Tobacco (kretek) smoking, betel quid chewing and risk of oral cancer in a selected Jakarta population.

PURPOSE: This study aimed to determine the association between tobacco consumption (kretek) and betel quid chewing with oral cancer risk. MATERIALS AND METHODS: A total of 81 cases of oral cancers were matched with 162 controls in this hospital-based study. Information on sociodemographic characteristics and details of risk habits (duration, frequency and type of tobacco consumption and betel quid chewing) were collected. Association between smoking and betel quid chewing with oral cancer were analysed using conditional logistic regression. RESULTS: Slightly more than half of the cases (55.6%) were smokers where 88.9% of them smoked kretek. After adjusting for confounders, smokers have two fold increased risk, while the risk for kretek consumers and those smoking for more than 10 years was increased to almost three-fold. Prevalence of betel quid chewing among cases and controls was low (7.4% and 1.9% respectively). Chewing of at least one quid per day, and quid combination of betel leaf, areca nut, lime and tobacco conferred a 5-6 fold increased risk. CONCLUSIONS: Smoking is positively associated with oral cancer risk. A similar direct association was also seen among betel quid chewers.

GSTM1, GSTT1 and CYP1A1 polymorphisms and risk of oral cancer: a case-control study in Jakarta, Indonesia.

PURPOSE: to investigate genetic polymorphisms in GSTM1, GSTT1 and CYP1A1 and the association with the risk of oral cancer in the Jakarta population. METHOD: A total of 81 cases and 162 controls matched for age and sex were selected from 5 hospitals in Jakarta. Sociodemographic data using questionnaires were obtained and peripheral blood samples were collected with informed consent for PCR-RFLP assay. Conditional logistic regression analysis was performed to obtain the association between the risk of oral cancer and GSTM1, GSTT1 and CYP1A1 polymorphisms. RESULTS: GSTM1 and GSTT1 null were slightly overrepresented among cases (60.5% and 45.7% respectively) compared to controls (55.6% and 41.4% respectively), but no statistically significant differences were observed. In contrast, the distribution of CYP1A1 polymorphism was higher among controls compared to cases (52.5 % versus 42.4 %). The odds ratio of null GSTM1 and GSTT1 genotypes was slightly higher compared to wild type genotypes (OR 1.19, 95% CI 0.70-2.02 and OR 1.19, 95% CI 0.72-2.05 respectively). Furthermore, the presence of CYP1A1 polymorphism did not increase the risk of oral cancer (OR 0.70, 95% 0.39-1.25). CONCLUSION: Genetic polymorphisms of GSTM1, GSTT1 and CYP1A1 may not be risk factors for oral cancer in the Jakarta population.

Dietary patterns and risk of oral cancer: a factor analysis study of a population in Jakarta, Indonesia.

A matched case-control, hospital-based study of oral cancer was conducted in Jakarta population. The sample included 81 cases and 162 controls. The purpose of this study was to determine the association between dietary pattern and oral cancer in a Jakarta population using factor analysis. Dietary data were collected using food frequency questionnaire and factor analysis was performed on 15 food groups resulting in four principle factors/components being retained. The first factor "preferred" was characterized by fast food, fermented food, canned food, snacks high in fat and sugar, cooked and raw vegetables, and seafood. The second factor labeled "combination" was loaded by the intake of dairy product, red meat, white meat and fruits. The third factor labeled "chemical related was loaded by processed food and monosodium glutamate and the fourth principle component consisted of drinks and grain was labeled as "traditional". The conditional logistic regression was done using STATA 8 to obtain the odds ratio (OR) of highest tertile of each component retained from factor analysis and the ORs were then adjusted with risk habits. The consumption the highest tertile of the "preferred" pattern increased the risk of oral cancer by two-times compared to the lowest tertile of consumption [adjusted odds ratio (aOR)=2.17; 95% confidence interval (CI)=1.05-4.50]. The chemical related" pattern showed higher risk of about threefold (aOR=2.56; 95% CI=1.18-5.54), while the "traditional" pattern showed an increased of risk by twofold (aOR=2.04; 95% CI=1.01-4.41). In contrast, the "combination" pattern displayed protective effects in relation to oral cancer (aOR=0.50; 95% CI=0.24-1.00). This finding suggests that factor analysis may be useful to determine the diet pattern of a big set of food type and establish the correlation with oral cancer.