Summary Among thyroid papillary carcinomas (PTCs), the follicular variant is the most common and includes encapsulated forms (EFVPTCs). Noninvasive EFVPTCs have very low risk of recurrence or other ...adverse events and have been recently proposed to be designated as noninvasive follicular thyroid neoplasm with papillary-like nuclear features or NIFTP , thus eliminating the term carcinoma . This proposal is expected to significantly impact the risk of malignancy associated with the currently used diagnostic categories of thyroid cytology. In this study, we analyzed the fine needle aspiration biopsy (FNAB) cytology features of 96 histologically proven NIFTPs and determined how the main nuclear features of NIFTP correlate between cytological and histological samples. Blind review of FNAB cytology from NIFTP nodules yielded the diagnosis of “follicular neoplasm” (Bethesda category IV) in 56% of cases, “suspicious for malignancy” (category V) in 27%, “atypia of undetermined significance/follicular lesion of undetermined significance” (category III) in 15%, and “malignant” (category VI) in 2%. We found good correlation (κ = 0.62) of nuclear features between histological and cytological specimens. NIFTP nuclear features (size, irregularities of contours, and chromatin clearing) were significantly different from those of benign nodules but not from those of invasive EFVPTC. Our data indicate that most of the NIFTP nodules yield an indeterminate cytological diagnosis in FNAB cytology and nuclear features found in cytology samples are reproducibly identified in corresponding histology samples. Because of the overlapping nuclear features with invasive EFVPTC, NIFTP cannot be reliably diagnosed preoperatively but should be listed in differential diagnosis of all indeterminate categories of thyroid cytology.
Background BRAF V600E mutation has been investigated by immunohistochemistry and has shown high sensitivity and specificity. We aim to investigate the accuracy of immunohistochemistry versus ...molecular testing of BRAF V600E in papillary thyroid cancer using a large number of polymerase chain reaction–positive BRAF V600E papillary thyroid cancer tissues. Methods We stained 130 formalin-fixed papillary thyroid cancer specimens using the VE1 antibody: 100 BRAF V600E positive and 30 BRAF V600E negative confirmed by PCR. The sensitivity, specificity, and predictive values of the antibody were assessed. Results Immunohistochemistry of BRAF V600E showed 98.0% sensitivity, 93.3% specificity, and positive and negative predictive values of 98.0% and 93.3%, respectively. Of 100 patients with BRAF V600E PCR-positive samples, 97 (97.0%) had cytoplasmic weak (4.0%), moderate (17.0%), and strong (76.0%) immunostaining. In BRAF V600E PCR-negative samples, cytoplasmic staining was not detected in 93.3% (28/30) of papillary thyroid cancer tissues. The receiver operating characteristic curve demonstrated a high validity and comparable immunohistochemistry method (area under the curve = 98.8%) compared with PCR testing. Conclusion The use of VE1 immunohistochemistry for the detection of BRAF V600E in papillary thyroid cancer tissues is a clinically applicable method with high specificity, sensitivity, and positive and negative predictive values. The reliable use of BRAF V600E immunohistochemistry should promulgate the routine use of this method for BRAF V600E detection in papillary thyroid cancer tissues.
Background Proton magnetic resonance spectroscopy of operative specimens has been reported to successfully differentiate normal tissue from malignant thyroid tissue. We used a new high-resolution ...magnetic resonance spectroscopy technique for the differentiation of benign and malignant thyroid neoplasms. Methods Histological specimens from 72 patients undergoing a total thyroidectomy were processed into a 4-mm ZrO2 high-resolution magic angle spinning (HRMAS) rotor with 5 μL of D2 O. A Bruker Avance spectrometer operating at 400 MHz for the1 H frequency and equipped with a1 H/13 C/31 P HRMAS probe was used. Results Normal and neoplastic thyroid tissues could be discriminated from each other by different relative concentrations of several amino acids and lipids, as well as benign and malignant neoplasms, that differed in terms of a greater lactate and taurine and a lesser lipid choline, phosphocholine, myo-inositol, and scyllo-inositol levels in malignant samples. A statistical analysis with a receiver operating characteristic curve revealed that 77% of the samples were accurately predicted. Similar results were obtained with specimens obtained from ex vivo aspirates. Conclusion A further development of this project will be to use the metabolomics approach on specimens obtained from aspirates in vivo after the resolution of technical problems attributable to possible contamination.
Objective A complete surgical resection is the cornerstone of therapy of thymic tumors. Unfortunately, there is no standard treatment for pleural recurrence. This article describes our overall ...experience with the surgical treatment of pleural implants in patients who previously underwent resection of a thymoma. Material and Methods From January 1980 to June 2006, 20 patients previously operated on for a thymoma were operated on for the surgical resection of pleural implants. Patients with the initial Masaoka stage IVA were excluded from our analysis. Our sample comprised 10 male and 10 female patients (12–65 years old). The surgical approach to the resection of the thymoma was as follows: video-assissted thoracic surgery in 2 patients, sternotomy in 13 patients, thoracotomy in 2 patients, and sternothoracotomy in 3 patients. The initial Masaoka stage of the thymoma was IIA in 2 patients, IIB in 7 patients, and III in 11 patients. Results The interval between resection of the thymoma and pleural implants ranged from 11 to 156 (median 60) months. Fifteen patients had a thymus-related syndrome (in 13 patients it resulted myasthenia gravis), and in 11 patients it improved or remitted after treatment of the pleural recurrence. All the resections were performed through a posterolateral thoracotomy. Three patients underwent an iterative resection of new pleural implants. At the latest follow-up, 10 patients are still alive (8 disease-free) and 10 have died (9 of a relapse and 1 of the complications of red cell aplasia). From the pleural recurrence resection, the overall 5- and 10-year survivals are 43.1% and 25.8%, respectively. Conclusions Repeat operation on patients with thymoma pleural recurrences is feasible and safe. It can produce satisfactory results in terms of overall survival and paraneoplastic syndrome control. Moreover, the multimodality treatment could improve the results of surgical treatment.
Background Cell adhesion molecules, represented by the immunoglobulin family and selectins, play an important role in the progression of cancer. A correlation between selectins and tumor ...aggressiveness has been demonstrated in several reports. Methods Eighty-eight patients (mean age, 41.0 ± 14 years) with papillary thyroid carcinoma (conventional variant and sized approximately 20 mm) were divided in 2 groups: 41 with encapsulated tumors and 47 with tumors with extrathyroidal extension. E-selectin expression was evaluated by immunohistochemical staining and semiquantitative real-time reverse-transcription polymerase chain reaction and normalized by calculating the z -score (positive: value above the population mean; negative: below the mean). Results Lymph node metastasis (LNM) was found in 2 of 41 encapsulated tumors (4.8%) and in 19 of 47 tumors (40.4%) with extrathyroidal extension. BRAF mutation was present in 21 encapsulated tumors (51.2%) and in 31 tumors with extrathyroidal extension (65.9%). The mean E-selectin z -score was −0.32 for encapsulated tumors and 0.28 for tumors with extrathyroidal extension. E-selectin expression correlates with neoplastic infiltration ( P = .04), the American Joint Commission on Cancer stage ( P = .02), and BRAF mutation ( P = .03). Conclusion E-selectin overexpression in association with BRAF mutation status could promote a more aggressive phenotype in papillary thyroid carcinoma.
Summary The histologic diagnosis of the follicular variant of papillary thyroid carcinoma (FVPTC) may be troublesome, especially in its encapsulated form. We evaluated the expression of galectin-3 ...(gal-3) and Hector Battifora mesothelial cell (HBME-1) in 200 formalin-fixed thyroid tissues with diagnosis of classical variant of papillary thyroid carcinoma or FVPTC, encapsulated or with infiltrative growth, with or without lymph node metastasis. All cases of classical variant of papillary thyroid carcinoma were consistently positive for gal-3; similar results have been obtained by using HBME-1. Interestingly, the invasive type of FVPTC, with or without metastasis, was strongly positive for gal-3 (78.2% and 96%, respectively), whereas only 46.8% of encapsulated FVPTCs without metastasis showed immunostaining for this marker. In the latter group, the HBME-1 expression achieved a significantly higher percentage of positivity (87%). Surprisingly, gal-3 immunodetection showed negative results in 4 encapsulated FVPTCs, despite the strong immunoreactivity in corresponding metastasis. Our data suggest that gal-3 immunodetection alone is not able to support the diagnosis of encapsulated FVPTCs.
To identify genes involved in the transformation of thyroid follicular cells, we explored, using DNA oligonucleotide microarrays, the transcriptional response of PC Cl3 rat thyroid epithelial cells ...to the ectopic expression of the RET/PTC oncogenes. We found that RET/PTC was able to induce the expression of CXCR4, the receptor for the chemokine CXCL12/SDF-1alpha/beta. We observed that CXCR4 expression correlated with the transforming ability of the oncoprotein and depended on the integrity of the RET/PTC-RAS/ERK signaling pathway. We found that CXCR4 was expressed in RET/PTC-positive human thyroid cancer cell lines, but not in normal thyroid cells. Furthermore, we found CXCR4 expression in human thyroid carcinomas, but not in normal thyroid samples by immunohistochemistry. Since CXCR4 has been recently implicated in tumor proliferation, motility and invasiveness, we asked whether treatment with SDF-1alpha was able to induce a biological response in thyroid cells. We observed that SDF-1alpha induced S-phase entry and survival of thyroid cells. Invasion through a reconstituted extracellular matrix was also supported by SDF-1alpha and inhibited by a blocking antibody to CXCR4. Taken together, these results suggest that human thyroid cancers bearing RET/PTC rearrangements may use the CXCR4/SDF-1alpha receptor-ligand pathway to proliferate, survive and migrate.
RET, BRAF and other protein kinases have been identified as major molecular players in thyroid cancer. To identify novel kinases required for the viability of thyroid carcinoma cells, we performed a ...RNA interference screening in the RET/PTC1(CCDC6-RET)-positive papillary thyroid cancer cell line TPC1 using a library of synthetic small interfering RNAs (siRNAs) targeting the human kinome and related proteins. We identified 14 hits whose silencing was able to significantly reduce the viability and the proliferation of TPC1 cells; most of them were active also in BRAF-mutant BCPAP (papillary thyroid cancer) and 8505C (anaplastic thyroid cancer) and in RAS-mutant CAL62 (anaplastic thyroid cancer) cells. These included members of EPH receptor tyrosine kinase family as well as SRC and MAPK (mitogen activated protein kinases) families. Importantly, silencing of the identified hits did not affect significantly the viability of Nthy-ori 3-1 (hereafter referred to as NTHY) cells derived from normal thyroid tissue, suggesting cancer cell specificity. The identified proteins are worth exploring as potential novel druggable thyroid cancer targets.
Inappropriate activation of the RET receptor tyrosine kinase causes development of papillary and medullary thyroid cancer. We have previously shown that pyrazolopyrimidine is a potent inhibitor of ...the RET kinase. Here, we show that 4-amino-5-(4-chloro-phenyl)-7-(t-butyl)pyrazolo3,4-dpyrimidine) (PP2), another pyrazolopyrimidine, blocks the enzymatic activity of the isolated RET kinase and RET/PTC1 oncoprotein at IC50 in the nanomolar range. PP2 blocked in vivo phosphorylation and signaling of the RET/PTC1 oncoprotein. PP2 prevented serum-independent growth of RET/PTC1-transformed NIH3T3 fibroblasts and of TPC1 and FB2, two human papillary thyroid carcinoma cell lines that carry spontaneous RET/PTC1 rearrangements. Finally, PP2 blocked invasion of type I collagen matrix by TPC1 cells. Thus, pyrazolopirimidines hold promise for the treatment of human cancers sustaining oncogenic activation of RET.
Context: The transmembrane glycoprotein CD44v6 is overexpressed in most papillary thyroid carcinomas (PTC). We previously reported that osteopontin (OPN), a secreted glycoprotein that functions as a ...ligand for CD44v6, is overexpressed in thyrocytes transformed by the RET/PTC oncogene.
Objective: In this study we asked whether OPN is overexpressed in human PTC samples, and whether its expression correlates with clinical and histological features of the tumors. Furthermore, we wanted to establish the functional role of the CD44-OPN axis in thyroid tumorigenesis.
Design: Thyroid samples from 117 patients who had undergone surgical resection of the thyroid gland for benign or malignant lesions were collected. OPN and CD44 expressions were evaluated by immunohistochemistry with specific monoclonal antibodies. OPN expression was correlated with different PTC histological variants, lymph node metastasis, and PTC size.
Results: In this study we show that OPN is overexpressed in human PTCs with respect to normal thyroid tissue, follicular adenomas, and multinodular goiters (P < 0.05). The prevalence and intensity of OPN staining were significantly correlated with the presence of lymph node metastases (P = 0.0091) and tumor size (P = 0.0001). We also show that treatment of human PTC cells with recombinant exogenous OPN stimulated Matrigel invasion and activated the ERK and V-AKT murine thymoma viral oncogene homolog 1/protein kinase B; signaling pathways. Blockage of anti-CD44 antibodies prevented these effects.
Conclusions: Given its prevalence and its correlation with aggressive features of human PTCs, we suggest that OPN might be used as a diagnostic and prognostic marker for these tumors. Furthermore, given the role of the OPN-CD44v6 axis in PTC cells, we suggest that CD44 and/or OPN may be molecular targets for therapeutic intervention in aggressive PTCs.
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