Ana Lívia Silva Galbiatti

Head and neck cancer: causes, prevention and treatment

UNLABELLED Although head and neck carcinoma ranks fifth among cancer types, patient survival rates have not changed significantly over the past years. OBJECTIVE To determine the risk factors, causes, therapies, and prevention measures for head and neck cancer. METHOD Risk factors, causes, therapies, and preventive measures for this disease were searched on databases PUBMED, MEDLINE, and SCIELO. RESULTS Alcohol and tobacco are still atop risk factors. Other factors may influence the development of head and neck carcinoma. Surgery is the main treatment option, and the addition of radiotherapy following surgery is frequent for patients in the early stages of the disease. Other therapies target specific genetic molecular components connected to tumor development. Disease preventive measures include smoking cessation, limiting alcohol intake, preventing exposure to tobacco smoke and environmental carcinogenic agents, early detection of infection by HPV, maintaining oral health, good eating habits, and managing stress. CONCLUSION Additional research is needed for a more thorough understanding of the development of head and neck carcinomas and to shed light on new ways to improve therapeutic approaches and interventions.

Association between 11 genetic polymorphisms in folate-metabolising genes and head and neck cancer risk

Genetic polymorphisms in folate metabolism may affect the risk of head and neck cancer (HNSCC) due to its involvement in DNA methylation and synthesis. We conducted a case-control study (265 HNSCC cases and 466 non-cancer controls) to investigate associations of MTHFR C677T and A1298C, MTR A2756G, MTRR A66G, RFC1 A80G, MTHFD1 G1958A, CBS 844ins68, TC2 C776G and A67G, SHMT C1420T and BHMT G742A polymorphisms with HNSCC risk. Interactions between polymorphisms and survival time, tobacco and alcohol habits, age, gender and tumour staging (TNM classification) were evaluated by multiple logistic regression analysis. We found that age ≥ 49 years (P<0.001), male gender (P=0.03), tobacco habit (P<0.001), MTHFR 1298AC/CC (P=0.028), MTR 2756AG/GG (P=0.010) and RFC1 80AG/GG (P=0.015) genotypes were associated with an increased risk of HNSCC. There were interactions between lower survival and CBS 844ins68 (P=0.005); age ≥ 49 years and MTR 2756 AG/GG (P=0.004) and RFC1 80AG/GG (P=0.006) genotypes; male gender and MTHFR 1298 AC/CC (P=0.030), MTR 2756 AG/GG (P=0.006) and RFC1 80 AG/GG (P=0.009); tobacco non-habit and MTHFD1 1958GA/AA (P=0.040); tobacco and MTHFR 1298 AC/CC (P=0.054) and MTR 2756 AG/GG (P=0.010); alcohol non-consume and RFC1 80 AG/GG (P=0.008) with HNSCC increased risk. MTHFR C677CT/TT genotypes were less frequently in advanced tumours (P=0.04). In conclusion, our data provide evidence that folate metabolism genetic polymorphisms associated with variables as advanced age, male gender, tobacco and alcohol increase HNSCC development; CBS 844ins68 and MTHFR C677T polymorphisms are associated with less survival time and advanced stage tumours, respectively.

GSTM1 and GSTT1 genes analysis in head and neck cancer patients

OBJECTIVE To establish the clinical and demographic profile and identify risk factors among patients with head and neck cancer and relate them to the polymorphism of GSTT1 and GSTM1. METHODS One hundred patients with head and neck cancer and 100 control group individuals without history of neoplasm were analyzed. . The molecular analysis were made by multiplex polymerase chain reaction. For statistical analysis, data were tabulated and compared by the Fishers exact test, the Chi-square test and multiple logistic regression were also used. RESULTS There was prevalence of smokers (OR = 5.32, CI 95% CI = 2.04-13.86 p = 0.0006), alcohol drinkers (OR = 5.04, CI 95% = 2.19-11.59 p = 0.0001) in head and neck cancer patients . The GSTT1 null genotype was found in 47% of the patient and 41% of the control group (OR = 0.67; CI 95%= 0.34-1.35; p = 0.2648). Likewise , the GSTM1 null genotype was found in 66% of the patient and 75% of the control group (OR = 2.25; CI 95%= 1.05 - 4.84; p = 0.0368). The combined GSTT1 and GSTM1 gene null genotype shown association between GSTM1 0/GSTT1 and occurrence of head and neck carcinoma (OR = 7.64; CI 95%= 1.72-34.04; p = 0.0076). Analysis of clinical-pathological features showed association between GSTT1 null genotype and larynx, the inverse relation between this genotype and pharynx. CONCLUSION In our study it was possible to establish association between GSTM1 null genotypes and head and neck cancer.

Câncer de cabeça e pescoço: polimorfismos genéticos e metabolismo do folato

UNLABELLED Epidemiological evidence suggests that genetic variants encoding enzymes involved in folate metabolism may modulate HNSCC risk by altering DNA methylation synthesis and genomic estability. AIM A review of the literature on genetic polymorphisms involved in folate metabolism and risk of head and neck cancer was carried out. METHODOLOGY An electronic search was made on the Medline database to select papers on head and neck cancer and polymorphisms involved in folate metabolism. RESULTS The association between MTHFR C677T polymorphism and the risk of this tumor type was evaluated in nine studies; there was an association with this disease in three papers. The MTR A2756G and MTRR A66G and RFC1 A80G polymorphisms were also associated with increased risk for HNSCC. MTHFD1 G1958A polymorphism was not associated with increased risk of this disease; the evaluation results of the MTHFR A1298C polymorphism in this neoplasm were contradictory. Other polymorphisms involved in folate metabolism were not studied for this neoplasm. CONCLUSION We conclude that polymorphisms involved in folate metabolism may modulate the risk of head and neck cancer, however, these results need to be demonstrated in different populations.

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.

5-Methyltetrahydrofolate-homocysteine methyltransferase gene polymorphism (MTR) and risk of head and neck cancer

The functional effect of the A>G transition at position 2756 on the MTR gene (5-methyltetrahydrofolate-homocysteine methyltransferase), involved in folate metabolism, may be a risk factor for head and neck squamous cell carcinoma (HNSCC). The frequency of MTR A2756G (rs1805087) polymorphism was compared between HNSCC patients and individuals without history of neoplasias. The association of this polymorphism with clinical histopathological parameters was evaluated. A total of 705 individuals were included in the study. The polymerase chain reaction-restriction fragment length polymorphism technique was used to genotype the polymorphism. For statistical analysis, the chi-square test (univariate analysis) was used for comparisons between groups and multiple logistic regression (multivariate analysis) was used for interactions between the polymorphism and risk factors and clinical histopathological parameters. Using univariate analysis, the results did not show significant differences in allelic or genotypic distributions. Multivariable analysis showed that tobacco and alcohol consumption (P < 0.05), AG genotype (P = 0.019) and G allele (P = 0.028) may be predictors of the disease and a higher frequency of the G polymorphic allele was detected in men with HNSCC compared to male controls (P = 0.008). The analysis of polymorphism regarding clinical histopathological parameters did not show any association with the primary site, aggressiveness, lymph node involvement or extension of the tumor. In conclusion, our data provide evidence that supports an association between the polymorphism and the risk of HNSCC.

Head and neck carcinogenesis: 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.

The association between CBS 844ins68 polymorphism and head and neck squamous cell carcinoma risk - a case-control analysis.

Introduction Susceptibility to head and neck squamous cell carcinoma may be modified by functional polymorphisms in genes involved in the folate pathway, such as cystathionine beta-synthase (CBS). The CBS 844ins68 polymorphism is associated with DNA methylation changes and cancer development. Material and methods A case-control retrospective study was conducted in 322 patients with head and neck squamous cell carcinoma and in 531 control subjects without cancer. The polymerase chain reaction-restriction fragment length polymorphism technique was used to genotype the polymorphism. For statistical analysis, χ2 test was conducted to examine whether the genotypic frequency of CBS 844ins68 was in Hardy-Weinberg equilibrium and multiple logistic regression was used for comparisons between groups, and for interactions between the polymorphism and risk factors and clinical histopathological parameters. Results No significant difference in CBS 844ins68 genotypic distribution was observed between the groups. Age > 50 years, male gender and tobacco consumption were predictors of the disease with increased risk of 7.89 (95% CI: 5.56-11.21), 2.49 (95% CI: 1.72-3.62), 6.44 (95% CI: 4.63-8.96) and 2.29 times (95% CI: 1.71-3.06) respectively. There was no association between the distribution of the CBS 844ins68 genotype and risk factors for this disease. According to clinical histopathological parameters, CBS 884ins68 polymorphism presented high frequency in oral cavity (p < 0.05) and patients with the polymorphism presented less survival time (p < 0.05). Conclusions We concluded that the CBS 844ins68 polymorphism is not associated with HNSCC risk and there is increased risk of this disease in male gender individuals smokers aged over 50 years. In adittion, the polymorphism is more frequent in patients with oral cavity as primary site and in patients with less survival time.

Carcinogênese de cabeça e pescoço: impacto do polimorfismo MTHFD1 G1958A

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.

Analysis of the TAX1BP1 gene in head and neck cancer patients

UNLABELLED In Brazil, there were 14,160 new estimated cases of head and neck cancer for the year of 2008. Smoking and drinking are the main risk factors established in the etiology of this disease. AIM To assess the T --> A polymorphism in gene TAX1BP1 (leu306ile) in patients with head and neck cancer and a control population. SERIES AND METHODS: A retrospective study in which we assessed the gender, age, smoking and drinking habits of 191 patients with head and neck cancer and 200 individuals without history of neoplasia. The molecular analysis was carried out after genomic DNA extraction by the PCR-RFLP method. RESULTS There is a predominance of males (84.82%), smokers (91.1%) and drinkers of alcohol (77.49%). Molecular assessment did not show statistically significant differences between the two groups (p =0.32). The analysis of clinical parameters and polymorphisms showed association with oral cavity cancer (OR: 2.38; CI 95%: 1.18-4.78; p = 0.01), the other parameters were not associated with the polymorphism. CONCLUSION There is evidence of association between TAX1BP1 gene polymorphism and oral cavity cancer. For the remaining parameters analyzed, the results do not suggest association with the TAX1BP1 gene polymorphism.