Association of a p53 Codon 72 Gene Polymorphism with Environmental Factors and Risk of Lung Cancer: a Case Control Study in Mizoram and Manipur, a High Incidence Region in North East India

BACKGROUND: A very high incidence of lung cancer is observed in Mizoram and Manipur, North East India. We conducted a population based case control study to establish associations of p53 codon 72 polymorphisms and interactions with environmental factors for this high incidence. MATERIAL AND METHODS: A total of 272 lung cancer cases and 544 controls matched for age (±5 years), sex and ethnicity were collected and p53 codon 72 polymorphism genotypes were analyzed using a polymerase chain based restriction fragment length polymorphism assay. We used conditional multiple logistic regression analysis to calculate adjusted odds ratios and 95% confidence intervals after adjusting for confounding factors. RESULTS: p53 Pro/Pro genotype was significantly associated with increased risk of lung cancer in the study population (adjusted OR=2.14, CI=1.35-3.38, p=0.001). Interactions of the p53 Pro/Pro genotype with exposure to wood smoke (adjusted OR=3.60, CI=1.85-6.98, p<0.001) and cooking oil fumes (adjusted OR=3.27, CI=1.55-6.87, p=0.002), betel quid chewing (adjusted OR=3.85, CI=1.96- 7.55, p<0.001), tobacco smoking (adjusted OR=4.42, CI=2.27-8.63, p<0.001) and alcohol consumption (adjusted OR=3.31, CI=1.10-10.03, p=0.034) were significant regarding the increased risk of lung cancer in the study population. CONCLUSIONS: The present study provided preliminary evidence that a p53 codon 72 polymorphism may effect lung cancer risk in the study population, interacting synergistically with environmental factors.