Freqüência de polimorfismo funcional na região promotora do gene 5-HTT como fator de risco para carcinoma de células escamosas cavidade bucal: um estudo caso-controle

Abstract

Even though tobacco and alcohol are considered risk factors for oral carcinoma, depression has also been identified as an important determinant. An association between polymorphism of the promoter region of serotonin transporter (5-HTTLPR) and tobacco and alcohol consumption has been demonstrated. The short allele (s) has been associated with a reduction in 5-HTT transcription. With the objective of assessing the frequency of such polymorphism in subjects with oral squamous cell carcinoma, a case-control study was carried out. One hundred and three subjects with oral carcinoma were paired for gender, age and tobacco use with 103 healthy controls. After approval by the Ethics Committee, interviews were conducted and mucous swabs collected from all subjects. Data analysis involved Pearson´s chi-squared test (p-value 0.05). No statistical differences (p= 0.118) were observed between allelic frequencies for case and control groups: long allele (l) (55.8% and 49.5%), short allele (s) (44.2% and 50.5%). No statistical differences (p= 0.408) were detected between genotypes distribution for cases (l/s 51.5%; l/l 30.1%; s/s 18.4%) and controls (l/s 42.7%; l/l 33.0%; s/s 24.3%). No statistical differences were identified between genotype distributions amongst cases and controls in relation to smokers and non-smokers, alcohol consumers and non-consumers, amount of tobacco and alcohol consumption and duration of such habits. It was therefore concluded that smoking and alcohol habits were not associated with polymorphisms of the promoter region of serotonin transporter (5-HTTLPR). This polymorphism was not a risk factor to oral squamous cell carcinoma.