Clinical and pathobiological effects of neoadjuvant total androgen ablation therapy on clinically localized prostatic adenocarcinoma

Mathematical Model of Clonal Evolution Proposes a Personalised Multi-Modal Therapy for High-Risk Neuroblastoma

Neuroblastoma is the most common extra-cranial solid tumour in children. Despite multi-modal therapy, over half of the high-risk patients will succumb. One contributing factor is the one-size-fits-all nature of multi-modal therapy. For example, during the first step (induction chemotherapy), the standard regimen (rapid COJEC) administers fixed doses of chemotherapeutic agents in eight two-week cycles. Perhaps because of differences in resistance, this standard regimen results in highly heterogeneous outcomes in different tumours. In this study, we formulated a mathematical model comprising ordinary differential equations. The equations describe the clonal evolution within a neuroblastoma tumour being treated with vincristine and cyclophosphamide, which are used in the rapid COJEC regimen, including genetically conferred and phenotypic drug resistance. The equations also describe the agents’ pharmacokinetics. We devised an optimisation algorithm to find the best chemotherapy schedules for tumours with different pre-treatment clonal compositions. The optimised chemotherapy schedules exploit the cytotoxic difference between the two drugs and intra-tumoural clonal competition to shrink the tumours as much as possible during induction chemotherapy and before surgical removal. They indicate that induction chemotherapy can be improved by finding and using personalised schedules. More broadly, we propose that the overall multi-modal therapy can be enhanced by employing targeted therapies against the mutations and oncogenic pathways enriched and activated by the chemotherapeutic agents. To translate the proposed personalised multi-modal therapy into clinical use, patient-specific model calibration and treatment optimisation are necessary. This entails a decision support system informed by emerging medical technologies such as multi-region sequencing and liquid biopsies. The results and tools presented in this paper could be the foundation of this decision support system.

Reprint of: morphologic spectrum of treatment-related changes in prostate tissue and prostate cancer: an updated review

A wide range of treatment options are available to patients with prostate cancer. Some treatments are standard (currently used) while some are emerging therapies. Androgen deprivation therapy is typically reserved for localized or metastatic prostate cancer not amenable to surgery. Radiation therapy may be offered to individuals for local therapy with curative intent in low- or intermediate-risk disease that may have a high probability of progression on active surveillance or where surgery is not suitable. Focal therapy/ablation treatment is an alternative approach for those who prefer to avoid radical prostatectomy for localized disease of low- or intermediate-risk or as salvage therapy after failed radiation therapy. Chemotherapy and immunotherapy remain under investigation and are currently used for androgen-independent disease or hormone-refractory prostate cancer; however, a better understanding of therapeutic efficacy is needed. Histopathologic changes observed in benign and malignant prostate tissue induced by hormonal therapies and radiation therapy are well described, whereas treatment-related effects secondary to novel therapies continue to be documented although their clinical significance is not absolutely clear. An informed and accurate evaluation of post-treatment prostate specimens requires pathologists with diagnostic acumen and knowledge relating to the histopathologic spectrum associated with each treatment option. In situations when clinical history is lacking, but morphologic features are suggestive of prior treatment, pathologists are encouraged to consult clinical colleagues regarding prior treatment history including details of when treatment was initiated and duration of therapy. This review aims to provide a concise update of current and emerging therapies for prostate cancer, histologic alterations and recommendations on Gleason grading.

Neoadjuvant Hormonal Therapy for Prostate Cancer: Morphologic Features and Predictive Parameters of Therapy Response

The primary goals of neoadjuvant hormonal therapy (NHT) in prostate cancer (PCa) are to reduce the size of the tumor, lower positive surgical margin rate, attempt to reach pathologic remission, and improve survival. Although NHT has not been recommended by the National Comprehensive Cancer Network as a primary treatment option for patients with localized PCa, NHT is increasingly used in clinical trials for locally advanced PCa. More importantly, with the development of novel androgen signaling inhibitors, such as abiraterone and enzalutamide, there has been renewed interests in revisiting the role of such treatment in the neoadjuvant setting. Following NHT, the PCa tissues shows characteristic morphologic alterations. Of note, the collapse of malignant glands most likely leads to an artificial increase of Gleason score in the residual disease. Communicating these changes to the clinician in a way that can help assess the tumor's response poses a challenge for pathologists. In addition, little is known of morphologic features and predictive makers both in pretreated and posttreated specimens that can be of value in predicting tumor response to NHT. In the current review, we summarize the morphologic changes associated with neoadjuvant-treated PCa, focusing on the predictive value of pathologic parameters to therapy response. We also describe the evaluation system in the stratification of pathologic response to NHT in PCa management.

Morphologic spectrum of treatment-related changes in prostate tissue and prostate cancer: An Updated Review

A wide range of treatment options is available to patients with prostate cancer. Some treatments are standard (currently used) while some are emerging therapies. Androgen deprivation therapy is typically reserved for localized or metastatic prostate cancer not amenable to surgery. Radiation therapy may be offered to individuals for local therapy with curative intent in low- or intermediate-risk disease that may have a high probability of progression on active surveillance or where surgery is not suitable. Focal therapy/ablation treatment is an alternative approach for those who prefer to avoid radical prostatectomy for localized disease of low- or intermediate-risk or as salvage therapy following failed radiation therapy. Chemotherapy and immunotherapy remain under investigation and are currently used for androgen-independent disease or hormone-refractory prostate cancer; however a better understand therapeutic efficacy is needed. Histopathologic changes observed in benign and malignant prostate tissue induced by hormonal therapies and radiation therapy is well described, while treatment-related effects secondary to novel therapies continue to be documented although their clinical significance is not absolutely clear. An informed and accurate evaluation of post-treatment prostate specimens requires pathologists with diagnostic acumen and knowledge relating to the histopathologic spectrum associated with each treatment option. In situations when clinical history is lacking, but morphologic features are suggestive of prior treatment, pathologists are encouraged to consult clinical colleagues regarding prior treatment history including details of when treatment was initiated and duration of therapy. This review aims to provide a concise update of current and emerging therapies for prostate cancer, histologic alterations and recommendations on Gleason grading.

Integrating evolutionary dynamics into cancer therapy

Many effective drugs for metastatic and/or advanced-stage cancers have been developed over the past decade, although the evolution of resistance remains the major barrier to disease control or cure. In large, diverse populations such as the cells that compose metastatic cancers, the emergence of cells that are resistant or that can quickly develop resistance is virtually inevitable and most likely cannot be prevented. However, clinically significant resistance occurs only when the pre-existing resistant phenotypes are able to proliferate extensively, a process governed by eco-evolutionary dynamics. Attempts to disrupt the molecular mechanisms of resistance have generally been unsuccessful in clinical practice. In this Review, we focus on the Darwinian processes driving the eco-evolutionary dynamics of treatment-resistant cancer populations. We describe a variety of evolutionarily informed strategies designed to increase the probability of disease control or cure by anticipating and steering the evolutionary dynamics of acquired resistance.

First Strike-Second Strike Strategies in Metastatic Cancer: Lessons from the Evolutionary Dynamics of Extinction

While clinical cancer research has produced many highly effective drugs, the diversity and evolutionary capacity of most cancer populations remain insurmountable barriers to cure. Here, we propose that curative outcomes may, nevertheless, be achieved by sequencing therapies that are individually effective but noncurative. Basic principles for such an approach are derived from the eco-evolutionary dynamics of background extinctions in which a "first strike" reduces the size and heterogeneity of the population. When followed immediately by demographic and ecological "second strikes," the population can be reduced below some minimum threshold, leading inevitably to extinction. This strategy bears strong similarity to the empirically-derived curative therapy in childhood acute lymphocytic leukemia.

Histopathology of Prostate Cancer

This review focuses on histopathological aspects of carcinoma of the prostate. A tissue diagnosis of adenocarcinoma is often essential for establishing a diagnosis of prostate cancer, and the foundation for a tissue diagnosis is currently light microscopic examination of hematoxylin and eosin (H&E)-stained tissue sections. Markers detected by immunohistochemistry on tissue sections can support a diagnosis of adenocarcinoma that is primary in the prostate gland or metastatic. Histological variants of carcinoma of the prostate are important for diagnostic recognition of cancer or as clinicopathologic entities that have prognostic and/or therapeutic significance. Histological grading of adenocarcinoma of the prostate, including use of the 2014 International Society of Urological Pathology (ISUP) modified Gleason grades and the new grade groups, is one of the most powerful prognostic indicators for clinically localized prostate cancer, and is one of the most critical factors in determination of management of these patients.

Detecting metastatic prostate carcinoma in pelvic lymph nodes following neoadjuvant hormone therapy: the eyes have it!

AIMS

Residual cancer morphology in radical prostatectomies (RPs) after neoadjuvant hormone therapy includes inconspicuous cytology, and treated tumour cells can be difficult to identify in lymph nodes. The aim of this study was to evaluate the role of immunohistochemistry (IHC) in identifying occult lymph node metastases following neoadjuvant hormone treatment of prostate cancer.

METHODS AND RESULTS

One hundred and twenty-eight lymph nodes from 24 patients treated with neoadjuvant hormone therapy, including abiraterone acetate alone or combined with leuprolide, were stained with antibodies against keratin AE1/AE3, prostate-specific antigen (PSA), prostate-specific acid phosphatase (PrAP), androgen receptor (AR), and NKX3.1. IHC slides were scored 'blind', and then retrospectively compared with haematoxylin and eosin (H&E)-stained slides and pathology reports. IHC identified carcinoma in six lymph nodes from three patients. All metastases were positive for NKX3.1 and AR, five of six were positive for AE1/AE3, and three of six were positive for PSA; PrAP was negative in all metastatic foci. All six lymph node metastases had been identified by H&E staining at the time of RP.

CONCLUSIONS

These findings suggest that routine use of IHC on lymph nodes from neoadjuvant-treated prostate carcinomas is not necessary. Nevertheless, for suspicious small foci of atypical cells in neoadjuvant-treated lymph nodes, NKX3.1 and AR appear to have the greatest sensitivity.

Prostate changes related to therapy: with special reference to hormone therapy

Hormone and radiation therapy have traditionally been used in prostate cancer (PCa). Morphological effects are often identified in needle biopsies and surgical specimens. A range of histological changes are seen in the non-neoplastic prostate and in the pre-neoplastic and neoplastic areas. Other ablative therapies, including cryotherapy, and emerging focal therapies, such as high-intensity focused ultrasound, photodynamic therapy and interstitial laser thermotherapy, may induce changes on the prostate. As new compounds are developed for prostate cancer treatment, it is important to document their effects on benign and neoplastic prostate tissue.

The effect of VEGF-targeted therapy on biomarker expression in sequential tissue from patients with metastatic clear cell renal cancer

PURPOSE

To investigate how biologically relevant markers change in response to antiangiogenic therapy in metastatic clear cell renal cancer (mRCC) and correlate these changes with outcome.

EXPERIMENTAL DESIGN

The study used sequential tumor tissue and functional imaging (taken at baseline and 12-16 weeks) obtained from three similar phase II studies. All three studies investigated the role of VEGF tyrosine kinase inhibitors (TKI) before planned nephrectomy in untreated mRCC (n = 85). The effect of targeted therapy on ten biomarkers was measured from sequential tissue. Comparative genomic hybridization (CGH) array and DNA methylation profiling (MethylCap-seq) was performed in matched frozen pairs. Biomarker expression was correlated with early progression (progression as best response) and delayed progression (between 12-16 weeks).

RESULTS

VEGF TKI treatment caused a significant reduction in vessel density (CD31), phospho-S6K expression, PDL-1 expression, and FOXP3 expression (P < 0.05 for each). It also caused a significant increase in cytoplasmic FGF-2, MET receptor expression in vessels, Fuhrman tumor grade, and Ki-67 (P < 0.05 for each). Higher levels of Ki-67 and CD31 were associated with delayed progression (P < 0.05). Multiple samples (n = 5) from the same tumor showed marked heterogeneity of tumor grade, which increased significantly with treatment. Array CGH showed extensive intrapatient variability, which did not occur in DNA methylation analysis.

CONCLUSION

TKI treatment is associated with dynamic changes in relevant biomarkers, despite significant heterogeneity in chromosomal and protein, but not epigenetic expression. Changes to Ki-67 expression and tumor grade indicate that treatment is associated with an increase in the aggressive phenotype of the tumor.

Patient-derived tissue slice grafts accurately depict response of high-risk primary prostate cancer to androgen deprivation therapy

Background

Effective eradication of high-risk primary prostate cancer (HRPCa) could significantly decrease mortality from prostate cancer. However, the discovery of curative therapies for HRPCa is hampered by the lack of authentic preclinical models.

Methods

We improved upon tumorgraft models that have been shown to predict drug response in other cancer types by implanting thin, precision-cut slices of HRPCa under the renal capsule of immunodeficient mice. Tissue slice grafts (TSGs) from 6 cases of HRPCa were established in mice. Following androgen deprivation by castration, TSGs were recovered and the presence and phenotype of cancer cells were evaluated.

Results

High-grade cancer in TSGs generated from HRPCa displayed characteristic Gleason patterns and biomarker expression. Response to androgen deprivation therapy (ADT) was as in humans, with some cases exhibiting complete pathologic regression and others showing resistance to castration. As in humans, ADT decreased cell proliferation and prostate-specific antigen expression in TSGs. Adverse pathological features of parent HRPCa were associated with lack of regression of cancer in corresponding TSGs after ADT. Castration-resistant cancer cells remaining in TSGs showed upregulated expression of androgen receptor target genes, as occurs in castration-resistant prostate cancer (CRPC) in humans. Finally, a rare subset of castration-resistant cancer cells in TSGs underwent epithelial-mesenchymal transition, a process also observed in CRPC in humans.

Conclusions

Our study demonstrates the feasibility of generating TSGs from multiple patients and of generating a relatively large number of TSGs from the same HRPCa specimen with similar cell composition and histology among control and experimental samples in an in vivo setting. The authentic response of TSGs to ADT, which has been extensively characterized in humans, suggests that TSGs can serve as a surrogate model for clinical trials to achieve rapid and less expensive screening of therapeutics for HRPCa and primary CRPC.

Hypoxia, notch signalling, and prostate cancer

The notch signalling pathway is involved in differentiation, proliferation, angiogenesis, vascular remodelling, and apoptosis. Deregulated expression of notch receptors, ligands, and targets is observed in many solid tumours, including prostate cancer. Hypoxia is a common feature of prostate tumours, leading to increased gene instability, reduced treatment response, and increased tumour aggressiveness. The notch signalling pathway is known to regulate vascular cell fate and is responsive to hypoxia-inducible factors. Evidence to date suggests similar, therapeutically exploitable, behaviour of notch-activated and hypoxic prostate cancer cells.

Variants and unusual patterns of prostate cancer: clinicopathologic and differential diagnostic considerations

Beyond the typical acinar morphology observed in the majority of prostatic adenocarcinomas, a spectrum of morphologic variants and prostate cancer subtypes exists. These unusual entities may be classified as: (1) cancer morphologies arising by divergent differentiation of prostatic ductal, acinar, or basal cells and associated with unique clinical features and/or therapeutic approaches, and (2) histologies occurring in the context of usual prostatic adenocarcinoma that may result in diagnostic misinterpretation or difficulties in Gleason grade assignment, especially in limited samples. This article details a number of variants, with emphasis on diagnostic criteria, differential diagnoses, and clinical significance.

Targeting ErbB3: the New RTK(id) on the Prostate Cancer Block

Most prostate cancers (PCa) are critically reliant on functional androgen receptor (AR) signaling. At its onset, PCa is androgen-dependent and although temporarily halted by surgically or pharmacologically blocking the AR (androgen ablation), the disease ultimately recurs as an aggressive, fatal castration resistant prostate cancer (CRPC). FDA-approved treatments like docetaxel, a chemotherapeutic agent, and Provenge, a cancer vaccine, extend survival by a scant 3 and 4 months, respectively. It is clear that more effective drugs targeting CRPC are urgently needed. The ErbB family (EGFR/ErbB1, ErbB2/HER2/neu, ErbB3/HER3 and ErbB4/HER4) of receptor tyrosine kinases (RTKs) have long been implicated in PCa initiation and progression, but inhibitors of ErbB1 and ErbB2 (prototypic family members) fared poorly in PCa clinical trials. Recent research suggests that another family member ErbB3 abets emergence of the castration-resistant phenotype. Considerable efforts are being directed towards understanding ErbB3-mediated molecular mechanisms of castration resistance and searching for novel ways of inhibiting ErbB3 activity via rational drug design. Antibody-based therapy that prevents ligand binding to ErbB3 appears promising and fully-humanized antibodies that inhibit ligand-induced phosphorylation of ErbB3 are currently in early development. Small molecule tyrosine kinase inhibitors are also being vigorously pursued, as are siRNA-based approaches and combination treatment strategies- the simultaneous suppression of ErbB3 and its signaling partners or downstream effectors - with the primary purpose of undermining the resiliency of ErbB3-mediated signal transduction. This review summarizes the existing literature and reinforces the importance of ErbB3 as a therapeutic target in the clinical management of prostate cancer.

PSA-detected prostate cancer and the potential for dedifferentiation--estimating the proportion capable of progression

The aims were to determine whether prostate-specific antigen (PSA)-detected prostate cancers progress to higher Gleason score during the preclinical screen-detectable phase, and, if so, to estimate the proportion of tumours with progressive potential. We developed two multi-state Markov chain models to represent the natural history of two tumour populations, one with (Model I) and the other without (Model II) the potential for progression. For each, we derived the transition rates between the states and used these estimates to calculate the expected prevalence of preclinical low and intermediate-to-high Gleason score prostate cancers, using data from the Prostate Testing for Cancer and Treatment (ProtecT) study on 2,310 prostate cancers detected by PSA testing in 71,511 men 50-69 years. We compared the expected prevalence for each tumour population to that of the observed based on ProtecT and the European Randomised Study on Screening for Prostate Cancer (ERSPC)-Rotterdam Centre's first round screening data, the latter allowing independent assessment of the two models. The overall expected proportion of low Gleason score tumours was 0.56 under Model I and 0.81 under Model II, whereas the observed proportion based on either ProtecT or ERSPC-Rotterdam was 0.69. Using the observed prevalence from ERSPC-Rotterdam, we estimated that 22, 33 and 66% of the tumours in men aged 55-59, 60-64 and 65-69 years, respectively, had the potential for progression in the preclinical phase. PSA-detected prostate cancers are a mixture of progressive and non-progressive tumours with respect to Gleason score. The former may potentially benefit from screening. Identifying cancers with the potential for progression is important to target screening.

First danish single-institution experience with radical prostatectomy: biochemical outcome in 1200 consecutive patients

Radical retropubic prostatectomy (RRP) as intended curative therapy for patients with clinically localized prostate cancer (PC) was initiated in 1995 in Denmark. This paper reports single-institution results from the first 1200 consecutive patients operated during a 15-year period. Median age at surgery was 63 years. Median PSA was 9 ng/mL. Palpable tumors (≤cT2) were present in 48% of patients. Gleason score at biopsy was ≤7 for 85% of patients. In sixty-five percent of patients, histopathology revealed localized PCa after RRP. Positive surgical margins were found in 39.2% of the cases. Biochemical recurrence (BR) occurred for 214 (18%) of patients. The estimated biochemical recurrence free survival (BRFS) was 71.7% and 63.2% after 5 and 10 years, respectively. When patients were stratified according to the D'Amico criteria, BRFS after 10 years was 75.3%, 59.7%, and 39.3% for low-, medium- and high-risk patients, respectively. In univariate analysis, clinical stage, PSA at diagnosis and type of surgery were significant predictors of BR. In multivariate analysis, Gleason score > 7, PSA > 10, and higher clinical stage were significant predictors of BR. Early Danish results in a population not subjected to screening demonstrate BRFS rates comparable with earlier reports from the prescreening era.

Tissue slice grafts: an in vivo model of human prostate androgen signaling

We developed a tissue slice graft (TSG) model by implanting thin, precision-cut tissue slices derived from fresh primary prostatic adenocarcinomas under the renal capsule of immunodeficient mice. This new in vivo model not only allows analysis of approximately all of the cell types present in prostate cancer within an intact tissue microenvironment, but also provides a more accurate assessment of the effects of interventions when tissues from the same specimen with similar cell composition and histology are used as control and experimental samples. The thinness of the slices ensures that sufficient samples can be obtained for large experiments as well as permits optimal exchange of nutrients, oxygen, and drugs between the grafted tissue and the host. Both benign and cancer tissues displayed characteristic histology and expression of cell-type specific markers for up to 3 months. Moreover, androgen-regulated protein expression diminished in TSGs after androgen ablation of the host and was restored after androgen repletion. Finally, many normal secretory epithelial cells and cancer cells in TSGs remained viable 2 months after androgen ablation, consistent with similar observations in postprostatectomy specimens following neoadjuvant androgen ablation. Among these were putative Nkx3.1(+) stem cells. Our novel TSG model has the appropriate characteristics to serve as a useful tool to model all stages of disease, including normal tissue, premalignant lesions, well-differentiated cancer, and poorly differentiated cancer.

Variants and Unusual Patterns of Prostate Cancer

Beyond the typical acinar morphology observed in most prostatic adenocarcinoma, a spectrum of morphologic variants and prostate cancer subtypes exists. These unusual entities may be further classified into (1) cancer morphologies arising by divergent differentiation of prostatic ductal, acinar, or basal cells and associated with unique clinical features or therapeutic approaches, and (2) histologies occurring in the context of usual prostatic adenocarcinoma that may result in diagnostic misinterpretation or difficulties in Gleason grade assignment, especially in limited samples. This article details several variants, with emphasis on diagnostic criteria, differential diagnoses, and clinical significance.

Morphological changes induced by androgen blockade in normal prostate and prostatic carcinoma

Maximal androgen blockade (MAB), combining a luteinizing hormone releasing hormone (LHRH) agonist and a pure or non-steroidal anti-androgen, induces significant morphologic changes in the prostate. The tumor volume, density, capsular penetration, and surgical margin involvement are strongly reduced following such treatment. On histology, normal prostate tissue and tumor undergo marked atrophy and shrinkage. Although residual cancer cells are readily identifiable in most cases, they may often be sparse and easily overlooked. The increased Gleason score apparent after MAB is most likely related to fragmentation of acinar structures, and grading is not recommended following MAB. Residual cancer cells show features of lower activity and increased apoptosis. Such therapy-induced changes may be reversible, although occasional clones of cancer cells are apparently not affected and have probably developed resistance. Finally, MAB leads to marked but reversible morphologic changes and reduction in prevalence and extent of prostatic intra-epithelial neoplasia (PIN). Monotherapy using a variety of agents causes comparable but often less extensive changes.

Primary combined androgen blockade in localized disease and its mechanism

In spite of clinical practice guidelines such as NCI-PDQ - in which primary androgen deprivation therapy (PADT) is not recommended as the primary treatment for localized prostate cancer - many patients have been treated with PADT. One of the reasons is that urologists themselves permit patients' desire because they know the effectiveness of PADT for some patients in their experiences. In this review we demonstrate basic mechanisms and the clinical efficacy of primary combined androgen blockade (PCAB) for localized or locally advanced prostate cancer. Then we discuss which patients are candidates for PCAB, and show that more than 30% of low- or intermediate-risk localized prostate cancers could be controlled in the long term with only PCAB. Short-term or intermittent PADT could not be recommended because of the possibilities of changing the character of the cancer cells by incomplete androgen ablation. We propose algorithms for the treatment of localized prostate cancer not only in low- and intermediate-risk groups but also in the high-risk group.

Prostate cancer prevention: past, present, and future

Prostate cancer is the most common male malignancy and the second or third leading cause of cancer death among men in the West. The descriptive epidemiology of prostate cancer suggests that it is a preventable disease. Prevention has the theoretical advantage of not only saving lives, but also reduce the morbidity of radical prostate cancer therapy. This article reviews the past, present, and future of prostate cancer prevention. In particular, the evidence and scientific data of a variety of prevention strategies are reviewed. Strategies reviewed include dietary fat reduction and supplementation with vitamins D and E, and selenium. Dietary intake of soy, green tea, and tomato-rich products (lycopene) are also reviewed. Data regarding pharmacological intervention with cyclo-oxygenease inhibitors, antiestrogens, and in particular 5-alpha reductase inhibitors are reviewed. The results of the Prostate Cancer Prevention Trial including the controversy surrounding higher-grade cancers among men randomized to finasteride are also summarized. Finally, a variety of trial designs as well as a roster of current phase 2 trials are presented. Probably no cancer is being investigated more thoroughly in the context of prevention as prostate cancer in 2007. Definitive answers to pivotal phase 3 trials will be available in the coming 2 to 7 years.

Xanthoma of the Prostate

Prostatic xanthoma may mimic high-grade prostatic adenocarcinoma or prostate cancer treated with hormone therapy. From 1995 to 2006, 40 cases of prostatic xanthoma were diagnosed at The Johns Hopkins Hospital. Thirty-four cases were received in consultation from outside institutions. Hematoxylin and eosin-stained or unstained slides were available in 27 cases (24 consultation cases; 3 in-house cases). Xanthoma was found on needle biopsy in 25 cases, with 2 cases noted on transurethral resection of prostate. Twenty-six cases contained only 1 focus of prostatic xanthoma with 1 case having 3 foci on the same core biopsy specimen. In 21 xanthomas, the lesions were small measuring <or=0.5 mm. Only 3 xanthomas were >1 mm with the largest one measuring 2.5 mm. Xanthoma cells had small uniform, benign-appearing nuclei, small inconspicuous nucleoli, and abundant vacuolated foamy cytoplasm. No mitoses were identified. Focal necrosis was identified in 1 case. Most xanthomas were arranged in circumscribed solid nodular pattern (17 cases). Ten xanthomas consisted of cords and individual cells infiltrating the prostatic stroma, further mimicking high-grade prostate carcinoma. Two xanthomas contained a mixed circumscribed nodular pattern and infiltrating pattern. Of cases with the lesion still present on slides for immunohistochemistry, CD68 was diffusely strongly positive in 18/19 (94.7%) and CAM5.2 was positive in none of the cases 0/14 (0%). One of 15 (6.7%), 2/17 (11.8%), and 1/12 (8.3%) cases were positive for prostate-specific antigen, prostate-specific acid phosphatase, and alpha-methylacyl-CoA racemase, respectively. Careful attention to morphology with adjunctive use of CD68 and CAM5.2 immunohistochemical stains are helpful in the diagnosis of prostatic xanthoma, especially in difficult cases with an infiltrative pattern.

Rapid androgen cycling as treatment for patients with prostate cancer

PURPOSE

To investigate the safety and feasibility of rapid androgen cycling for men with progressive prostate cancer.

EXPERIMENTAL DESIGN

Schedule 1 included a 4-week induction of androgen depletion, followed by 4-week treatment cycles of a monthly gonadotropin-releasing hormone agonist, testosterone on days 1 to 7, and an estrogen patch on days 8 to 21. Schedule 2 included a 12-week induction of androgen depletion followed by 4-week cycles of gonadotropin-releasing hormone agonist and testosterone, but no estrogens for patients with a prostate-specific antigen (PSA) nadir <1 ng/mL after induction. The primary end point was serially declining PSA trough values over six treatment cycles.

RESULTS

Thirty-six patients were treated; 27 were evaluable after cycling, of whom 8 of 12 (67%) and 9 of 15 (60%) on schedules 1 and 2, respectively, reached the end point. Five patients with PSA >1 ng/mL following induction did not cycle. No patient progressed radiographically or clinically during cycling. Three posttherapy PSA patterns were observed: a decline followed by a rapid increase in trough levels, a sustained decline with a plateau at a detectable nadir, and a decline to an undetectable nadir. Mean testosterone levels were castrate at the time of trough and in the normal physiologic range following androgen repletion. Major toxicities included grades 1 and 2 fatigue, hepatitis, gynecomastia, and hot flashes.

CONCLUSIONS

Rapid hormonal cycling is feasible and well tolerated, and successive declines in PSA troughs are achievable. Although the sample size was small, the proportion of patients achieving declining PSA at the end of six cycles was comparable with that reached with continuous androgen depletion therapy.

Early effects of pharmacological androgen deprivation in human prostate cancer

OBJECTIVES

To assess the early histological effects of pharmacological androgen deprivation (AD), which have been assessed only over longer periods, as surgical castration leads rapidly to diminished cell proliferation and enhanced cell death within the prostate.

PATIENTS AND METHODS

With Institutional Review Board approval, 35 patients were randomly assigned (seven in each group) to receive 0, 7, 14, 21 and 28 days of AD (flutamide, 250 mg orally three times/day, and one injection with leuprolide acetate 7.5 mg) before radical prostatectomy. The surgical specimens were assessed by conventional histology and immunohistochemistry, while macroarray analysis and quantitative real-time polymerase chain reaction (QRT-PCR) were used to examine gene expression.

RESULTS

There were morphological changes within the prostatic tissues as early as 7 days after initiating AD, similar to the response to castration. There was tumour cell vacuolization indicating cellular injury, glandular atrophy and mononuclear cell infiltration as prominent and progressive effects but, by contrast with castration studies, there were no changes in epithelial proliferation or apoptosis. Macroarray analysis, validated by QRT-PCR and immunohistochemistry, showed up-regulation of numerous and potentially counter-effective genes involved in the cell cycle and apoptosis.

CONCLUSIONS

Pharmacological AD induces significant involution within prostatic tissues over 7-28 days, but allows the persistence of some viable tumour cells capable of proliferation.

α-methylacyl-CoA racemase (P504S)/34βE12/p63 triple cocktail stain in prostatic adenocarcinoma after hormonal therapy

Alpha-methylacyl-CoA racemase (AMACR) has recently been shown to be a highly sensitive marker for the diagnosis of prostate cancer. However, there is limited information concerning its utility as a marker for prostate carcinoma after hormonal therapy. Our current investigation was conducted to evaluate the expression of AMACR in patients with prostate carcinoma after hormonal therapy and assess its diagnostic utility in combination with p63 and high molecular weight cytokeratin (34betaE12) staining. Prostate tissues from 49 patients who had been treated with hormonal therapy were immunohistochemically analyzed for AMACR, 34betaE12, and p63 expression by a triple antibody cocktail stain. The staining intensities and the percentages of positively staining tumor cells were recorded. The correlations between AMACR expression and metastatic status, associated hormonal therapy regimens, and the extent of hormone therapy effect were analyzed. All malignant acini were completely negative for both basal cell markers (34betaE12 and p63). Tumor cells failed to demonstrate expression of AMACR in 14 (29%) of 49 cases. In the remaining 35 cases (71%), positive immunostaining for AMACR was noted, but with variable intensities and percentages of cells stained. Positive staining for AMACR in benign glands was not seen in any case. In all cases, basal cells were strongly stained by p63 in benign acini with a mean positive percentage of 96%. Similarly, basal cells in benign acini displayed moderate staining intensities for 34betaE12 in 3 (7%) of 41 cases and strong immunostaining for this marker in the remaining 38 cases (93%); the mean percentage of positive cells was 92%. alpha-methylacyl-CoA racemase expression may be substantially diminished or entirely lost in prostate carcinoma after hormonal therapy. This variation in AMACR expression does not correlate with the metastatic status, the modality of hormonal therapy, or the extent of therapy-related effect. It is important that pathologists be aware that some hormonally treated prostate carcinomas do not express AMACR, and that immunostaining in such cases must be interpreted with caution. A triple cocktail stain using AMACR, 34betaE12, and p63 can be helpful in evaluating prostate specimens for the presence of residual or recurrent carcinoma after hormonal therapy for cancer.

Secondary prostatic adenocarcinoma: A cytopathological study of 50 cases

Positive diagnosis of metastatic prostate adenocarcinoma (PAC) can be made by microscopic examination of the cytologic specimens and immunostaining for prostate-specific antigen (PSA) and prostate acid phosphatase (PAP). Immunohistochemical markers have been known to display negative, weak, or focal staining in poorly differentiated PAC and in patients with prior hormonal and/or radiation therapy. The purpose of this study is to characterize the cytopathology of metastatic PAC as it has not been documented in large series. Fifty cases of metastatic PAC with cytological specimens consisting of 41 fine-needle aspiration biopsies (FNAB), 6 pleural fluid aspirates, and 3 catheterized urine samples were reviewed and correlated with the surgical specimens and the clinical charts. Immunostaining for PSA, PAP, cytokeratin AE1/3, cytokeratin 7 (CK7), cytokeratin 20 (CK20), vimentin, and carcinoembryonic antigen (CEA) was done. Mean patient age was 77 +/- 8 yr; serum PSA, 4.1 +/- 2.3; and primary PAC Gleason score, 8.1 +/- 1.5. Cytologically, the specimens consisted of cell clusters or cell sheets with overlapping uniform hyperchromatic nuclei with or without nucleoli. Twelve cases were not reactive to PSA and PAP and 44 cases displayed negative immunoreactivity to both CK7 and CK20. Carcinoid-like lesions and small cell carcinomas were seen in 4 cases and were misdiagnosed as nonprostatic origin based on the following features: negative immunoreactivity to PSA and PAP with or without positive reactivity to CEA, and different histopathological features when compared with the primary PAC. In addition to the frequency of high-grade PAC, awareness of the negative immunoreactivity to PSA and PAP, the discrepancy in the histopathological patterns between the primary and secondary tumors, especially the frequent neuroendocrine differentiation, are helpful features for the diagnosis of metastases of prostatic origin.

Presence of prostate cancer metastasis correlates with lower lymph node reactivity

BACKGROUND

Several reports suggest that the dissemination of neoplastic cells and cancer progression are associated with the generation of an immunosuppressive environment.

METHODS

In this report, we investigated immunological effects of prostate cancer by comparing metastastic and non-metastatic pelvic lymph nodes (LNs) from 25 patients with carcinomatous involvement of LNs to the non-metastatic LNs from 26 control patients with no metastatic involvement by immunohistochemistry and histological analyses.

RESULTS

Our results showed a decreased abundance of CD20+ B lymphocytes (P = 0.031), CD38+ activated lymphocytes (P = 0.038), and CD68+ macrophages (P < 0.001), and less evidence of follicular hyperplasia (P = 0.014), sinus hyperplasia (P < 0.001), and fibrosis (P=0.028) in metastatic LNs comparatively to control LNs. Finally, we observed that metastatic LNs were significantly smaller than control LNs (P = 0.005).

CONCLUSIONS

Our results suggest that the development of prostate cancer LN metastasis is accompanied with smaller LN size and decreased LN reactivity suggesting the development of an immununosuppressive microenvironment.

Gleason score, age and screening: modeling dedifferentiation in prostate cancer

Tumor differentiation as measured by the Gleason score is highly predictive of the course of prostatic cancer after diagnosis. Since the introduction of the prostate-specific antigen (PSA) test tumors are diagnosed with a favorable tumor stage and differentiation grade. Does screening with PSA just detect more tumors with favorable characteristics or is dedifferentiation actually being prevented by early detection and consequent treatment? The latter option implies that tumors dedifferentiate in the preclinical screen-detectable phase. To model the natural history of prostate cancer, we analyzed the age-specific distribution of clinical stage and Gleason score of 2,204 tumors diagnosed in the ERSPC-Rotterdam trial. We fitted 2 MISCAN simulation models to the observed data: Model I where tumors dedifferentiate before becoming screen-detectable and Model II where dedifferentiation occurs during the screen-detectable preclinical phase. The hypothesis of dedifferentiation during the screen-detectable phase was tested by a goodness of fit test of both models. In ERSPC-Rotterdam, we observed a significantly more favorable distribution of Gleason scores in screen-detected cancers compared to cancers found in the control arm, and in cancers detected in the second round compared to cancers detected in the first round of screening. Also, a significant association between Gleason score and age at diagnosis was found, most notably in cancers detected in the first round of screening. These findings were reproduced by Model II and less so by Model I, with a significant difference in goodness of fit between the 2 models (p < 0.001). This study provides epidemiological evidence of dedifferentiation as a major mechanism of progression in prostate cancer. Tumors dedifferentiate during the screen-detectable phase and consequently screening with PSA and early treatment can possibly prevent dedifferentiation.

Should finasteride be used to prevent prostate cancer?

Prostate cancer is an important public health problem. Chemoprevention offers an attractive solution because it may lead to decreased disease-specific mortality. Furthermore, because many men are treated radically for prostate cancers that pose little or no threat to life, chemoprevention may also provide an excellent strategy for diminishing treatment-related costs and adverse effects such as erectile and urinary dysfunction. The Prostate Cancer Prevention Trial was a 7-year randomized study of finasteride versus placebo among men aged older than 55 years. All men were intended to have a prostate biopsy at study conclusion. At trial's end, there was a 25% reduction in period prevalence in all prostate cancers (24.4% for placebo vs 18.4% for finasteride). This represents a 6% absolute risk reduction. A larger number of higher-grade cancers were noted among men randomized to finasteride, which post hoc analyses and studies suggest are almost certainly related to previously unrecognized biases in trial design. There continues to be great debate as to the clinical significance of the cancers prevented. It is our opinion that among men who warrant 5-alpha reductase inhibitors (5ARIs) as part of their benign prostatic hyperplasia regimen, cancer prevention should be recognized as an additional benefit of treatment. Furthermore, men with high risk of clinically significant prostate cancer, such as significant family history, abnormal prostate biopsy histologies, and African descent, should be made aware of these findings. Men with significant anxiety or concern about prostate cancer should also be made aware of the risks and benefits of this therapy. Additional trials of antiestrogens, micronutrients, and other 5ARIs, which will mature over the next 2 to 5 years, will better define the role of 5ARIs in prostate cancer chemoprevention.

The effect of neoadjuvant androgen suppression on prostate cancer-related outcomes after high-intensity focused ultrasound therapy

OBJECTIVE

To explore the effect of neoadjuvant androgen suppression (AS) compared to no AS on cancer-related outcomes after radical high-intensity focused ultrasound (HIFU) therapy for men with presumed organ-confined prostate cancer.

PATIENTS AND METHODS

Between January 1999 and January 2005, 250 patients underwent HIFU for presumed localized adenocarcinoma of the prostate; 154 had received neoadjuvant hormonal therapy and 96 had not. The primary outcome measure was treatment failure, as defined by the presence of prostate cancer on the biopsy taken 6 months after HIFU. Multiple logistic regression was used to examine relationships between the use of HIFU with and with no neoadjuvant AS and treatment failure.

RESULTS

The treatment failure rate was slightly lower in patients receiving neoadjuvant AS (31% vs 34%), but this was not statistically significant (P = 0.119).

CONCLUSION

In this unrandomized comparison between neoadjuvant or no AS before HIFU for men with presumed organ-confined prostate cancer, there appeared to be little if any benefit associated with the previous administration of AS.

Therapieinduzierte Tumorregression des Prostatakarzinoms

Regressive changes following pretreatment of prostate cancer may represent a big challenge for the histopathologist not familiar with the assessment of pretreated specimens. Characteristic changes after antiandrogen therapy in non-malignant prostate tissue include glandular atrophy, basal cell prominence and/or basal cell hyperplasia as well as a hypercellular stroma. Morphologic changes in prostate cancer include cytoplasmic clearing and vacuolization, nuclear pyknosis and even complete cell destruction. On the glandular level, changes are characterized by various degrees of involutional changes, ranging from almost non-regressive tumor glands to complete glandular disruption with scattered isolated tumor cells dispersed in the stroma. Knowledge about these changes, the selective use of immunohistochemistry as well as a very thorough histological workup is essential for the correct assessment of these specimens.

Elevated E-cadherin and alpha/beta-catenin expression after androgen deprivation therapy in prostate adenocarcinoma

The histological patterns of anti-androgen-treated prostate adenocarcinoma mimic high grade tumors classified according to the widely used Gleason scoring system. However, the biological characteristics of anti-androgen treated carcinoma are largely unknown. E-cadherin, alpha-catenin, and beta-catenin adhesion molecules are down-regulated in pharmacologically untreated high grade prostate carcinoma. In this study, we used immunohistochemical techniques to investigate their expression in twenty acinar adenocarcinomas after anti-androgen therapy in prostatectomy specimens. After adrogen ablation therapy, expression of all these adhesion molecules was higher than that of pretreatment biopsies of the same patient group and high grade matched untreated controls. These results emphasize the inaccuracy of the Gleason score for anti-androgen-treated prostate adenocarcinoma and the more differentiated phenotype of prostate adenocarcinoma after anti-hormonal therapy.

Androgen receptor in prostate cancer

The normal development and maintenance of the prostate is dependent on androgen acting through the androgen receptor (AR). AR remains important in the development and progression of prostate cancer. AR expression is maintained throughout prostate cancer progression, and the majority of androgen-independent or hormone refractory prostate cancers express AR. Mutation of AR, especially mutations that result in a relaxation of AR ligand specificity, may contribute to the progression of prostate cancer and the failure of endocrine therapy by allowing AR transcriptional activation in response to antiandrogens or other endogenous hormones. Similarly, alterations in the relative expression of AR coregulators have been found to occur with prostate cancer progression and may contribute to differences in AR ligand specificity or transcriptional activity. Prostate cancer progression is also associated with increased growth factor production and an altered response to growth factors by prostate cancer cells. The kinase signal transduction cascades initiated by mitogenic growth factors modulate the transcriptional activity of AR and the interaction between AR and AR coactivators. The inhibition of AR activity through mechanisms in addition to androgen ablation, such as modulation of signal transduction pathways, may delay prostate cancer progression.

Does Finasteride Alter the Pathology of the Prostate and Cancer Grading?

All forms of androgen-deprivation therapy, including finasteride, induce distinctive histologic changes in benign and neoplastic prostatic epithelial cells, including cytoplasmic clearing, nuclear and nucleolar shrinkage, and chromatin condensation. Treated cancer has a significantly higher architectural (Gleason) grade, lower nuclear grade, and smaller nucleolar diameter than untreated controls, creating the potential for grading bias. Recognition of these changes may be difficult in needle biopsies and lymph node metastases with treated cancer because of the subtle infiltrative pattern and inconspicuous nucleoli. The effects of finasteride may be less pronounced than other forms of therapy with variable distribution throughout the prostate; further, there may be greater sensitivity of low and intermediate-grade cancer than high-grade cancer. The Gleason grading system for cancer should not be used after finasteride treatment as it is not validated in this setting and is likely to overestimate the biologic potential of high-grade cancer observed after therapy. Chemoprevention trials with agents such as finasteride that alter morphology should not rely on cancer grading as a secondary endpoint owing to grading bias.

Gene expression analysis of human prostate carcinoma during hormonal therapy identifies androgen-responsive genes and mechanisms of therapy resistance

The androgen-signaling pathway is critical to the development and progression of prostate cancer and androgen ablation is a mainstay of therapy for this disease. We performed a genome-wide expression analysis of human prostate cancer during androgen ablation therapy to identify genes regulated by androgen and genes differentially expressed after the development of resistance. Six hundred and fifty-four of 63,175 probe sets detected significant expression changes after 3 months of treatment with goserelin and flutamide. This included 149 genes that were also differentially expressed 36 hours after androgen withdrawal in LNCaP cells. These genes reflect the physiological changes that occur in treated tumors and include potential direct targets of the androgen receptor. Expression profiles of androgen ablation-resistant tumors demonstrated that many of the gene expression changes detected during therapy were no longer present suggesting a reactivation of the androgen response pathway in the absence of exogenous hormone. Therapy resistance was associated with differential expression of a unique set of genes that reflect potential mechanisms of reactivation. Specifically an up-regulation of the androgen receptor and key enzymes for steroid biosynthesis suggest that resistant tumors have increased sensitivity to and endogenous synthesis of androgenic hormones. The specific pathways of reactivation provide opportunities for classification of resistant tumors and targeted therapies.

The Evolving Role of Chemotherapy and Other Systemic Therapies for Managing Localized Prostate Cancer

PURPOSE

The recent literature is reviewed regarding the use of neoadjuvant and adjuvant chemotherapy, and promising new molecular targeted agents in patients with high risk localized prostate cancer.

MATERIALS AND METHODS

A MEDLINE literature review was performed of studies evaluating chemotherapy and other systemic therapies for localized prostate cancer.

RESULTS

Patients with prostate cancer at high risk for recurrence despite local therapy include those with clinical stage T3 disease, biopsy Gleason scores of 8 to 10 or serum prostate specific antigen greater than 20 ng/ml. Although hormonal therapy has palliative benefit for the majority of patients with metastatic disease, randomized trials have not demonstrated a survival benefit from its administration before surgery for high risk localized disease. Recent trials have shown that cytotoxic chemotherapy has significant activity in hormone refractory prostate cancer, which has led to ongoing clinical trials that are investigating the use of chemotherapy in the neoadjuvant setting. Published and ongoing clinical trials in the use of systemic therapy for localized prostate cancer are reviewed.

CONCLUSIONS

Systemic therapy for advanced prostate cancer is improving. Efforts to use such therapies for managing localized disease are ongoing.

Distinguishing atrophy and high-grade prostatic intraepithelial neoplasia from prostatic adenocarcinoma with and without previous adjuvant hormone therapy with the aid of cytokeratin 5/6

We evaluated the sensitivity and specificity of cytokeratin (CK) 5/6 for distinguishing foci of atrophy from prostatic adenocarcinoma with and without previous hormonal adjuvant therapy and observed the intensity and pattern of staining in mimickers of prostatic adenocarcinoma (basal cell hyperplasia, atypical adenomatous hyperplasia, and tangentially cut high-grade prostatic intraepithelial neoplasia [PIN]). We reviewed 146 acinar proliferations in 81 specimens (radical prostatectomy, previously untreated, 41; radical prostatectomy, following androgen-deprivation therapy, 11; transurethral resection, previously untreated, 29). All benign acinar proliferations stained positively for CK5/6, with immunoreactivity restricted to basal cells. Untreated and androgen-deprived prostatic adenocarcinomas were invariably negative. The pattern of staining was continuous in 79% of the atrophy cases (15/19), and all foci stained with CK5/6. Characteristic double-layer staining in basal cell hyperplasia was observed in 93% of cases (13/14), and foci of high-grade PIN had a characteristic "checkerboard" staining with areas of discontinuity. Foci of atypical adenomatous hyperplasia showed continuous staining, including cauterized acini in 53% of cases (8/15), with a fragmented basal cell layer pattern in 47% of cases (7/15). CK5/6 staining of the basal cells in foci of atrophy is sensitive and specific for excluding prostatic adenocarcinoma with and without androgen-deprivation effect.

Pathological effects of neoadjuvant hormonal therapy help predict progression of prostate cancer after radical prostatectomy

BACKGROUND

It is not clear whether pathological changes following neoadjuvant hormonal therapy (NHT) prior to radical prostatectomy have any value as predictors of progression in prostate cancer.

METHODS

We conducted a study of 100 patients with prostate cancer who underwent radical prostatectomy following NHT. We used the Japanese general rule as the criterion to assess the biochemical recurrence rate and pathological changes after NHT.

RESULTS

In terms of preoperative risk factors, the probability of recurrence was significantly higher for patients with more than 20 ng/mL of pretreatment serum prostate-specific antigen (PSA) and/or a Gleason score of 7 or higher for biopsy specimens. We defined these pretreatment findings as high-risk factors. Among 65 patients with high-risk factors, patients with a post-NHT pathological effect of grade 3 according to the Japanese general rule showed no recurrence, whereas patients with a grade 0 had a poor prognosis. Patients with a PSA nadir 0.5 ng/mL or less tended to have a better prognosis.

CONCLUSION

Despite preoperative high-risk factors, patients showing good pathological effects after NHT tend to have a favorable prognosis after radical prostatectomy. Therefore; assessment of the pathological effects of NHT using the Japanese general rule as the criterion proved to be useful for the prediction of biochemical recurrence.

Radical prostatectomy for the patient with locally advanced prostate cancer

The proper management of patients with locally advanced adenocarcinoma of the prostate has been contentious and too frequently based on antiquated misconceptions. Non-extirpative treatments, even when combined with neoadjuvant hormonal therapy, are inferior to the surgical removal of the prostate for controlling local progression and distant dissemination of the cancer. Radical prostatectomy combined with early adjunctive hormonal therapy for patients with nodal metastasis is superior to all other forms of therapy and should be considered the standard of care. This approach provides survival rates comparable with patients with clinically organ-confined prostate cancer.

Basal cell hyperplasia in the peripheral zone of the prostate

Basal cell hyperplasia in the prostate is often viewed as a transition zone proliferation, related to usual, nodular glandular, and stromal hyperplasia. Basal cell hyperplasia in the prostatic peripheral zone, the most common site for development of prostatic intraepithelial neoplasia and carcinoma, has not been previously characterized. We characterized the incidence and histomorphological attributes of basal cell hyperplasia in a series of 500 consecutive sextant needle core biopsy samples and in 26 completely embedded prostate glands from radical prostatectomy specimens. Comparative proliferation indices (by MIB-1 staining) and apoptotic indices (by TUNEL labeling) were quantitated for peripheral zone versus transition zone basal cell hyperplasia versus normal basal cells. The incidence of basal cell hyperplasia in prostate needle biopsy tissue was 10.2% (51 of 500 cases). Usual basal cell hyperplasia was detected in 8.2% of the 500 cases, and basal cell hyperplasia with prominent nucleoli, in 2.0% of cases. Basal cell hyperplasia in needle biopsy tissue was typically focal and associated with inflammation, which was usually lymphocytic, in 84% of cases. Peripheral zone basal cell hyperplasia was found in 23% of whole prostate glands. Peripheral zone basal cell hyperplasia was not observed to be in direct physical continuity with intraepithelial or invasive neoplasia. Peripheral zone and transition zone basal cell hyperplasia exhibited similar mean proliferation and apoptotic indices, at 1% and 0.07%, respectively. This proliferation index was elevated, and apoptotic index was decreased, relative to normal basal cells (P = 1 x 10(-7)). Basal cell hyperplasia in the peripheral zone is present in a significant minority of prostate needle biopsy samples and whole prostate glands. The presence of prominent nucleoli in basal cell hyperplasia may cause diagnostic concern for a neoplastic proliferation. The increase in cell number in basal cell hyperplasia appears to be due to a coordinate increase in proliferation index coupled with a diminished apoptotic index. The presence of inflammation in the majority of basal cell hyperplasia foci suggests that peripheral zone basal cell hyperplasia in untreated patients may represent a stereotyped response to injury such as that sustained because of inflammation.

Contemporary pathology of prostate cancer

In less than 20 years since the introduction of serum PSA and the spring-loaded 18-gauge prostatic biopsy needle, pathologists have adjusted to the limited tissue requirements of narrow needle specimens to apply criteria for diagnosis and grading of prostate cancer, borrowing from lessons learned from radical prostatectomies. Substantial gains have been made during this period in the understanding of precancerous lesions, mimics of malignancy, the criteria for minimal cancer, variants of cancer, and treatment-induced changes. The light microscopic findings remain the criterion standard for diagnosis against which all new techniques should be measured. Numerous findings have proven to be of value, including simple quantitation of histopathologic features, cancer volume, perineural invasion, and others.

Pathologic effects of neoadjuvant cyproterone acetate on nonneoplastic prostate, prostatic intraepithelial neoplasia, and adenocarcinoma: a detailed analysis of radical prostatectomy specimens from a randomized trial

Neoadjuvant hormonal therapy (NHT; androgen ablation) is used prior to radical prostatectomy (RP) in an attempt to pathologically "downstage" prostatic adenocarcinoma and ultimately to improve disease-free survival. This study describes the pathologic effects of NHT with the antiandrogen cyproterone acetate, 300 mg/day for 12 weeks, on the RP specimens from men with clinically localized (stage T1 or T2) prostatic adenocarcinoma. There were 101 men in the pretreatment group (CPA) and 91 men in a control group who were treated with surgery alone. The prevalence and extent of morphologic effects were recorded for the nonneoplastic prostate, high-grade prostatic intraepithelial neoplasia, and invasive adenocarcinoma. The commonest effects on the nonneoplastic prostate were atrophy and basal cell hyperplasia and prominence. High-grade prostatic intraepithelial neoplasia was more commonly identified in the surgery alone group than the CPA group (p <0.01). In the CPA group, flat and low tufted patterns of high-grade prostatic intraepithelial neoplasia predominated. Following NHT, the adenocarcinoma showed characteristic morphologic alterations, including reduction in cytoplasmic quantity, cytoplasmic vacuolation, nuclear pyknosis, reduced gland diameter, and mucinous breakdown. In many cases there was prominence of collagenous stroma, obscuring malignant glands. Compared with the surgery alone group, the CPA group RP specimens had a significantly lower mean specimen weight (40.3 g vs 46.5 g, p = 0.025) and less tumor extent by several measures. Organ-confined tumor (stage pT2, margin negative) was found in 41.6% of the CPA group compared with 19.8% of the surgery alone group (p = 0.0017). The overall rate of margin positivity was lower in the CPA group (27.7% vs 64.8%, p = 0.001). We consider that the difference in margin positivity is the result of tumor shrinkage with a decreased likelihood of sampling in routine sections. There was no significant difference in the rate of extraprostatic extension between the two groups. There was elevation of the Gleason score in the RP specimens versus baseline biopsy in 60% of the CPA group compared with 33% of the surgery alone group (p = 0.02). The higher rate of elevation in the CPA group largely resulted from an increase in primary or secondary Gleason score 5 tumor, a morphologic artifact introduced by NHT. Because of this, we recommend not giving a Gleason grade to RP specimens following NHT. Monotherapy with CPA has similar pathologic effects on benign and malignant prostate tissue as does dual agent androgen blockade. Prolonged follow-up of these patients is required to determine if NHT with CPA leads to improved disease-free survival.

Precancerous lesions and conditions of the prostate: from morphological and biological characterization to chemoprevention

Prostatic intraepithelial neoplasia (PIN) is composed of dysplastic cells with a luminal cell phenotype, expressing the androgen receptor as well as prostate-specific antigen. PIN is characterized by progressive abnormalities of phenotype that are intermediate between normal prostatic epithelium and cancer, indicating impairment of cell differentiation and regulatory control with advancing stages of carcinogenesis. High-grade PIN is considered the most likely precursor of prostatic carcinoma, according to virtually all available evidence. Androgen deprivation decreases the prevalence and extent of PIN and the degree of capillary vascularization (e.g., angiogenesis) in the surrounding stroma via suppression of vascular endothelial growth factor production. Prostatic carcinoma is also likely to arise from precursor lesions other than high-grade PIN such as low-grade PIN, atypical adenomatous hyperplasia, malignancy-associated foci, and atrophy.