Long-term carcinogenicity of pan masala in Swiss mice.

Carcinogenicity of pan masala, a dry powdered chewing mixture of areca nut, catechu, lime, spices and flavoring agents was evaluated by means of the long-term animal bio-assay 6- to 7-week old male and female S/RVCri mice were divided randomly into intermediate and lifetime exposure groups and fed normal diet without pan masala-(zero dose) or diet containing 2.5% and 5% pan masala. Animals in the intermediate-exposure group (n = 10/gender/dose group) were killed after 6, 12 or 18 months of treatment, while those in the lifetime-exposure group (n = 54/gender/dose group) were killed when moribund or at the termination of the experiment at 24 months. Several tissues were processed for histopathological examination. The body weight and survival rate of mice fed pan masala were lower than that of the controls. Histopathological observations of tissues from control animals did not reveal any neoplastic alterations. However, lifetime feeding of pan masala induced adenoma of the liver, stomach, prostate and sebaceous glands, also forestomach papilloma, liver hamartoma, hepatoma and hemangioma, carcinoma of the forestomach, adenocarcinoma of the lung and liver, and testicular lymphoma. Neoplastic lesions appeared mainly in the liver (n = 13), stomach (n = 3) and lung (n = 8). Lung adenocarcinoma, the most frequent malignant tumor type, was observed in 2/120 mice in the intermediate-exposure group and in 8/216 animals in the lifetime-exposure group. Statistical analysis of tumor-induction data revealed a significant dose-related increase in lung adenocarcinomas but not in liver and stomach neoplasms indicating that lung is the major target tissue for the carcinogenic action of pan masala.

Occupation and cancers of the lung and bladder: a case-control study in Bombay.

Associations between occupation and cancers of the lung (n = 246) and bladder (n = 153) were examined in a case-control study. Controls (n = 212) comprised cases of oral (75%) and pharyngeal cancers (13%) and non-neoplastic oral diseases (12%) at the same hospital. Only males were studied. A personal interview was conducted and a lifetime occupational history and information on demographic and relevant confounding factors including tobacco use were obtained. For lung cases, comparing 'ever' employed with 'never' employed in a particular occupation, significantly elevated risks (adjusted for smoking) were found for textile workers (odds ratio [OR] = 1.99, 95% confidence interval [CI]: 1.3-3.6) and cooks (OR = 4.48, 95% CI: 1.2-16.9). High risks were also observed among ship and dockyard workers (OR = 2.87, 95% CI: 0.8-10.1) and wood workers (OR = 2.88, 95% CI: 0.9-9.6). For bladder cancers, significantly elevated risk was observed only for chemical/pharmaceutical plant workers (OR = 4.48; 95% CI: 1.2-16.5). Two other sets of risk estimates were obtained: one by comparison with a second unexposed group made up of occupations where there was little likelihood of exposure to any cancer-causing occupational agent, and the other by fitting logistic regression models to the data. All methods yielded similar risk estimates. Tobacco smoking but not tobacco chewing was a risk factor for both sites.

Tobacco usage in school children in Bombay, India. A study of knowledge, attitude and practise.

A study of knowledge, attitude and practice with regard to tobacco usage was conducted in 1278 boys and 353 girls studying in the final year in various schools in Bombay. The proportion of boys given to one or the other form of tobacco usage (including experimenters/triers) was significantly higher in private English median schools (22.5%) compared to private Indian language schools (6.9%) or municipal Indian language schools (13.8%). There was also a significant difference between the two types of Indian schools. Girls from only Indian language schools were entered into the study and the proportion of tobacco users in them was very low (1.1%). Most (86%) boys who used tobacco were smokers. Hence the detailed analysis is restricted to smokers. Several probable factors influencing smoking behavior were studied. It was found that significantly higher proportion of boys smoked if their father or best friend smoked. Generally boys were more sensitive to best friend's or elder brother's disapproval than to parental. They were well informed about harmfulness of smoking but knowledge about specific health hazards was limited. Most of them had a positive attitude towards nonsmoking and smoking control programmes. Tobacco use has been proven to be a major health hazard. Although its use in adults in India is common, prevalence in adolescents in urban schools is not yet high. Before the situation changes we need to mount anti-tobacco educational programmes and work towards a non-tobacco generation to contain the harmful consequences of tobacco usage.

Role of alcohol in cancers of the upper alimentary tract: use of models in risk assessment.

A case-control study of cancers of the upper alimentary tract was conducted in a hospital to assess the role of several risk factors, including alcohol consumption, which is reported here. Male patients from one community with cancers of the oral cavity (n = 278), pharynx (n = 225), and oesophagus (n = 236) formed the case group. Patients diagnosed as not having cancer (n = 215) formed one control group, and a comparable sample of individuals from the general population (n = 177) formed another control group. The risk of regular alcohol consumption along with the two well established risk factors of tobacco smoking and chewing were assessed from the linear logistic model fitted. The process of model fitting has been elaborated. Adjusted odds ratios of alcohol consumption in those under 60 years of age varied from 1.3 to 3.6-fold for developing oral cavity cancer, from 1.9 to 5.4-fold for pharyngeal cancer, and from 1.5 to 2.7-fold for oesophageal cancer, in different age groups. No association was observed between alcohol consumption and cancer in those over 60 years of age. A synergistic effect was observed for the combined habit of alcohol drinking with tobacco smoking and/or chewing. The fact that age is a risk factor independent of habit is also demonstrated.

Differential effects of phorbol ester tumor promoters on 3-methylcholanthrene-induced epithelial and mesenchymal skin tumorigenesis.

The effects of TPA, PDD, PDB, PDA, or MEZ on epithelial and mesenchymal skin tumors induced by a s.c. injection of MCA were studied histologically. Group-I mice received only MCA. At 6 weeks after MCA injection, mice in groups II to VII received acetone, 1.8 nmol TPA, PDD, PDB, PDA, or 6.1 nmol MEZ respectively in 0.1 ml acetone twice weekly until tumor development. Alterations in skin tumor induction patterns were also studied in animals that had been exposed to TPA or acetone for 10 weeks prior to s.c. injection of MCA. Exposure of mouse skin to TPA before or after carcinogen administration increased 2- to 3.5-fold, the incidence of carcinoma and mixed tumors of epithelial and mesenchymal histogenesis. The average time of tumor induction decreased in mice treated with MCA + TPA and 100% of the test animals in the TPA + MCA group developed tumors. In contrast, TPA-related phorbol esters inhibited skin tumor development, particularly trichoepithelioma and fibrosarcoma and increased the average time of tumor induction.

Role of diet in upper aerodigestive tract cancers.

A case-control interview study for assessing the role of dietary factors in selected cancers was undertaken in a hospital. Male patients from one community, with cancers of the oral cavity (n = 278), pharynx (n = 225), esophagus (n = 236), and larynx (n = 80) formed the case group. Patients diagnosed as not having cancer (n = 215) formed one control group, and a comparable sample of individuals from the general population (n = 177) formed another control group. All risks were adjusted for subjects' ages and habits of chewing and/or smoking tobacco, which are the two most important risk factors for cancers at these sites. A protective effect was observed with the intake of vegetables (twofold risk in nondaily vs. daily consumers) and fish (two- to threefold risk in those who did not eat at least once a week vs. those who did), and to a certain extent with pulses and buttermilk, in comparison with either one or both control groups. Intake of vegetables and fish were also observed to be risk modifiers for those who chewed and/or smoked tobacco. Lower levels of fat consumption was associated with elevated risk levels. The use of red chili powder emerged as a risk factor for all sites (two- to threefold risk with a dose-response relationship) compared with population controls. Tea drinking was also observed to be a risk factor for esophageal cancers, and to a lesser extent, for pharyngeal cancers.