PRDM16 Inhibits Cell Proliferation and Migration via Epithelial-to-Mesenchymal Transition by Directly Targeting Pyruvate Carboxylase in Papillary Thyroid Cancer.

PRDM16 (known as MEL1), a member of the PR domain zinc finger family, has been implicated in multiple biological processes, including cancers. It is not clear yet whether PRDM16 is involved in tumor progress of papillary thyroid cancer (PTC). We identified the PRDM16 expression level in PTC tissues by qRT-PCR and analyzed its relationship with clinical characteristics in both Fudan University Shanghai Cancer Center (FUSCC) and TCGA cohorts. We tested the function of PRDM16 in PTC cells both in vivo and in vitro. We found a direct downstream target of PRDM16, pyruvate carboxylase (PC), by RNA-sequencing, rescue experiments, luciferase assay, and chromatin immunoprecipitation assay. PRDM16 was downregulated in papillary thyroid cancer tissues and was significantly related with lymph node metastases and extrathyroidal extension in both FUSCC and TCGA cohorts. Overexpression of PRDM16 could attenuate proliferation and migration of PTC cells via inhibiting the epithelial-to-mesenchymal transition process. PC was upregulated in papillary thyroid cancer tissues. Knockdown of PC could inhibit proliferation and migration in TPC-1 and K1 cells. The repression effect on cell proliferation and migration from PRDM16 was PC dependent. PRDM16 could directly bind to the PC promoter and inhibit its expression at the transcription level. Moreover, the mRNA expression level of PRDM16 and PC was negatively related in human PTC tissues. In conclusion, PRDM16 exhibited an antitumor effect and EMT inhibition function in PTC by directly binding with the PC promoter. PRDM16 may be a novel therapeutic target in papillary thyroid cancer.

IL-2 enhanced MHC class I expression in papillary thyroid cancer with Hashimoto's thyroiditis overcomes immune escape in vitro.

The impact of Hashimoto's thyroiditis (HT) on the progression of papillary thyroid cancer (PTC) is still unclear. Interleukin-2 (IL-2) is a growth factor and crucial for HT development. This study aimed at investigating the effect of IL-2 on MHC class I expression in PTC cells and immune activation with experimental treatment for PTC using PTC cell lines. We assessed the expression of IL-2, HLA class I, PD-L1, CD3, CD8 and CD16 molecules in paired PTC tissues and HLA-ABC and PD-L1 expression in IL-2 pre-treated K1, TPC-1 and BCPAP cells by immunohistochemistry, qPCR, flow cytometry and Western blotting. The effect of IL-2 on immunogenicity of PTC cells to stimulate activated human T cells was determined for the percentages of activated CD8+ T cells and their cytokine production as well as PD-1 and PD-L1 expression. Compared with non-tumor tissues, we found that IL-2 expression was up-regulated in PTC tissues, particularly in PTC+HT tissues and correlated positively with HLA-class I, CD3 and CD8 expression in PTC+HT tissues. Conversely, PD-L1 expression decreased in PTC+HT tissues. Treatment with IL-2 significantly up-regulated HLA-class I expression, but down-regulated PD-L1 expression in PTC cells. Co-culture with IL-2-pre-treated PTC cells significantly promoted the proliferation of activated CD8+ T cells and their IL-2 secretion, but decreased their PD-1 expression, accompanied by decreased PD-L1 expression in IL-2-treated PTC cells in vitro. In conclusion, IL-2 up-regulated HLA-class I expression and enhanced anti-tumor T cell immunity during the development of PTC and HT. IL-2 may be a promising immunotherapy for PTC.

The application of selective neck dissection while preserving the cutaneous branches of cervical plexus in the surgical treatment of differentiated thyroid cancer-experiences from thousands of cases.

Differentiated thyroid cancer (DTC) is associated with the highest propensity for lymph node metastases, given the significant morbidity associated with sacrificing the spinal accessory nerve, surgeons increasingly looked to minimizing functional deficits while maintaining oncologic outcome. We have detailed the technique of a selective neck dissection with more attention to preserving the cervical sensory nerves since 1999 in Fudan University Shanghai Cancer Center. We found that the radical dissection with preservation of the cutaneous branches including the great auricular nerve, the less occipital nerve and the supraclavicular nerve can maximally decrease the complications of paresthesia and dysesthesia postoperatively in the lower neck, the shoulders and the area around the ear in DTC cases when indications were allowed. As long as the principles of cancer surgery are strictly followed, our approach guarantees radical tumor removal and exhibit more functional preservation.

Verteporfin inhibits papillary thyroid cancer cells proliferation and cell cycle through ERK1/2 signaling pathway.

Verteporfin, a FDA approved second-generation photosensitizer, has been demonstrated to have anticancer activity in various tumors, but not including papillary thyroid cancer (PTC). In current pre-clinical pilot study, we investigate the effect of verteporfin on proliferation, apoptosis, cell cycle and tumor growth of PTC. Our results indicate verteporfin attenuates cell proliferation, arrests cell cycle in G2/S phase and induces apoptosis of PTC cells. Moreover, treatment of verteporfin dramatically suppresses tumor growth from PTC cells in xenograft mouse model. We further illustrate that exposure to MEK inhibitor U0126 inactivates phosphorylation of ERK1/2 and MEK in verteporfin-treated PTC cells. These data suggest verteporfin exhibits inhibitory effect on PTC cells proliferation and cell cycle partially via ERK1/2 signalling pathway, which strongly encourages the further application of verteporfin in the treatment against PTC.

Histone methyltransferase KMT5A gene modulates oncogenesis and lipid metabolism of papillary thyroid cancer in vitro.

KMT5A (known as PR-Set7/9, SETD8 and SET8), a member of the SET domain containing methyltransferase family specifically targeting H4K20 for methylation, has been implicated in multiple biological processes. In the present study, we identified that KMT5A was elevated in 50 pairs of papillary thyroid cancer tissue samples and in cell lines K1 and TPC-1 by qRT-PCR and western blotting, as well as by immunohistochemical staining. CCK-8 assay and flow cytometric analysis revealed that inhibition of KMT5A attenuated proliferation and induced apoptosis. Transwell assays revealed that cell migration and invasion were suppressed in KMT5A-knockdown cells. Moreover, the inhibition of KMT5A arrested the cell cycle in the G1/S phase of papillary thyroid cancer cells. The TCGA data revealed that elevated KMT5A expression was significantly correlated with extrathyroidal extension, lymph node metastasis and advanced pathological stage of papillary thyroid cancer. Furthermore, we observed that inhibition of KMT5A suppressed the expression of SREBP1, SCD, FASN and ACC, key molecules involved in lipid metabolism and decreased the level of malondialdehyde in papillary thyroid cancer cells. In conclusion, KMT5A may be a novel oncogenic factor, specifically a regulator for lipid metabolism in papillary thyroid carcinoma.

The Positive Lymph Node Number and Postoperative N-Staging Used to Estimate Survival in Patients with Differentiated Thyroid Cancer: Results from the Surveillance, Epidemiology, and End Results Dataset (1988-2008).

BACKGROUND: Lymph node metastasis is important when evaluating the prognosis of patients with differentiated thyroid cancer (DTC). However, the current N-staging system cannot fully reflect the clinical significance of cervical lymph node metastasis in DTC. In this study, we employed Surveillance, Epidemiology, and End Results (SEER)-registered DTC cases with lymph node metastasis to determine whether the positive lymph node number (PLNN) could be used to improve stratification of patients in terms of survival. METHODS: We used the SEER dataset to identify all DTC patients with at least one positive cervical lymph node who were examined between 1988 and 2008. Multivariable modeling was used to compare cancer-specific survival (CSS) and overall survival (OS) and to calculate different PLNN cutoff points. RESULTS: In total, 14,359 pN + DTC patients identified in the SEER were included. In multivariate Cox regression analysis, the PLNN was significantly associated with both CSS and OS, whereas neither the lymph node ratio (LNR) nor the (numbers of) lymph nodes examined (LNE) were so associated. The highest C-index value (0.933) and the lowest AIC value (9362.687) obtained indicated that the PLNN better predicted the CSS of DTC than did the LNR or LNE. As the p values for both CSS and OS were minimized, and as the PLNN performed best when cases were grouped, PLNN cutoff points of 10 and 3/10 efficiently stratified DTC patients into two and three levels, respectively. Based on the 3/10 trichotomy, the benefits of radioactive iodine (RAI) treatment were evaluated for each group. Such treatment afforded about a 10% survival benefit in patients with more than 10 lymph node metastases. CONCLUSIONS: Compared with the LNR and LNE under different statistical models, PLNN was superior in terms of DTC staging. A cutoff point of 3/10 was optimal for stratifying patients according to prognosis and was of clinical significance in terms of RAI treatment selection.

Yes-associated protein 1 promotes papillary thyroid cancer cell proliferation by activating the ERK/MAPK signaling pathway.

Yes-associated protein 1 (YAP1) stimulates cell proliferation, epithelial-to-mesenchymal transition, invasion and metastasis in several cancers. Here, we investigated the involvement of YAP1 in papillary thyroid carcinoma (PTC) by assessing YAP1 mRNA and protein levels in PTC tissues and matched normal thyroid epithelial tissues from 50 patients. YAP1 mRNA and protein levels were higher in PTC tumor tissues than in control tissues, and correlated positively with the levels of proliferation-related genes (KI67 and c-MYC). We also used lentiviral vectors to overexpress or silence YAP1 expression in the K1 PTC cell line so that we could investigate the effects of YAP1 on cancer cell proliferation. YAP1 overexpression enhanced PTC cell proliferation by activating ERK1/2 and AKT, and these effects were impaired by treating the cells with the MEK inhibitor U0126 or the AKT inhibitor GSK690693. Finally, YAP1 overexpression dramatically induced growth of tumors from PTC cells in a xenograft mouse model. These results suggest that YAP1 enhances cell proliferation in PTC, and thus may be a promising target in the treatment of PTC.

BRAF-activated LncRNA functions as a tumor suppressor in papillary thyroid cancer.

Long non-coding RNAs (lncRNAs) participate in cancer cell tumorigenesis, cell cycle control, migration, proliferation, apoptosis, metastasis and drug resistance. The BRAF-activated non-coding RNA (BANCR) functions as both an oncogene and a tumor suppressor. Here, we investigated BANCR's role in papillary thyroid carcinoma (PTC) by assessing BANCR levels in PTC and matched normal thyroid epithelial tissues from 92 patients using qRT-PCR. We also used lentiviral vectors to establish PTC cell lines to investigate the effects of BANCR overexpression on cancer cell proliferation, apoptosis, migration and invasion. Our results indicate BANCR levels are lower in PTC tumor tissues than control tissues. Decreased BANCR levels correlate with tumor size, the presence of multifocal lesions and advanced PTC stage. BANCR overexpression reduced PTC cell proliferation and promoted apoptosis, which inhibited metastasis. It also inactivated ERK1/2 and p38, and this effect was enhanced by treatment with the MEK inhibitor U0126. Finally, BANCR overexpression dramatically inhibited tumor growth from PTC cells in xenograft mouse models. These results suggest BANCR inhibits tumorigenesis in PTC and that BANCR levels may be used as a novel prognostic marker.

Metastatic lymph node ratio can further stratify risk for mortality in medullary thyroid cancer patients: A population-based analysis.

Medullary thyroid cancer (MTC) has a propensity to cervical lymph node metastases (LNM). Recent studies have shown that both the number of involved lymph nodes (LNs) and the metastatic lymph node ratio (MLNR) confer prognostic information. This study was to determine the predictive value of MLNR on cancer-specific survival (CSS) in SEER (Surveillance, Epidemiology and End Results)-registered MTC patients treated with thyroidectomy and lymphadenectomy between 1991 and 2012, investigate the cutoff points for MLNR in stratifying risk of mortality and provide evidence for selection of appropriate treatment strategies. X-tile program determined 0.5 as optimal cut-off value for MLNR in terms of CSS in 890 MTC patients. According to multivariate Cox regression analysis, MLNR (0.50-1.00) is a significant independent prognostic factor for CSS (hazard ratio 2.161, 95% confidence interval 1.327-3.519, p=0.002). MLNR (0.50-1.00) has a greater prognostic impact on CSS in female, non-Hispanic white, T3/4, N1b and M1 patients. The lymph node yield (LNY) influences the effect of MLNR on CSS; LNY ≥9 results in MLNR (0.50-1.00) having a higher HR for CSS than MLNR (0.00-0.49). In conclusion, higher MLNRs predict poorer survival in MTC patients. Eradication of involved nodes ensures accurate staging and maximizes the ability of MLNR to predict prognosis.

Prognostic significance and optimal cutoff of age in medullary thyroid cancer.

Age has been found to correlate with the prognosis for medullary thyroid cancer (MTC). This study was conducted to investigate whether age can predict long-term unfavorable prognosis and evaluate its predictive accuracy associated with TNM staging, using data of patients diagnosed with MTC between 2000 and 2010 from Surveillance, Epidemiology and End Results database. The relationship between the patients' age at diagnosis and cancer-specific survival (CSS) was evaluated using multivariate Cox regression analysis. Age stratifications were combined into a nomogram model to predict the CSS of MTC. The X-tile program determined 49 and 69 as optimal age cutoff values for CSS. On multivariate analysis, independent factors for survival were age (50-69 years, HR 2.853, 95% CI 1.631-4.991; ≥70 years, HR 5.804, 95% CI 2.91-11.555), race (white, HR 0.344, 95% CI 0.188-0.630), T (T3/4, HR 3.931, 95% CI 2.093-7.381), N (N1a, HR 3.269, 95% CI 1.386-7.710) and M (M1, HR 3.998, 95% CI 2.419-6.606). The C-index for CSS prediction with TNM, age (cutoff of 45)/sex/race/TNM and age (cutoff of 49 and 69)/sex/race/TNM were 0.832 (95% CI 0.763-0.901), 0.863 (95% CI 0.799-0.928), and 0.876 (95% CI 0.817-0.935), respectively. Subgroup multivariate analyses also showed that age significantly increased the risk for CSS in females, non-Hispanic white patients, and those with stage IV MTC. In conclusion, CSS was independently associated with ages between 49 and 69 years, which might be applied for risk stratification in MTC patients.

miR-584 Suppresses Invasion and Cell Migration of Thyroid Carcinoma by Regulating the Target Oncogene ROCK1.

BACKGROUND: Uncovering the target gene of miR-584 to control thyroid carcinoma (TC) invasion and migration is of central importance in the diagnosis, treatment, and prognosis of TC. To validate whether miR-584 has a tumor-suppressive role in thyroid cancer cells by targeting ROCK1, a series of experiments were conducted to figure out the mechanism of action of miR-584. MATERIAL AND METHODS: Migration analyses and cell proliferation assays were performed using miR-584-transfected cells. The expression levels of miR-584 in TC were detected by using real-time polymerase chain reaction (PCR). Western blot analyses were conducted to find out the relationship between the tumor suppressor miR-584 and the target oncogene ROCK1 protein expression levels. Wound healing experiments were used to examine the relationships between miR-584 and the migration of thyroid cancer K1 cells and the effects of ROCK1 knockdown on K1 cell motility. RESULTS: Our results demonstrate that altering the miR-584 levels affects human thyroid cancer cell migration, but has no effect on cell proliferation. The relative ROCK-1 expression levels were 1 and 0.54 in the scrambled-sequence control group and the miR-584 group, respectively. K1 cells transfected with siRNA-ROCK-1 showed weaker cell migration than cells transfected with siRNA-NC (negative control); the cell motility ratios were 18% and 27%, respectively. CONCLUSION: These results indicate that miR-584 could inhibit the expression of ROCK1, and ROCK1 knockdown would further affect the migration ability of K1 cells.

Association study of single nucleotide polymorphisms in mature microRNAs and the risk of thyroid tumor in a Chinese population.

MicroRNAs (miRNAs) are small non-coding RNA molecules that are involved in a variety of cellular functions. Single nucleotide polymorphisms (SNPs) have been identified in mature miRNAs (mmSNPs), some of which have been linked to cancer risk; however, it is unclear which mmSNPs contribute to the susceptibility to thyroid tumors. In the present study, we examined the influence of selected mmSNPs on the risk of thyroid tumor. After systematic in silico screening, seventeen mmSNPs were identified and genotyped in a Chinese population including 828 patients with papillary thyroid cancer (PTC), 488 patients with benign thyroid tumor (BN), and 1038 cancer-free controls. Multivariate logistic regression analyses were conducted to evaluate the association of SNP genotypes and alleles with the risk of developing PTC and BN. Three SNPs (rs67106263 in mir-3144, GA versus GG, OR = 1.35, 1.09-1.68; rs4919510 in mir-608, CC versus GG/GC, OR = 0.76, 0.60-0.97; and rs79402775 in mir-933, AA versus GG/GA, OR = 1.76, 1.00-3.12) were associated with PTC risk. A combined effect of unfavorable genotypes was observed to give increased PTC risk in a dose-dependent manner. In addition, three SNPs (rs10061133 in mir-449b, rs79402775 in mir-933 and rs4919510 in mir-608) showed at least borderline correlations with the risk of BN. False-positive report probability was assessed for significant findings. The rs67106263 SNP was associated with the expression level of mir-3144 in thyroid tissue. These results indicate that mmSNPs may contribute to genetic susceptibility to thyroid tumors. Large validation and functional studies are required to further explore the role of mmSNPs in carcinogenesis.

Number of tumor foci predicts prognosis in papillary thyroid cancer.

BACKGROUND: Papillary thyroid cancer (PTC) often presents as multifocal. However, the association of multifocality with poor prognosis remains controversial. The aim of this retrospective study was to identify the characteristics of PTC with multiple foci and to evaluate the association between multifocality and prognosis. METHODS: We reviewed the medical records of 496 patients who underwent total thyroidectomy for PTC. Patients were classified as G1 (1 tumor focus), G2 (2 foci), and G3 (3 or more foci). We analyzed the clinicopathological features and clinical outcomes in each classification. A Cox regression model was used to assess the relationship between multifocality and recurrence or cancer mortality. RESULTS: The G1, G2 and G3 groups included 287, 141 and 68 patients, respectively. The mean age was 47.1±16.1 yr in G1, 41.1±18.4 yr in G2, and 35.5±15.9 yr in G3 and differed significantly among the 3 groups (p=0.001). The proportion of extrathyroidal extension, central lymph node metastasis (CLNM), and lateral lymph node metastasis (LLNM) in the G1 to G3 groups increased with increasing number of tumor foci. The Kaplan-Meier curves revealed that G3 had the shortest recurrence-free survival, and differences were significant among the 3 groups (p=0.001, Log Rank test). Furthermore, cancer-specific survival rates decreased significantly with increasing number of tumor foci (p=0.041). Independent predictors of recurrence by multivariate Cox analysis included >3 tumor foci [HR 2.60, 95% confidence interval (CI) 1.53-4.39, p=0.001] and extrathyroidal extension (HR 1.95, CI 1.12-3.38, p=0.018). CONCLUSION: An increase in the number of tumors is associated with a tendency toward more aggressive features and predicts poor prognosis in PTC.

Association of the miR-149 Rs2292832 polymorphism with papillary thyroid cancer risk and clinicopathologic characteristics in a Chinese population.

(1) BACKGROUND: The genetic predisposition to papillary thyroid cancer (PTC) is far from clearly elucidated. Rs2292832 is a genetic polymorphism that located in the precursor of mir-149 and has been studied in diverse cancers. Thus far, the role of rs2292832 in PTC tumorigenesis and progression was unclear; (2) METHOD: Rs2292832 was genotyped in 838 PTCs, 495 patients with thyroid benign tumors (BNs) and 1006 controls in a Chinese Han population. Clinicopathological data was collected and compared. The expression level of mature mir-149 was examined in 55 normal thyroid tissue samples; (3) RESULTS: The CC genotype of rs2292832 was significantly associated with an increased risk of PTC compared with TT homozygote (OR = 1.60, 95% CI: 1.72-2.20, p = 0.003) and TT/TC combined genotype (OR = 1.54, 95% CI: 1.14-2.09, p = 0.005). Rs2292832 is an independent risk factor correlated with tumor invasion (p = 0.006) and higher T stage in PTC patients (p = 0.007), but uncorrelated with short-term disease persistence of PTC. PTC subjects carrying CC genotype have lower mir-149-5p expression than those with TC genotype (p = 0.002). Twelve predicted target genes have been identified by collaboratively using computational tools; (4) CONCLUSION: Rs2292832 was possibly involved in the susceptibility and local progression of PTC in Chinese patients, by altering the expression level of mir-149-5p and its target genes.

The chemokine receptor-CXCR2 plays a critical role in the invasion and metastases of oral squamous cell carcinoma in vitro and in vivo.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is one of the most common cancers in the world with about 50% survival rate over 5 years. OSCC has a highly invasive potency and frequently metastasizes to the cervical lymph nodes, which is the principle reason leading to poor prognosis. CXCR2, the receptor of CXC chemokines, has been reported to be involved in invasion and metastasis in multiple types of malignancy. However, the accurate role of CXCR2 in OSCC has been little noticed. METHODS: In this study, we determined the expression of CXCR2 in OSCC using immunohistochemical staining (IHC) and analyzed the association between the expression of CXCR2 and the biobehavior of OSCC. Then, we established stable OSCC cell lines with interference of CXCR2 and observed the effect of CXCR2 knockdown on cell proliferation, migration, invasion, and morphological changes in vitro and in vivo. RESULTS: CXCR2 was positively expressed in 55.3% of OSCC patients and was statistically associated with the high cervical lymph node metastasis in OSCC. CXCR2 silencing markedly inhibited migration and invasion of OSCC cells in vitro and in vivo. Moreover, CXCR2 silencing led to morphological changes and decreased lamellipodial structures in OSCC cells. However, CXCR2 silencing showed no effect on proliferation of OSCC cells in vitro and in vivo. CONCLUSIONS: CXCR2 plays a critical role in the invasion and metastases of OSCC. And it is probably by regulating actin cytoskeletal remodeling that CXCR2 takes part in the invasion and metastases of OSCC.

Lymph node ratio for postoperative staging of laryngeal squamous cell carcinoma with lymph node metastasis.

BACKGROUND: Lymph node metastasis has a significant impact on laryngeal cancer prognosis. The role of lymph node ratio (LNR, ratio of metastatic to examined nodes) in the staging of laryngeal cancer was not reported. PATIENTS AND METHODS: Records of laryngeal cancer patients with lymph node involvement from Surveillance, Epidemiology, and End Results database (SEER, training set, N = 1963) and Fudan University Shanghai Cancer Center (FDSCC, validating set, N = 27) were analyzed for the prognostic value of LNR. Kaplan-Meier survival estimates, the Log-rank χ² test and Cox proportional hazards model were used for univariate and multivariate analysis. Optimal LNR cutoff points were identified by X-tile. RESULTS: Optimal LNR cutoff points classified patients into three risk groups R1 (≤0.09), R2 (0.09-0.20) and R3 (>0.20), corresponding to 5-year cause-specific survival and overall survival in SEER patients of 55.1%, 40.2%, 28.8% and 43.1%, 31.5%, 21.8%, 2-year disease free survival and disease specific survival in FDSCC patients of 74.1%, 62.5%, 50.0%, and 67.7%, 43.2%, 25.0%, respectively. R3 stratified more high risk patients than N3 with the same survival rate, and R classification clearly separated N2 patients to 3 risk groups and N1 patients to 2 risk groups (R1-2 and R3). CONCLUSIONS: R classification is a significant prognostic factor of laryngeal cancer and should be used as a complementary staging system of N classification.

Confirmation of papillary thyroid cancer susceptibility loci identified by genome-wide association studies of chromosomes 14q13, 9q22, 2q35 and 8p12 in a Chinese population.

BACKGROUND: Five single nucleotide polymorphisms (SNPs) were previously reported to be associated with thyroid cancer in European populations in two genome-wide association studies (GWAS): rs965513 (9q22.33), rs944289 (14q13.3), rs116909374 (14q13.3), rs966423 (2q35) and rs2439302 (8p12). Only the first two SNPs have been validated in independent populations and none were replicated in Chinese populations. METHODS: The above five SNPs were genotyped in 845 papillary thyroid cancer (PTC) and 503 benign thyroid tumour (BN) patients and 1005 controls in a Chinese population using the SNaPshot multiplex single nucleotide extension system. RESULTS: Significant associations were detected among PTC and rs944289 (p=8.007e-11), rs965513 (p=1.013e-4), rs966423 (p=1.688e-3) and rs2439302 (p=1.096e-4) in a dominant model, while the rs116909374 SNP was not detected in the Chinese population. The PTC risk increased with rise in accumulative numbers of risk alleles carried by individuals (p=5.929e-13). The PTC OR of carriers of six risk alleles (1.4% of the control population) was 23.587 compared with non-risk homozygotes (1.0% of the control population, with zero risk alleles). No individuals were homozygous for all the four SNPs (carriers of eight risk alleles) and only three PTC cases were carriers of seven risk alleles. A significant association between 14q13.3 SNP rs944289T and BN was also found (p=0.0014). CONCLUSIONS: Four candidate loci, rs965513 (9q22.33), rs944289 (14q13.3), rs966423 (2q35) and rs2439302 (8p12), identified by GWAS for PTC risk were confirmed in a Chinese population. The PTC risk of accumulative risk allele carriers increased with the number of risk alleles.

Association between the rs2910164 polymorphism in pre-Mir-146a sequence and thyroid carcinogenesis.

BACKGROUND: Rs2910164, a Single nucleotide polymorphism (SNP) located in the precursor microRNA sequence of miR-146a, is the only MicroRNA sequence SNP studied in papillary thyroid cancer (PTC). Association studies had been performed in US and UK-Northern European populations, but results were inconsistence. This study evaluated the association between rs2910164 and the risk of PTC as well as benign thyroid tumor (BN), and examined the clinicopathological characteristics of PTC and BN for different genotypes. METHODS: This case-control study genotyped rs2910164 in 753 PTCs, 484 BNs and 760 controls in a Chinese Han population. Clinicopathological and genetic data were collected and compared. Multivariate logistic regression was performed to calculate adjusted odds ratios (ORs). RESULTS: There were no differences in rs2910164 genotype distributions between the three groups. PTC cases with three genotypes (CC, CG, GG) had similar clinicopathological characteristics except the existence of "para-cancer" BN (PTC/BN, P = 0.006). PTC/BN patients were older (P = 0.009), and had smaller cancer lesions (P<0.001), lower serum thyrotropin levels (1.82±1.42 vs. 2.21±1.74, P = 0.04), and lower rates of level VI lymph node metastasis (20.8% vs. 52.7%, P<0.001) and lateral neck lymph node metastasis (11.5% vs. 23.0%, P = 0.011) compared with PTC only. Then we supposed a possible progression from BN to PTC which may involve rs2910164 in and performed a multivariate logistic regression analysis of PTC/BN and BN cases to determine risk factors of this progression. Results showed that the rs2910164 GG homozygote (OR = 2.25, 95% CI 1.22-4.14, P = 0.01) was the only risk factor in this study. CONCLUSION: Rs2910164 was not associated with increased risk of PTC and BN in Chinese patients, but may play a latent role in the transformation from BN to PTC.

Impact of lymph node ratio on the survival of patients with hypopharyngeal squamous cell carcinoma: a population-based analysis.

OBJECTIVE: To analyze the impact of the lymph node ratio (LNR, ratio of metastatic to examined nodes) on the prognosis of hypopharyngeal cancer patients. METHODS: SEER (Surveillance, Epidemiology and End Results)-registered hypopharyngeal cancer patients with lymph node metastasis were evaluated using multivariate Cox regression analysis to identify the prognostic role of the LNR. The categorical LNR was compared with the continuous LNR and pN classifications to predict cause-specific survival (CSS) and overall survival (OS) rates of hypopharyngeal cancer patients. RESULTS: Multivariate analysis of 916 pN+ hypopharyngeal cancer cases identified race, primary site, radiation sequence, T classification, N classification, M classification, the number of regional lymph nodes examined, the continuous LNR (Hazard ratio 2.415, 95% CI 1.707-3.416, P<0.001) and age as prognostic variables that were associated with CSS in hypopharyngeal cancer. The categorical LNR showed a higher C-index and lower Akaike information criterion (AIC) value than the continuous LNR. When patients (n = 1152) were classified into four risk groups according to LNR, R0 (LNR = 0), R1 (LNR ≤ 0.05), R2 (LNR 0.05-0.30) and R3 (LNR >0.30), the Cox regression model for CSS and OS using the R classification had a higher C-index value and lower AIC value than the model using the pN classification. Significant improvements in both CSS and OS were found for R2 and R3 patients with postoperative radiotherapy. CONCLUSIONS: LNR is a significant prognostic factor for the survival of hypopharyngeal cancer patients. Using the cutoff points 0.05/0.30, the R classification was more accurate than the pN classification in predicting survival and can be used to select high risk patients for postoperative treatment.

The clinical features of papillary thyroid cancer in Hashimoto's thyroiditis patients from an area with a high prevalence of Hashimoto's disease.

BACKGROUND: The goal of this study was to identify the clinicopathological factors of co-existing papillary thyroid cancer (PTC) in patients with Hashimoto's thyroiditis (HT) and provide information to aid in the diagnosis of such patients. METHODS: This study included 6109 patients treated in a university-based tertiary care cancer hospital over a 3-year period. All of the patients were categorised based on their final diagnosis. Several clinicopathological factors, such as age, gender, nodular size, invasive status, central compartment lymph node metastasis (CLNM) and serum thyroid-stimulating hormone (TSH) level, were compared between the various groups of patients. RESULTS: There were 653 patients with a final diagnosis of HT. More PTC was found in those with HT (58.3%; 381 of 653) than those without HT (2416 of 5456; 44.3%; p < 0.05). The HT patients with co-occurring PTC were more likely to be younger, be female, have smaller nodules and have higher TSH levels than those without PTC. A multivariate analysis indicated that the presence of HT and higher TSH levels were risk factors for a diagnosis of PTC. In the PTC patients, the presence of HT or another benign nodule was a protective factor for CLNM, whereas no significant association was found for TSH levels. CONCLUSION: PTC and HT have a close relationship in this region of highly prevalent HT disease. Based on the results of our study, we hypothesise that long-term HT leads to elevated serum TSH, which is the real risk factor for thyroid cancer.