The percentage of tobacco use in all the eight north-eastern states is much higher than the national average for both males and females [1 2]. This may be one of the reasons north eastern states cancer incidence is much above of rest of India especially in gastric cancer.  In India, not only tobacco smoking but tobacco chewing is also highly prevalent. Tobacco is used in various forms like, hukka, snuff, bidis, cigarettes, taibur, meizioletc[3,4,5,6]

A study from Mizoram, a North-eastern state of India, reported that tobacco use in any form (chewing, smoking and drinking) was observed to increase the risk of gastric cancer[3].

References:

1. Phukan RK, Narain K, Zomawia E, Hazarika NC, Mahanta J. Dietary habits and stomach cancer in Mizoram, India.J Gastroenterol. 2006 May;41(5):418-24.
2. Dikshit RP, Mathur G, Mhatre S, et al. Epidemiological review of gastric cancer in India. Indian J Med PaediatrOncol. 2011 Jan-Mar; 32(1): 3–11.doi: 10.4103/0971-5851.81883 PMCID: PMC3124986.
3. Trédaniel J, Boffetta P, Buiatti E, et al. Tobacco smoking and gastric cancer: Review and meta-analysis. IJC 1997 72, Issue 4 565–573.
4. Ladusingh L, Dhillon P, Narzary PK. Why Do the Youths in Northeast India Use Tobacco? Journal of Environmental and Public Health Volume 2017 (2017), Article ID 1391253, https://doi.org/10.1155/2017/1391253
5. Ministry of Health and Family Welfare (MoHFW) Government of India (GOI), International Institute for Population Sciences (IIPS) (2010) Global Adult Tobacco Survey India Report (GATS India), 2009-2010. Ministry of Health and Family Welfare, New Delhi; International Institute for Population Sciences, Mumbai.
6. NFHS 2005-06 International Institute for Population Sciences (IIPS) and Macro International (2007). National Family Health Survey (NFHS-3), 2005-06: India: Volume I. Mumbai: IIPS.