Smokeless Tobacco: An Etiological Risk Factor for High Incidence of Pyriform Sinus Cancer in Assam, India

Background: Cancer incidence in northeast India including Assam state is higher than the Indian national average. The incidence of hypopharyngeal cancer mainly pyriform sinus is high in (14.7/100,000) Assam and other northeastern state like Meghalaya (East Khasi Hills). Recently published Global Adult Tobacco Survey (GATS 2) report has shown that there is a decrease in tobacco consumption in India from 34.6% to 28.6%. However, in Assam the rate has increased from 39.3% to 48.2% mainly in the form of smokeless tobacco. Cigarette smoker reduce from 8.8% (GATS 1, 2009-10) to 6.1% (GATS 2, 2017), but smokeless users increase from 32.7% (GATS 1, 2009-10) to 41.7% (GATS 2, 2017). By now in India we only have gutka and pan masala (Prohibition) act 2015, by which there is ban on gutka but not other smokeless tobacco product. Because of COTPA (Cigarettes-and Other Tobacco Products (Prohibition of Advertisement and Regulation of Trade and Commerce, Production, Supply and Distribution) Act, there is reduction of smoking in India as well as in the state of Assam. But as we don't have stringent laws to control the use of smokeless tobacco, the users are increasing. Aim: To study the role of smokeless tobacco as a substantial etiological risk factor for high incidence of pyriform sinus cancer in Assam and to advocate for a strict law to prohibit or ban of smokeless tobacco in Assam. Methods: This is a retrospective study archived from hospital cancer registry database. 708 patients diagnosed with pyriform sinus carcinoma from January 2016 to December 2016 were analyzed. The relation between forms of tobacco use and gender, age group, place of residence and level of education were analyzed using IBM SPSS version 19. P < 0.05 was considered as statistically significant. Results: 584 (82.5%) patients had the habit of tobacco consumption of whom 128 (21.9%) were smokers, 220 (37.6%) consumed smokeless tobacco and the remaining 237 (40.5%) cases consumed both forms of tobacco products. Forms of tobacco use differ significantly with patient's gender ( P < 0.05). The patients in the age group ≥ 50 years or above 50 years, the highest frequency was observed in both forms of tobacco consumption (61/144 = 42.4% and 176/441 = 39.9%) respectively. Most of the patients from rural areas were habituated to both forms of tobacco use (201/499 = 40.3%) and most of them are mainly smokeless tobacco user. Conclusion: The current study shows that the incidence of smokeless tobacco user is alarmingly increasing in Assam and the northeastern part of India leading to high incidence of hypopharyngeal cancers. At present only gutka is banned in the India. So, further policies should be implemented to bring down the use of smokeless tobacco and thus reducing the burden of hypopharyngeal cancer in this part of the country.