Darya Buehler

Papillary Thyroid Carcinoma Variants

Papillary thyroid carcinomas are the most common thyroid cancers and constitute more than 70% of thyroid malignancies. The most common etiologic factor is radiation, but genetic susceptibility and other factors also contribute to the development of papillary thyroid carcinoma. The most common variants include conventional, follicular variant and tall cell variant. However, many other uncommon variants have been described including oncocytic, columnar cell, diffuse sclerosing and solid forms. Immunohistochemical staining with TTF-1 and thyroglobulin is very useful in confirming the diagnosis of papillary thyroid carcinoma especially in metastatic sites. Markers such as HBME-1 and CITED1 can assist in separating some difficult cases of follicular variants of papillary thyroid carcinomas from follicular adenomas. Molecular studies have shown that the BRAF V600E mutation is found mainly in papillary and anaplastic thyroid carcinomas. Other molecular markers such as HMGA2 and insulin-like growth factor II mRNA binding protein 3 have been used recently as molecular tests to separate papillary thyroid carcinoma and its variants from follicular adenomas and other benign thyroid nodules.

Expression of epithelial-mesenchymal transition regulators SNAI2 and TWIST1 in thyroid carcinomas

Epithelial–mesenchymal transition is an important mechanism of epithelial tumor progression, local invasion and metastasis. The E-cadherin (CDH1) repressor SLUG (SNAI2) and the basic helix–loop–helix transcription factor TWIST1 inhibit CDH1 expression in poorly differentiated malignancies as inducers of epithelial–mesenchymal transition. Epithelial–mesenchymal transition has been implicated in progression from well to poorly differentiated/anaplastic thyroid carcinoma but the expression of SNAI2 and TWIST1 proteins and their phenotypic association in human thyroid cancers has not been extensively studied. We examined the expression of SNAI2, TWIST1 and CDH1 by immunohistochemistry in a panel of well-differentiated and anaplastic thyroid cancers and by qRT-PCR in thyroid cell lines. Ten normal thyroids, 33 follicular adenomas, 56 papillary thyroid carcinomas including 28 follicular variants, 27 follicular carcinomas and 10 anaplastic thyroid carcinomas were assembled on a tissue microarray and immunostained for SNAI2, TWIST1 and CDH1. Most (8/10) anaplastic thyroid carcinomas demonstrated strong nuclear immunoreactivity for SNAI2 with associated absence of CDH1 in 6/8 cases (75%). TWIST1 was expressed in 5/10 anaplastic thyroid carcinomas with absence of CDH1 in 3/5 (60%) cases. These findings were confirmed in whole sections of all anaplastic thyroid carcinomas and in a separate validation set of 10 additional anaplastic thyroid carcinomas. All normal thyroids, follicular adenomas, papillary and follicular thyroid carcinomas were negative for SNAI2 and TWIST1 (P<0.0001) and all showed strong diffuse immunoreactivity for CDH1 (P=0.026). Expression of SNAI2, TWIST1 and CDH1 mRNA varied in a normal thyroid, papillary carcinoma and two anaplastic thyroid carcinoma cell lines tested, but the highest levels of CDH1 mRNA were detected in the normal thyroid cell line while the anaplastic thyroid carcinoma cell line demonstrated the highest levels of SNAI2 and TWIST1 mRNA. Our findings support the role of epithelial–mesenchymal transition in the development of anaplastic thyroid carcinoma.

Antitumor Activity of Triolimus: A Novel Multidrug-Loaded Micelle Containing Paclitaxel, Rapamycin, and 17-AAG

Triolimus is a first-in-class, multidrug-loaded micelle containing paclitaxel, rapamycin, and 17-AAG. In this study, we examine the antitumor mechanisms of action, efficacy, and toxicity of Triolimus in vitro and in vivo. In vitro cytotoxicity testing of Triolimus was conducted using two aggressive adenocarcinomas including the lung cancer cell line, A549, and breast cancer cell line, MDA-MB-231. The three-drug combination of paclitaxel, rapamycin, and 17-AAG displayed potent cytotoxic synergy in both A549 and MDA-MB-231 cell lines. Mechanistically, the drug combination inhibited both the Ras/Raf/mitogen-activated protein kinase and PI3K/Akt/mTOR pathways. Triolimus was advanced into tumor xenograft models for assessment of efficacy, toxicity, and mechanisms of action. In vivo, a three-infusion schedule of Triolimus inhibited A549 and MDA-MB-231 tumor growth far more potently than paclitaxel-containing micelles and effected tumor cures in MDA-MB-231 tumor-bearing animals. Tumor growth delays resulted from a doubling in tumor cell apoptosis and a 50% reduction in tumor cell proliferation compared with paclitaxel-containing micelles. Enhanced antitumor efficacy was achieved without clinically significant increases in acute toxicity. Thus, Triolimus displays potent synergistic activity in vitro and antitumor activity in vivo with comparable toxicity to paclitaxel. These observations provide strong support for further development of Triolimus and an important proof of concept for safe, effective nanoparticle-based delivery of three complementary anticancer agents. Mol Cancer Ther; 11(10); 2233–42. ©2012 AACR.

CIC-DUX sarcomas demonstrate frequent MYC amplification and ETS-family transcription factor expression.

Recent molecular advances have identified a novel, clinically aggressive subgroup of undifferentiated round cell sarcomas defined molecularly by oncogenic fusion of the gene, CIC, and either DUX4 or its paralog, DUX4L, herein termed CIC-DUX sarcomas. Morphologically, CIC-DUX sarcomas are round cell sarcomas with high-grade nuclear features, including vesicular chromatin and nucleoli, patchy clear cell foci, myxoid change, and necrosis. Here, we studied a cohort of 10 cases, including 6 newly identified cases, 2 with paired metastases. Given our prior observation of trisomy 8 in these tumors, we assayed for amplification and expression of MYC (c-Myc) and representative downstream targets. Trisomy 8 was detected in 5/7 testable cases, with further amplification of MYC locus in 6/7 testable cases and immunohistochemical expression of MYC in 10/10. The canonical MYC transcriptional target, p21, but not MTDH, was differentially expressed compared with Ewing sarcomas. Given prior observation of induction of ETS-family transcription factors by the fusion oncoprotein, we assayed and identified highly prevalent positivity for ERG (9/10) and FLI1 (8/8). These findings are cautionary regarding use of these immunostains in prospective case workup, whereas the prevalent MYC amplification may represent a therapeutically targetable oncogenic pathway in CIC-DUX sarcomas.

Angiosarcoma outcomes and prognostic factors: a 25-year single institution experience.

Objective:Angiosarcoma is an aggressive malignancy with endothelial differentiation and notoriously poor prognosis despite aggressive therapy. Limited data are available to guide management decisions. To address this limitation, we present a large retrospective analysis of angiosarcoma patients treated at a single institution over a 25-year period. Methods:To identify factors that impact angiosarcoma outcomes, we reviewed demographic, tumor, and treatment characteristics of angiosarcoma patients evaluated at the University of Wisconsin Hospital between 1987 and 2012. Results:The cohort included 81 patients diagnosed at ages 19 to 90 years (median, 67 y). Fifty-five (68%) patients presented with localized disease, whereas 26 (32%) presented with metastases. The primary sites were visceral/deep soft tissue (42%), head and neck/cutaneous (37%), breast (16%), and limbs in the setting of Stewart-Treves (5%). The 5-year overall survival was 40% with a median of 16 months. By univariate analysis, significant adverse predictors of survival included metastases at presentation, visceral/deep soft tissue tumor location, tumor size>5 cm, tumor necrosis, and the absence of surgical excision. A trend toward prolonged survival was observed with radiation therapy and for chemotherapy in patients with metastases. Age, sex, and prior radiation showed no correlation with survival. Conclusions:Our large single institution series confirms the poor prognosis of angiosarcoma, supports a central role for surgical excision in management, and highlights the need for novel therapies particularly in patients who present with metastatic disease.

Nondiagnostic fine-needle aspirations of the thyroid: is the risk of malignancy higher?

BACKGROUND Nondiagnostic fine-needle aspirations (FNAs) pose a dilemma in the management of patients with thyroid nodules. In most cases, these patients undergo either repeat FNA or surgical resection. However, a significant number of patients will only be observed, assuming that the risk of malignancy is low. Therefore, the purpose of this study was to determine whether the risk of malignancy is higher in patients with thyroid nodules and nondiagnostic FNAs. METHODS We reviewed reports from 4286 consecutive FNA biopsies performed on patients with thyroid nodules at our institution between 2002 and 2010. We divided FNAs into two categories: diagnostic and nondiagnostic. We collected demographic, follow-up, and pathology data from both groups and then analyzed them with analysis of variance and chi-square tests. RESULTS Of the 4286 FNAs, 259 were classified as nondiagnostic (6%). We saw no significant differences in age or gender between patients with diagnostic versus nondiagnostic FNAs. Of the patients with nondiagnostic FNAs, 62 underwent diagnostic thyroidectomy (24%), 74 had a repeat FNA (29%), and 123 had observation only (47%); thus, 136 patients had a cytologic or pathologic diagnosis. Patients with nondiagnostic FNAs had a significantly higher rate of all types of thyroid cancer, compared with those with diagnostic FNAs (12% versus 5%, respectively; P < 0.001). Impressively, the chance of papillary thyroid cancer was twofold higher in patients with nondiagnostic FNAs. CONCLUSIONS The percentage of nondiagnostic FNA at our institution during this period (6%) was relatively low. However, the incidence of malignancy in these patients was significantly higher. Therefore, we recommend that patients with thyroid nodules and nondiagnostic FNAs undergo either repeat biopsy or diagnostic thyroidectomy.

Endoscopic ultrasound in the evaluation of pancreatic neoplasms-solid and cystic: A review

Pancreatic neoplasms have a wide range of pathology, from pancreatic adenocarcinoma to cystic mucinous neoplasms. Endoscopic ultrasound (EUS) with or without fine needle aspiration (FNA) is a helpful diagnostic tool in the work-up of pancreatic neoplasms. Its utility in pancreatic malignancy is well known. Over the last two decades EUS-FNA has become a procedure of choice for diagnosis of pancreatic adenocarcinoma. EUS-FNA is highly sensitive and specific for solid lesions, with sensitivities as high as 80%-95% for pancreatic masses and specificity as high as 75%-100%. Multiple aspects of the procedure have been studied to optimize the rate of diagnosis with EUS-FNA including cytopathologist involvement, needle size, suctioning and experience of endoscopist. Onsite pathology is one of the most important elements in increasing diagnostic yield rate in EUS-FNA. EUS-FNA is valuable in diagnosing rare and atypical pancreatic neoplasms including neuroendocrine, lymphoma and metastatic disease. As more and more patients undergo cross sectional imaging, cystic lesions of the pancreas are becoming a more common occurrence and EUS-FNA of these lesions can be helpful for differentiation. This review covers the technical aspects of optimizing pancreatic neoplasm diagnosis rate, highlight rare pancreatic neoplasms and role of EUS-FNA, and also outline the important factors in diagnosis of cystic lesions by EUS-FNA.

Fine Needle Aspiration of the Thyroid: A Contemporary Experience of 3981 Cases

BACKGROUND Fine needle aspiration (FNA) is an essential tool for the management of thyroid nodules. Recently, several national organizations have recommended FNA of all thyroid nodules >1 cm. With the increase use of imaging in the practice of medicine over the last decade, the number of incidentally discovered thyroid nodules is rising. Therefore, we analyzed our experience to determine if these changes in practice led to alterations in the population of patients undergoing FNA at our institution. MATERIALS AND METHODS Data were collected from 981 consecutive patients who underwent thyroid FNA at our institution between 2002 and 2009. Patients were divided in two groups: the early time period 2002-2005 (group 1) and later time period 2006-2009 (group 2). Data from the two groups were analyzed with t-test and χ(2) tests (SPSS, Inc., Chicago, IL). RESULTS Comparing the groups, the number of FNAs performed in the later time period increased significantly by 250%. Patients in the later time period (group 2) were more likely to be female and were significantly older. With regard to FNA diagnoses, the number of benign FNAs increased, while the percentage of FNAs diagnosed as malignant and as follicular neoplasm decreased. There also appears to be an increase in the incidence of thyroiditis. CONCLUSIONS The use of thyroid FNA has markedly increased during this contemporary series. This rise in thyroid FNA appears to be due to biopsy of benign thyroid nodules. With time, more females and older patients have undergone FNA, possibly reflecting the increased use of imaging studies in this patient population.

The evolving concept of cancer stem-like cells in thyroid cancer and other solid tumors

The cancer stem-like cell (CSC) hypothesis postulates that a small population of cells in a cancer has self-renewal and clonal tumor initiation properties. These cells are responsible for tumor initiation, growth, recurrence and for resistance to chemotherapy and radiation therapy. CSCs can be characterized using markers such as SSEA-1, SSEA-4, CD44, CD24, ALDEFLUOR and others. CSCs form spheres when they are cultured in serum-free condition in low attachment plates and can generate tumors when injected into immune-deficient mice. During epithelial to mesenchymal transition (EMT), cells lose cellular adhesion and polarity and acquire an invasive phenotype. Recent studies have established a relationship between EMT and increased numbers of CSCs in some solid malignancies. Non-coding RNAs such as microRNAs and long non-coding RNAs (lncRNAs) have been shown to have important roles during EMT and some of these molecules also have regulatory roles in the proliferation of CSCs. Specific lncRNAs enhanced cell migration and invasion in breast carcinomas, which was associated with the generation of stem cell properties. The tumor microenvironment of CSCs also has an important role in tumor progression. Recent studies have shown that the interaction between tumor cells and the local microenvironment at the metastatic site leads to the development of premetastatic niche(s) and allows for the proliferation of the metastatic cells during colonization. The role of exosomes in the microenvironment during the EMT program is currently a major area of research. This review examines CSCs and the relationship between EMT and CSCs in solid tumors with emphasis on thyroid CSCs. The role of non-coding RNAs and of the microenvironment in EMT and in tumor progression are also examined. This review also highlights the growing number of studies that show the close association of EMT and CSCs and the role of exosomes and other elements of the tissue microenvironment in CSC metastasis. A better understanding of these mechanisms will lead to more effective targeting of primary and metastatic malignancies.

Merkel Cell Carcinoma Analysis of Outcomes: A 30-Year Experience

Background Merkel cell carcinoma (MCC) is an aggressive cutaneous malignancy with poor prognosis. Limited data exists to guide treatment decisions. Here we report on our institutional experience and outcomes treating patients with MCC. Methods A database search (1984-2014) of patients treated at the University of Wisconsin Hospital and Clinics was used to identify patients with histologically confirmed MCC. Patient, tumor, and treatment characteristics were examined via review of medical records. Statistical analyses were performed to assess outcomes and associated prognostic factors. Results A total of 87 patients with MCC were identified with a median follow-up of 17 months (mean: 38, range: 0-210 months). Two and five-year overall survival rates were 53.9% and 32.8%, respectively. Recurrence was documented in 31.0% of patients (85.2% locoregional, 48.1% distant and 33.3% both). Patients with a history of immunosuppression exhibited significantly worse survival (hazard ratio, 2.01; 95% CI, 1.1-3.7) when compared to immune-competent individuals. The head and neck region was the most common location of primary lesion (N=49) followed by the extremities (N=31). Upper extremity primaries predicted significantly better overall survival (hazard ratio, 0.48; 95% CI, 0.23-0.99) while lower extremity primaries did not have significantly better results (hazard ratio, 0.5; 95% CI, 0.21-1.2) in comparison to head and neck site of primary. Nodal involvement (hazard ratio, 2.95; 95% CI, 1.5-5.79) was also a negative prognostic factor associated with poor overall survival when compared with clinically node negative patients. Primary tumor size > 2 cm (hazard ratio, 1.76; 95% CI, 0.91-3.4) was not associated with survival. Conclusions This study highlights the role of various factors in determining prognosis of Merkel cell carcinoma; history of immunosuppression, nodal involvement, and head/neck primary predicted worse overall survival. These findings suggest that improvements in both distant and locoregionally directed therapies might play an important role in control of MCC and identify areas for future study.