Therapy-associated effects in the prostate gland

Diverse therapies are used to treat both benign prostatic hyperplasia and adenocarcinoma. Transurethral resection, a common surgical procedure, may give rise to characteristic necrobiotic granulomas that manifest in subsequent pathology samples. Radiation and hormone therapy have traditionally been used in prostatic adenocarcinoma. Morphological effects are often identified in needle biopsy specimens, transurethral resectates, and radical prostatectomy specimens. A range of histological changes are noted in the non-neoplastic prostate tissue, as well as in the pre-neoplastic and carcinomatous areas. Other ablative therapies, such as cryotherapy, and emerging focal therapies, including high-intensity focused ultrasound, photodynamic therapy, and interstitial laser thermotherapy, may have morphological effects on prostate tissue. It is important for the pathologist to be aware of the spectrum of histological changes affecting the prostate gland post-therapy. The treatment effects may obscure residual carcinoma, and make measurements of tumour extent and stage difficult. Furthermore, some therapies can profoundly alter the neoplastic glands to such an extent that Gleason scoring is no longer valid. As new therapies are developed for prostate cancer, it is important to document their effects on benign and malignant prostate tissue and to understand possible implications for traditional prognostic factors, especially Gleason grade.     

Konsenskonferenz 2014 der ISUP zur Gleason-Graduierung des Prostatakarzinoms

In 2005 the International Society of Urological Pathology (ISUP) held a concensus conference on Gleason grading in order to bring this grading system up to the current state of contemporary practice; however, it became clear that further modifications on the grading of prostatic carcinoma were necessary. The International Society of Urological Pathology therefore held a further consensus conference in 2014 to clarify these points. This article presents the essential results of the Chicago grading meeting.     

The Gleason grading system: where are we now?

The most commonly used pathologic grading system for prostatic carcinoma (PCa) was first described by Donald F. Gleason in 1966. It is remarkable that, more than 40 years after the inception of the Gleason grading system, it remains one of the most powerful prognostic factors in prostate cancer. In part, this system has remained timely by gradual adaptations of the system to accommodate the changing practice of medicine. The 2005 International Society of Urological Pathology (ISUP) conference helped to codify these adaptations as well as gain consensus in areas where there was divergence in practice. The consensus conference and subsequent articles proposing further modifications help pathologists adapt the Gleason grading system to current day practice in a more uniform manner. In particular, narrowing the scope of pattern 3 carcinoma and widening the scope of pattern 4 carcinoma have played an important role in improving the prognostic value and inter-observer reproducibility of Gleason’s system. Whether these changes have a significant impact on the clinical treatment of the disease remains to be seen. The differences between the original Gleason grading system and the 2005 ISUP modified Gleason system make difficult to compare data sets assessing patient outcomes in PCa over time.     

Decreased immunoexpression of prostate inhibin peptide in prostatic carcinoma: a study with monoclonal antibody

Prostate inhibin peptide (PIP) is a follicle-stimulating hormone (FSH) regulating peptide produced by the prostate. The mechanism of its endocrine role in regulating prostate growth is believed to be androgen-independent but FSH-dependent. Previous studies using polyclonal antibody proposed PIP as a prostatic-specific marker in cancer diagnosis. However, the recently available monoclonal antibody has not yet been evaluated. Paraffin sections of 72 prostatectomy specimens for prostate cancer with or without hormonal blockage therapy and 10 nonneoplastic prostate tissues from autopsy were stained by using PIP monoclonal antibody (clone: 4A6A6) with the avidin-biotin complex method. PIP reactivity was semiquantitatively estimated in prostatic carcinoma (PCA), prostatic intraepithelial neoplasia (PIN), benign prostatic hyperplasia (BPH) and normal tissue in each case when ever present. Statistical analyses were performed accordingly. PIP expression is predominantly cytoplasmic. Urothelium, seminal vesicles, inflamed prostatic glands, basal cells, and squamous metaplasia were negative for PIP. Average percentage of cells expressing PIP was significantly decreased in PIN (40%) and PCA (14%) when compared with BPH (81%) and normal tissue (68%). There was no correlation of tumor PIP level with patient's age, tumor size, Gleason score, tumor stage, or the usage of preoperative hormonal blockage therapy. PIP monoclonal antibody should be used with caution as a prostate-specific marker in surgical pathology. The mechanism for this alteration and the effect of PIP on prostatic tumor growth, particularly in patients under a variety of hormonal therapies, needs further study.     

Preoperative therapy for localized prostate cancer: A comprehensive overview

At the 2012 American Society of Clinical Oncology (ASCO) Annual Meeting, two studies of preoperative systemic therapy for localized prostate cancer garnered significant attention. In the first, investigators evaluated various permutations of conventional hormonal therapies prior to prostatectomy, with detailed biomarker studies focused on tissue androgens. In the second, investigators assessed the novel CYP17 lyase inhibitor abiraterone prior to prostatectomy. Both studies provide a wealth of biological information, but the question remains – will preoperative systemic therapy ultimately be incorporated into clinical algorithms for prostate cancer? Herein, the existing literature for both preoperative hormonal and chemotherapeutic approaches is reviewed. We performed a MEDLINE search of published prospective and retrospective clinical studies assessing preoperative systemic therapy for prostate cancer from 1982 onwards, revealing a total of 75 publications meeting these criteria. Of these, 55 possessed a number of patients (i.e., greater than 10) deemed worth of the current analysis. Beyond outlining these datasets, we discuss the relevance of clinical and pathologic endpoints in assessing preoperative therapy.     

Immunohistochemistry in diagnostic surgical pathology of the prostate

Immunohistochemistry (IHC) can play an important role in diagnostic surgical pathology of the prostate. Basal cell markers, such as the 34betaE12 antibody and antibodies directed against cytokeratin 5 and 6 or p63, are very useful for demonstration of basal cells as their presence argues against a diagnosis of invasive prostatic carcinoma (PC). However, several benign mimickers of PC, including atrophy, atypical adenomatous hyperplasia (AAH), nephrogenic adenoma, and mesonephric hyperplasia, can stain negatively with these markers, and thus, a negative basal cell marker immunostain alone does not exclude a diagnosis of benignancy. Although there are examples in the literature of high grade PC that stain focally with some of the basal cell markers, these cases are usually readily diagnosed based on H&E appearances and are unlikely to be confused with these benign mimickers. Alpha-methylacyl-coenzyme-A racemase (AMACR) is a sensitive marker of PC (except for a few uncommon variants: atrophic, foamy gland, and pseudohyperplastic variants), and its detection by immunohistochemical staining in atypical prostatic lesions can be very useful in confirming an impression of adenocarcinoma. AMACR expression can also be identified in high grade prostatic intraepithelial neoplasia (PIN), prostatic atrophy, AAH, and benign prostatic glands, and accordingly, a diagnosis of PC should not be based solely on a positive AMACR immunostain, especially when the luminal staining is weak and/or noncircumferential. The use of AMACR/basal cell antibody cocktails has been found to greatly facilitate the distinction between PC and its benign mimickers, especially when only limited tissue is available for staining. Prostate specific antigen (PSA) and prostate specific acid phosphatase (PSAP) are both quite sensitive and fairly specific markers of PC (there are a few nonprostatic tumors that can express one or both), and are both very helpful in establishing or confirming the diagnosis of PC when the differential diagnosis includes other tumors that can involve the prostate such as urinary bladder urothelial carcinoma. 34betaE12, p63, thrombomodulin, and uroplakin III are additional urothelial associated markers useful in this differential diagnosis. CDX2 and villin are useful markers to diagnostically separate colonic adenocarcinoma from PC. AMACR positivity and negative basal cell marker reactions are useful to confirm the presence of residual PC after hormonal or radiation therapy. Pan-cytokeratin, PSA, and PSAP can also highlight subtle infiltrates of PC with hormonal or radiation therapy effect. PSA and PSAP immunohistochemical stains are valuable in confirming metastatic carcinoma as being of prostatic origin and should always be utilized in the diagnostic evaluation of metastatic adenocarcinoma of unknown primary origin in males.     

Update on the Gleason grading system for prostate cancer: results of an international consensus conference of urologic pathologists

The Gleason system for prostate cancer was based on a study of 270 patients from the Minneapolis Veterans Administration Hospital in 1966-1967. In 1974, Gleason and the Veterans Administrative Cooperative Urological Research Group expanded this study to 1032 men. These studies formed the basis of the Gleason grading system, which is now endorsed as the primary grading system for prostate cancer by the World Health Organization, the Armed Forces Institute of Pathology Fascicle on prostate cancer, the Association of Directors of Anatomic and Surgical Pathology, and the College of American Pathologists. In the nearly 40 years since its inception, several aspects about prostate cancer and its management have changed, most notably serum prostate-specific antigen, transrectal ultrasonography, 18-gauge needle biopsy sampling, immunohistochemistry for the diagnosis of cancer, and radical prostatectomy and radiation therapy as primary treatment modalities. Several aspects of the disease, and consequently the reporting needs, have changed such as reporting cancer on multiple cases in needle biopsies, multiple nodules in prostatectomy, tertiary patterns, variants and variations in prostate cancer. The application of the Gleason system, therefore, has varied considerably in contemporary surgical pathology practice. An International Consensus Conference attended by 80 urologic pathologists from 20 countries was convened to discuss clarifications and modifications to the Gleason system. This article serves as a brief overview and summary of the proceedings that have been published in detail in recent literature.     

Classification of canine urinary bladder urothelial tumours based on the World Health Organization/International Society of Urological Pathology consensus classification

One hundred canine urinary bladder urothelial (transitional cell) tumours, including roughly equal numbers of benign and malignant forms, were retrospectively categorized in accordance with the newly described human consensus classification of the World Health Organization/International Society of Urological Pathology (WHO/ISUP). The tumours were reviewed and classified by three veterinary pathologists from Michigan State University and two human pathologists from the Armed Forces Institute of Pathology (AFIP). The current human WHO/ISUP classification system was considered to be readily applicable to the dog. Canine tumours, however, differed from human tumours in that the great majority showed extensive glandular differentiation (or metaplasia) and hyperplastic lesions tended to be more florid than those seen in human beings. The various diagnoses and grades assigned to the tumours were highly consistent between all reviewing pathologists. This paper presents the salient features of the new WHO and ISUP consensus classification and provides illustrations of the various tumour types that were directly applicable to the dog.     

The use of immunohistochemistry in metastatic prostatic adenocarcinoma to the breast.

Since the introduction of hormonal therapy for the treatment of metastatic prostatic adenocarcinoma, there have been 33 reports of metastases of prostate carcinoma to the breast. We report two cases of diethylstilbestrol (DES)-treated patients with metastatic prostate adenocarcinoma who developed breast masses. The lesions had infiltrative patterns simulating primary breast carcinoma. Immunoperoxidase stains, prostate-specific antigen (PSA), and prostatic acid phosphatase (PAP) were positive, identifying these cases as metastatic prostatic carcinoma to the breast. Differentiating primary from secondary tumors in these patients is difficult since there have been 10 reports of primary breast carcinoma occurring in DES-treated patients with prostatic adenocarcinoma. Their differentiation is important to direct appropriate therapy, and PSA and PAP immunoperoxidase stains are important in their correct classification.     

Alpha-methylacyl-CoA racemase (P504S)/34betaE12/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.     

Significance of mucin stain in differentiating benign and malignant lesions of prostate

In an attempt to assess the significance of mucin stains in benign and malignant lesions of prostate, 200 prostatic biopsies in the department of Pathology, Pt. B.D. Sharma PGIMS, Rohtak were studied. All the biopsies were subjected to PAS and alcian blue staining along with H&E stain. Neutral mucin (PAS positive) was more frequently observed in benign prostatic lesions (93.3%) as compared to carcinoma (36%) while acid mucin (AB positive) was found more in carcinoma prostate (68%) as compared to benign prostatic lesions (16%). The positivity for acid mucin was more in well differentiating tumour decreasing significantly in high grade malignancies. With both types of mucin, luminal positivity was slightly more as compared to cytoplasmic positivity.     

Proximal prostatic stem cells are programmed to regenerate a proximal-distal ductal axis

Prostate carcinoma and benign prostatic hypertrophy may both originate in stem cells, highlighting the importance of the characterization of these cells. The prostate gland contains a network of ducts each of which consists of a proximal (adjacent to the urethra), an intermediate, and a distal region. Here, we report that two populations of cells capable of regenerating prostatic tissue in an in vivo prostate reconstitution assay are present in different regions of prostatic ducts. The first population (with considerable growth potential) resides in the proximal region of ducts and in the urethra, and the survival of these cells does not require the presence of androgens. The second population (with more limited growth potential) is found in the remaining ductal regions and requires androgen for survival. In addition, we find that primitive proximal prostate cells that are able to regenerate functional prostatic tissue in vivo are also programmed to re-establish a proximal-distal ductal axis. Similar to their localization in the intact prostate, cells with the highest regenerative capacity are found in the proximal region of prostatic ducts formed in an in vivo prostate reconstitution assay. The primitive proximal cells can be passaged through four generations of subrenal capsule grafts. Together, these novel findings illustrate features of primitive prostate cells that may have implications for the development of therapies for treating proliferative prostatic diseases.     

Can conception of prostate cancer stem cells influence treatment dedicated to patients with disseminated disease?

No survival profit has been achieved for patients with disseminated prostate cancer since hormonal therapy was introduced. It is proposed that dissemination of rare prostatic cancer stem cells may lead to metastatic disease and that resistance of these cells to androgen ablation makes them responsible for failure of current treatments. In this paper, we will discuss the significance of the stem cell model for understanding prostate cancer pathogenesis. The concept of prostate cancer as a stem cell disease has the potential to change our view of its treatment in the particular case of disseminated disease. The major cellular target of prostate cancer therapy has to be directed against neoplastic stem cells. The combination of molecular-targeted therapy with the concept of the cancer stem cells should be introduced for the treatment of disseminated prostate cancer. Disseminated prostate cancer must be treated with agents directed toward stem cells, while hormone-therapy must be only an additional treatment leading to the decrease of tumor burden.     

Update on prostate pathology

This update on prostate pathology is very timely, as we celebrate the 20 anniversary of our great society, the International Society of Urological Pathologists (ISUP). Most of the key advances in this field over the past two decades have been made by several distinguished members of our society, as will be demonstrated herein. I am therefore indeed honored and privileged to be given the opportunity to present this paper. I will start with a brief historical perspective prior to delving into the update on prostate pathology over the past two decades and beyond. The topics discussed in this update will be somewhat limited, but will include The Gleason grading system; handling and staging of radical prostatectomy specimens; variants of prostatic adenocarcinoma; treatment effect on the prostate; other primary and secondary tumours involving the prostate, and biomarkers of prostate cancer.     

Prostate cancer]

Carcinoma of the prostate constitutes a major and escalating international health problem. In many developed countries prostate cancer is the most commonly diagnosed malignancy in men, and seems to overtake lung cancer as major cause of cancer mortality. In Japan mortality of the prostate cancer is relatively low, but future incidence and mortality of the prostate cancer will be dramatically increased. Risk factors of the prostate cancer were well known as Western-type lifestyle and diet. Carcinoma of the prostate are detected early by prostatic specific antigen and systematic trans-rectal ultrasonography guided prostatic needle biopsy. Once prostate cancer has been diagnosed in a patient, histologically graded, and staged as accurately as possible, clinicians are duty bound to offer the best advice about treatment options, even though the risks and benefits of competing therapies. Radical prostatectomy and radiation therapy are known as treatment of localized prostate cancer, antiandrogen therapy is known as treatment of advanced prostate cancer. Alternative approaches utilizing, for example microable inhibitors, inhibitor of growth factors and gene therapy also hold exciting promise.     

Neuroendokrine Differenzierung im Prostatakarzinom

Neuroendocrine (NE) differentiation frequently occurs in common prostatic malignancies but usually escapes pathological and clinical detection. The present review focuses on biological properties of NE tumor cells making them resistant to androgen deprivation and radiation therapy. Recent data have shown that NE prostate cancer cells (as defined by the most commonly used endocrine marker chromogranin A) are arrested in the G0-phase of the cell cycle and do not undergo apoptosis. This particular phenotype consistently lacks the nuclear androgen receptor in both benign and malignant conditions but produces a series of hormonal growth factors exerting mitogenic stimuli on adjacent, exocrine tumor cells.Neoplastic NE cells devoid of the nuclear androgen receptor constitute an androgen-insensitive cell population in prostate cancer. The absence of proliferative and apoptotic activity makes NE tumor cells particularly resistant towards cytotoxic drugs and radiation therapy. Pathological and clinical detection of NE features is recommended for all prostate cancer patients for whom radiation therapy and androgen deprivation is being considered.     

前列腺疾病中TK1和Ki-67的表达

目的通过对前列腺癌、前列腺上皮内瘤变、前列腺良性增生及其正常前列腺组织中胸苷激酶1（TK1）和细胞增殖蛋白（MIB-1）标记Ki-67的表达，探讨其对前列腺癌的治疗、预后所起的作用。方法采用免疫组化ABC法检测前列腺癌（PCa）42例，前列腺上皮内瘤变（PIN）35例，良性前列腺增生（BPH）25例和正常前列腺（NP）组织10例中TK1及Ki-67的表达。结果良性前列腺增生及正常前列腺组织中几乎检测不到增殖细胞，在前列腺上皮内瘤中增殖细胞所占的百分比大约为16％～17％，在前列腺癌组织中TK1阳性表达率57．1％，高于Ki-67阳性表达率（47．6％，P〈0．05）。结论TK1不仅同Ki-67一样，可作细胞增殖的指标，还因其参与DNA合成及细胞间“旁观者效应”等原因，从而给临床提供治疗及预后方面有价值的参考。     

Bilateral ethmoid sinusitis with unilateral proptosis as an initial manifestation of metastatic prostate carcinoma.

This article presents a case of bilateral ethmoid sinusitis with unilateral proptosis as a presenting sign of an unsuspected prostate carcinoma. A 59-year-old Hispanic male presented to his primary care physician with nasal congestion and rhinitis. He was treated with antibiotics and antihistamine decongestants for 3 weeks without improvement. A trial of steroids resulted in brief improvement followed by a rapid onset of nasal obstruction with proptosis. A computed tomography scan revealed opacification of the ethmoid sinus with right proptosis. The presumptive diagnosis was orbital cellulitis secondary to chronic ethmoid sinusitis. Endoscopic sinusotomy and bilateral ethmoidectomies were performed. Biopsy results returned as metastatic adenocarcinoma, probably of prostate origin. Urological work-up and evaluation with biopsy confirmed the diagnosis of prostatic carcinoma. The patient was treated with chemotherapy and radiation therapy. He died 7 months later with disseminated disease.     

Differential expression of interleukin-8 and its receptors in the neuroendocrine and non-neuroendocrine compartments of prostate cancer

Hormonal therapy (androgen ablation and/or inhibition of androgen action) is the treatment of choice for advanced prostate cancer. After an initial response in most patients, tumors invariably progress to an androgen-independent state. It is unclear how prostate cancer cells proliferate without androgen. Recent studies suggest that interleukin-8 may promote androgen-independent proliferation, but the source of interleukin-8 in the prostate is unknown. Using immunohistochemistry, we show that interleukin-8 was expressed by the neuroendocrine tumor cells in human prostate cancer tissue. Expression of the interleukin-8 receptor CXCR1 was negative or low in benign prostatic tissue and was frequently increased in malignant cells of high-grade prostatic intraepithelial neoplasia and prostate cancer; however, CXCR1 was not detected in the neuroendocrine tumor cells, suggesting a paracrine mechanism by which interleukin-8 produced by neuroendocrine tumor cells stimulates androgen-independent proliferation of prostate cancer. Neuroendocrine tumor cells expressed another type of interleukin-8 receptor, CXCR2, suggesting an autocrine mechanism by which interleukin-8 regulates the differentiation or function of the neuroendocrine cells. These results, combined with previous reports that neuroendocrine differentiation is induced by hormonal therapy, suggest that neuroendocrine cells play an important role in promoting androgen-independent growth of prostate cancer through interleukin-8 signaling.