A randomized phase III double-blind placebo-controlled trial of first line chemotherapy and trastuzumab with or without bevacizumab for patients with HER2/neu-positive metastatic breast cancer: a trial of the ECOG-ACRIN Cancer Research Group (E1105).

Background: In 2008, bevacizumab received accelerated Food and Drug Administration (FDA) approval for use in human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC). Based on the preclinical and preliminary clinical activity of the trastuzumab and bevacizumab combination, ECOG-ACRIN E1105 trial was developed to determine if the addition of bevacizumab to a chemotherapy and trastuzumab combination for first-line therapy would improve progression-free survival (PFS) in patients with HER2-positive MBC. Findings: 96 patients were randomized to receive standard first-line chemotherapy and trastuzumab with or without bevacizumab between November 2007 and October 2009, and 93 began protocol therapy. Induction therapy was given for 24 weeks, followed by maintenance trastuzumab with or without bevacizumab. 60% (56/93) began carboplatin and 74% (69/93) completed 6 cycles of induction therapy. Primary endpoint was PFS. Median PFS was 11.1 and 13.8 months for placebo and bevacizumab arms, respectively (hazard ratio [HR] 95%, Confidence Interval [Cl] for bevacizumab vs. placebo: 0.73 [0.43-1.23], p = 0.24), and at a median follow-up of 70.7 months, median survival was 49.1 and 63 months (HR [95% Cl] for OS: 1.09 [0.61-1.97], p = 0.75). The most common toxicities across both arms were neutropenia and hypertension, with left ventricular systolic dysfunction, fatigue, and sensory neuropathy reported more frequently with bevacizumab. Conclusions: In this trial, the addition of bevacizumab did not improve outcomes in patients with metastatic HER2-positive breast cancer. Although the trial was underpowered due to smaller than anticipated sample size, these findings corroborated other clinical trials during this time.

Tissue Contamination Challenges the Credibility of Machine Learning Models in Real World Digital Pathology.

Machine learning (ML) models are poised to transform surgical pathology practice. The most successful use attention mechanisms to examine whole slides, identify which areas of tissue are diagnostic, and use them to guide diagnosis. Tissue contaminants, such as floaters, represent unexpected tissue. Although human pathologists are extensively trained to consider and detect tissue contaminants, we examined their impact on ML models. We trained 4 whole-slide models. Three operate in placenta for the following functions: (1) detection of decidual arteriopathy, (2) estimation of gestational age, and (3) classification of macroscopic placental lesions. We also developed a model to detect prostate cancer in needle biopsies. We designed experiments wherein patches of contaminant tissue are randomly sampled from known slides and digitally added to patient slides and measured model performance. We measured the proportion of attention given to contaminants and examined the impact of contaminants in the t-distributed stochastic neighbor embedding feature space. Every model showed performance degradation in response to one or more tissue contaminants. Decidual arteriopathy detection--balanced accuracy decreased from 0.74 to 0.69 ± 0.01 with addition of 1 patch of prostate tissue for every 100 patches of placenta (1% contaminant). Bladder, added at 10% contaminant, raised the mean absolute error in estimating gestational age from 1.626 weeks to 2.371 ± 0.003 weeks. Blood, incorporated into placental sections, induced false-negative diagnoses of intervillous thrombi. Addition of bladder to prostate cancer needle biopsies induced false positives, a selection of high-attention patches, representing 0.033 mm2, and resulted in a 97% false-positive rate when added to needle biopsies. Contaminant patches received attention at or above the rate of the average patch of patient tissue. Tissue contaminants induce errors in modern ML models. The high level of attention given to contaminants indicates a failure to encode biological phenomena. Practitioners should move to quantify and ameliorate this problem.

Chromophobe Renal Cell Carcinoma with Sarcomatoid Differentiation: Clinicopathologic Correlation and Molecular Findings.

Introduction: Sarcomatoid differentiation has been reported in approximately 8% of chromophobe renal cell carcinoma (RCC) and is associated with a worse prognosis. We aim to describe the clinicopathologic and molecular findings of chromophobe RCC with sarcomatoid differentiation. Methods: Surgical pathology database was searched to identify chromophobe RCC with sarcomatoid differentiation from January 2015 to December 2021. Results: Five patients were diagnosed with chromophobe RCC with sarcomatoid differentiation. The median age at the time of diagnosis was 57 years (range 51-61 years). Three patients died after median follow-up of 12.1 months (range 1.6-18.2 months). The median tumor size was 10.7 cm (range 5.6-13.6 cm). The median percentage of sarcomatoid component was 60% (range 10-90%), and the median percentage of necrosis was 30% (range 10-50%). One tumor demonstrated osteoid formation. PAX8, keratin 7, KIT (CD117), and Hale colloidal iron were positive in the epithelial component, whereas the sarcomatoid component was positive for vimentin, CD10, and high Ki67 proliferative index. Molecular testing was performed in three specimens: all were TP53 mutated and microsatellite stable. One aggressive tumor had RB1 frameshift mutation and copy number gains for TERT and CUL4A. Conclusion: Chromophobe RCC with sarcomatoid differentiation is a rare entity with aggressive behavior. Percentage of sarcomatoid component, necrosis, and the occurrence of metastasis is associated with worse prognosis. Molecular profiling reveals frequent TP53 mutation. While TERT promoter mutation has no prognostic implication, FLCN inactivation may be associated with a less aggressive course. The clinical significance of RB1 loss is unclear.

Tissue contamination challenges the credibility of machine learning models in real world digital pathology.

Machine learning (ML) models are poised to transform surgical pathology practice. The most successful use attention mechanisms to examine whole slides, identify which areas of tissue are diagnostic, and use them to guide diagnosis. Tissue contaminants, such as floaters, represent unexpected tissue. While human pathologists are extensively trained to consider and detect tissue contaminants, we examined their impact on ML models. We trained 4 whole slide models. Three operate in placenta for 1) detection of decidual arteriopathy (DA), 2) estimation of gestational age (GA), and 3) classification of macroscopic placental lesions. We also developed a model to detect prostate cancer in needle biopsies. We designed experiments wherein patches of contaminant tissue are randomly sampled from known slides and digitally added to patient slides and measured model performance. We measured the proportion of attention given to contaminants and examined the impact of contaminants in T-distributed Stochastic Neighbor Embedding (tSNE) feature space. Every model showed performance degradation in response to one or more tissue contaminants. DA detection balanced accuracy decreased from 0.74 to 0.69 +/- 0.01 with addition of 1 patch of prostate tissue for every 100 patches of placenta (1% contaminant). Bladder, added at 10% contaminant raised the mean absolute error in estimating gestation age from 1.626 weeks to 2.371 +/ 0.003 weeks. Blood, incorporated into placental sections, induced false negative diagnoses of intervillous thrombi. Addition of bladder to prostate cancer needle biopsies induced false positives, a selection of high-attention patches, representing 0.033mm2, resulted in a 97% false positive rate when added to needle biopsies. Contaminant patches received attention at or above the rate of the average patch of patient tissue. Tissue contaminants induce errors in modern ML models. The high level of attention given to contaminants indicates a failure to encode biological phenomena. Practitioners should move to quantify and ameliorate this problem.

Cytomorphology, immunoprofile, and clinicopathologic correlation of metastatic prostatic carcinoma.

It may be challenging to diagnose metastatic prostatic carcinoma (PC). This study focused on clinicopathologic correlation, and pitfalls of cytomorphology and immunostains of metastatic PCs. A total of 146 metastatic PCs including 134 (92%) PC without neuroendocrine differentiation-prostatic adenocarcinoma (PAC) and 12 (8%) with neuroendocrine differentiation (PC-NED) were retrieved. Triplicate tissue microarrays (TMA) of 54 surgically excised PCs were constructed for immunostains. Most cases showed Gleason 4 or 5 patterns. Nine percent of cases did not have a prior history of PC and 7% had 2 or more primary malignancies. PAC metastasized more commonly to lymph nodes (49%), and PC-NED metastasized more commonly to liver (58%). Cytologically, metastatic PCs show acini, cribriform, nest, and solid clusters. Most PACs showed conspicuous or prominent nucleoli. PC-NEDs showed typical cytologic features of low-grade or high-grade neuroendocrine neoplasm, or small cell carcinoma features. PACs could be immunoreactive to CDX2 (25%), CK20 (11%), NKX3.1 (99%), PSA (88%), PSAP (78%), and PSMA (92%). PC-NEDs were immunoreactive to neuroendocrine immunomarkers (CD56 [100%], chromogranin [67%], and synaptophysin [100%]) and p63 (25%), and lost expression of prostate-specific markers (NKX3.1, PSA, PSAP, and PSMA). Both PACs and PC-NEDs might be immunoreactive to CK7 (18% versus 33%), GATA3 (4% versus 0%), PAX8 (2% versus 50%, P < .05), and TTF1 (3% versus 57%, P < .05). It is critical to recognize these cytologic features and abbreviation of immunomarkers of metastatic PCs to avoid misinterpretation as metastatic carcinoma from nonprostate organs and inappropriate treatment. In addition, NED may be seen after hormone and chemoradiation treatment.

Common Diagnostic Challenges and Pitfalls in Genitourinary Organs, With Emphasis on Immunohistochemical and Molecular Updates.

CONTEXT.­: Lesions in the genitourinary (GU) organs, both benign and malignant, can demonstrate overlapping morphology, and practicing surgical pathologists should be aware of these potential pitfalls and consider a broad differential diagnosis for each specific type of lesion involving the GU organs. The following summary of the contents presented at the 6th Annual Chinese American Pathologists Association (CAPA) Diagnostic Course (October 10-11, 2020), supplemented with relevant literature review, exemplifies the common diagnostic challenges and pitfalls for mass lesions of the GU system of adults, including adrenal gland, with emphasis on immunohistochemical and molecular updates when relevant. OBJECTIVE.­: To describe the common mass lesions in the GU system of adults, including adrenal gland, with emphasis on the diagnostic challenges and pitfalls that may arise in the pathologic assessment, and to highlight immunohistochemical workups and emerging molecular findings when relevant. DATA SOURCES.­: The contents presented at the course and literature search comprise our data sources. CONCLUSIONS.­: The diagnostic challenges and pitfalls that arise in the pathologic assessment of the mass lesions in the GU system of adults, including adrenal gland, are common. We summarize the contents presented at the course, supplemented with relevant literature review, and hope to provide a diagnostic framework to evaluate these lesions in routine clinical practice.

The 2019 Genitourinary Pathology Society (GUPS) White Paper on Contemporary Grading of Prostate Cancer.

CONTEXT.­: Controversies and uncertainty persist in prostate cancer grading. OBJECTIVE.­: To update grading recommendations. DATA SOURCES.­: Critical review of the literature along with pathology and clinician surveys. CONCLUSIONS.­: Percent Gleason pattern 4 (%GP4) is as follows: (1) report %GP4 in needle biopsy with Grade Groups (GrGp) 2 and 3, and in needle biopsy on other parts (jars) of lower grade in cases with at least 1 part showing Gleason score (GS) 4 + 4 = 8; and (2) report %GP4: less than 5% or less than 10% and 10% increments thereafter. Tertiary grade patterns are as follows: (1) replace "tertiary grade pattern" in radical prostatectomy (RP) with "minor tertiary pattern 5 (TP5)," and only use in RP with GrGp 2 or 3 with less than 5% Gleason pattern 5; and (2) minor TP5 is noted along with the GS, with the GrGp based on the GS. Global score and magnetic resonance imaging (MRI)-targeted biopsies are as follows: (1) when multiple undesignated cores are taken from a single MRI-targeted lesion, an overall grade for that lesion is given as if all the involved cores were one long core; and (2) if providing a global score, when different scores are found in the standard and the MRI-targeted biopsy, give a single global score (factoring both the systematic standard and the MRI-targeted positive cores). Grade Groups are as follows: (1) Grade Groups (GrGp) is the terminology adopted by major world organizations; and (2) retain GS 3 + 5 = 8 in GrGp 4. Cribriform carcinoma is as follows: (1) report the presence or absence of cribriform glands in biopsy and RP with Gleason pattern 4 carcinoma. Intraductal carcinoma (IDC-P) is as follows: (1) report IDC-P in biopsy and RP; (2) use criteria based on dense cribriform glands (>50% of the gland is composed of epithelium relative to luminal spaces) and/or solid nests and/or marked pleomorphism/necrosis; (3) it is not necessary to perform basal cell immunostains on biopsy and RP to identify IDC-P if the results would not change the overall (highest) GS/GrGp part per case; (4) do not include IDC-P in determining the final GS/GrGp on biopsy and/or RP; and (5) "atypical intraductal proliferation (AIP)" is preferred for an intraductal proliferation of prostatic secretory cells which shows a greater degree of architectural complexity and/or cytological atypia than typical high-grade prostatic intraepithelial neoplasia, yet falling short of the strict diagnostic threshold for IDC-P. Molecular testing is as follows: (1) Ki67 is not ready for routine clinical use; (2) additional studies of active surveillance cohorts are needed to establish the utility of PTEN in this setting; and (3) dedicated studies of RNA-based assays in active surveillance populations are needed to substantiate the utility of these expensive tests in this setting. Artificial intelligence and novel grading schema are as follows: (1) incorporating reactive stromal grade, percent GP4, minor tertiary GP5, and cribriform/intraductal carcinoma are not ready for adoption in current practice.

Malignant melanoma arising in a primary mediastinal germ cell tumor.

Primary mediastinal germ cell tumors with somatic malignancies are rare. We report a case of a 34-year old man with melanoma arising in a primary mediastinal mixed germ cell tumor. On initial biopsy, the patient was found to have a germ cell tumor containing yolk sac and embryonal components only. After chemotherapy, histopathological evaluation of the residual tumor in the wide local resection specimen revealed a mature teratoma with melanoma. Molecular studies demonstrated that the residual germ cell tumor harbored KIT and NRAS mutations associated with malignant melanoma.

Application and Pitfalls of Immunohistochemistry in Diagnosis of Challenging Genitourinary Cases.

CONTEXT.­: Immunohistochemistry (IHC) has become increasingly important in the evaluation of pathologic conditions in the genitourinary (GU) organs. In addition to careful evaluation of hematoxylin-eosin sections and generation of a differential diagnosis, choosing the optimal panel of IHC markers becomes even more important when the biopsy material is very limited. The following summary of our experience supplemented with relevant literature review exemplifies how to use IHC to facilitate pathologic diagnosis in the GU system. OBJECTIVE.­: To describe our experience with the most common immunohistochemical markers used in GU pathology. DATA SOURCES.­: Institutional experience and literature search comprise our data sources. CONCLUSIONS.­: Application of IHC provides enormous benefits to the interpretation of GU pathologic conditions, including benign and malignant lesions. However, both insufficient and excessive types of use of IHC, as well as incorrect interpretations in common and rare GU conditions, could present pitfalls in diagnosis.

Pathologic characterization of renal epithelial neoplasms arising in nonfunctioning kidneys.

Nonfunctioning kidneys secondary to various etiologies display different histopathological features. Studies focused on incidence and types of renal neoplasms using the new World Health Organization and International Society of Urological Pathology classification system in various types of nonfunctioning kidneys are very limited. We identified 311 nephrectomies of nonfunctioning kidneys and categorized them into 5 categories: acquired cystic kidney disease (ACKD, n = 61); end-stage renal disease, nonspecific (ESRD, n = 63); adult polycystic kidney disease (APKD, n = 49); failed transplant kidney (FTK, n = 96); and those caused by obstructive conditions in the kidney (OCK, n = 42). ACKD (70%) and ESRD (43%) had higher cancer incidences than the other 3 groups (APKD = 2%, FTK = 0%, and OCK = 5%). Besides clear cell renal cell carcinoma (RCC) and papillary RCC, clear cell papillary RCC had a much higher incidence within ACKD patients (13/61) compared to other groups. ACKD-associated RCC was only identified in ACKD patients. ACKD patients had significantly longer dialysis duration compared to ESRD, APKD, and FTK. Although they had similar risk for clear cell RCC and papillary RCC, ACKD patients had a much higher risk for ACKD-associated RCC and clear cell papillary RCC than ESRD patients. Although most RCCs arising in these nonfunctioning kidneys were early pT1 stage, 6 ACKD patients and 3 ESRD patients had higher-stage diseases, which can be fatal if not treated appropriately. Therefore, precise clinicopathological classification of these nonfunctioning kidneys is important for predicting kidney cancer risk. These results indicate the need for active monitoring of the patients with high-risk nonfunctioning kidney diseases and appropriate surgical treatment when necessary.

Activation of MAPK Signaling by CXCR7 Leads to Enzalutamide Resistance in Prostate Cancer.

Castration-resistant prostate cancer (CRPC) that has developed resistance to the new-generation androgen receptor (AR) antagonist enzalutamide is a lethal disease. Transcriptome analysis of multiple prostate cancer models identified CXCR7, an atypical chemokine receptor, as one of the most upregulated genes in enzalutamide-resistant cells. AR directly repressed CXCR7 by binding to an enhancer 110 kb downstream of the gene and expression was restored upon androgen deprivation. We demonstrate that CXCR7 is a critical regulator of prostate cancer sensitivity to enzalutamide and is required for CRPC growth in vitro and in vivo. Elevated CXCR7 activated MAPK/ERK signaling through ligand-independent, but ß-arrestin 2-dependent mechanisms. Examination of patient specimens showed that CXCR7 and pERK levels increased significantly from localized prostate cancer to CRPC and further upon enzalutamide resistance. Preclinical studies revealed remarkable efficacies of MAPK/ERK inhibitors in suppressing enzalutamide-resistant prostate cancer. Overall, these results indicate that CXCR7 may serve as a biomarker of resistant disease in patients with prostate cancer and that disruption of CXCR7 signaling may be an effective strategy to overcome resistance. SIGNIFICANCE: These findings identify CXCR7-mediated MAPK activation as a mechanism of resistance to second-generation antiandrogen therapy, highlighting the therapeutic potential of MAPK/ERK inhibitors in CRPC.

Anaplastic Lymphoma Kinase Mutation (ALK F1174C) in Small Cell Carcinoma of the Prostate and Molecular Response to Alectinib.

Purpose: Small cell carcinoma of the prostate (SCCP) is an aggressive disease that can arise de novo or by transdifferentiation from prostate adenocarcinoma. Alterations in anaplastic lymphoma kinase (ALK) gene are involved in neuroblastoma, lung cancer, and other malignancies, but its role in SCCP has not been documented. We describe a patient with refractory de novo SCCP with ALK F1174C-activating mutation who obtained clinical benefit from treatment with ALK inhibitor.Experimental Design: Next-generation sequencing (NGS) was used to analyze primary and circulating tumor DNA (ctDNA). Prostate cancer databases were queried for alterations in ALK gene, mRNA, and its impact in clinical outcomes. In vitro prostate cell line/organoid models were generated by lentiviral-mediated expression of ALK and ALK F1174C and assessed for response to ALK inhibitors crizotinib and alectinib.Results: NGS analysis of the primary tumor and ctDNA of a 39-year-old patient with refractory SSCP identified ALK F1174C mutation. Treatment with second-generation ALK inhibitor alectinib resulted in radiographic stable disease for over 6 months, symptomatic improvement, and significant molecular response as reflected by declining ctDNA allele fraction. Analysis of prostate cancer datasets showed that ALK amplification was associated with poor outcome. In prostate cancer cells and organoids, ALK F1174C expression enhanced growth and induced expression of the neuroendocrine marker neuron-specific enolase. Alectinib was more effective than crizotinib in inhibiting ALK F1174C-expressing cell growth.Conclusions: These findings implicate ALK-activating mutations in SCCP pathogenesis and suggest the therapeutic potential of targeting ALK molecular alterations in some patients with SCCP. Clin Cancer Res; 24(12); 2732-9. ©2018 AACR.

Preparation and characterization of the antibody recognizing AMACR inside its catalytic center.

Alpha-methylacyl-CoA racemase (AMACR) catalyzes the ß-oxidation of fatty acids and is overexpressed in carcinomas in various organs, while its inactivation results in the inhibition of cancer growth. In the present study, we prepared and characterized 20 different mouse monoclonal antibodies against human AMACR. In the course of biopanning of a phage peptide commercial library against in-house prepared 6H9 and 2A5, and commercial 13H4 antibodies, 10 phage mimotopes recognized by each type of the antibody were selected. Using the program Pepitope and the crystal structure of AMACR from Mycobacterium tuberculosis, we reveal for the first time, at least to the best of our knowledge, that the epitopes recognizing the antibody against AMACR are composed of conformation sequences localized inside the AMACR catalytic center. When delivered into live HeLa cells using cationic lipid-based PULSin reagent, the specific antibodies against AMACR were co-localized with peroxisomes. The in-house made 6H9 antibody exhibited a low level of this co-localization compared to the commercially available 63340 antibody, and did not inhibit the growth rate of HeLa and T98G cells. The results obtained suggest that antibody against AMACR may possess anti-AMACR catalytic activity and needs to be further investigated as a potential drug for use in anticancer therapy. On the whole, in this study, we generated several clones of AMACR antibodies and demonstrated that these antibodies can be colonized into live cells. Currently, we are testing the growth inhibitory properties of these antibodies against AMACR.

Efficacy Against Human Prostate Cancer by Prostate-specific Membrane Antigen-specific, Transforming Growth Factor-ß Insensitive Genetically Targeted CD8+ T-cells Derived from Patients with Metastatic Castrate-resistant Disease.

Current immunotherapy has limited efficacy on metastatic castrate-resistant prostate cancer (mCRPC). We therefore sought to improve the antitumor ability of mCRPC patient-derived CD8+ T-cells by the endowment of specificity to prostate-specific membrane antigen (PSMA) and insensitivity to immunosuppressant molecule transforming growth factor-ß (TGF-ß) under the control of herpes simplex virus-1 thymidine kinase. CD8+ T-cells were collected by leukapheresis and cultured in a Food and Drug Administration-approved Cell Processing Work Station. We developed a chimeric antigen receptor retroviral construct using an anti-PSMA chimeric immunoglobulin-T-cell receptor(ζ) gene (PZ1) and dominant negative TGF-ß type II receptor (TßRIIDN), that could induce CD8+ T-cells to be PSMA reactive and insensitive to TGF-ß. Cr51 release assay was performed on PC-3 and PC-3-PSMA. The further antitumor functions of PSMA-specific, TGF-ß insensitive CD8+ T-cells was evaluated using an immunodeficient RAG-1-/- mouse model. We found PSMA-specific, TGF-ß insensitive CD8+ T-cells from mCRPC were expanded with strong expression of PZ1 and thymidine kinase genes, and their growth was not suppressed by TGF-ß. The survival of these cells decreased sharply after treatment with ganciclovir. Treatment of PSMA-specific TGF-ß, insensitive CD8+ T-cells was associated with 61.58% specific lysis on PC-3-PSMA, and significantly suppressed PC3-PSMA tumor compared with the PC3 tumor. A large amount of tumor apoptosis and CD8+ T-cell infiltration were found only in the PC3-PSMA tumor. This study verified that PSMA-specific, TGF-ß insensitive CD8+ T-cells derived from mCRPC patients could be successfully expanded and used to overcome the immunosuppressive effects of the tumor microenvironment to control PSMA-expressing PC in vitro and in vivo. This may provide a promising approach for men with mCRPC who fail androgen deprivation therapy. PATIENT SUMMARY: We investigated the role of a novel chimeric antigen receptor T-immunotherapy based on autologous metastatic castrate-resistant prostate cancer patient-derived prostate-specific membrane antigen (PSMA)-specific, transforming growth factor-ß insensitive CD8+ T-cells on PSMA-positive prostate cancer. We found that this chimeric antigen receptor T-cells could kill PSMA-positive prostate cancer specifically. The results suggest that this novel immunotherapy treatment is a potential new approach for men with metastatic castrate-resistant prostate cancer.

Practical Applications of Immunohistochemistry in the Diagnosis of Genitourinary Tumors.

CONTEXT: - Pathologic diagnosis of tumors in the genitourinary system can be challenging based on morphology alone, particularly when diagnostic material is limited, such as in core biopsies. Immunohistochemical stain can be a useful tool to aid in the diagnosis. OBJECTIVE: - To provide an update on practical applications and interpretation of immunohistochemical stains in the diagnosis of tumors in prostate, kidney, bladder, and testis. We particularly focus on difficult differential diagnoses, providing our insights in frequently encountered challenging situations. Commonly used immunohistochemical panels are discussed. DATA SOURCES: - Review of literature and our own experience. CONCLUSION: - Immunohistochemical stain is a valuable tool in the diagnosis of genitourinary tumors when appropriately used.

Extraprostatic Extension Is Extremely Rare for Contemporary Gleason Score 6 Prostate Cancer.

BACKGROUND: A significant proportion of men with Gleason score 6 (GS6) prostate cancer undergo treatment with radiation or surgery. OBJECTIVE: To assess pathologic stage of pure GS6 at radical prostatectomy (RP). DESIGN, SETTING, AND PARTICIPANTS: In the period 2003-2014, 7817 patients underwent RP at two institutions. Of 2502 patients with GS6 at surgery, 60 were identified as stage pT3a-b on initial pathologic review, 55 with pT3a (extraprostatic extension, EPE), and five with pT3b (seminal vesicle invasion; SVI). All cases of GS6 with pT3 disease underwent contemporary pathologic evaluation for Gleason grade, stage, and extent of EPE. At one institution, all GS≥7 pT3b cases were re-reviewed for downgrading. The 2014 International Society of Urological Pathology (ISUP) Gleason grading criteria and 2009 ISUP recommendations on pT3 staging were applied. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Calculated incidence (%) of pT3a, pT3b, pT4, and lymph node-positive disease. RESULTS AND LIMITATIONS: Of the 60 GS6 pT3a-b cases identified in the period 2003-2014, seven (0.28% of entire GS6 cohort) with GS6 and pT3a were identified after re-review, all focal EPE. Among the re-examined cohort, no cases of GS6 with pT3b were observed. None of the 132 GS≥7 pT3b cases were downgraded to GS6. Limitations include partial embedding of specimens and separate pathologic review at each institution. CONCLUSIONS: In a large prostatectomy cohort, GS6 never had seminal vesicle invasion (0%) and was very rarely (0.28%) associated with extraprostatic extension. PATIENT SUMMARY: GS6 prostate cancer rarely spreads outside the prostate. A new finding in this study was that GS6 prostate cancer never spread to the seminal vesicles.

Nuclear size measurement for distinguishing urothelial carcinomas from reactive urothelium on tissue sections.

BACKGROUND: Pathological diagnosis of urothelial carcinoma (UC) is primarily based on cytological atypia. It has previously been shown that high-grade (HG) UC, particularly UC in situ cells (CIS), can be over five times the size of a lymphocyte. However, this has not been demonstrated in comparison to reactive urothelium. The objective of this study was to empirically compare the difference in nuclear size of UC cells with reactive urothelial cells. METHODS: Using CellSens imaging software, we measured urothelial nuclear length (l) and width (w) on digital images of H&E sections. The area (a) of a nucleus was calculated based on the oval shape of most urothelial cells. Lymphocytes were measured to calculate normalized urothelial linear and area ratios. RESULTS: A total of 1085 urothelial cell nuclei from 60 cases were measured from reactive urothelium, low grade (LG) UC, HG UC and CIS. CIS nuclei were found to have an a 2.75 times larger than reactive nuclei (p < 0.001). A nuclear size cut-off of 11 um for l and 7 um for w was found to be sensitive [98.09 % (95 % CI: 95.60-99.38 %) and 89.31 % (95 % CI: 83.6-91.82 %) for l and w, respectively] and specific [92.60 % (95 % CI: 87.13-95.82 %) and 85.71 % (95 % CI: 79.49-90.63 %) for l and w, respectively] for distinguishing CIS from reactive atypia. CONCLUSIONS: Nuclear morphometry can be used to differentiate CIS from reactive atypia. A l over 11 um and a w over 7 um and is highly sensitive and specific for CIS compared to reactive urothelium. This difference in nuclear size may be used as a tool for differentiating the flat urothelial lesions from reactive urothelium in daily practice.

Value of SATB2 immunostaining in the distinction between small intestinal and colorectal adenocarcinomas.

AIMS: Special AT-rich sequence-binding protein 2 (SATB2) is a novel immunomarker that is expressed in glandular cells of the lower gastrointestinal tract with retained expression in the majority of primary and metastatic colorectal adenocarcinomas (CRCs). Because of its tissue specificity, SATB2 has been shown to be a clinically useful marker to distinguish CRC from non-CRC. In this study, we investigated whether or not SATB2 can help differentiate CRC from small intestinal adenocarcinoma (SIA), a practical diagnostic challenge due to their morphological and immunophenotypic similarities. METHODS: Fifty surgically resected primary SIAs and 50 CRCs were immunohistochemically examined for the expression of SATB2. Positive staining was graded as 1+ (5-25% of the tumour cells stained), 2+ (26-50%), 3+ (51-75%) or 4+ (>75%), as well as weak, intermediate or strong for staining intensity. RESULTS: Positive SATB2 immunoreactivity was observed in 23 (46%) SIAs in contrast to 48 (96%) CRCs (p<0.0001). Among these, only 4 (8%) SIAs showed strong and diffuse (4+) SATB2 staining compared with 38 (76%) of CRCs (p<0.0001). CONCLUSIONS: SATB2 is not entirely CRC-specific and is expressed in a subset of SIAs. Unlike CRC, however, SIA infrequently shows a strong and diffuse staining pattern, which still makes SATB2 a useful immunomarker to distinguish SIA from CRC.