Exclusive use of different types of tobacco products, exposure to secondhand tobacco smoke and risk of subtypes of head and neck cancer among Indian males.

Tobacco products are used in vary many forms in India. Although the risk of tobacco uses in developing head and neck cancer (HNC) is known, risk by exclusive use of different tobacco products on HNC and its subtypes is poorly understood. A case-control study was conducted at a tertiary cancer hospital, which receives cases from different geographical regions of India with use of different types of tobacco products. The study included 824 oral cavity (OC), 149 oropharynx (OPX) 104 hypopharyngeal (HPX) and 81 larynx (LX) cancer cases and 1206 visitor controls. Information on 11 different types of tobacco products and exposure to secondhand smoke was collected through structured questionnaires. Odds ratios (OR) and 95% confidence intervals (CI), for the association of various HNC subtypes with exclusive use of each tobacco product compared to nonusers of tobacco were estimated using logistic regression models, after adjusting for potential confounders. Exclusive use of any type of smokeless tobacco product was strongly associated with all subtypes of HNC. Gutka chewing (only) had highest risk (OR = 33.67; 95% CI = 19.8-57.0) while exclusive users of betel quid with tobacco (BQ + T), tobacco quid, Khaini, Mawa and Mishri users had a OR of 14.77, 24.20, 5.33, 2.96 and 3.32, respectively, for development of OC. Bidi smoking and secondhand smoke was independently associated with increased risk of HNC. Our study indicates that tobacco control policies should focus on product specific awareness messaging that switching between tobacco product types is not a safe alternative to complete cessation.

Mustard oil consumption, cooking method, diet and gallbladder cancer risk in high- and low-risk regions of India.

The current study aimed to investigate the role of cooking with mustard oil and other dietary factors in relation to gallbladder cancer (GBC) in high- and low-incidence regions of India. A case-control study was conducted including 1,170 histologically confirmed cases and 2,525 group-matched visitor controls from the largest cancer hospital in India. Dietary data were collected through a food frequency questionnaire. For oil consumption, we enquired about monthly consumption of 11 different types of cooking oil per family and the number of individuals usually sharing the meal to estimate per-individual consumption of oil. Information about method of cooking was also requested. Odds ratios (ORs) and 95% confidence intervals (CIs) quantifying the association of GBC risk consumption of different types of oil, method of cooking, and dietary food items, were estimated using logistic regression models, after adjusting for potential confounders. High consumption of mustard oil was associated with GBC risk in both high- and low-risk regions (OR = 1.33, 95% CI = 0.99-1.78; OR = 3.01, 95% CI = 1.66-5.45), respectively. An increased risk of GBC was observed with deep frying of fresh fish in mustard oil (OR = 1.57, 95% CI = 0.99-2.47, p-value = 0.052). A protective association was observed with consumption of leafy vegetables, fruits, onion and garlic. No association was observed between consumption of meat, spicy food, turmeric, pulses or with any other oil as a cooking medium. The effect of high consumption of mustard oil on GBC risk, if confirmed, has implications for the primary prevention of GBC, via a reduced consumption.

Occupations and the risk of buccal mucosa cancer in Indian men: A multi-centre case-control study.

OBJECTIVE: This study aimed to investigate the association between lifetime occupational history and risk of buccal mucosa cancer (BMC). METHODS: We utilized a multi-centric, hospital-based case-control study across five centres of Tata Memorial Centre, Mumbai, India. Cases included men aged 20-75-years with histological confirmed primary cancer of the buccal mucosa. Visitor controls were frequency matched to cases for age (10 years interval) and current residential zone. Study participants were interviewed face-to-face. Logistic regression was performed to estimate odds ratio (OR) and 95 % confidence intervals (CI). RESULTS: Among ever employed males, we identified 1969 BMC cases and 2145 controls. We observed an increased risk of BMC in 'Craft and Related Trades Workers' (OR 1.37; 95 % CI 1.13-1.65), 'Plant and Machine Operators and Assemblers' (OR: 1.26; 95 % CI 1.01-1.56), and 'Elementary Occupations' (OR:1.33; 95 % CI 1.12-1.58). More specifically, the increased risk was observed for 'Metal, Machinery and Related Trades Workers', 'Handicraft and Printing Workers', 'Drivers and Mobile Plant Operators', and 'Laborers in Mining, Construction, Manufacturing and Transport'. CONCLUSION: Our findings suggest that certain occupations may be at a higher risk of BMC. Some fraction of BMC can be prevented by reducing exposure to hazardous agents used in these occupations. Further research is needed to identify which exposures are responsible for the increased risk. Moreover, tobacco control and early detection activities can be focused towards these occupations as tobacco consumption is also high in them, which may also be the reason for increased risk observed in these groups.