RESUMO
Smokeless tobacco (SLT) causes the excessive production of reactive oxygen species, leading to oxidative damage and carcinogenesis. The present study aimed to evaluate the levels of biomarkers, such as glutathione (GSH) in the blood, as well as serum albumin and total protein levels in SLT users with oral precancerous and cancerous lesions. A cross-sectional, prospective study was conducted on 240 patients aged 30-60 years, divided into four groups with 60 patients in each group as follows: Group 1, control group, non-tobacco users; group 2, 60 subjects with a history of SLT use and no oral lesions; group 3, SLT users with precancerous oral lesions; and group 4, SLT users with cancerous lesions. GSH levels in the blood, serum albumin levels and total protein levels were evaluated in all groups. ANOVA and Tukey's test post hoc were used to compare the levels of the biomarkers in all groups. Receiver operating characteristic curves were used to assess the reliability of the biomarkers, and regression analysis was used to determine the associations between the variables. The use of SLT was predominantly observed in males. The mean GSH and serum albumin levels were lowest in group 4 and highest in the control group (P<0.001). The total serum protein levels were higher in group 4 than in group 3. On the whole, as demonstrated herein, GSH and serum albumin were reliable biomarkers, whereas total protein was a weak biomarker. GSH and serum albumin levels may thus be efficiently used for the early diagnosis and prognosis of oral malignancies in SLT users.
