the incremental diagnostic value of additional TZB an MAB to sextant PZB.

RESULTS

Within a cohort of 412 patients with a median PSA of 7.5 ng/ml, 178 (43.2 %) patients were diagnosed with PCa upon baseline TRUS-guided biopsies. In 102 cases, at least one TZB was positive for PCa, with 6/412 (1.4 %) cases displaying PCa in the TZB only. MAB alone was positive for PCa in 4/412 (1.0 %) cases. One case (1/412; 0.2 %) had only a TZB and a MAB positive for PCa without positive PZB. Thus, 11/412 (2.7 %) of cases would not have been diagnosed with PCa at baseline TRUS-guided biopsy had only sextant PZ biopsy been performed. TZB detected a high-grade Gleason component (Gleason 4 and/or 5) not present in the PZB in 2.4 % of PCa cases.

CONCLUSIONS

There is limited value for TZB and MAB in the context of sextant PZB at baseline TRUS-guided biopsies for PCa.

Microvascularity in transition zone prostate tumors resembles normal prostatic tissue

BACKGROUND

The objective of this study was comparison of characteristics of the microvasculature in transition zone tumor (TZT) and benign nodular hyperplasia (BPH) with normal prostatic transition zone (NTZ), applying accurate and objective quantification based on digital image analysis. Results of this study may increase understanding of prostate dynamic contrast enhanced (DCE) MRI analysis.

METHODS

Radical prostatectomy specimens of 28 patients containing TZT ranging from pT2-pT4 were used. In 11 patients a concomitant peripheral zone tumor (PZT) was present. Microvessels were visualized by CD31 immunohistochemistry. Specimens were scanned using a computer-controlled microscope with automatic recognition of microvessels. Pseudocolor maps were produced displaying microvessel density, perimeter, and area of an entire prostate transection. Mean, 75th percentile (p75) and coefficient of variation (CV) were calculated automatically in manually indicated areas of the tumor and corresponding contralateral normal tissue, and BPH.

RESULTS

Large variability was seen in TZT microvascular parameters, indicating presence of patients having both hypo and hypervascularized tumors compared to NTZ. In contrast, areas of BPH showed a more consistent increase in vascular parameters, with decreased CV. Analysis of PZT confirmed results of our previous study, with mean and p75 of all vascular parameters being significantly increased and a decrease in CV. No correlation was found for clinicopathological parameters and microvascular parameters.

CONCLUSION

Microvasculature of transition zone tumor showed increased heterogeneity compared to BPH and peripheral zone tumors, possibly explaining the difficulty of TZT detection on DCE-MRI.

Prostate cancers of different zonal origin: clinicopathological characteristics and biochemical outcome after radical prostatectomy

OBJECTIVE

To evaluate the effect of prostate cancer zonal origin on the biochemical outcome after radical prostatectomy, to analyze clinicopathological features of tumors arising in different zones and to test the ability of the nomogram to predict the probability of transition zone cancer at radical prostatectomy.

METHODS

Our cohort consisted of 1441 patients who underwent radical prostatectomy who did not receive neoadjuvant treatment. Clinicopathological characteristics and biochemical outcomes were compared between the groups of men with different zonal location of prostate cancer. Performance of the nomogram in predicting cancer location was evaluated with respect to discrimination and calibration.

RESULTS

The rates of positive margin were similar in men with transition zone and mixed tumors and were significantly higher than those with peripheral zone tumors. Most of the positive margins in patients with transition zone and mixed cancers were located at the apico-anterior part of the gland. On multivariate analysis, transition zone cancer location was associated with better biochemical recurrence-free survival (P = .043). The Harrel c-index of the models that did and did not include zonal origin of cancer was 0.810 and 0.807, respectively. Performance of the nomogram was poor.

CONCLUSION

The association between transition zone tumor origin and the risk of biochemical recurrence does not add important predictive value to the standard prognostic factors. Although information about the risk of prostate cancer involvement of the transition zone may be important for surgical planning, our ability to predict this risk preoperatively is limited.

[Transrectal biopsy scheme can predict incorrect histological grading in prostate cancer]

OBJECTIVE

To identify factors that might explain why a prostate with a Gleason score (GS) <7 in the biopsy specimen can turn out to have a GS ≥7 in the surgical specimen.

MATERIAL AND METHODS

We compared the GS of biopsy specimens with the GS of surgical specimens in 185 patients who underwent surgery for prostate cancer. We calculated the sensitivity, specificity, and predictive values for the GS of the biopsy specimens. We used Cohen's kappa to determine the degree of concordance between a GS of <7 and ≥7 for the biopsy specimen and the surgical specimen. Age, a family history of prostate cancer, total prostate-specific antigen (tPSA), digital rectal examination, prostate structure and volume, and the number of biopsy cores (biopsy scheme) were analyzed using multivariable logistic regression.

RESULTS

Histological study of biopsy specimens yielded high sensitivity (98%) but low specificity (49%) for GS ≤6 and low sensitivity (35, 26%) and high specificity (93, 99%) for GS=7 and GS ≥7, respectively. Cohen's kappa for the GS from the biopsy and surgical specimens was 0.43 (95% CI=30-56%). The biopsy scheme was the only predictor of discordance in the GS between the two techniques. Among the other variables included in the model, only tPSA showed a slightly significant association. Taking a scheme with less than 7 cores as a reference, we found no difference with 8 to 9 cores but we did find a difference with 10 to 11 cores and with 12 or more cores, with a prevalence ratio of 0.138 (95% CI=0.030-0.513) and 0.277 (95% CI=0.091-0.806), respectively.

CONCLUSION

The GS of the biopsy depends on the scheme. This factor must be taken into account when choosing a treatment option in patients with low tumor grade in biopsy specimens.

Multifocal prostate cancer: biologic, prognostic, and therapeutic implications

Prostatic adenocarcinoma is the most common cancer diagnosed in men and is often multifocal. Ongoing controversy exists about the most appropriate system of tumor classification and grading and the optimal curative treatment approaches. This review examines recent progress in the pathogenesis of multifocal prostatic adenocarcinoma and its biologic, pathologic, prognostic, and therapeutic implications. Prostatic cancer multifocality makes accurate clinical staging difficult, and repeated revisions have been undertaken in an effort to optimize prognostic accuracy. Although the 2010 revision represents an improvement over the previous systems, the clinical significance of the T2 substaging is questionable. Also discussed is the potential impact of tumor multifocality and clonal heterogeneity on the oncologic efficacy of novel focal ablative approaches. The clinical significance of smaller secondary tumors and the relationship between extent of chromosomal abnormalities and the metastatic potential of an individual tumor focus were reviewed.

Is transition zone biopsy valuable in benign prostatic hyperplasia patients with serum prostate-specific antigen >10 ng/ml and prior negative peripheral zone biopsy?

OBJECTIVES

To evaluate the importance of transition zone (TZ) biopsy in benign prostatic hyperplasia (BPH) patients with serum prostate-specific antigen (PSA) >10 ng/ml and prior negative peripheral zone (PZ) biopsy and to estimate the sensitivity of TZ biopsy.

MATERIAL AND METHODS

A total of 273 BPH patients with PSA >10 ng/ml and prior negative PZ biopsy underwent an extended biopsy protocol. In patients with a TZ volume <25 cm(3), four TZ biopsies were taken (two cores per side from the apex and base). In patients with a TZ volume > or =25 cm(3) (n=183), six TZ biopsies were taken (three cores per side from the apex, middle and base). Overall, 215 patients were subjected to either transurethral resection of the prostate (n=162) or open enucleation of the adenoma (n=53).

RESULTS

The extended biopsy revealed prostate cancers in 21.2% of cases (58/273). The zonal distribution of the positive cores was as follow: PZ cancers only in 67.2% of cases (39/58), TZ cancers only in 13.8% (8/58) and PZ+TZ cancers in 19% (11/58). Overall, 73.6% (14/19) and 36.8% (7/19) of TZ cancers were detected at the apex and middle of the TZ, respectively, while no TZ cancers at all were detected at the base (p=0.00015). The incidence of carcinoma on definitive pathology was 5.6% (12/215). Consequently, TZ biopsy detected only 61.3% (19/31) of TZ cancers. The incidence of pure TZ cancers was 7.3%. On the chi(2) test, patient age, serum PSA, transrectal ultrasonography findings and PSA density did not correlate significantly with the detection rate of TZ cancer. Prostate volume (p=0.023), TZ volume (p=0.027) and PSA/TZ density (p=0.007) were predictive of TZ cancers.

CONCLUSIONS

Although TZ biopsy was the sole site of cancer in only 2.9% of cases (8/273), it improved the cancer detection rate by 14% in this selected group of patients. The majority (74%) of TZ cancers were detected at the apex site. TZ biopsy has a low sensitivity (61%).

Selenium and vitamin E: cell type- and intervention-specific tissue effects in prostate cancer

BACKGROUND

Secondary analyses of two randomized, controlled phase III trials demonstrated that selenium and vitamin E could reduce prostate cancer incidence. To characterize pharmacodynamic and gene expression effects associated with use of selenium and vitamin E, we undertook a randomized, placebo-controlled phase IIA study of prostate cancer patients before prostatectomy and created a preoperative model for prostatectomy tissue interrogation.

METHODS

Thirty-nine men with prostate cancer were randomly assigned to treatment with 200 microg of selenium, 400 IU of vitamin E, both, or placebo. Laser capture microdissection of prostatectomy biopsy specimens was used to isolate normal, stromal, and tumor cells. Gene expression in each cell type was studied with microarray analysis and validated with a real-time polymerase chain reaction (PCR) and immunohistochemistry. An analysis of variance model was fit to identify genes differentially expressed between treatments and cell types. A beta-uniform mixture model was used to analyze differential expression of genes and to assess the false discovery rate. All statistical tests were two-sided.

RESULTS

The highest numbers of differentially expressed genes by treatment were 1329 (63%) of 2109 genes in normal epithelial cells after selenium treatment, 1354 (66%) of 2051 genes in stromal cells after vitamin E treatment, and 329 (56%) of 587 genes in tumor cells after combination treatment (false discovery rate = 2%). Validation of 21 representative genes across all treatments and all cell types yielded Spearman correlation coefficients between the microarray analysis and the PCR validation ranging from 0.64 (95% confidence interval [CI] = 0.31 to 0.79) for the vitamin E group to 0.87 (95% CI = 0.53 to 0.99) for the selenium group. The increase in the mean percentage of p53-positive tumor cells in the selenium-treated group (26.3%), compared with that in the placebo-treated group (5%), showed borderline statistical significance (difference = 21.3%; 95% CI = 0.7 to 41.8; P = .051).

CONCLUSIONS

We have demonstrated the feasibility and efficiency of the preoperative model and its power as a hypothesis-generating engine. We have also identified cell type- and zone-specific tissue effects of interventions with selenium and vitamin E that may have clinical implications.

Transition zone and anterior stromal prostate cancers: zone of origin and intraprostatic patterns of spread at histopathology

BACKGROUND

To describe the precise location of transition zone (TZ) and anterior fibromuscular stroma (AFMS) prostate cancers (TZ/AFMS) within histological zones at various stages of development and to demonstrate their pattern of intraprostatic spread from their site of origin.

METHODS

Anterior TZ/AFMS cancers excluding the anterolateral part of peripheral zone, were identified from radical prostatectomy specimens. Morphometric histopathological study included largest surface area, volume and spatial distribution.

RESULTS

Out of 91 TZ/AFMS cancers, 79 were <4 cm3 and 69 <2 cm3. Fifty percent and 70% of cancers <4 cm3 were located in the anterior third and inferior half of TZ and/or AFMS, respectively. Cancers <2 cm3 could be classified into three types according to their location related to histologic zone boundaries: TZ type 1 (40%) for cancers confined to one TZ lobe; TZ type 2 (35%) for cancers most represented in one TZ lobe but crossing its anterior boundary; type AFMS (25%) for cancers confined to AFMS. These results form the rationale for the hypothesis that AFMS cancers originate from anterior and medial TZ and due to benign prostatic hypertrophy they become excluded from TZ, anteriorly into AFMS. TZ anterior limit would then act as a barrier to their posterior extension.

CONCLUSIONS

TZ/AFMS cancers contours and locations are predictable and conform to histological zones boundaries. Knowledge of these cancer origin and pattern of spread in TZ and AFMS are of importance for imaging diagnosis, guidance for biopsy and focal therapy.

Prognostic significance of Gleason score discrepancies between needle biopsy and radical prostatectomy

OBJECTIVES

Discordance between the Gleason score (GS) on needle biopsy (NB) and the GS of the radical prostatectomy (RP) specimen is a common finding. The objective of this study was to evaluate the prognostic significance of these discrepancies with respect to outcomes following RP.

METHODS

In the study, 6625 men treated by RP were categorized as having NB=RP (68.8%), NB<RP (25.0%) or NB>RP (6.2%) GS, and stratified for analyses into RP GS groups. The Kaplan-Meier method was used to analyze differences in biochemical recurrence-free survival (BRFS), and multivariate Cox analyses were performed to estimate the independent relative risk of progression associated with GS discrepancies.

RESULTS

Across multiple RP GS strata (3+4, 7, 8, 8-10), patients with a lower NB GS experienced significantly better BRFS than patients with equal NB and RP GS (all p<0.05). NB<RP GS was independently associated with better (pooled HR, 0.76, p=0.001) BRFS, within and across RP GS strata. Similarly, patients with NB>RP GS had poorer BRFS than patients with NB=RP GS across multiple RP GS strata (< or =3+3, 3+4, 7; all p<0.05). NB>RP GS was independently associated with worse (pooled HR, 1.91, p<0.001) BRFS probabilities, within and across RP GS strata.

CONCLUSIONS

Our data suggest that the GS of the NB adds additional prognostic value to the RP GS in a consistent manner that may be applicable to strategies of risk stratification and patient counseling after surgery.

Development and internal validation of preoperative transition zone prostate cancer nomogram

OBJECTIVES

Up to 20% of men may harbor a transition zone (TZ) prostate cancer (PCa) at radical prostatectomy (RP). TZ PCa may be associated with more favorable RP pathologic findings than peripheral zone (PZ) PCa. To identify these men, we developed a model capable of predicting the probability of TZ PCa at RP.

METHODS

The study cohort consisted of 945 consecutive men treated with RP, with clinical stage, prostate-specific antigen (PSA) level, and detailed biopsy and RP pathology data available. The preoperative variables were used as predictors in the multivariate logistic regression models to predict the rate of TZ PCa at RP. PCa was defined as a TZ tumor when more than 50% of the planimetrically measured tumor volume was situated within the TZ. Regression coefficients were used to develop nomograms, which were subjected to 200 bootstrap resamples to reduce overfit bias.

RESULTS

TZ PCa at the final pathologic examination was recorded in 110 patients (11.6%). After 200 bootstraps, the most parsimonious and most accurate nomogram was 77.3% accurate in predicting the probability of TZ PCa.

CONCLUSIONS

This nomogram is ideally suited to identify patients with markedly elevated, nearly metastatic serum PSA levels who harbor a TZ tumor that is highly treatable by RP.

Analysis of differences in clinicopathological features between prostate cancers located in the transition and peripheral zones

BACKGROUND

The objective of this study was to retrospectively characterize differences in the clinicopathological features of prostate cancer according to the zonal origin.

METHODS

Among 185 consecutive patients who underwent radical prostatectomy without any neoadjuvant hormonal therapies, this study included 134 patients who were diagnosed as having either transition zone (TZ) or peripheral zone (PZ) cancer according to the following criteria: TZ or PZ cancers were considered when more than 70% of the cancer area was located in the TZ or PZ, respectively. The various clinicopathological features were then compared according to this classification.

RESULTS

In this series, 27 patients were diagnosed as having TZ cancer, while the remaining 107 were diagnosed as having PZ cancer. The percent of positive biopsy cores in TZ cancers was significantly lower than that in PZ cancers; however, there were no significant differences in the anatomical location of positive cores between these two groups except for the middle of prostate where TZ cancer showed a significantly lower rate of positive biopsies than PZ cancer. The preoperative serum prostate-specific antigen (PSA) value in patients with TZ cancer was significantly higher than that in those with PZ cancer. Furthermore, tumor volume in TZ cancers was significantly greater than that in PZ cancers. However, there was no significant difference in biochemical recurrence-free survival between patients with TZ and PZ cancers.

CONCLUSIONS

Despite the significantly high PSA value as well as great tumor volume compared with those of PZ cancers, TZ cancers had similar biochemical cure rates following radical prostatectomy, suggesting a less aggressive phenotype of TZ cancers than that of PZ cancers.

Newer Modalities of Ultrasound Imaging and Treatment of the Prostate

Gray-scale ultrasound is widely used for assessing BPH and for obtaining prostate biopsies. However, it has limited value for evaluating cancer in the prostate. To improve ultrasound as an imaging modality of the prostate, many new technologies, such as color and power Doppler, 3-dimensional ultrasound of the prostate, and contrast-enhanced ultrasound have been developed. In addition, treatment modalities using ultrasound for the treatment of BPH have been developed. This review presents the recent developments in ultrasound of the prostate.

Cancer de la prostate : les aspects cliniques, biologiques et histopathologiques utiles au radiologue

Medical imaging has an important role in the diagnosis and treatment options of prostate cancer (TRUS guided biopsies, MRI). The knowledge of the different types of cancers, their preferred topography, imaging features, extension pattern, and also the important items that may help the surgical procedure (or any other treatment) are as many crucial key points for optimal management of patients.

A comparison of the biological features between prostate cancers arising in the transition and peripheral zones

OBJECTIVES

To investigate differences in the biological features of prostate cancer according to the zonal origin.

PATIENTS AND METHODS

Among 172 consecutive patients who had a radical prostatectomy (RP), the study included 124 diagnosed as having either transition zone (TZ) or peripheral zone (PZ) cancer, defined according to whether there was > 70% of the cancer area in the TZ or PZ, respectively. The clinicopathological features were then compared between these groups. In addition, the RP specimens were stained immunohistochemically with antibodies to Ki-67, Bcl-2, matrix metalloproteinase-2 (MMP-2), MMP-9 and vascular endothelial growth factor (VEGF).

RESULTS

Twenty-four patients were diagnosed as having TZ cancer and the remaining 100 as having PZ cancer. Prostate specific antigen (PSA) values in patients with TZ cancer were significantly higher than in those with PZ cancer. Tumour volume in TZ cancer was significantly greater than that in PZ cancer, but there was no significant difference in biochemical recurrence-free survival between the groups. Immunohistochemistry showed that despite there being no differences in Bcl-2 and VEGF expression between TZ and PZ cancers, there was significantly greater expression of Ki-67, MMP-2 and MMP-9 in PZ than TZ cancers.

CONCLUSIONS

Despite there being no significant difference in biochemical recurrence-free survival after RP between patients with TZ and PZ cancers, there was less cell proliferation and biomarker levels related to invasive potential in TZ than in PZ cancers.

Transition zone cancers undermine the predictive accuracy of Partin table stage predictions

PURPOSE

The Partin tables represent the most widely used predictor of pathological stage in men with localized prostate cancer (PCa). The accuracy and performance of the tables have been tested across different populations. However, to our knowledge the potential limitations that may stem from differences between transition zone (TZ) and peripheral zone (PZ) prostate cancers has not been explored. We tested the predictive accuracy and performance of the Partin tables according to TZ vs PZ tumor predominance.

MATERIALS AND METHODS

Preoperative serum prostate specific antigen, clinical stage and biopsy Gleason sum data on 1,990 patients treated with radical retropubic prostatectomy were used to define the 2001 Partin probabilities of organ confinement and seminal vesicle invasion (SVI). Data on 1,320 patients who underwent staging pelvic lymphadenectomy and radical retropubic prostatectomy were used to define the probabilities of lymph node invasion (LNI) and organ confined disease (OC). ROC area under the curve was used to assess the predictive accuracy of the 2001 Partin tables relative to observed extracapsular extension (ECE), SVI, LNI and OC. Performance characteristics for each prediction were explored graphically with local regression, nonparametric smoothing plots. Results were compared between 222 TZ cancers and 1,768 PZ cancers.

RESULTS

The 1,990 radical retropubic prostatectomy specimens demonstrated ECE in 689 cases (34.6%) (TZ in 58 or 27.1% and PZ in 631 or 35.8%) and SVI in 224 (TZ in 13 or 6.1% and PZ in 211 or 11.9%). The 1,320 lymphadenectomy specimens demonstrated LNI in 56 cases (TZ in 2 or 0.9% and PZ in 54 or 4.6%). OC was found in 784 cases (59.4%) (TZ in 95 or 69.9% and PZ in 689 or 58.2%). Predictive accuracy was for ECE 76.4% (TZ 69.0% and PZ 77.2%), 78.0% for SVI (TZ 73.5% and PZ 78.3%), 78.6% for LNI (TZ 44.5% and PZ 79.9%) and 79.4% for OC (TZ 73.8% and PZ 80.0%).

CONCLUSIONS

The biological tumor characteristics of TZ PCa differ from those of PZ PCa. These differences appear to undermine the accuracy of pathological stage predictions.

Transition Zone Carcinoma of the Prostate Gland: Evaluation of the Incidence and Biological Behaviour

About 25% of all prostate cancers occur in the transition zone (TZ). TZ carcinoma are often well differenziateci and considered clinically unimportant. On the other site a subset of these tumours characterized by high tumour grade has a significant risk of extraprostatic spread, margin positivity and possible biochemical failure. Routine TZ biopsy does not substantially increase the prostate cancer detection rate; however, it can be useful in patients that require repeat biopsy.

We retrospectively analyzed 13 patients with TZ prostate carcinoma in order to evaluate the incidence and the biological behaviour of these types of neoplasm.

Extended and saturation needle biopsy for the diagnosis of prostate cancer

The diagnosis of prostate cancer hinges on the use of systematic ultrasound-guided transrectal needle biopsy. The choice of technique is important, especially for patients with a history of a negative biopsy. Saturation biopsy can be considered for patients at risk of cancer who are willing to accept the side effects and who understand that clinically insignificant cancers can be detected. For patients with previous negative sextant biopsies, expanding the zones sampled and increasing the number of biopsy cores can help detect significant cancers while they are still confined. However, as extended biopsy becomes more commonly performed for initial diagnosis, there likely will be less need for saturation biopsy protocols.

Update of staging and risk assessment for prostate cancer patients

PURPOSE OF REVIEW

This paper will review the current staging system for prostate adenocarcinoma patients, and will also review new information that can be combined with clinical and pathological staging in order to assess a patient's risk of success or failure of treatment.

RECENT FINDINGS

There has been significant stage migration of prostate cancer patients in the past 15 years, such that patients are currently being diagnosed younger, with lower clinical stages and serum prostate-specific antigen levels, and a lower risk of metastatic disease than previously. The incorporation of the results of extended prostate biopsy schemes, with stage, grade and serum prostate-specific antigen levels, improves the risk assessment of newly diagnosed prostate cancer patients. New imaging techniques, such as transrectal ultrasound Doppler flow and magnetic resonance spectroscopy hold promise for improving risk assessment. Molecular biomarkers may improve risk assessment in the future, although none are currently approved by the US Food and Drug Administration for this indication. Gene chip arrays may further refine risk assessment and assist with the identification of therapeutic targets.

SUMMARY

There has been significant stage migration of prostate cancer patients in the prostate-specific antigen era. Incorporating biopsy information into nomograms and risk assessment equations improves upon clinical staging and risk assessment. New imaging techniques, molecular markers and gene chip arrays hold promise for future risk assessment.