Integrating a 92-Gene Expression Analysis for the Management of Neuroendocrine Tumors of Unknown Primary

Background: Neuroendocrine tumors (NETs) are rare tumors that can originate from any part of the body. Often, imaging or exploratory surgery can assist in the identification of the tumor primary site, which is critical to the management of the disease. Neuroendocrine tumors (NETs) of unknown primary constitute approximately 10-15% of all NETs. Determining the original site of the tumor is critical to providing appropriate and effective treatment. Methods: We performed a retrospective review of neuroendocrine tumors at our institution between 2012 and 2016 using a 92-gene cancer ID analysis. Results: 56 patients with NETs of unknown primary were identified. Samples for 38 of the 56 underwent the 92-gene cancer ID analysis. The primary site of the tumor was identified with >95% certainty in 35 of the 38 patients. Conclusion: The 92-gene cancer ID analysis identified a primary site in 92% of our NETs study cohort that previously had been unknown. The results have direct implications on management of patients with regard to FDA-approved treatment options.

Prostate Cancer Biomarkers: Current Status.

Prostate cancer (PCa) is the second most frequently diagnosed cancer among men worldwide. Given the biological heterogeneity in localized PCa and its variable clinical course, a personalized approach to patient risk stratification and management is needed. A variety of high-throughput technologies, such as next-generation sequencing, transcriptomic, epigenetic, and metabolomic modalities have led to an improved understanding of the genomic basis of PCa and the identification of PCa biomarkers. Novel genomic approaches offer additional information to improve clinical decision making. The goal of this report is to review the use of currently available molecular biomarkers in the diagnosis and prognostication of PCa outcome.

The utility of tetraspanin CD9 as a biomarker for metastatic clear cell renal cell carcinoma.

The use of tetraspanin CD9 as a biomarker for renal cell carcinomas (RCC) has been explored with minor conclusions. Identification of a biomarker that not only distinguishes between the different types of renal cell carcinomas, but also predicts the metastatic potential of these tumors would significantly advance diagnosis and prognosis of kidney cancers. We utilized established cell lines to better understand the contribution of CD9 to the metastatic potential of clear cell renal cell carcinomas, and then applied our findings to the TCGA database and immunohistochemical analysis of human samples based on tumor grading to determine the utility of CD9 as a biomarker for RCC. Clear cell renal cell carcinoma (ccRCC) cell expression of tetraspanin CD9 was compared to normal kidney cells and found to be elevated. Upon knockdown of CD9, ccRCC cells obtained a more metastatic phenotype. We found E-cadherin expression to be repressed and the endothelial to mesenchymal transition markers Snail, Twist1, and Zeb1 to be elevated upon CD9 knockdown. Upon observing these gene expression changes in the TCGA database and in 10 cases, we found that CD9 and E-cadherin expression was lowered in higher grade ccRCC tumors. There was a significant correlation between CD9 and either E-cadherin, Snail, or Zeb1 in these tumors. Collectively, using tetraspanin CD9 in tandem with E-cadherin as a biomarker in renal cell carcinoma will help to not only distinguish between types, but also predict the metastatic potential of RCC.

Cotargeting Polo-Like Kinase 1 and the Wnt/ß-Catenin Signaling Pathway in Castration-Resistant Prostate Cancer.

The Wnt/ß-catenin signaling pathway has been identified as one of the predominantly upregulated pathways in castration-resistant prostate cancer (CRPC). However, whether targeting the ß-catenin pathway will prove effective as a CRPC treatment remains unknown. Polo-like kinase 1 (Plk1) is a critical regulator in many cell cycle events, and its level is significantly elevated upon castration of mice carrying xenograft prostate tumors. Indeed, inhibition of Plk1 has been shown to inhibit tumor growth in several in vivo studies. Here, we show that Plk1 is a negative regulator of Wnt/ß-catenin signaling. Plk1 inhibition or depletion enhances the level of cytosolic and nuclear ß-catenin in human prostate cancer cells. Furthermore, inhibition of Wnt/ß-catenin signaling significantly potentiates the antineoplastic activity of the Plk1 inhibitor BI2536 in both cultured prostate cancer cells and CRPC xenograft tumors. Mechanistically, axin2, a negative regulator of the ß-catenin pathway, serves as a substrate of Plk1, and Plk1 phosphorylation of axin2 facilitates the degradation of ß-catenin by enhancing binding between glycogen synthase kinase 3ß (GSK3ß) and ß-catenin. Plk1-phosphorylated axin2 also exhibits resistance to Cdc20-mediated degradation. Overall, this study identifies a novel Plk1-Wnt signaling axis in prostate cancer, offering a promising new therapeutic option to treat CRPC.

Atypical ductal hyperplasia: interobserver and intraobserver variability.

Interobserver reproducibility in the diagnosis of benign intraductal proliferative lesions has been poor. The aims of the study were to investigate the inter- and intraobserver variability and the impact of the addition of an immunostain for high- and low-molecular weight keratins on the variability. Nine pathologists reviewed 81 cases of breast proliferative lesions in three stages and assigned each of the lesions to one of the following three diagnoses: usual ductal hyperplasia, atypical ductal hyperplasia and ductal carcinoma in situ. Hematoxylin and eosin slides and corresponding slides stained with ADH-5 cocktail (cytokeratins (CK) 5, 14. 7, 18 and p63) by immunohistochemistry were evaluated. Concordance was evaluated at each stage of the study. The interobserver agreement among the nine pathologists for diagnosing the 81 proliferative breast lesions was fair (κ-value=0.34). The intraobserver κ-value ranged from 0.56 to 0.88 (moderate to strong). Complete agreement among nine pathologists was achieved in only nine (11%) cases, at least eight agreed in 20 (25%) cases and seven or more agreed in 38 (47%) cases. Following immunohistochemical stain, a significant improvement in the interobserver concordance (overall κ-value=0.50) was observed (P=0.015). There was a significant reduction in the total number of atypical ductal hyperplasia diagnosis made by nine pathologists after the use of ADH-5 immunostain. Atypical ductal hyperplasia still remains a diagnostic dilemma with wide variation in both inter- and intraobserver reproducibility among pathologists. The addition of an immunohistochemical stain led to a significant improvement in the concordance rate. More importantly, there was an 8% decrease in the number of lesions classified as atypical ductal hyperplasia in favor of usual hyperplasia; in clinical practice, this could lead to a decrease in the number of surgeries carried out for intraductal proliferative lesions.

Sarcomatoid carcinoma of the urinary bladder: the final common pathway of urothelial carcinoma dedifferentiation.

Sarcomatoid carcinoma of the urinary bladder is an unusual malignancy composed of both carcinomatous and sarcomatous components. It is an aggressive tumor that presents at an advanced stage and confers a much poorer prognosis than conventional urothelial carcinoma. The proper nomenclature and histogenesis of these tumors have been subjects of debate for some time. There is an emerging consensus that sarcomatoid carcinoma is the most appropriate term for these neoplasms. The recent World Health Organization classification has applied this term to all tumors showing morphologic and/or immunologic evidence of both malignant epithelial and mesenchymal differentiation. Such tumors have been postulated to represent either multiclonal collision tumors or monoclonal cancers with divergent differentiation; recent molecular studies favor the latter theory. In this study, we discuss the nomenclature, clinical features, pathology, differential diagnosis, molecular genetics, and histogenesis of sarcomatoid carcinoma. We emphasize the importance of molecular genetic studies in providing insight into the histogenesis of this neoplasm. Sarcomatoid carcinoma seems to represent the final common pathway of urothelial carcinoma dedifferentiation.

Urothelial lesions with inverted growth patterns: histogenesis, molecular genetic findings, differential diagnosis and clinical management.

A number of well-recognized urothelial lesions with inverted morphology occur in the urinary bladder. Some are so common that they are considered normal variants of urothelium, whereas others are rare. It is important for the surgical pathologist to recognize these lesions and their overlapping morphological features, because in some cases establishing an accurate diagnosis is challenging. In this article, we review the spectrum of inverted urothelial lesions of the bladder. Emphasis is placed on differential diagnosis, molecular genetic findings, morphology and histogenesis.

Clonality and TP53 mutation analysis of focal nodular hyperplasia of the liver.

Focal nodular hyperplasia (FNH) is considered a benign tumor of the liver. However, the biologic nature and clonality status of FNH are not well established. We sought to determine the clonality and TP53 mutation status of FNH to better characterize the nature of FNH. We analyzed 15 cases of FNH from female patients who underwent surgical resection of their lesions. Genomic DNA was extracted from paraffin-embedded tissue sections using laser-capture microdissection and analyzed for X-chromosome inactivation status and TP53 mutations by direct DNA sequencing. Thirteen cases were informative for X-chromosome inactivation analysis. Of the 13 informative cases, 4 (31%) showed a nonrandom pattern of X-chromosome inactivation, consistent with monoclonal origin. No TP53 mutations were detected in any of the FNH cases. The clonality status was not associated with any clinicopathologic parameters such as age and lesion size. Our data indicate that a significant proportion of FNH lesions have a monoclonal origin, suggesting that they are neoplastic rather than reactive.

Clonal origin of multifocal hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma is the most common primary tumor of the liver. Patients frequently have multiple histologically similar, but anatomically separate tumors. The clonal origin of multiple hepatocellular carcinomas is uncertain. METHODS: The authors analyzed 31 tumors from 12 different patients (11 women, 1 man), who had multiple hepatocellular carcinomas involving 1 or both lobes. Genomic DNA was extracted from formalin-fixed, paraffin-embedded tissue using laser capture microdissection. DNA was analyzed for loss of heterozygosity (LOH), X chromosome inactivation status, and TP53 gene mutations. RESULTS: Ten (83%) of the 12 patients showed LOH in at least 1 of the analyzed microsatellite markers. Concordant LOH patterns between separate hepatocellular carcinomas in individual patients were seen in 8 (80%) of 10 cases, whereas discordant patterns were seen in 2 (20%) of 10 cases. Five (50%) of 10 informative female patients showed identical nonrandom X chromosome inactivation patterns in multiple tumors; 1 case showed discordant nonrandom X chromosome inactivation pattern. TP53 mutations were identified in 8 (67%) of 12 patients. Tumors in 7 (88%) of these 8 patients showed different point mutations. Three patients (Cases 4, 5, and 10) had tumors with additional TP53 point mutations, indicating additional genetic abnormalities in these tumors. CONCLUSIONS: The data suggested that the significant proportion of patients with multifocal hepatocellular carcinomas have tumors of common clonal origin.

Clinical utility of immunohistochemistry in the diagnoses of urinary bladder neoplasia.

Urothelial carcinomas demonstrate diverse morphologic and immunologic features that frequently lead to diagnostic challenges. Recent advances have identified a number of immunohistochemical stains that, when used in the context of a panel, can be a valuable tool in properly classifying primary urothelial carcinoma and carcinomas secondarily involving the urinary bladder. In addition, new biomarkers prove helpful in the staging of bladder carcinoma. In this article, we review the clinical utility of immunohistochemistry in a series of diagnostic scenarios, including flat urothelial lesions with atypia, rare variants of urothelial carcinoma, primary adenocarcinoma versus secondary colorectal tumors, distinguishing prostate from urothelial carcinoma, and the utility of smoothelin in staging bladder carcinoma. Emphasis is placed on panels of commonly used biomarkers to establish diagnoses.

Expression of KISS1 and MMP-9 in non-small cell lung cancer and their relations to metastasis and survival.

KISS1 and matrix metalloproteinase-9 (MMP-9) may play important roles as metastasis suppressor and metastasis promoter genes, respectively, in a variety of malignancies. However, there is little information about their possible roles in non-small cell lung cancer (NSCLC). The goals of this study were to determine the mRNA and protein expressions of KISS1 and MMP-9 in NSCLC and their relations to metastasis and prognosis. The mRNA and protein expressions of KISS1 and of MMP-9 protein were detected by in situ hybridization and immunohistochemistry respectively in 85 cases of NSCLC, and their matched lymph node metastases. Expressions of KISS1 mRNA and protein were significantly higher in low TNM stages of NSCLC (I-II) compared to more advanced stages (III-IV) (p<0.05). Moreover, in advanced TNM stages, cases without metastasis had higher KISS1 gene expression compared to those with lymph node metastasis (p<0.05). In contrast, MMP-9 expression was higher in stage III-IV NSCLC cases compared to stage I-II tumors (p<0.05) and higher in NSCLC cases with metastasis than those without metastasis (p<0.05). There was negative correction between KISS1 and MMP-9 protein expression (p<0.01). The 5-year survival rate in cases with higher KISS1 protein expression was significantly higher than in those with low expression (20.9 vs. 2.4%, p<0.01). However, the 5-year survival rate of patients with high MMP-9 protein expression were lower than those with low expression (19 vs. 4.7%, p<0.05). Our data suggest that KISS1 and MMP-9 may serve as potential prognostic and therapeutic markers in lung cancer.

Urothelial dysplasia and other flat lesions of the urinary bladder: clinicopathologic and molecular features.

The 2004 World Health Organization classification system for urothelial neoplasia classifies flat-related preneoplastic lesions as urothelial hyperplasia (flat and papillary), reactive urothelial atypia, urothelial atypia of unknown significance, urothelial dysplasia (low-grade intraurothelial neoplasia), and urothelial carcinoma in situ (high-grade intraurothelial neoplasia). Each lesion is defined with precise nomenclature and strict morphologic criteria. In many cases, morphologic features alone suffice for diagnosis. Other cases may require a panel of immunohistochemical antibodies consisting of cytokeratin 20, p53, and CD44 for diagnosis. Recent molecular studies have provided further insight into the premalignant potential of these urothelial lesions. Herein, we present a review of flat urothelial lesions of the urinary bladder as defined by the 2004 World Health Organization classification with focus on the clinicopathologic, immunohistochemical, and molecular features.

Evidence for transformation of fibroadenoma of the breast to malignant phyllodes tumor.

Fibroadenoma (FA) and phyllodes tumor (PT) of the breast are biphasic tumors composed of variable proportions of epithelial and stromal cells. We identified a case of synchronous FA and PT in the same breast mass. Using laser capture microdissection, loss of heterozygosity analysis was performed on these components to gain potential insight into the histogenetic relationship between FA and PT. Genomic DNA was analyzed at 10 microsatellite loci by polymerase chain reaction. Both tumors showed allelic loss at D7S522. In addition, phylloid tumor showed allelic loss at TP53 and D22S264, not observed in FA. Our data suggest that FA and PT are clonally related and allelic loss at TP53 and D22S264 may be implicated in the progression of FA to phyllode tumor.