Ecological analysis to study association between prevalence of smokeless tobacco type and head-and-neck cancer

Abstract

Context: Head-and-neck cancers (HNCs) are most common cancer in Indian cancer registries. However, there is a huge variation and heterogeneity in use of different types of smokeless tobacco (SLT) consumption across India. Aims: The aims and objectives of this study were to investigate how different types of SLT use are distributed across Indian states and examined its association with different subsites of HNC incidence rates. Settings and Design: Ecological analysis of correlation between SLT prevalence and incidence rates from population-based cancer registries. Methods: Incidence data was extracted from population-based cancer registries report from the National Cancer Registry Programme database 2012-2014. The current SLT uses the prevalence of all Indian States and Union territories from Global Adult Tobacco Survey 2009-2010. Statistical Analysis Used: Pearson's correlation coefficient was used to estimate an ecological correlation between the prevalence of types of SLT uses in different region of India and age-adjusted incidence rate of different subsites of HNC. Results: In our brief analysis, we found a significant correlation between certain types of SLT use and subsite of HNC. Betel quid and tobacco use are correlated (r = 0.53) with oropharynx cancer incidence. Khaini use is correlated with hypopharynx cancer incidence (r = 0.48). Gutka use is correlated with mouth cancer incidence (r = 0.54). Oral tobacco is correlated with mouth cancer incidence (r = 0.46). Other SLT use is correlated for hypopharynx cancer incidence (r = 0.47). Conclusions: The variations in SLT use across Indian states account for differences in incidence rates of HNC subsites across the states. The inferences from this brief analysis can be used as a base to modify and design observational epidemiological studies in the future.