Milton W. Datta

The 2005 International Society of Urological Pathology (ISUP) Consensus Conference on Gleason Grading of Prostatic Carcinoma.

Five years after the last prostatic carcinoma grading consensus conference of the International Society of Urological Pathology (ISUP), accrual of new data and modification of clinical practice require an update of current pathologic grading guidelines. This manuscript summarizes the proceedings of the ISUP consensus meeting for grading of prostatic carcinoma held in September 2019, in Nice, France. Topics brought to consensus included the following: (1) approaches to reporting of Gleason patterns 4 and 5 quantities, and minor/tertiary patterns, (2) an agreement to report the presence of invasive cribriform carcinoma, (3) an agreement to incorporate intraductal carcinoma into grading, and (4) individual versus aggregate grading of systematic and multiparametric magnetic resonance imaging-targeted biopsies. Finally, developments in the field of artificial intelligence in the grading of prostatic carcinoma and future research perspectives were discussed.

Sex-Determining Region Y Box 4 Is a Transforming Oncogene in Human Prostate Cancer Cells

Prostate cancer is the most commonly diagnosed noncutaneous neoplasm and second most common cause of cancer-related mortality in western men. To investigate the mechanisms of prostate cancer development and progression, we did expression profiling of human prostate cancer and benign tissues. We show that the SOX4 is overexpressed in prostate tumor samples compared with benign tissues by microarray analysis, real-time PCR, and immunohistochemistry. We also show that SOX4 expression is highly correlated with Gleason score at the mRNA and protein level using tissue microarrays. Genes affected by SOX4 expression were also identified, including BCL10, CSF1, and NcoA4/ARA70. TLE-1 and BBC3/PUMA were identified as direct targets of SOX4. Silencing of SOX4 by small interfering RNA transfection induced apoptosis of prostate cancer cells, suggesting that SOX4 could be a therapeutic target for prostate cancer. Stable transfection of SOX4 into nontransformed prostate cells enabled colony formation in soft agar, suggesting that, in the proper cellular context, SOX4 can be a transforming oncogene.

A working group classification of focal prostate atrophy lesions

Focal atrophy is extremely common in prostate specimens. Although there are distinct histologic variants, the terminology is currently nonstandardized and no formal classification has been tested for interobserver reliability. This lack of standardization hampers the ability to study the biologic and clinical significance of these lesions. After informal and formal meetings by a number of the authors, focal atrophy lesions were categorized into 4 distinct subtypes as follows: (i) simple atrophy, (ii) simple atrophy with cyst formation, (iii) postatrophic hyperplasia, and (iv) partial atrophy. In phase 1 of the study, pathologists with varying levels of experience in prostate pathology were invited to view via the Internet a set of “training” images with associated descriptions of lesions considered typical of each subtype. In phase 2 of the study, each participant provided diagnoses on a series of 140 distinct “test” images that were viewed over the Internet. These test images consisted of the 4 subtypes of atrophy and images of normal epithelium, high grade prostatic intraepithelial neoplasia, and carcinoma. The diagnoses for each image from each pathologist were compared with a set of “standard” diagnoses and the κ statistic was computed. Thirty-four pathologists completed both phases of the study. The interobserver reliability (median κ) for classification of lesions as normal, cancer, prostatic intraepithelial neoplasia, or focal atrophy was 0.97. The median κ for the classification of atrophy lesions into the 4 subtypes was 0.80. The median percent agreement with the standard diagnosis for the atrophy subtypes were: simple 60.6%, simple with cyst formation 100%; postatrophic hyperplasia 87.5%; partial atrophy 93.9%. The lower percentage for simple atrophy reflected a propensity to diagnose some of these as simple atrophy with cyst formation. Seven pathologists completed the phase 2 analysis a second time, and their intraobserver reproducibility was excellent. Three of 4 pathologists with low agreement with the standard diagnosis for simple atrophy improved their scores after repeating the analysis after re-examination of the “training set” of images. In conclusion, these criteria for variants of focal prostate atrophy may facilitate studies to examine the relation between various patterns of prostate atrophy and prostate cancer.

Sonic Hedgehog signaling in advanced prostate cancer.

Abstract.The Hedgehog family of growth factors activate a highly conserved signaling system for cell-cell communication that regulates cell proliferation and differentiation during development. Abnormal activation of the Hedgehog pathway has been demonstrated in a variety of human tumors, including those of the skin, brain, lung and digestive tract. Hedgehog pathway activity in these tumors is required for cancer cell proliferation and tumor growth. Recent studies have uncovered the role for Hedgehog signaling in advanced prostate cancer and demonstrated that autocrine signaling by tumor cells is required for proliferation, viability, and invasive behavior. The level of Hedgehog activity correlates with the severity of the tumor and is both necessary and sufficient for metastatic behavior. Blockade of Hedgehog signaling leads to tumor shrinkage and remission in preclinical tumor xenograft models. Thus, Hedgehog signaling represents a novel pathway in prostate cancer that offers opportunities for prognostic biomarker development, drug targeting and therapeutic response monitoring.

Perlecan, a candidate gene for the CAPB locus, regulates prostate cancer cell growth via the Sonic Hedgehog pathway

BackgroundGenetic studies associated the CAPB locus with familial risk of brain and prostate cancers. We have identified HSPG2 (Perlecan) as a candidate gene for CAPB. Previously we have linked Perlecan to Hedgehog signaling in Drosophila. More recently, we have demonstrated the importance of Hedgehog signaling in humans for advanced prostate cancer.ResultsHere we demonstrate Perlecan expression in prostate cancer, and its function in prostate cancer cell growth through interaction and modulation of Sonic Hedgehog (SHH) signaling. Perlecan expression in prostate cancer tissues correlates with a high Gleason score and rapid cell proliferation. Perlecan is highly expressed in prostate cancer cell lines, including androgen insensitive cell lines and cell lines selected for metastatic properties. Inhibition of Perlecan expression in these cell lines decreases cell growth. Simultaneous blockade of Perlecan expression and androgen signaling in the androgen-sensitive cell line LNCaP was additive, indicating the independence of these two pathways. Perlecan expression correlates with SHH in tumor tissue microarrays and increased tumor cell proliferation based on Ki-67 immunohistochemistry. Inhibition of Perlecan expression by siRNA in prostate cancer cell lines decreases SHH signaling while expression of the downstream SHH effector GLI1 rescues the proliferation defect. Perlecan forms complexes with increasing amounts of SHH that correlate with increasing metastatic potential of the prostate cancer cell line. SHH signaling also increases in the more metastatic cell lines. Metastatic prostate cancer cell lines grown under serum-starved conditions (low androgen and growth factors) resulted in maintenance of Perlecan expression. Under low androgen, low growth factor conditions, Perlecan expression level correlates with the ability of the cells to maintain SHH signaling.ConclusionWe have demonstrated that Perlecan, a candidate gene for the CAPB locus, is a new component of the SHH pathway in prostate tumors and works independently of androgen signaling. In metastatic tumor cells increased SHH signaling correlates with the maintenance of Perlecan expression and more Perlecan-SHH complexes. Perlecan is a proteoglycan that regulates extracellular and stromal accessibility to growth factors such as SHH, thus allowing for the maintenance of SHH signaling under growth factor limiting conditions. This proteoglycan represents an important central regulator of SHH activity and presents an ideal drug target for blocking SHH effects.

The Cooperative Prostate Cancer Tissue Resource: A Specimen and Data Resource for Cancer Researchers

Purpose: The Cooperative Prostate Cancer Tissue Resource (CPCTR) is a National Cancer Institute-supported tissue bank that provides large numbers of clinically annotated prostate cancer specimens to investigators. This communication describes the CPCTR to investigators interested in obtaining prostate cancer tissue samples. Experimental Design: The CPCTR, through its four participating institutions, has collected specimens and clinical data for prostate cancer cases diagnosed from 1989 onward. These specimens include paraffin blocks and frozen tissue from radical prostatectomy specimens and paraffin blocks from prostate needle biopsies. Standardized histopathological characterization and clinical data extraction are performed for all cases. Information on histopathology, demography (including ethnicity), laboratory data (prostate-specific antigen values), and clinical outcome related to prostate cancer are entered into the CPCTR database for all cases. Materials in the CPCTR are available in multiple tissue formats, including tissue microarray sections, paraffin-embedded tissue sections, serum, and frozen tissue specimens. These are available for research purposes following an application process that is described on the CPCTR web site (www.prostatetissues.org). Results: The CPCTR currently (as of October 2003) contains 5135 prostate cancer cases including 4723 radical prostatectomy cases. Frozen tissues, in some instances including patient serum samples, are available for 1226 cases. Biochemical recurrence data allow identification of cases with residual disease, cases with recurrence, and recurrence-free cases. Conclusions: The CPCTR offers large numbers of highly characterized prostate cancer tissue specimens, including tissue microarrays, with associated clinical data for biomarker studies. Interested investigators are encouraged to apply for use of this material (www.prostatetissues.org).

Transition from In Situ to Invasive Testicular Germ Cell Neoplasia is Associated with the Loss of p21 and Gain of mdm-2 Expression

Introduction: The tumor suppressor gene p53 has been shown to transcriptionally regulate expression of the cell cycle dependent kinase inhibitor p21. p53 is in turn regulated by the ubiquitin ligase mouse double minute-2 (mdm-2). We have set out to examine p21 expression in testicular germ cell tumors and its relationship with p53 and mdm-2 expression. Methods: Immunohistochemical analysis was performed on formalin-fixed paraffin-embedded tissue for p53, p21, and mdm-2 in 31 testicular germ cell tumors, which included 17 pure seminomas and 14 mixed germ cell tumors composed predominantly of embryonal carcinoma. Twenty-seven cases contained adjacent areas of intratubular germ cell neoplasia (ITGCN). Results: 17 out of 17 seminomas and 14 out of 14 embryonal carcinomas expressed p53 in both ITGCN and the invasive tumor. In contrast, none of the 17 seminomas and only 2 of 14 embryonal carcinomas revealed positive staining for p21 protein. p21 expression was noted in 18 of 27 cases (67%) of ITGCN, and in 16 of these cases (89%) the corresponding invasive tumor had lost p21 expression. In nine additional cases p21 expression was absent in both the invasive and intratubular tumor. mdm-2 expression was present in 8 out of 17 (47%) seminomas and 13 out of 14 (93%) embryonal carcinomas but was present in only 2 out of 27 (7%) cases of ITGCN. Statistically significant associations for loss of p21 and gain of mdm-2 expression in invasive tumors were present (P < .0001). Conclusions: The co-expression of p53 and p21 in ITGCN is consistent with preservation of p53-directed induction of p21. The loss of p21 expression in invasive tumors suggests a disruption of the p53 regulatory pathway. The inverse correlation of p21 and mdm-2 expression in both ITGCN and invasive tumors could indicate that loss of the functional p53 regulatory pathway may be correlated with the onset of mdm-2 expression. These results raise the possibility that the loss of p21 expression may be associated with the development of invasive germ cell tumors from ITGCN. Persistent p53 expression in the presence of mdm-2 suggests that in testicular germ cell tumors, while mdm-2 can block the transactivation potential of p53, it can no longer target p53 for degradation.

Further characterization of the muscle layers and lamina propria of the urinary bladder by systematic histologic mapping: Implications for pathologic staging of invasive urothelial carcinoma

The muscularis mucosae (MM) and muscularis propria (MP) are important landmarks for pathologic tumor (pT) staging of urinary bladder cancer, which is the quintessential prognostic factor. In our routine practice, we have occasionally noted patterns of MM, which do not always conform to the originally described configuration of thin slender bundles arranged in a single layer of interrupted, dispersed, or continuous muscle. We evaluated the lamina propria (LP), MM, and MP characteristics in 35 urinary bladder resection specimens with systematic sampling from the dome, trigone, anterior, posterior, right, and left lateral walls. Among the subsites, the trigone had a relatively flatter surface and attenuated LP depth (0.46 to 1.58 mm), about half of the thickest region which was the dome (0.98 to 3.07 mm). The MM was typically in individual or small groups of slender and wavy fascicles or wispy fibers. MM also had focal to rarely extensive hyperplastic appearance (53%, most common in dome) with 2 recognizable patterns: (a) aggregates of hyperplastic MM with haphazard outlines (33%) distinct from that of MP, and (b) hyperplastic compact MM with parallel muscle fibers and regular outline arranged singly or in small groups (45%) that occasionally strongly resembled MP muscle but distinguishable from it on the basis of the location in the LP. By distribution, these muscle bundles were more typically dispersed or formed a discernable layer (41%) as discontinuous or infrequently near-continuous layer. The LP vascular plexus was present in every section most often in association with the MM muscle; however, variations in the distribution were observed. The MP most commonly had a relatively regular interface with the LP. A distinctive pattern was noted in the trigone where occasionally there was gradual diminution of size of the MP muscle bundles as they extended to almost a suburothelial location. In 22%, isolated or small groups of compact regular hyperplastic MM muscle bundles were noted in deep LP situated between the more typical slender MM layer and the MP. In conclusion, there are additional patterns of MM other than previously described. Awareness of the occasionally hyperplastic appearance of MM muscle is important to prevent overstaging of invasive urothelial carcinoma. In transurethral resection specimens, lack of orientation may preclude distinction of the hyperplastic MM from true MP in these rare situations. The number and orientation of muscle bundles, relationship to urothelium and vascular plexus, and comparison with more characteristic MP, if present, would be helpful; isolated bundles immediately adjacent to the urothelium with loose haphazard fiber orientation and irregular outlines favor MM over MP muscle. The hyperplastic MM mimicking MP may be more challenging; isolated muscle bundles immediately adjacent to the urothelium would favor hyperplastic pattern of MM over MP muscle. Topographical variations exist among the subsites, the more superficial location of the MP and the rarity of MM in the trigone, relative abundance of hyperplastic MM in dome, and presence of the more superficial ureteral MP at its insertion in the bladder complicate the traditional pT stage evaluation of invasion in these regions. The inconsistency of a distinct MM layer and variations in the LP vascular plexus indicate that substaging of pT1 would be problematic and thus provides further support to the World Health Organization/International Society of Urological Pathology 1998 and World Health Organization 2004 recommendation against its implementation at the current time.

Renal cell carcinoma metastatic to the testis and its adnexa: a report of five cases including three that accounted for the initial clinical presentation.

Five cases of renal cell carcinoma metastatic to the testis or its adnexa are described, including 3 that represented the initial presentation and mimicked primary testicular neoplasms. The patients ranged from 46 to 85 years of age. Three presented with self-identified testicular masses. One patient was investigated because of fever of unknown origin and was found to have a left rib metastasis. Further work-up led to the discovery of a testicular mass. The final patient had a tumor of the spermatic cord that was examined without knowledge that he had a prior renal neoplasm. All the tumors were unilateral. They ranged from 1.8 to 5.0 cm; multiple tumor nodules were present in one of them but the others were discrete solitary masses. Four tumors were yellow/yellow-tan, and one was gray. On microscopic examination all the tumors were of the clear cell type. Patterns included solid sheets, acini, cysts, alveoli, and trabeculae. Two had prominent vascular invasion. Diagnoses initially entertained in these cases included Sertoli cell tumor, Sertoli-Leydig cell tumor, and clear cell cystadenoma of the epididymis. In 3 cases a kidney tumor was discovered 2 to 4 weeks after the diagnosis of renal cell carcinoma metastatic to the testis was rendered. On follow-up two patients died of tumor, and two were alive (5 months and 1 year) after orchiectomy. The diagnosis of renal cell carcinoma metastatic to the testis should be considered in evaluating a clear cell tumor of the testis, particularly in an older male or if the appearance suggests a Sertoli cell tumor. The differences in survival between metastatic renal cell carcinoma and sex cord-stromal tumors indicate the importance of considering the former in the differential.

An informatics model for tissue banks – Lessons learned from the Cooperative Prostate Cancer Tissue Resource

BackgroundAdvances in molecular biology and growing requirements from biomarker validation studies have generated a need for tissue banks to provide quality-controlled tissue samples with standardized clinical annotation. The NCI Cooperative Prostate Cancer Tissue Resource (CPCTR) is a distributed tissue bank that comprises four academic centers and provides thousands of clinically annotated prostate cancer specimens to researchers. Here we describe the CPCTR information management system architecture, common data element (CDE) development, query interfaces, data curation, and quality control.MethodsData managers review the medical records to collect and continuously update information for the 145 clinical, pathological and inventorial CDEs that the Resource maintains for each case. An Access-based data entry tool provides de-identification and a standard communication mechanism between each group and a central CPCTR database. Standardized automated quality control audits have been implemented. Centrally, an Oracle database has web interfaces allowing multiple user-types, including the general public, to mine de-identified information from all of the sites with three levels of specificity and granularity as well as to request tissues through a formal letter of intent.ResultsSince July 2003, CPCTR has offered over 6,000 cases (38,000 blocks) of highly characterized prostate cancer biospecimens, including several tissue microarrays (TMA). The Resource developed a website with interfaces for the general public as well as researchers and internal members. These user groups have utilized the web-tools for public query of summary data on the cases that were available, to prepare requests, and to receive tissues. As of December 2005, the Resource received over 130 tissue requests, of which 45 have been reviewed, approved and filled. Additionally, the Resource implemented the TMA Data Exchange Specification in its TMA program and created a computer program for calculating PSA recurrence.ConclusionBuilding a biorepository infrastructure that meets todays research needs involves time and input of many individuals from diverse disciplines. The CPCTR can provide large volumes of carefully annotated prostate tissue for research initiatives such as Specialized Programs of Research Excellence (SPOREs) and for biomarker validation studies and its experience can help development of collaborative, large scale, virtual tissue banks in other organ systems.