HIGHER LUNG-CANCER RISK FOR YOUNGER AFRICAN-AMERICANS WITH THE PRO PRO P53 GENOTYPE/

A restriction fragment length polymorphism in codon 72 of the p53 gene has been implicated in lung cancer risk, although the functional sign ificance of the polymorphism has not been determined, This association was examined in 109 lung cancer cases (67 African-American and 42 Mex ican-American) and 114 controls (74 African-American and 40 Mexican-Am erican) identified from a molecular epidemiological study of lung canc er, The susceptible Pro/Pro genotype was associated with a 1.56-fold h igher risk of lung cancer in African-Americans and a 1.95-fold in Mexi can-Americans, although neither estimate was statistically significant , In fact, the prevalence of the Pro/Pro genotype was only 2.5% in Mex ican-American controls, compared with 20.3% for African-American contr ols, Patients with the susceptible genotype appeared to have earlier a ge at diagnosis and lower mean cigarette pack-year exposures than did patients with the Arg/Arg or Arg/Pro genotypes, Risk estimates for the susceptible genotype were 11.29 (1.1, 111.3) for patients <53 years o f age and 14.1 (1.5, 130.6) for patients who reported <30 pack-years o f smoking, The Pro/Pro genotype was not associated with elevated risk in older patients, nor with heavier smokers, If Pro/Pro is a susceptib le genotype, the lower prevalence evident in Mexican-Americans may par tly explain their lower rates of lung cancer.