Anatomy of the prostate and distribution of early prostate cancer

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.

Updated prevalence of latent prostate cancer in Chinese population and comparison of biopsy results: An autopsy-based study

Prostate cancer detected by autopsy is named latent prostate cancer. As the repertoire of clinical prostate cancer, latent cancer may better reflect the disease burden. Unlike clinical prostate specimens, which are obtained exclusively from biopsy-positive cases, prostate specimens obtained through autopsy provide information on biopsy-negative cases, helping calculate the true sensitivity of prostate biopsy. From 2014 to 2021, we collected autopsy specimens of the prostate from body donors in China and performed transperineal and transrectal biopsies on specimens before step-sectioning and pathological measurements. We found that the crude prevalence of latent prostate cancer in middle-aged and elderly men was 35.1% (81/231), which was higher than previous estimates for Chinese populations. The overall per-patient sensitivities of transperineal and transrectal biopsies were not significantly different (33.3% vs. 32.1%, p = 0.82), but the two approaches differed in preferential sampling area along the proximal-distal axis of the prostate. Transperineal biopsy had a higher sensitivity for detecting clinically significant lesions in the distal third (34.7% vs. 16.3%, p = 0.02) and distal half (30.6% vs. 18.1%, p = 0.04), while transrectal biopsy had a higher sensitivity for lesions in the proximal half (25.0% vs. 13.9%, p = 0.046). Both transperineal and transrectal methods of biopsy missed most small lesions (<0.1 mL) and 35.3% (6/17) of large lesions (>0.5 mL). In conclusion, the prevalence of latent prostate cancer in China has increased over the past 2 decades. Systematic transperineal and transrectal methods of biopsy had comparable sensitivities but had different preferential sampling areas. Both approaches miss one-third of large lesions.

Importance of Estrogenic Signaling and Its Mediated Receptors in Prostate Cancer

Prostate cancer (PCa) treatment was first established by Huggins and Hodges in 1941, primarily described as androgen deprivation via interference of testicular androgen production. The disease remains incurable with relapse of hormone-refractory cancer after treatments. Epidemiological and clinical studies disclosed the importance of estrogens in PCa. Discovery of estrogen receptor ERβ prompted direct estrogenic actions, in conjunction with ERα, on PCa cells. Mechanistically, ERs upon ligand binding transactivate target genes at consensus genomic sites via interactions with various transcriptional co-regulators to mold estrogenic signaling. With animal models, Noble revealed estrogen dependencies of PCa, providing insight into potential uses of antiestrogens in the treatment. Subsequently, various clinical trials were conducted and molecular and functional consequences of antiestrogen treatment in PCa were delineated. Besides, estrogens can also trigger rapid non-genomic signaling responses initiated at the plasma membrane, at least partially via an orphan G-protein-coupled receptor GPR30. Activation of GPR30 significantly inhibited in vitro and in vivo PCa cell growth and the underlying mechanism was elucidated. Currently, molecular networks of estrogenic and antiestrogenic signaling via ERα, ERβ and GPR30 in PCa have not been fully deciphered. This crucial information could be beneficial to further developments of effective estrogen- and antiestrogen-based therapy for PCa patients.

Effect of material property heterogeneity on biomechanical modeling of prostate under deformation

Biomechanical model based deformable image registration has been widely used to account for prostate deformation in various medical imaging procedures. Biomechanical material properties are important components of a biomechanical model. In this study, the effect of incorporating tumor-specific material properties in the prostate biomechanical model was investigated to provide insight into the potential impact of material heterogeneity on the prostate deformation calculations. First, a simple spherical prostate and tumor model was used to analytically describe the deformations and demonstrate the fundamental effect of changes in the tumor volume and stiffness in the modeled deformation. Next, using a clinical prostate model, a parametric approach was used to describe the variations in the heterogeneous prostate model by changing tumor volume, stiffness, and location, to show the differences in the modeled deformation between heterogeneous and homogeneous prostate models. Finally, five clinical prostatectomy examples were used in separately performed homogeneous and heterogeneous biomechanical model based registrations to describe the deformations between 3D reconstructed histopathology images and ex vivo magnetic resonance imaging, and examine the potential clinical impact of modeling biomechanical heterogeneity of the prostate. The analytical formulation showed that increasing the tumor volume and stiffness could significantly increase the impact of the heterogeneous prostate model in the calculated displacement differences compared to the homogeneous model. The parametric approach using a single prostate model indicated up to 4.8 mm of displacement difference at the tumor boundary compared to a homogeneous model. Such differences in the deformation of the prostate could be potentially clinically significant given the voxel size of the ex vivo MR images (0.3  ×  0.3  ×  0.3 mm). However, no significant changes in the registration accuracy were observed using heterogeneous models for the limited number of clinical prostatectomy patients modeled and evaluated in this study.

Multiparametric magnetic resonance imaging (MRI) and subsequent MRI/ultrasonography fusion-guided biopsy increase the detection of anteriorly located prostate cancers

OBJECTIVE

To describe the detection rate of anteriorly located prostate cancer (PCa) with the addition of magnetic resonance imaging (MRI)/ultrasonography (US) fusion-guided biopsy (FGB) to the standard transrectal ultrasonography (TRUS)-guided biopsy.

PATIENTS AND METHODS

All patients, regardless of their biopsy history, who were referred for clinical suspicion of PCa (i.e elevated prostate-specific antigen (PSA) level and abnormal digital rectal examination) underwent 3T multiparametric-MRI (mpMRI) screening; and those with suspicious lesions in the anterior region of the prostate were identified. Patients then received a FGB of all suspicious lesions in addition to a systematic 12-core extended sextant TRUS-guided biopsy. We conducted a lesion-based analysis comparing cancer detection rates of anterior targets using FGB vs systematic cores taken from the same anatomic sextant within the prostate. Lengths of cancer in the most involved core were also compared between the two biopsy techniques used. Patients with only anterior targets were analysed separately.

RESULTS

Of 499 patients undergoing FGB, 162 had a total of 241 anterior lesions. The mean age, PSA level and prostate volume in this group were 62 years, 12.7 ng/dL, and 57 mL, respectively. In total, PCa was diagnosed in 121 anterior lesions (50.2%) identified on mpMRI. Sixty-two (25.7%) of these anterior lesions were documented as positive for cancer on systematic 12-core TRUS-guided biopsy cores, while 97 (40.2%) were positive on the targeted FGB cores (P = 0.001). In lesions that were positive on both FGB and TRUS biopsy, the most involved core was 112% longer on FGB (3.7 vs 1.6 mm, P ≤ 0.01). Forty-two patients had only anterior lesions on mpMRI; of these, 24 (57.1%) were found to have cancer on the FGB + TRUS biopsy platform. Six patients were positive on FGB only and 13 were positive on both biopsy techniques; however, 7/13 patients were upgraded to a higher Gleason score after FGB. All five patients positive on TRUS biopsy only were candidates for active surveillance.

CONCLUSION

The results showed that FGB detects significantly more anteriorly located PCa than does TRUS-guided biopsy alone and it may serve as an effective tool for the subset of patients with such tumours.

TMPRSS2-ERG rearrangement in dominant anterior prostatic tumours: incidence and correlation with ERG immunohistochemistry

AIM

To study prostate cancer zonal differences in TMPRSS2-ERG gene rearrangement.

METHODS AND RESULTS

We examined 136 well-characterized dominant anterior prostatic tumours, including 61 transition zone (TZ) and 75 anterior peripheral zone (PZ) lesions, defined using strict anatomical considerations. TMPRSS2-ERG FISH and ERG protein immunohistochemistry were performed on tissue microarrays. FISH results, available for 56 TZ and 71 anterior PZ samples, were correlated with ERG staining and TZ-associated 'clear cell' histology. Fewer TZ cancers (four of 56; 7%) were rearranged than anterior PZ cancers (18 of 71; 25%) (P = 0.009); deletion was the sole mechanism of TZ cancer rearrangement. ERG protein overexpression was present in 4% (two of 56; both FISH+) and 30% (21 of 71; 17 FISH+) of TZ and anterior PZ tumours, respectively. 'Clear cell' histology was present in 21 of 56 (38%) TZ and eight of 71 (11%) anterior PZ tumours. Seven per cent of cancers with and 21% without this histology had rearrangement, regardless of zonal origin.

CONCLUSIONS

TMPRSS2-ERG rearrangement occurs in dominant TZ and anterior PZ prostate cancers, with all rearranged TZ cancers in this cohort showing deletion. ERG immunohistochemistry demonstrated excellent sensitivity (86%) and specificity (96%) for TMPRSS2-ERG rearrangement. TMPRSS2-ERG fusion is rare in TZ tumours and present at a low frequency in tumours displaying 'clear cell' histology.

Anatomy of the prostate revisited: implications for prostate biopsy and zonal origins of prostate cancer

Over the past 25 years, our understanding of prostatic disease has evolved secondary to the increased detection, treatment and study of both benign and neoplastic prostatic lesions. The advent of aggressive prostate-specific antigen screening and standardization of extended transrectal needle biopsy protocols has resulted in significant stage migration and earlier detection of prostate cancers, a growing proportion of which are lower-volume posterior peripheral zone tumours. Consequently, an increased incidence of anterior-predominant prostate cancers has been observed. Given the histomorphological complexity of the prostate, these developments have necessitated a reconsideration of prostatic anatomy, biopsy strategies in the detection of anterior tumours and the determination and relevance of zonal origin in prostate cancer. This review will provide a contemporary update of these topics, while highlighting specific areas in which a keen understanding of prostatic histoanatomy may influence biopsy interpretation.

The TMPRSS2:ERG rearrangement, ERG expression, and prostate cancer outcomes: a cohort study and meta-analysis

BACKGROUND

Whether the genomic rearrangement transmembrane protease, serine 2 (TMPRSS2):v-ets erythroblastosis virus E26 oncogene homolog (ERG) has prognostic value in prostate cancer is unclear.

METHODS

Among men with prostate cancer in the prospective Physicians' Health and Health Professionals Follow-Up Studies, we identified rearrangement status by immunohistochemical assessment of ERG protein expression. We used Cox models to examine associations of ERG overexpression with biochemical recurrence and lethal disease (distant metastases or cancer-specific mortality). In a meta-analysis including 47 additional studies, we used random-effects models to estimate associations between rearrangement status and outcomes.

RESULTS

The cohort consisted of 1,180 men treated with radical prostatectomy between 1983 and 2005. During a median follow-up of 12.6 years, 266 men experienced recurrence and 85 men developed lethal disease. We found no significant association between ERG overexpression and biochemical recurrence [hazard ratio (HR), 0.99; 95% confidence interval (CI), 0.78-1.26] or lethal disease (HR, 0.93; 95% CI, 0.61-1.43). The meta-analysis of prostatectomy series included 5,074 men followed for biochemical recurrence (1,623 events), and 2,049 men followed for lethal disease (131 events). TMPRSS2:ERG was associated with stage at diagnosis [risk ratio (RR)(≥T3 vs. T2), 1.23; 95% CI, 1.16-1.30) but not with biochemical recurrence (RR, 1.00; 95% CI, 0.86-1.17) or lethal disease (RR, 0.99; 95% CI, 0.47-2.09).

CONCLUSIONS

These results suggest that TMPRSS2:ERG, or ERG overexpression, is associated with tumor stage but does not strongly predict recurrence or mortality among men treated with radical prostatectomy.

IMPACT

This is the largest prospective cohort study to examine associations of ERG overexpression and lethal prostate cancer among men treated with radical prostatectomy.

International Society of Urological Pathology (ISUP) Consensus Conference on Handling and Staging of Radical Prostatectomy Specimens. Working group 2: T2 substaging and prostate cancer volume

The 2009 International Society of Urological Pathology consensus conference in Boston made recommendations regarding the standardization of pathology reporting of radical prostatectomy specimens. Issues relating to the substaging of pT2 prostate cancers according to the TNM 2002/2010 system, reporting of tumor size/volume and zonal location of prostate cancers were coordinated by working group 2. A survey circulated before the consensus conference demonstrated that 74% of the 157 participants considered pT2 substaging of prostate cancer to be of clinical and/or academic relevance. The survey also revealed a considerable variation in the frequency of reporting of pT2b substage prostate cancer, which was likely a consequence of the variable methodologies used to distinguish pT2a from pT2b tumors. Overview of the literature indicates that current pT2 substaging criteria lack clinical relevance and the majority (65.5%) of conference attendees wished to discontinue pT2 substaging. Therefore, the consensus was that reporting of pT2 substages should, at present, be optional. Several studies have shown that prostate cancer volume is significantly correlated with other clinicopathological features, including Gleason score and extraprostatic extension of tumor; however, most studies fail to demonstrate this to have prognostic significance on multivariate analysis. Consensus was reached with regard to the reporting of some quantitative measure of the volume of tumor in a prostatectomy specimen, without prescribing a specific methodology. Incorporation of the zonal and/or anterior location of the dominant/index tumor in the pathology report was accepted by most participants, but a formal definition of the identifying features of the dominant/index tumor remained undecided.

Human prostate fibroblasts induce growth and confer castration resistance and metastatic potential in LNCaP Cells

BACKGROUND

The tumor microenvironment is important for progressive and metastatic disease.

OBJECTIVE

To study the hypothesis that prostate fibroblasts have differential ability to induce castration-resistant prostate cancer (PCa) and metastatic progression and whether this effect might vary depending on the zonal origin of the fibroblast.

DESIGN, SETTING, AND PARTICIPANTS

Human prostate fibroblasts from the peripheral (PZ), transition (TZ) and central (CZ) zones of radical prostatectomy specimens (n=13) were isolated and compared for their ability to promote androgen independence and metastatic progression in androgen-responsive PCa lymph node carcinoma of the prostate (LNCaP) cells in vivo.

INTERVENTIONS

By coinoculating marginally tumorigenic LNCaP cells with PZ or TZ and by altering host hormonal milieu, a series of tumorigenic and metastatic LNCaP epithelial sublines-P4, P4-2 (derivatives from interaction with PZ), T4, and T4-2 (derivatives from interaction with TZ)-were established and characterized.

MEASUREMENTS

In vivo and in vitro evaluation of induction of tumor growth and metastatic potential.

RESULTS AND LIMITATIONS

1) LNCaP sublines were permanently altered in their cytogenetic and biologic profiles after cellular interaction with prostate stromal fibroblasts. LNCaP sublines grew faster under anchorage-dependent and -independent conditions, expressed 1-12-fold more prostate-specific antigen in vitro than LNCaP cells, and gained metastatic potential; 2) zonal differences of stromal fibroblasts in their ability to induce the growth and progression of LNCaP tumors as xenografts in mice may exist but need further analysis; 3) PZ-conditioned medium induced more anchorage-independent growth of LNCaP cells in vitro. TZ had a higher growth rate and were more sensitive to dihydrotestosterone.

CONCLUSIONS

We demonstrate that prostate fibroblasts have growth inductive potential on PCa cells and affect their subsequent progression to castration resistance and development of a metastatic phenotype.

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.

Do prostatic transition zone tumors have a distinct morphology?

Previous studies have proposed that the morphologic spectrum of prostatic glands of variable size with tall columnar cells displaying basally oriented nuclei and clear to pale pink cytoplasm (TZ-LOOK) is characteristic of the well to moderately differentiated component of transition zone (TZ) tumors. However, the specificity of these findings has not been well studied. In a recent report, we identified dominant peripheral zone (PZ) and TZ tumors situated anterior to the prostatic urethra. Currently, we evaluate the histopathologic features of 215 dominant tumors, including 63 TZ and 73 anterior PZ lesions and an additional cohort of 79 posterior PZ tumors, in radical prostatectomy specimens, to identify the prevalence of this morphology in tumors of different zonal origin. Each dominant tumor was assigned a TZ-LOOK extent score of 0 to 4, with 0 = no such morphology, 1 = 1% to 25%, 2 = 26% to 50%, 3 = 51% to 75%, and 4 = >75%. Overall, 121/215 (56%) tumors showed some degree of this histology, including 56 of 63 (89%) TZ tumors and 65 of 152 (43%) PZ tumors (P<0.0001). Thirty-seven of 215 (17%) lesions had scores of 3 to 4, with 31 (84%) of these being of TZ origin. However, only 31/63 (49%) TZ tumors had >50% TZ-LOOK. Among PZ tumors, 6/152 (4%) had predominant (>50%) TZ-LOOK morphology, yet 23/152 (15%) of all PZ tumors and 23/65 (35%) of PZ tumors displaying any degree of TZ-LOOK had scores of 2 to 3 (>25%; nonfocal). In tumors of both zones with predominant (scores 3 to 4; >50%) TZ-LOOK histology, darker glands of usual acinar adenocarcinoma was often seen at the periphery. Conversely, in tumors with nonpredominant TZ-LOOK (scores 1 to 2; 50% of this histology are very likely of TZ origin, but this scenario occurs in only half of TZ tumors. Importantly, the TZ-LOOK is nonfocal in up to 35% of PZ tumors exhibiting any degree of this morphology. Given this lack of specificity, caution should be exercised in assigning zone of origin based on this histologic appearance, especially in limited samples such as prostate needle biopsy.

Anatomy of the anterior prostate and extraprostatic space: a contemporary surgical pathology analysis

Over 25 years ago, McNeal described a model of prostatic zonal anatomy based on autopsy dissections in various planes. As opposed to the cone-shaped organ seen in vivo, radical prostatectomy specimens are typically spherical, owing to tissue contraction at surgical removal and subsequent processing. Sectioning from apex to base yields topography at the Surgical Pathology "sign-out" that may vary from McNeal's descriptions. There are no in depth studies of anterior prostatic anatomic variability, including the periurethral region, peripheral (PZ) and transition (TZ) zones, anterior fibromuscular stroma (AFMS), and anterior extraprostatic space (EPS) using modern prosecting techniques. Detailed analysis of 197 entirely submitted, whole-mounted radical prostatectomy specimens focused on differences in zonal anatomy from apex through base, the relationship of AFMS to PZ and TZ, and the nature of the anterior EPS revealed features that may have significant impact on determination of zonal origin and pathologic staging of anteriorly situated prostate cancer. Among these observations are the predominant nature of the anterior PZ at the apex and the potential for its broad contact with the AFMS at this location, the differing volumes and location of the TZ in prostates with and without benign prostatic hyperplasia, and the composition of the anterior EPS, including adipose tissue, blood vessels, and skeletal muscle at the apex varying to include medium to large smooth muscle bundles at the base.

Complex patterns of ETS gene alteration arise during cancer development in the human prostate

An ERG gene 'break-apart' fluorescence in situ hybridization (FISH) assay has been used to screen whole-mount prostatectomy specimens for rearrangements at the ERG locus. In cancers containing ERG alterations the observed pattern of changes was often complex. Different categories of ERG gene alteration were found either together in a single cancerous region or within separate foci of cancer in the same prostate slice. In some cases the juxtaposition of particular patterns of ERG alterations suggested possible mechanisms of tumour progression. Prostates harbouring ERG alterations commonly also contained cancer that lacked rearrangements of the ERG gene. A single trans-urethral resection of the prostate specimen examined harboured both ERG and ETV1 gene rearrangements demonstrating that the observed complexity may, at least in part, be explained by multiple ETS gene alterations arising independently in a single prostate. In a search for possible precursor lesions clonal ERG rearrangements were found both in high grade prostatic intraepithelial neoplasia (PIN) and in atypical in situ epithelial lesions consistent with the diagnosis of low grade PIN. Our observations support the view that ERG gene alterations represent an initiating event that promotes clonal expansion initially to form regions of epithelial atypia. The complex patterns of ERG alteration found in prostatectomy specimens have important implications for the design of experiments investigating the clinical significance and mechanism of development of individual prostate cancers.

An abnormal digital rectal examination is an independent predictor of Gleason > or =7 prostate cancer in men undergoing initial prostate biopsy: a prospective study of 790 men

OBJECTIVE

To evaluate our experience with a referral population of 790 patients undergoing initial prostate biopsy in the prostate-specific antigen (PSA) era, to assess the role of a digital rectal examination (DRE) in predicting the outcome of prostate needle biopsy (PNB) and to evaluate if DRE findings were associated with cancer grade.

PATIENTS AND METHODS

We analysed 790 consecutive men who had an initial PNB from September 1999 to July 2005 by one urologist (C.P.). All data were collected in a prospective database. Multivariate logistic regression analysis was used to determine the relationship between an abnormal DRE and the presence of cancer and cancer grade on PNB.

RESULTS

An abnormal DRE was an independent predictor for prostate cancer on multivariate analysis (odds ratio 2.18, 95% confidence interval 1.53-3.10, P < 0.001). In all patients biopsied, an abnormal DRE was associated with a Gleason sum of > or = 7 on multivariate analysis (odds ratio 3.39, 2.07-5.53, P = 0.001).

CONCLUSION

A DRE is a useful and important tool to use when assessing patients for a PNB. An abnormal DRE independently predicted high-grade disease in these men. These results might have important implications in the prediction of men with other than indolent prostate cancer.

Bladder neck involvement in pathological stage pT4 radical prostatectomy specimens is not an independent prognostic factor

PURPOSE

Bladder neck invasion by prostate cancer in radical prostatectomy specimens is uncommon and, thus, its influence on disease recurrence has not been well defined. Consequently the classification of bladder neck invasion in the TNM staging system is controversial. We studied our cohort of patients with stage pT4 disease and bladder neck invasion to clarify the true clinical behavior and prognostic significance of bladder neck invasion in radical prostatectomy specimens.

MATERIALS AND METHODS

The study group consisted of 4,090 consecutive patients treated with radical prostatectomy at one of our institutions between 1983 and 2001. Median followup was 53.1 months (range 1 to 189). After excluding from analysis patients treated with neoadjuvant androgen withdrawal or preoperative irradiation 72 of the remaining 2,571 (2.8%) with bladder neck invasion were classified with stage pT4 disease and their specimens were reviewed. Progression-free probability was determined by Kaplan-Meier analysis. Using the Cox proportional hazards model the independent prognostic significance of bladder neck invasion was assessed after controlling for pretreatment prostate specific antigen, final Gleason sum, extracapsular extension, surgical margins status, seminal vesicle invasion and lymph node involvement.

RESULTS

Of the 72 patients categorized with stage pT4 disease 14 (19%) had poorly differentiated Gleason sum 8 to 10 cancer, 38 (53%) had established extracapsular extension, 24 (33%) had seminal vesicle invasion and 8 (11%) had lymph node involvement. However, 26 patients (36%) had cancer confined to the prostate and 28 (39%) had negative surgical margins except for the bladder neck site. The mean 5-year progression-free probability plus or minus SD in all stage pT4 cases was 68% +/- 7%, which was better than in cases of seminal vesicle invasion (52% +/- 5%, log rank test p = 0.0156) but worse than in those of extracapsular extension (84% +/- 4.1%). Univariate analysis of the stage pT4 cohort revealed that higher prostatectomy Gleason sum, more extensive extracapsular extension and seminal vesicle invasion were significantly associated with an adverse prognosis. However, in a multivariate model that included all radical prostatectomy cases the finding of bladder neck invasion or stage pT4 disease did not independently predict prostate specific antigen recurrence.

CONCLUSIONS

Stage pT4 disease comprises a heterogeneous group of tumors with various pathological features and inconsistent outcomes. Assigning the pT4 stage to cases of microscopic bladder neck invasion provides no independent ability for predicting disease progression after adjusting for other adverse disease features. Due to this and previously reported data the definition of stage pT4 disease should be modified in the next version of the TNM staging system.

Lymphatic drainage of prostatic transition and peripheral zones visualized on a three-dimensional workstation

OBJECTIVES

To determine whether the prostate has lymphatic/lymph node drainage that is not sampled by conventional lymphadenectomy and whether the transition and peripheral zones of the prostate have a different lymphatic drainage, because up to one quarter of lymph-node-negative patients who undergo radical prostatectomy will develop distant metastases.

METHODS

Ten patients (mean age 62.3 years, range 50 to 76) scheduled for transrectal ultrasound-guided sextant biopsy because of an elevated serum prostate-specific antigen level of 4 to 10 ng/mL and a normal digital rectal examination were included in this study. All patients underwent ultrasound-guided sextant biopsies. Subsequently, an oily contrast medium was injected into the transition zone (group A, n = 5) or peripheral zone (group B, n = 5) of the prostate under transrectal ultrasound guidance and fluoroscopy. Immediately, 1 hour, and 24 hours after the procedure, anteroposterior and lateral radiographs were obtained. In addition, spiral computed tomography of the abdomen was performed 10 minutes after the procedure and analyzed on a three-dimensional workstation.

RESULTS

No difference in the lymphatic drainage system between the transition and peripheral zones of the prostate was found. In all patients (n = 10), the lymphatic drainage comprised three major routes: (1) the prostate to the lymph nodes along the lateral bony wall of the pelvis to the angle of internal/external iliac lymph nodes to the common iliac lymph nodes, (2) the prostate to the perineal floor to the pudenda internal lymph nodes to the angle of the internal/external iliac lymph nodes to the common iliac lymph nodes, and (3) the prostate to the sacral lymph nodes. In all 10 patients, main contrast medium enhancement was seen immediately after procedure indicating drainage from the prostate to the lymph nodes along the lateral bony wall of the pelvis. Presacral lymph node enhancement was seen in all patients only in the late (24 hours after contrast injection) radiograph.

CONCLUSIONS

Our data suggest that the main lymphatic drainage, irrespective of the prostatic region (transition or peripheral zone), runs to the pelvic regions that are mostly removed by standard lymphadenectomy techniques. However, one has to bear in mind that the prostate has some lymphatic drainage that is not covered by standard lymphadenectomy and therefore carries the risk of metastatic tumor spread.

Detailed mapping of prostate carcinoma foci: biopsy strategy implications

BACKGROUND

Prostate carcinoma exhibits considerable anatomic heterogeneity. Detailed characterization of prostate carcinoma distribution could lead to improved detection procedures and biopsy strategies. We mapped all 607 tumor foci from 180 serially sectioned whole mount radical prostatectomy specimens and used a computer algorithm to plot and summarize the distribution of these foci. We investigated whether specimen and clinical variables predicted differences in tumor distribution.

METHODS

The volume and anatomic location of each tumor focus were determined and digitized. A computer-based algorithm was used to fit the digitized tumor foci to a paradigm prostate. Pseudo-color summary plots of tumor distribution then were computed for selected cases.

RESULTS

Of the 180 specimens, 149 (83%) specimens had more than one cancer focus. Most foci (448 of 607 tumor foci, 74%) were in the peripheral zone (PZ). PZ foci near the apex had a significant midline component. Toward the base, PZ foci diverged laterally. Only 3 (2%) of 180 specimens contained foci solely in the transition zone (TZ). Total TZ cancer volume was </= 0.5 cm(3) in 55% (52 of 94) of patients. Computer plots of patients with T1c classification (UICC/AJCC) and specimen Gleason score </= 6 had greater proportions of TZ tumor.

CONCLUSIONS

Almost all TZ foci occurred with PZ foci. The small volume of most TZ foci may explain the ineffectiveness of TZ biopsies to detect additional cancers during screening. Further, our results suggested that biopsies may be more effective if laterally directed biopsy samples are obtained nearer to the base of the prostate and if apical biopsy samples are obtained more medially.

DNA ploidy and survival of patients with clinically localized prostate cancer treated without intent to cure

BACKGROUND

The optimal approach to diagnosis and treatment of localized prostate cancer remains controversial. Deoxyribonucleic acid (DNA) ploidy has been suggested as an important predictor for outcome in prostate cancer. The purpose of this study was to correlate DNA ploidy with disease-specific survival in patients with clinically localized prostate cancer treated with no intent to cure.

METHODS

DNA ploidy was determined by flow cytometry in archival formalin fixed, paraffin embedded tumor tissue obtained at diagnosis in 120 patients with clinically localized prostate cancer with a nearly complete follow-up.

RESULTS

Ninety (75%) of the tumors were diploid, while only 11 (9%) tumors were categorized as tetraploid. Tumor DNA ploidy (diploid versus nondiploid) significantly associated with histopathological grade (P=0.002) and disease-specific survival (P=0.011), while there was no association with tumor stage (P=0.054). In a multivariate Cox analysis, histopathological grade (P=0.005) was the only significant predictor of disease-specific death, while analyzing the 96 low-grade tumors separately, DNA ploidy became significant (P= 0.024).

CONCLUSIONS

Flow cytometric determined nondiploidy was associated with disease-specific death in patients with clinically localized prostate cancer, but DNA ploidy provided additional prognostic information in patients with low-grade tumors only.