Objective: To assess associations between codon 72 polymorphisms (Pro or B and Arg or b alleles) of the TP53 gene and lung cancer risk among Bangladeshis.
Materials and methods: The distribution of the BB, Bb, and bb genotypes and the frequencies of the B and b alleles were determined by PCR-RFLP method using DNA extracted from leucocytes of 50 confirmed lung cancer patients and 50 age-matched controls and the data were analysed.
Results: The ratio of BB, Bb, and bb genotypes were in Hardy-Weinberg equilibrium except for the male patients (χ2=4.6). The B allele is overrepresented among all patients (OR=2.0, p=0.02) and the female patients (OR=4.1, p≤0.01) compared to the controls. The BB/bb ratio was also higher among the patients (OR=3.0, p=0.03). The relative risk of cancer for having BB over bb genotype was 1.8 (p=0.04) but no effect was observed for the Bb genotype. The B allele was overrepresented among patients with adenocarcinomas (OR=2.4, p≤0.01) and squamous cell carcinomas (OR=2.7, p≤0.01) over the controls but the difference was not significant for those with small cell lung carcinomas (OR=1.1, p=0.66). The B allele was overrepresented among patients age 50 or younger (OR=2.7, p≤0.01), but not for older patients (OR=1.7, p=0.07), and among smokers compared to the controls (OR=1.8-10.0, p≤0.01-0.03). However, no correlation between increasing pack-years and lung cancer was observed.
Conclusions: The Pro/Pro (BB) genotype and the B allele are risk factors for lung cancer among Bangladeshis, particularly for people under age 50, women and smokers.