Gene Polymorphisms Involved in Folate Metabolism and DNA Methylation with the Risk of Head and Neck Cancer.

BACKGROUND: Folate is essential for DNA synthesis, repair, and methylation. Polymorphisms in genes associated with folate metabolism may alter these processes and, consequently, modulate cancer development. AIM: We aimed to assess DNMT3B -149C/T (rs2424913), DNMT3B -283T/C (rs6087990), DNMT3B -579G/T (rs2424909), DHFR 19-pb ins/del (rs70991108), SHMT1 1420C/T (rs1979277), and TYMS 28-bp tandem repeat (rs34743033) polymorphisms with risk of head and neck cancer. METHODS: A case-control study was conducted in 1,086 Brazilian individuals. Real-time and conventional polymerase chain reactions-PCR were performed for genotyping the polymorphisms. RESULTS: The single nucleotide polymorphism (SNP), DNMT3B -283T/C, revealed a higher risk of head and neck squamous cell carcinoma (HNSCC) when compared with the C group in the codominant (p < 0.001), dominant (p <0.001), and overdominant (p= 0.001) models for T/C and C/C genotypes. DNMT3B -149C/T and DNMT3B -579G/T revealed no association between groups in any model. The DHFR 19-pb ins/del polymorphism protected against HNSCC development compared to the C group by the codominant (p < 0.001), dominant (p < 0.001), and overdominant (p < 0.001) models. In the TYMS, the 3R/3R genotype had a protective effect against HNSCC development compared with the C group by the recessive models (p= 0.009). In contrast, SHMT1 1420 C/T presented no association between the HNSCC and C groups. DHFR 19-pb ins/del polymorphisms protected against oral cavity cancer (p= 0.003), and only TYMS-28 3R/3R decreased the risk of tumor progression (p= 0.023). In the Kaplan-Meier curve, an association was found between DHFR ins/ins and TYMS -28 3R carriers with respect to relapse-free time; further, DNMT3B -579 T and TYMS-28 2R/2R carriers had longer survival times. CONCLUSION: DNMT3B -283T/C is associated with higher risk, whereas DHFR 19-pb ins/del and TYMS 28 3R/3R protect against head and neck cancer. We also highlighted the association of TYMS 3R/3R genotype carriers with relapse-free cancer protection and survival time.

Profile and speech-language rehabilitation of patients with laryngeal cancer. / Perfil e reabilitação fonoaudiológica de pacientes com câncer de laringe.

PURPOSE: to describe the clinical and sociodemographic profile and analyze the voice rehabilitation outcomes of patients with laryngeal cancer. METHODS: cross-sectional study with 204 individuals with laryngeal cancer treated between 1989 and 2015. The variables describing the patients' profile were presented in absolute values (n) and percentage (%). The association between the speech-language therapy outcome and the sociodemographic and clinical characterization variables was verified by means of uni- and multivariate techniques. RESULTS: 95.1% of the patients are male; 53.43% are aged 60 or more; 77.37% have elementary education; 44.12% are in the service industry; 81.63% smoke and consume alcohol; 30.4% are stage T3. Absence of nodules was found in 72.00%, and of metastasis, in 85.6% of patients. The most frequent therapeutic procedure was complete or partial laryngectomy (69.61%). There was an association among education, disease stage, habits, and therapeutic outcome with speech-language therapy (p<0.001). CONCLUSION: Several causes can affect the prognosis of vocal rehabilitation in patients with laryngeal cancer. Optimization and diversification of new therapeutic procedures are challenges for these patients' speech-language rehabilitation.

OBJETIVO: descrever o perfil clínico e sociodemográfico e o desfecho da reabilitação fonoaudiológica de pacientes com câncer de laringe. MÉTODO: estudo transversal com 204 pessoas atendidas entre 1989 e 2015. A associação entre desfecho da fonoterapia e variáveis de caracterização sociodemográfica e clínicas foi verificada por técnicas univariadas e multivariadas. RESULTADOS: prevalência do gênero masculino (95,10%), 60 anos ou mais (53,43%), ensino fundamental (77,37%), setor de serviços (44,12), tabagistas e etilistas (81,63%); estágio T3 (30,4%), ausência de nódulos (72,00%) e de metástase (85,6%). O procedimento terapêutico mais frequente foi a laringectomia total ou parcial (69,61%). Houve associação da escolaridade, estágio da doença, hábitos e procedimento terapêutico com desfecho da fonoterapia (p<0,001). CONCLUSÃO: fatores sociodemográficos e clínicos podem interferir no prognóstico da reabilitação vocal de pessoas com câncer de laringe. A otimização e diversificação de novos procedimentos terapêuticos são desafios na reabilitação fonoaudiológica destas pessoas.

Perfil e reabilitação fonoaudiológica de pacientes com câncer de laringe / Profile and speech-language rehabilitation of patients with laryngeal cancer

RESUMO Objetivo descrever o perfil clínico e sociodemográfico e o desfecho da reabilitação fonoaudiológica de pacientes com câncer de laringe. Método estudo transversal com 204 pessoas atendidas entre 1989 e 2015. A associação entre desfecho da fonoterapia e variáveis de caracterização sociodemográfica e clínicas foi verificada por técnicas univariadas e multivariadas. Resultados prevalência do gênero masculino (95,10%), 60 anos ou mais (53,43%), ensino fundamental (77,37%), setor de serviços (44,12), tabagistas e etilistas (81,63%); estágio T3 (30,4%), ausência de nódulos (72,00%) e de metástase (85,6%). O procedimento terapêutico mais frequente foi a laringectomia total ou parcial (69,61%). Houve associação da escolaridade, estágio da doença, hábitos e procedimento terapêutico com desfecho da fonoterapia (p<0,001). Conclusão fatores sociodemográficos e clínicos podem interferir no prognóstico da reabilitação vocal de pessoas com câncer de laringe. A otimização e diversificação de novos procedimentos terapêuticos são desafios na reabilitação fonoaudiológica destas pessoas.

ABSTRACT Purpose to describe the clinical and sociodemographic profile and analyze the voice rehabilitation outcomes of patients with laryngeal cancer. Methods cross-sectional study with 204 individuals with laryngeal cancer treated between 1989 and 2015. The variables describing the patients' profile were presented in absolute values (n) and percentage (%). The association between the speech-language therapy outcome and the sociodemographic and clinical characterization variables was verified by means of uni- and multivariate techniques. Results 95.1% of the patients are male; 53.43% are aged 60 or more; 77.37% have elementary education; 44.12% are in the service industry; 81.63% smoke and consume alcohol; 30.4% are stage T3. Absence of nodules was found in 72.00%, and of metastasis, in 85.6% of patients. The most frequent therapeutic procedure was complete or partial laryngectomy (69.61%). There was an association among education, disease stage, habits, and therapeutic outcome with speech-language therapy (p<0.001). Conclusion Several causes can affect the prognosis of vocal rehabilitation in patients with laryngeal cancer. Optimization and diversification of new therapeutic procedures are challenges for these patients' speech-language rehabilitation.

DNMT3B C46359T and SHMT1 C1420T polymorphisms in the folate pathway in carcinogenesis of head and neck.

Folate is an essential nutrient with important roles in the synthesis, repair, and DNA methylation. Polymorphisms in genes encoding enzymes involved in folate metabolism can change these processes and modulate cancer development. We investigated DNMT3B C46359T (rs2424913) and SHMT1 C1420T (rs1979277) polymorphisms related to folate pathway in head and neck cancer (HNC) risk and the association of the disease with gender, risk factors and clinical histopathological parameters. A case-control study was conducted in 725 individuals (237 patients with HNC and 488 control individuals). Real-time PCR technique was performed for genotyping. Chi square and multiple logistic regression tests were used for statistical analysis. Male gender (OR 1.80; 95 % CI 1.11-2.94; P < 0.02) and tobacco consumption (OR 6.14; 95 % CI 4.13-9.13; P < 0.001) were associated with increased risk for this neoplasia. There were no significant associations between the polymorphisms and risk of disease, however, the tobacco and alcohol habits together showed association with SHMT1 C1420T polymorphism (OR 1.48; 95 % CI 1.08-2.03; P = 0.014). SHMT1 C1420T polymorphism was associated with larynx tumor (OR 0.48; 95 % CI 0.27-0.86; P < 0.05). In conclusion, tobacco habit and male gender can be predictors for HNC risk. SHMT1 C1420T and DNMT3B C46359T polymorphisms are not associated with HNC development in Brazilian population, however, SHMT1 C1420T polymorphism is less frequent in patients with primary site of tumor in larynx and more frequent in individuals who consume tobacco and alcohol together. Further studies involving gene-gene interactions in folate pathway in different populations can contribute to the understanding of the polymorphisms effect on HNC risk.

Clinical and epidemiological characteristics of patients in the head and neck surgery department of a university hospital.

CONTEXT AND OBJECTIVES: Head and neck cancer is the fifth most common type of cancer worldwide. The objective of this study was to evaluate the clinical and epidemiological parameters in a head and neck surgery service. DESIGN AND SETTING: Cross-sectional study using patients' records, developed in otolaryngology and head and neck department of a university hospital in the northwest of the state of São Paulo. METHODS: A total of 995 patients in the head and neck surgery service between January 2000 and May 2010 were evaluated. The variables analyzed included: age, gender, skin color, tobacco and alcohol consumption, primary site, staging and histological tumor type, treatment and number of deaths. RESULTS: The disease was more frequent among men (79.70%), smokers (75.15%) and alcohol abusers (58.25%). The most representative sites were oral cavity (29.65%) and larynx (24.12%) for the primary site; squamous cell carcinoma (84.92%) was the most frequent histological type, and surgery (29.04%) and radiotherapy (14.19%) were the most common treatments. CONCLUSION: The cancer that affects patients assisted by the head and neck surgery service occurs mainly men, smokers and alcohol abusers, and the oral cavity and larynx are the sites with the highest incidence. The high rate of patients with stages III and IV indicates late diagnosis by the treatment centers, which reflects the need for prevention education campaigns for early diagnosis of the disease.

Polymorphisms and haplotypes in methylenetetrahydrofolate reductase gene and head and neck squamous cell carcinoma risk.

Functional polymorphisms in genes encoding enzymes involved in folate metabolism might modulate head and neck carcinoma risk because folate participates in DNA methylation and synthesis. We therefore conducted a case-control study of 853 individuals (322 head and neck cancer cases and 531 non-cancer controls) to investigate associations among MTHFR C677T and MTHFR A1298C polymorphisms and head and neck squamous cell carcinoma risk. Interactions between these two polymorphisms and risk factors and clinical histopathological parameters were also evaluated. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used to genotype the polymorphisms and Chi-square test and multiple logistic regression were used for statistical analyses. The variables age≥49 years, male gender, tobacco habits and alcohol consumption, MTHFR 1298 AC or CC genotypes, combined genotypes with two or more polymorphic alleles and 677T and 1298C polymorphic alleles were associated with increased risk for this disease (P<0.05). Furthermore, we found that 1298 AC or CC genotypes were associated with age≥49 years, tobacco and alcohol habits (P<0.05). Regarding clinical histopathological parameters, the A1298C polymorphism was more frequent in patients with oral cavity as primary site (P<0.05). MTHFR polymorphisms may contribute for increase risk for head and neck carcinoma and the variables age≥49 years, male gender, tobacco and alcohol habits were associated with MTHFR 1298AC or CC genotypes, confirming that individuals with these variables and MTHFR A1298C polymorphism has higher risk for this disease.

Polymorphisms of the CYP1A1 and CYP2E1 genes in head and neck squamous cell carcinoma risk.

Polymorphisms in genes that encode P450 cytochrome enzymes may increase carcinogen activation or decrease their inactivation and consequently, promote the development of cancer. The aims of this study were to identify the MspI-CYP1A1, PstI-CYP2E1 and DraI-CYP2E1 polymorphisms in patients with head and neck cancer and to compare with individuals without cancer; to evaluate the association of these polymorphisms with risk factors and clinical histopathological parameters. In the study group, 313 patients were evaluated for CYP1A1, 217 for CYP2E1 (PstI) and 211 for CYP2E1 (DraI) and in the control group 417, 334 and 374 individuals, respectively. Molecular analysis was performed by PCR-RFLP technique, and chi-square and multiple logistic regression tests were used for statistical analysis. The result of analysis regarding individuals evaluated for CYP1A1 (MspI) showed that age (OR: 8.15; 95% CI 5.57-11.92) and smoking (OR: 5.37; 95% CI 3.52-8.21) were predictors for the disease; for the CYP2E1 (PstI and DraI), there were associations with age (PstI-OR: 9.10; 95% CI 5.86-14.14/DraI-OR: 8.07; 95% CI 5.12-12.72), smoking (PstI-OR: 4.10; 95% CI 2.44-6.89/DraI-OR: 5.73; 95% CI 3.34-9.82), alcohol (PstI-OR: 1.93; 95% CI 1.18-3.16/DraI-OR: 1.69; 95% CI 1.02-2.81), respectively, with disease development. CYP2E1 (PstI) was less frequent in patient group (OR: 0.48; 95% CI 0.23-0.98). Regarding clinical histopathological parameters, CYP1A1 polymorphism was less frequent in the larynx primary anatomic site (OR = 0.45; 95% CI = 0.28-0.73; P = 0.014). In conclusion, we confirm that age, smoking and alcohol consumption are risk factors for this disease and the polymorphisms investigated have no association with the development of head and neck cancer.

MTHFD1 G1958A, BHMT G742A, TC2 C776G and TC2 A67G polymorphisms and head and neck squamous cell carcinoma risk.

Alterations in folate metabolism may contribute to the process of carcinogenesis by influencing DNA methylation and genomic stability. Polymorphisms in genes encoding enzymes involved in this pathway may alter enzyme activity and consequently interfere in concentrations of homocysteine and S-adenosylmethionine that are important for DNA synthesis and cellular methylation reactions. The objectives were to investigate MTHFD1 G1958A, BHMT G742A, TC2 C776G and TC2 A67G polymorphisms involved in folate metabolism on head and neck cancer risk and the association between these polymorphisms with risk factors. Polymorphisms were investigated in 762 individuals (272 patients and 490 controls) by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and Real Time-PCR. Chi-square and Multiple logistic regression were used for the statistical analysis. Multiple logistic regression showed that tobacco and male gender were predictors for the disease (P < 0.05). Hardy-Weinberg equilibrium showed that the genotypic distributions were in equilibrium for both groups in all polymorphisms studied. The BHMT 742GA or AA genotypes associated with tobacco consumption (P = 0.016) increase the risk for head and neck squamous cell carcinoma (HNSCC). The present study suggests that BHMT 742GA polymorphism associated to tobacco modulate HNSCC risk. However, further investigation of gene-gene interactions in folate metabolism and studies in different populations are needed to investigate polymorphisms and HNSCC risk.

Clinical and epidemiological characteristics of patients in the head and neck surgery department of a university hospital / Características clínicas e epidemiológicas de pacientes do departamento de cirurgia de cabeça e pescoço em um hospital universitário

CONTEXT AND OBJECTIVES: Head and neck cancer is the fifth most common type of cancer worldwide. The objective of this study was to evaluate the clinical and epidemiological parameters in a head and neck surgery service. DESIGN AND SETTING: Cross-sectional study using patients' records, developed in otolaryngology and head and neck department of a university hospital in the northwest of the state of São Paulo. METHODS: A total of 995 patients in the head and neck surgery service between January 2000 and May 2010 were evaluated. The variables analyzed included: age, gender, skin color, tobacco and alcohol consumption, primary site, staging and histological tumor type, treatment and number of deaths. RESULTS: The disease was more frequent among men (79.70%), smokers (75.15%) and alcohol abusers (58.25%). The most representative sites were oral cavity (29.65%) and larynx (24.12%) for the primary site; squamous cell carcinoma (84.92%) was the most frequent histological type, and surgery (29.04%) and radiotherapy (14.19%) were the most common treatments. CONCLUSION: The cancer that affects patients assisted by the head and neck surgery service occurs mainly men, smokers and alcohol abusers, and the oral cavity and larynx are the sites with the highest incidence. The high rate of patients with stages III and IV indicates late diagnosis by the treatment centers, which reflects the need for prevention education campaigns for early diagnosis of the disease.

CONTEXTO E OBJETIVOS: O câncer de cabeça e pescoço é o quinto tipo mais comum entre todas as neoplasias no mundo. O objetivo do estudo foi avaliar os parâmetros clínicos e epidemiológicos em um serviço de cirurgia de cabeça e pescoço. TIPO DE ESTUDO E LOCAL: Estudo transversal com coleta de dados de prontuários, realizado no departamento de otorrinolaringologia e cabeça e pescoço de um hospital universitário do noroeste do estado de São Paulo. MÉTODOS: Um total de 995 pacientes do serviço de cirurgia de cabeça e pescoço foi avaliado entre janeiro de 2000 a maio de 2010. As variáveis analisadas foram: idade, gênero, cor da pele, consumo de álcool e tabaco, sítio primário, estádio e tipo histológico do tumor, tratamento e número de mortes. RESULTADOS: A doença foi mais frequente entre homens (79,70%), tabagistas (75,15%) e etilistas (58,25%). Os locais mais representativos foram: cavidade oral (29,65%) e laringe (24,12%) para sítio primário; carcinoma espinocelular (84,92%) foi o tipo histológico mais frequente e cirurgia (29,04%) e radioterapia (14,19%) foram os tratamentos mais comuns. CONCLUSÃO: O câncer que afeta os pacientes assistidos pelo serviço de cirurgia de cabeça e pescoço ocorre, em sua maioria, entre homens, tabagistas e etilistas, tendo a cavidade oral e a laringe maior incidência. A alta taxa de pacientes com estádios III e IV indica diagnóstico tardio pelos centros de tratamento, o que reflete a necessidade de campanhas de prevenção para o diagnóstico precoce da doença.

Head and neck carconogenesis: impact of MTHFD1 G1958A polymorphism.

OBJECTIVE: To investigate the MTHFD1 G1958A polymorphism involved in the folate metabolism as a risk for head and neck cancer, and to find the association of the polymorphism with the risk factors and clinical and histopathological characteristics. METHODS: Retrospective study investigating MTHFD1 G1958A polymorphism in 694 subjects (240 patients in the Case Group and 454 in the Control Group) by Restriction Fragment Length Polymorphism (RFLP) Analysis. Multiple logistic regression and chi-square tests were used in the statistical analysis. RESULTS: Multivariable analysis showed that smoking and age over 42 years were disease predictors (p < 0.05). MTHFD1 1958GA or AA genotypes were associated with smoking (p = 0.04) and alcoholism (p = 0.03) and were more often found in more advanced stage tumors (p = 0.04) and in patients with a shorter survival (p = 0.03). CONCLUSION: The presence of MTHFD1 G1948A polymorphism associated with smoking and alcoholism raises the head and neck cancer risk.

Carcinogênese de cabeça e pescoço: impacto do polimorfismo MTHFD1 G1958A / Head and neck carconogenesis: impact of MTHFD1 G1958A polymorphism

OBJETIVO: Investigar o polimorfismo MTHFD1 G1958A envolvido no metabolismo do folato no risco para o câncer de cabeça e pescoço e verificar a associação entre esse polimorfismo com fatores de risco e características clínico-histopatológicas. MÉTODOS: Estudo retrospectivo que avaliou o polimorfismo MTHFD1 G1958A em 694 indivíduos (240 pacientes e 454 controles), por meio da técnica de análise de polimorfismo de comprimento de fragmento de restrição. Para análise estatística foram utilizados os testes de regressão logística múltipla e qui-quadrado. RESULTADOS: Tabagismo e idade superior a 42 anos foram preditores da doença (p < 0,05). Os genótipos MTHFD1 1958GA ou AA foram associados ao tabagismo (p = 0,04) e etilismo (p = 0,03) e estão presentes em maior proporção em tumores com estádios mais avançados (p = 0,04) e em pacientes com menor sobrevida (p = 0,03). CONCLUSÃO: A presença do polimorfismo MTHFD1 G1958A associada aos hábitos tabagista e etilista aumenta o risco para desenvolvimento de câncer de cabeça e pescoço.

OBJECTIVE: To investigate the MTHFD1 G1958A polymorphism involved in the folate metabolism as a risk for head and neck cancer, and to find the association of the polymorphism with the risk factors and clinical and histopathological characteristics. METHODS: Retrospective study investigating MTHFD1 G1958A polymorphism in 694 subjects (240 patients in the Case Group and 454 in the Control Group) by Restriction Fragment Length Polymorphism (RFLP) Analysis. Multiple logistic regression and chi-square tests were used in the statistical analysis. RESULTS: Multivariable analysis showed that smoking and age over 42 years were disease predictors (p < 0.05). MTHFD1 1958GA or AA genotypes were associated with smoking (p = 0.04) and alcoholism (p = 0.03) and were more often found in more advanced stage tumors (p = 0.04) and in patients with a shorter survival (p = 0.03). CONCLUSION: The presence of MTHFD1 G1948A polymorphism associated with smoking and alcoholism raises the head and neck cancer risk.

A80G polymorphism of reduced folate carrier 1 (RFC1) gene and head and neck squamous cell carcinoma etiology in Brazilian population.

Reduced folate carrier is an essential folate transporter and the A80G polymorphism in reduced folate carrier 1 gene (rs1051266) has been shown to be associated with alterations in folate metabolism and consequently cancer development. We evaluated the association of this polymorphism with head and neck squamous cell carcinoma risk in a case-control study of 322 head and neck carcinoma patients and 531 individuals without cancer in a Brazilian population and association of this polymorphism with clinical histopathological parameters, and gender and lifestyle factors. The PCR-RFLP technique was used to genotype the polymorphism and multiple logistic regression was used for comparison between the groups and for interaction between the polymorphism and risk factors and clinical histopathological parameters. We observed association between the RFC1 A80G polymorphism and the risk of this disease. Male gender, tobacco habit and RFC1 AG or GG genotypes may be predictors of this disease (P < 0.05). The genotype, 80AG or GG was associated with for >50 years, male gender and non alcohol consumption (P ≤ 0.05). The polymorphism did not show any association with the primary site, aggressiveness, lymph node involvement or extension of the tumor. In conclusion tobacco and male gender are associated with etiology of this disease and our data provide evidence that supports an association between the RFC1 A80G polymorphism and head and neck squamous cell carcinoma risk, male gender, alcohol non consumption and age over 50 years. However, further studies of folate and plasma concentrations may contribute to the better understanding of the factors involved in the head and neck squamous cell carcinoma etiology.

Polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene and risk of head and neck squamous cell carcinoma.

UNLABELLED: Methylenetetrahydrofolate reductase gene (MTHFR) C677T polymorphism may be a risk factor for head and neck squamous cell carcinoma due to changes in folate levels that can induce disorders in the methylation pathway, which results in carcinogenesis. AIM: To evaluate MTHFR C677T polymorphism in patients with head and neck squamous cell carcinoma and in individuals with no history of cancer, and to assess the association of this disease with clinical histopathological parameters. SERIES AND METHODS: A retrospective study that assessed gender, age, tobacco, alcohol consumption and clinical histopathological parameters in 200 patients (100 with disease and 100 with no history of cancer). PCR-RFLP molecular analysis was carried out and the chi-square test and multiple logistic regression were applied for the statistical analysis. RESULTS: There was no association between MTHFR C677T polymorphism and head and neck cancer (p = 0.50). Significant differences between the study and control groups were observed at age over 50 years, tobacco use, and male gender (p <0.001). There was no association of disease with clinical-histopathological parameters. CONCLUSION: No association between the MTHFR C677T polymorphism and head and neck squamous cell carcinoma was possible in this study.

Polimorfismo do gene metilenotetra-hidrofolato redutase (MTHFR) e o risco de carcinoma espinocelular de cabeça e pescoço / Polymorphism of methylenetetrahydrofolate reductase (MTHFR) gene and risk of head and neck squamous cell carcinoma

O polimorfismo C677T do gene metilenotetra-hidrofolato redutase (MTHFR) pode ser um fator de risco para o carcinoma espinocelular de cabeça e pescoço devido a alterações nos níveis de folato que podem induzir alterações na metilação intracelular, promovendo a carcinogênese. OBJETIVO: Avaliar o polimorfismo MTHFR C677T em pacientes com carcinoma espinocelular de cabeça e pescoço e em indivíduos sem história de neoplasia e verificar a associação desta doença com as características clínico-patológicas. CASUÍSTICA E MÉTODOS: Estudo retrospectivo no qual foram avaliados gênero, idade, tabagismo, etilismo e parâmetros clínico-histopatológicos em 200 indivíduos (100 com a doença e 100 sem história de neoplasia). A análise molecular foi realizada pela técnica de PCR- RFLP e os testes qui-quadrado de Pearson e Regressão Logística Múltipla foram utilizados para análise estatística. RESULTADOS: Não houve associação entre o polimorfismo MTHFR C677T e a doença (p=0,50). Diferenças significantes entre o grupo de pacientes e o grupo controle foram observadas para idade superior a 50 anos, hábito tabagista e gênero masculino (p<0,001). Não houve associação da doença com os parâmetros clínico-histopatológicos. CONCLUSÃO: Não foi possível estabelecer uma associação entre o polimorfismo MTHFR C677T e o carcinoma espinocelular de cabeça e pescoço.

Methylenetetrahydrofolate reductase gene (MTHFR) C677T polymorphism may be a risk factor for head and neck squamous cell carcinoma due to changes in folate levels that can induce disorders in the methylation pathway, which results in carcinogenesis. AIM: To evaluate MTHFR C677T polymorphism in patients with head and neck squamous cell carcinoma and in individuals with no history of cancer, and to assess the association of this disease with clinical histopathological parameters. SERIES AND METHODS: A retrospective study that assessed gender, age, tobacco, alcohol consumption and clinical histopathological parameters in 200 patients (100 with disease and 100 with no history of cancer). PCR-RFLP molecular analysis was carried out and the chi-square test and multiple logistic regression were applied for the statistical analysis. RESULTS: There was no association between MTHFR C677T polymorphism and head and neck cancer (p = 0.50). Significant differences between the study and control groups were observed at age over 50 years, tobacco use, and male gender (p <0.001). There was no association of disease with clinical-histopathological parameters. CONCLUSION: No association between the MTHFR C677T polymorphism and head and neck squamous cell carcinoma was possible in this study.

Salivary and serum proteomics in head and neck carcinomas: before and after surgery and radiotherapy.

Several body fluids have been evaluated as new sources for cancer biomarker discovery. In this context, salivary and serum proteomics seem promising diagnostic and predictive tools for head and neck diseases. In the present study, we performed a proteomic analysis of saliva and serum from patients presenting head and neck squamous cell carcinoma (HNSCC) and compared the results before and after therapy. In saliva of cancer patients, we observed an altered protein profile, including over-expression of PLUNC and zinc-alpha-2-glycoprotein. Both proteins may contribute to control tumor growth and, therefore, represent targets for new analysis. We also detected serotransferrin and a modified transthyretin form with altered levels in serum from patients. Comparing preoperative and postreatment samples, the results showed that the protein profile after treatment reverted to a pattern closer to those observed for controls. These results add information on the role of secreted proteins in the cancer process and emphasize the potential of saliva and serum analysis for diagnosis and monitoring of HNSCC.