Preoperative distinction of follicular thyroid carcinoma (FTC) from follicular thyroid adenoma (FTA) is a diagnostic challenge. Our aim was to investigate whether the Ki-67 proliferation index in fine needle aspiration material can contribute to the diagnosis of FTC.

The ETS family transcription factor GABPA is suggested as an oncogenic element, which is further supported by the recent reporting of it as the sole ETS member to activate the mutant TERT promoter in thyroid carcinomas (TC). However, it remains unclear how GABPA contributes to TC pathogenesis. The present study is designed to address this issue. TERT expression was significantly diminished in TERT promoter-mutated TC cells upon GABPA inhibition. Surprisingly, GABPA depletion led to robustly increased cellular invasion independently of TERT promoter mutations and TERT expression. DICER1, a component of the microRNA machinery, was identified as a downstream effector of GABPA. GABPA facilitated Dicer1 transcription while its depletion reduced Dicer1 expression. The mutation of the GABPA binding site in the DICER1 promoter led to diminished basal levels of DICER1 promoter activity and abolishment of GABPA-stimulated promoter activity as well. The forced DICER1 expression abrogated the invasiveness of GABPA-depleted TC cells. Consistently, the analyses of 93 patients with papillary thyroid carcinoma (PTC) revealed a positive correlation between GABPA and DICER1 expression. GABPA expression was negatively associated with TERT expression and promoter mutations, in contrast to published observations in cancer cell lines. Lower GABPA expression was associated with distant metastasis and shorter overall/disease-free survival in PTC patients. Similar results were obtained for PTC cases in the TCGA dataset. In addition, a positive correlation between GABPA and DICER1 expression was seen in multiple types of malignancies. Taken together, despite its stimulatory effect on the mutant TERT promoter and telomerase activation, GABPA may itself act as a tumor suppressor rather than an oncogenic factor to inhibit invasion/metastasis in TCs and be a useful predictor for patient outcomes.

Survival after loco-regional failure (LRF) of breast cancer was investigated at the population level.

Background: Loco-regional recurrence (LRR) of breast cancer is a significant cause of morbidity and mortality. It is poorly described how prognosis after LRR has evolved over time at the population level. Methods: 2272 patients diagnosed with LRR between 1980-2014 were identified within the Stockholm cancer registry and divided in 7 cohorts by the year of LRR diagnosis. Post-relapse event free survival (EFS) and overall survival (OS) were analyzed separately in local and loco-regional relapses and compared across the cohorts by Cox regression method. Primary tumor size, axillary node status, estrogen receptor (ER) status, type of surgery, adjuvant chemotherapy, LRR free survival, and age at LRR were the covariates for Cox model adjustment. Results: In 1615 patients diagnosed with local relapse, 903 post-LRR events were registered (Table). A significant improvement in median EFS (p < .001) and OS (p < .001) was observed in patients diagnosed 2010-14 compared with previous time periods. Among 657 patients with loco-regional recurrences, 476 experienced a post-LRR event (Table). EFS and OS independently improved over time (p <.001 and p <.001, respectively). Smaller primary tumors, negative axillary lymph nodes, ER positive status, breast-conserving surgery, longer LRR-free interval and younger age at LRR occurrence were independently associated with longer survival after LRR. No association was observed between survival and type of surgery or LRR-free interval in LRRs. An improvement in survival over time was also demostrated when cohorts 1980-84 and 2010-14 were excluded from the model.Table288PLocal recurrenceLocoregional recurrenceType of post-ILRR relapseN (%)N (%)Loco-regional117 (13%)57 (12%)Distant438 (49%)305 (64%)Loco-regional + distant13 (1%)3 (1%)Death335 (37%)111 (23%)Total903 (100%)476 (100%) Open table in a new tab Conclusions: Survival after LRR has gradually improved over the last 35 years regardless of other recognized prognostic factors. Legal entity responsible for the study: Karolinska Institutet Funding: Dagmar Ferbsminnesfond Disclosure: All authors have declared no conflicts of interest.

Medullary thyroid carcinomas (MTCs) exhibit telomerase activation in strong association with shorter patient survival. To understand the background of telomerase activation we quantified TERT copy numbers and TERT promoter methylation in 42 MTCs and normal thyroid references. Gain of TERT was demonstrated by quantitative PCR in 5/39 sporadic MTC. Increased methylation index (MetI) for CpG methylation at the TERT promoter was found in sporadic MTCs (P < 0.0001) and in MEN 2 associated MTCs (P = 0.011) vs. normal thyroid tissues. MetI correlated positively with TERT gene expression (r = 0.432, P = 0.006) and negatively with telomere length (r = -0.343, P = 0.032). MTC cases with MetI above the median of 52% had shorter survival as compared to cases with lower MetI (P = 0.005 for overall survival and P = 0.007 for disease-related survival).Protein expression profiles obtained by mass spectrometry were then studied in relation to telomerase activation in MTCs. Comparing protein levels between tumors defined by telomerase activity status, 240 proteins were associated with telomerase activity. Among telomerase activation positive cases a set of proteins was found to discriminate between MTCs with high and low TERT gene expression with enrichment for proteins involved in telomerase regulation. XRCC5 mRNA expression was found increased in MTCs vs. normal thyroid (P = 0.007). In conclusion the findings suggest a role for TERT copy number gain, TERT promoter methylation and XRCC5 expression in telomerase activation and telomere maintenance of MTC.

Cystic papillary thyroid carcinoma (cPTC) is a subgroup of PTC presenting a diagnostic challenge at fine needle aspiration biopsy (FNAB). To further investigate this entity we aimed to characterize protein profiles of cyst fluids from cPTC and benign thyroid cystic lesions. In total, 20 cPTCs and 56 benign thyroid cystic lesions were studied. Profiling by liquid chromatography tandem mass spectrometry (LC-MS/MS) was performed on cyst fluids from a subset of cases after depletion, and selected proteins were further analyzed by Western blot (WB), immunohistochemistry (IHC) and enzyme-linked immunosorbent assay (ELISA). A total of 1,581 proteins were detected in cyst fluids, of which 841 were quantified in all samples using LC-MS/MS. Proteins with different expression levels between cPTCs and benign lesions were identified by univariate analysis (41 proteins) and multivariate analysis (59 proteins in an orthogonal partial least squares model). WB analyses of cyst fluid and IHC on corresponding tissue samples confirmed a significant up-regulation of cytokeratin 19 (CK-19/CYFRA 21-1) and S100A13 in cPTC vs. benign lesions. These findings were further confirmed by ELISA in an extended material of non-depleted cyst fluids from cPTCs (n = 17) and benign lesions (n = 55) (p<0.05). Applying a cut-off at >55 ng/ml for CK-19 resulted in 82% specificity and sensitivity. For S100A13 a cut-off at >230 pg/ml revealed a 94% sensitivity, but only 35% specificity. This is the first comprehensive catalogue of the protein content in fluid from thyroid cysts. The up-regulations of CK-19 and S100A13 suggest their possible use in FNAB based preoperative diagnostics of cystic thyroid lesions.

BACKGROUNDThe telomerase reverse transcriptase (TERT) promoter mutations C228T and C250T have been found in many malignancies, including in thyroid carcinomas. However, it is unclear how early these mutations occur in thyroid tumorigenesis.METHODSThe study included primary tumors from 58 patients initially diagnosed with follicular thyroid adenoma (FTA), a benign entity, 18 with atypical FTA (AFTA) having an uncertain malignant potential, and 52 with follicular thyroid carcinoma (FTC). Sanger sequencing was used to investigate the mutational status of the TERT promoter. Telomere length and TERT messenger RNA (mRNA) expression were determined using quantitative polymerase chain reaction (PCR). Telomerase activity was assessed using a Telomerase PCR enzyme‐linked immunosorbent assay kit.RESULTSThe C228T mutation was identified in 1 of 58 FTA (2%) and 3 of 18 AFTA (17%) samples. These 4 tumors all expressed TERT mRNA and telomerase activity, whereas the majority of C228T‐negative adenomas lacked TERT expression (C228T versus wild‐type, P = .008). The C228T mutation was associated with NRAS gene mutations (P = .016). The patient with C228T‐mutated FTA later developed a scar recurrence and died of FTC, whereas none of the remaining 57 patients with FTA had recurrence. No recurrence occurred in 3 patients with AFTA who carried C228T during the follow‐up period (36‐285 months). Nine of the 52 FTCs (17%) exhibited the TERT mutation (8 of 9 C228T and 1 of 9 C250T), and the presence of the mutation was associated with shorter patient survival.CONCLUSIONSTERT promoter mutations may occur as an early genetic event in thyroid follicular tumors that have not developed malignant features on routine histopathological workup. Cancer 2014;120:2965–2979. © 2014 American Cancer Society.

Context: Telomere maintenance via telomerase activation and the alternative lengthening of telomeres (ALT) mechanism was assessed in medullary thyroid carcinoma.Setting and Design: In total, 42 medullary thyroid carcinomas (MTC) were studied including 24 rearranged during transfection (RET)- mutated cases. Relative telomerase reverse transcriptase (TERT) expression, splice forms, and telomere length were determined by PCR-based methods, and telomerase activity by ELISA. The ALT mechanism was detected by Southern blot analysis and immunofluorescence.Results: TERT expression and telomerase activity were detected in 21/42 tumors (50%), and was independent of the common somatic M918T RET mutation. Mean telomere length was shorter in MTCs compared with thyroids. Telomerase activation was associated with large tumor size (P = .027), advanced clinical stage (P = .0001), and short survival (P = .0001). Full-length TERT and the alpha(-) and beta(-)-deletion forms were revealed, and the full-length form was associated with short survival (P = .04). A subset of cases without telomerase activation showed involvement of the ALT mechanism, which was associated with a low MIB-1 proliferation index (P = .024).Conclusions: Stabilization of telomeres by telomerase activation occurs in half of the MTCs and by the ALT mechanism in a subset of cases. Telomerase activation may be used as an additional prognostic marker in medullary thyroid carcinoma.

Telomerase activation through induction of its catalytic component telomerase reverse transcriptase (TERT) expression is essential for malignant transformation. TERT promoter mutations namely C228T and C250T that stimulate TERT transcription and telomerase activation have recently been identified in many human malignancies. We thus determined these mutations and their biological and clinical implications in thyroid carcinomas in the present study. The TERT promoter was sequenced in 10 thyroid cancer cell lines and 144 tumors from 20 patients with anaplastic thyroid carcinoma (ATC), 51 with papillary thyroid carcinoma (PTC), 36 with follicular thyroid carcinoma (FTC), and 37 with medullary thyroid carcinoma (MTC). We identified C228T or C250T mutation in 6/8 of ATC cell lines, as well as in tumor tissue from 10/20, 13/51, 8/36 and 0/37 patients with ATC, PTC, FTC and MTC, respectively. In PTC patients, these mutations were exclusively present in the group with age >45 years (P<0.0001), and highly correlated shorter telomeres (P<0.0001) and distant metastasis (P=0.028). The previous radioactivity exposure did not induce the mutation. The presence of C228T or C250T was an independent predictor associated with shorter disease-related survival (DRS) in the entire cohort (P<0.0001), as well as among patients >45 years (P=0.021). ATC patients carrying the mutation survived shorter than those without mutations, although not statistically significant (P=0.129). The TERT promoter mutation was associated with overall survival (P=0.038) and DRS (P=0.058) of FTC patients. Taken together, age- and shorter telomere-dependent TERT promoter mutations occur frequently in follicular cell-derived thyroid carcinoma (ATC, PTC and FTC) but not in parafollicular cell-originated MTC, and may serve as a marker for aggressive disease and poor outcome.

ObjectiveThyroid proteomics is a new direction in thyroid cancer research aiming at etiological understanding and biomarker identification for improved diagnosis.MethodsTwo-dimensional electrophoresis was applied to cytosolic protein extracts from frozen thyroid samples (ten follicular adenomas, nine follicular carcinomas, ten papillary carcinomas, and ten reference thyroids). Spots with differential expression were revealed by image and multivariate statistical analyses, and identified by mass spectrometry.ResultsA set of 25 protein spots significant for discriminating between the sample groups was identified. Proteins identified for nine of these spots were studied further including 14-3-3 protein beta/alpha, epsilon, and zeta/delta, peroxiredoxin 6, selenium-binding protein 1, protein disulfide-isomerase precursor, annexin A5 (ANXA5), tubulin alpha-1B chain, and α1-antitrypsin precursor. This subset of protein spots carried the same predictive power in differentiating between follicular carcinoma and adenoma or between follicular and papillary carcinoma, as compared with the larger set of 25 spots. Protein expression in the sample groups was demonstrated by western blot analyses. For ANXA5 and the 14-3-3 proteins, expression in tumor cell cytoplasm was demonstrated by immunohistochemistry both in the sample groups and an independent series of papillary thyroid carcinomas.ConclusionThe proteins identified confirm previous findings in thyroid proteomics, and suggest additional proteins as dysregulated in thyroid tumors.

Background Increased incidence of papillary thyroid carcinoma (PTC) is observed as a consequence of radiation exposure in connection to the Chornobyl nuclear plant accident in 1986. In this study, we report a cohort of adult Ukrainian patients diagnosed with PTC from 2004 to 2008 following exposure at the age of 18 years or younger. Methods In total, 70 patients were identified and clinically characterized. The common BRAF 1799T>A mutation was assessed by pyrosequencing, the RET/PTC1 and RET/PTC3 (NCOA4) rearrangements by RT-PCR, and the expression of Ki-67 (MIB-1 index), BCL2, cyclin A, and cyclin D1 by immunohistochemistry. Results In total, 46/70 (66%) cases carried a BRAF mutation and/or a RET/PTC rearrangement. A BRAF mutation was detected in 26 tumors, RET/PTC1 in 20 cases, and RET/PTC3 in four cases. In four of these cases, BRAF mutation and RET/PTC rearrangement were coexisting. The BRAF mutation was underrepresented among PTCs with accompanying chronic lymphocytic thyroiditis (CLT) compared with PTCs without this feature (12 vs 44%). MIB-1 proliferation index determined by double staining with leukocyte common antigen was low (mean 0.8%; range 0.05–4.5%). Moreover, increased expression of cyclin A was observed in PTCs with a tumor size >2 cm compared with PTCs ≤2 cm (1.2 vs 0.6%). BCL2 and cyclin D1 showed frequent expression but without associations to clinical characteristics or amplification of the CCND1 locus. Conclusions Our results suggest that this cohort has frequent BRAF mutation, RET/PTC1 rearrangement, and low proliferation index. Furthermore, BRAF 1799T>A was underrepresented in PTCs with CLT, and cyclin A expression was associated with increased PTC tumor size.

We have investigated in vitro effects of anticancer therapy with the histone deacetylase inhibitor (HDACi) 4-phenylbutyrate (4-PB) combined with receptor tyrosine kinase inhibitors (RTKi) gefitinib or vandetanib on the survival of glioblastoma (U343MGa) and medulloblastoma (D324Med) cells. In comparison with individual effects of these drugs, combined treatment with gefitinib/4-PB or vandetanib/4-PB resulted in enhanced cell killing and reduced clonogenic survival in both cell lines. Our results suggest that combined treatment using HDACi and RTKi may beneficially affect the outcome of cancer therapy.

BACKGROUND:The accurate diagnosis of thyroid tumors is challenging. Proteomics has emerged as a promising approach for the discovery of molecular diagnostic markers as a potential complement to routine diagnostics.METHODS:Protein fractions from 29 frozen thyroid tumor tissue samples (10 papillary carcinomas, 9 follicular carcinomas, and 10 follicular adenomas) as well as from normal thyroid tissue were analyzed by surface enhanced laser desorption/ionization time-of-flight mass spectrometry followed by validation by Western blotting and immunohistochemistry.RESULTS:A Ca2+ binding protein belonging to the S100 family, S100A6, was differentially expressed between papillary and follicular thyroid tumors. Moreover, two posttranslationally modified forms of S100A6 were observed and verified by liquid chromatography-coupled tandem mass spectrometry. Validation by Western blotting displayed a significantly higher expression of S100A6 in papillary thyroid carcinoma (PTC) in comparison with the other tumor groups or normal tissue (p < 0.05). Immunohistochemical analysis on 98 tumors showed that PTC cases had a significantly stronger cytosolic staining and a larger proportion of stained nuclei than follicular tumors. BRAF gene mutation was not significantly associated with S100A6 protein levels.CONCLUSION:This study supports a role of S100A6 in thyroid tumorigenesis and as a potential aid in the discrimination between follicular thyroid tumors and PTC.

Abstract Introduction: Most patients with papillary thyroid cancer (PTC) have an excellent prognosis. Ki-67 is marker of proliferation, and proliferative index more than 5% as calculated with the MIB-1 antibody indicates a worse prognosis in PTC. This study was performed in order to investigate and evaluate expression of MIB-1 in a cohort of adult PTC patients who were exposed in their childhood to radioactivity from the Chornobyl accident in 1986. Materials and Methods: 70 patients (60 females and 10 males, mean age 30,5 (19-39)) operated on for PTC during 2004-2008 were identified for the study. Two groups were established according to diagnosis. Group 1 consisted of patients with PTC only (n=53). Group 2 consisted of patients with PTC and co-existing chronic lymphatic thyroiditis (n= 17). Proliferative activity was measured by immunohistochemistry using monoclonal MIB-1 antibody against nuclear factor Ki-67. A minimum of 2000 tumor cells were calculated and the percentage of positive cells (MIB-1 index) was compared with clinical data. Results: MIB-1 index was higher in Group 2 (mean 3,65) compared with Group 1 (mean 1,97) (p=0,005). No other clinical features could be correlated with the MIB-1 index. 26% of patients in Group 1 had lymph node metastases, and 23% in Group 2. The mean tumor size was slightly higher in Group 1 (2 cm) compared with Group 2 (1,75 cm). Age at diagnosis (30,5) and age at the Chornobyl accident (11) were identical between the groups. Conclusions: The clinical features of this cohort of adult PTC patients exposed to the radioactive fallout from the Chornobyl accident seem no different to other PTC cohorts. However, a rather large proportion of patients showed signs of coexisting thyroiditis. Whether the elevated MIB-1 index in this group of patients reflects a worse prognosis is yet not possible to say due to the short follow-up time. Still, a closer follow-up may be justified. Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-219.

Fine needle aspiration biopsy (FNAB) is the preferred technique for the initial diagnostic evaluation of thyroid lesions, which nevertheless poses a diagnostic challenge for all clinicians involved. The latter necessitates the use of molecular markers on thyroid cytology. MIB-1 is a molecular marker already used in the cytological evaluation of various tumors. In this study, we assessed whether MIB-1 proliferation index adds diagnostic information to the conventional cytological analysis of thyroid nodules and prognostic information in thyroid cancers. MIB-1 index for various thyroid lesions was retrospectively reviewed in a series of 504 patients. Furthermore, the prognostic value of MIB-1 index was investigated for 183 of the patients with papillary thyroid cancer (PTC). MIB-1 index was significantly higher in anaplastic thyroid cancer (ATC) compared to other tumor types (p<0.01). No significant difference in MIB-1 index was observed between thyroid adenomas and follicular carcinomas. In PTC, MIB-1 index equal to or >4% was found to be an independent factor significantly associated with higher risk of distant metastasis and disease-related mortality (p<0.05). Conclusively, this study shows that preoperative MIB-1 index assessment in FNAB of thyroid nodules offers little diagnostic information as far as follicular tumors are concerned. In cases of PTC, though, MIB-1 may serve as a prognostic indicator of disease spreading and poor survival and hence influence the planning of the overall treatment scheme.

We report a protocol for pre-fractionation of proteins from frozen tumours. Using this protocol two separate protein fractions are extracted: Fraction 1 is enriched for cytosolic and Fraction 2 for nuclear/nuclear membrane proteins. The accuracy and reproducibility of the protocol were demonstrated by Western blot analyses and SELDI–TOF-MS profilings. The resulting protein profiles were similar within the respective groups of Fractions 1 and 2 samples, without differences between freshly prepared tumours or those obtained as frozen tissue from biobanks.