Hemamali Samaratunga

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.

Micropapillary variant of urothelial carcinoma of the urinary bladder; a clinicopathological and immunohistochemical study

Aims:  To investigate whether prognosis in micropapillary urothelial carcinoma is related to the proportion of the micropapillary component (MPC), and to identify the immunohistochemical features of MPC.

Use of multiple biomarkers for a molecular diagnosis of prostate cancer.

The identification of biomarkers capable of providing a reliable molecular diagnostic test for prostate cancer (PCa) is highly desirable clinically. We describe here 4 biomarkers, UDP‐N‐Acetyl‐α‐D‐galactosamine transferase (GalNAc‐T3; not previously associated with PCa), PSMA, Hepsin and DD3/PCA3, which, in combination, distinguish prostate cancer from benign prostate hyperplasia (BPH). GalNAc‐T3 was identified as overexpressed in PCa tissues by microarray analysis, confirmed by quantitative real‐time PCR and shown immunohistochemically to be localised to prostate epithelial cells with higher expression in malignant cells. Real‐time quantitative PCR analysis across 21 PCa and 34 BPH tissues showed 4.6‐fold overexpression of GalNAc‐T3 (p = 0.005). The noncoding mRNA (DD3/PCA3) was overexpressed 140‐fold (p = 0.007) in the cancer samples compared to BPH tissues. Hepsin was overexpressed 21‐fold (p = 0.049, whereas the overexpression for PSMA was 66‐fold (p = 0.047). When the gene expression data for these 4 biomarkers was combined in a logistic regression model, a predictive index was obtained that distinguished 100% of the PCa samples from all of the BPH samples. Therefore, combining these genes in a real‐time PCR assay represents a powerful new approach to diagnosing PCa by molecular profiling. (Supplemental material for this article can be found on the International Journal of Cancer website at http://www.interscience.wiley.com/jpages/0020‐7136/suppmat/index.html.)

Expression analysis of delta-catenin and prostate-specific membrane antigen: Their potential as diagnostic markers for prostate cancer

The current approach to prostate cancer diagnosis has major limitations including the inability of prostate‐specific antigen (PSA) assays to accurately differentiate between prostate cancer and benign prostate hyperplasia (BPH) and the imprecision of transrectal ultrasound (TRUS) biopsy sampling. We have employed cDNA microarray screening to compare gene expression patterns in BPH and tumour samples to identify expression markers that may be useful in discriminating between these conditions. Screening of 3 individual cDNA arrays identified 8 genes with expression 3‐fold greater in 6 tumour tissues than in 1 nontumour sample and 1 BPH sample. Real‐time PCR was used to confirm the overexpression of these 8 genes and 12 genes selected from the literature against a panel of 17 tumours and 11 BPH samples. Two genes, δ‐catenin (delta‐catenin; CTNND2) and prostate‐specific membrane antigen (PSMA; FOLH1), were significantly overexpressed in prostate cancer compared to BPH. Prostate epithelial cells stained positively for δ‐catenin and PSMA in our prostate cancer tissues, whereas the majority of our BPH tissues were negative for both markers. Thus we have identified δ‐catenin (not previously associated with prostatic adenocarcinoma) and confirmed the potential of PSMA as potential candidates for the diagnosis and management of prostate cancer.

Comparison of WHO/ISUP and WHO classification of noninvasive papillary urothelial neoplasms for risk of progression

OBJECTIVES To investigate the relation of the World Health Organization/International Society of Urological Pathology (WHO/ISUP) system for bladder neoplasia to prognosis. METHODS A total of 134 patients with pTa bladder tumors were identified. We excluded cases with prior or concurrent carcinoma in situ or invasion (pT1 or pT2). Progression was defined as a tumor recurrence with either lamina propria (pT1) or muscularis propria (pT2) invasion or carcinoma in situ. Age at diagnosis, sex, tumor size, multifocality, and grade (WHO, WHO/ISUP) were entered into a Cox multivariate analysis to predict progression. RESULTS The distribution of WHO papilloma, WHO G1, WHO G2, and WHO G3 was 5.2%, 31.3%, 59%, and 4.5%, respectively. The distribution of WHO/ISUP papilloma, tumors of low malignant potential, low-grade carcinomas, and high-grade carcinomas was 2.2%, 21.6%, 13%, and 21.6%, respectively. The mean and median follow-up was 56.2 and 50 months, respectively. The 90-month actuarial risk of progression for WHO papilloma, G1, G2, and G3 was 0%, 11%, 24%, and 60%, respectively. The corresponding progression rate for WHO/ISUP papilloma, tumors of low malignant potential, low-grade carcinoma, and high-grade carcinoma was 0%, 8%, 13%, and 51%, respectively. In separate analyses, WHO grade (P = 0.003) and tumor size (P = 0.03), as well as WHO/ISUP (P = 0.002) and tumor size (P = 0.04), independently predicted progression. CONCLUSIONS WHO G3 has a more rapid progression rate and a slightly worse long-term progression rate compared with WHO/ISUP high-grade carcinoma. However, although only 4.5% of tumors were WHO G3, we were able to classify 21.6% as WHO/ISUP high-grade carcinoma with a poor prognosis. Use of the WHO/ISUP system allows urologists to more closely follow a larger group of patients at high risk of progression.

Kallikrein-related Peptidase 4 (KLK4) Initiates Intracellular Signaling via Protease-activated Receptors (PARs) KLK4 AND PAR-2 ARE CO-EXPRESSED DURING PROSTATE CANCER PROGRESSION

Kallikrein-related peptidase 4 (KLK4) is one of the 15 members of the human KLK family and a trypsin-like, prostate cancer-associated serine protease. Signaling initiated by trypsin-like serine proteases are transduced across the plasma membrane primarily by members of the protease-activated receptor (PAR) family of G protein-coupled receptors. Here we show, using Ca2+ flux assays, that KLK4 signals via both PAR-1 and PAR-2 but not via PAR-4. Dose-response analysis over the enzyme concentration range 0.1–1000 nm indicated that KLK4-induced Ca2+ mobilization via PAR-1 is more potent than via PAR-2, whereas KLK4 displayed greater efficacy via the latter PAR. We confirmed the specificity of KLK4 signaling via PAR-2 using in vitro protease cleavage assays and anti-phospho-ERK1/2/total ERK1/2 Western blot analysis of PAR-2-overexpressing and small interfering RNA-mediated receptor knockdown cell lines. Consistently, confocal microscopy analyses indicated that KLK4 initiates loss of PAR-2 from the cell surface and receptor internalization. Immunohistochemical analysis indicated the co-expression of agonist and PAR-2 in primary prostate cancer and bone metastases, suggesting that KLK4 signaling via this receptor will have pathological relevance. These data provide insight into KLK4-mediated cell signaling and suggest that signals induced by this enzyme via PARs may be important in prostate cancer.

A new lyssavirus - The first endemic rabies-related virus recognized in Australia

A previously undiscovered lyssavirus has been identified in fruit bats in Australia. Although close to classical rabies virus, antigenically and genetically, the Australian bat lyssavirus represents a new genotype. It causes central nervous system pathology in bats and has caused the death of one woman.

Expression of the Disintegrin Metalloprotease, ADAM-10, in Prostate Cancer and Its Regulation by Dihydrotestosterone, Insulin-Like Growth Factor I, and Epidermal Growth Factor in the Prostate Cancer Cell Model LNCaP

Purpose: The disintegrin metalloprotease ADAM-10 is a multidomain metalloprotease that is potentially significant in tumor progression due to its extracellular matrix-degrading properties. Previously, ADAM-10 mRNA was detected in prostate cancer (PCa) cell lines; however, the presence of ADAM-10 protein and its cellular localization, regulation, and role have yet to be described. We hypothesized that ADAM-10 mRNA and protein may be regulated by growth factors such as 5α-dihydrotestosterone, insulin-like growth factor I, and epidermal growth factor, known modulators of PCa cell growth and invasion. Experimental Design: ADAM-10 expression was analyzed by in situ hybridization and immunohistochemistry in prostate tissues obtained from 23 patients with prostate disease. ADAM-10 regulation was assessed using quantitative reverse transcription-PCR and Western blot analysis in the PCa cell line LNCaP. Results: ADAM-10 expression was localized to the secretory cells of prostate glands, with additional basal cell expression in benign glands. ADAM-10 protein was predominantly membrane bound in benign glands but showed marked nuclear localization in cancer glands. By Western blot, the 100-kDa proform and the 60-kDa active form of ADAM-10 were synergistically up-regulated in LNCaP cells treated with insulin-like growth factor I plus 5α-dihydrotestosterone. Epidermal growth factor also up-regulated both ADAM-10 mRNA and protein. Conclusions: This study describes for the first time the expression, regulation, and cellular localization of ADAM-10 protein in PCa. The regulation and membrane localization of ADAM-10 support our hypothesis that ADAM-10 has a role in extracellular matrix maintenance and cell invasion, although the potential role of nuclear ADAM-10 is not yet known.

Micropapillary urothelial carcinoma of the urinary bladder: a clinicopathological analysis of 72 cases

Aim: Micropapillary carcinoma (MPC) of the bladder is an aggressive variant of urothelial carcinoma (UC). It is unknown if any amount of a micropapillary component justifies the diagnosis of MPC. It is also unknown if surface MPC also has aggressive potential. Methods: We studied 72 patients with UC with a micropapillary component in transurethral resections of bladder (TURB) diagnosed between 1998 and 2008. Fifty‐seven patients were treated with radical cystectomy. Tumours were classified according to pathological (pT) stage and percentage of MPC (≤10%, 10–49%, 50–100%). This was correlated with clinical data and follow up. Significant factors in univariate analysis were entered into a multivariate analysis. Results: In the TURB specimens, 12 had pTa, 33 pT1 and 27 pT2 tumours with 23% also displaying urothelial carcinoma in situ (CIS). On cystectomy, the MPC component was upstaged in 79% of cases. Twenty‐five (35%) patients had metastases at presentation or nodal metastases at cystectomy and 27 patients (38%) died of disease. Mean survival was 17.8 months. Of 12 pTa MPC cases, eight were treated with cystectomy, all displaying invasive carcinoma including five (62%) with pT2–pT4 disease. Three (25%) of these patients died of disease. Seven patients had a MPC component of <10% all of whom had cystectomy. Six of these had invasive carcinoma including two (33%) with pT2–pT4 disease. One (15%) of these patients died of disease. On univariate analysis, the proportion of the MPC component on TURB and pathological stage predicted disease specific survival (p = 0.01 and 0.004, respectively), while presence of CIS predicted recurrence (p = 0.03). On multivariate analysis, CIS predicted recurrence (p = 0.003); however, the proportion of MPC in TURB did not remain significant in predicting disease specific survival. The pathological stage of MPC remained significant in predicting disease specific survival (p = 0.04). Conclusions: Any amount of MPC, even <10% is significant in urothelial carcinoma and should be reported. Surface MPC is associated with invasive carcinoma in most cases which can be high stage. Adequate sampling to include detrusor muscle is crucial in these cases. Associated CIS is important to be recognised and reported as this also impacts on clinical outcome.

Non-rabies Lyssavirus human encephalitis from fruit bats: Australian bat Lyssavirus (pteropid Lyssavirus) infection

A 39‐year‐old woman died of encephalitis a few weeks after being scratched by fruit bats. Autopsy disclosed meningoencephalomyelitis, and revealed neuronal intracytoplasmic inclusions which had similarities to Negri bodies of rabies. Laboratory investigations detected a Lyssavirus type previously identified only in fruit bats. This appears to be the first human case of encephalitis due to this Lyssavirus type.