CYTOCHROME-P-450 IA1 GENOTYPE IN LUNG-CANCER PATIENTS AND CONTROLS INRIO-DE-JANEIRO, BRAZIL

MspI restriction fragment length polymorphism in cytochrome P-450 IA1 (CypIA1) gene, which has been associated with lung cancer susceptibili ty in Japanese, was studied in persons from Rio de Janeiro, in the fra mework of a hospital-based, age, race (black or nonblack), and gender- matched case-control study (n = 222; 110 cases and 112 controls). Cont rary to the hypothesis, there was no difference in the frequency of th e C genotype (MspI site-present homozygous), even after racial breakdo wn. There were no significant differences between cases and controls w hen categorized according to tobacco consumption. The lifetime quantit y of tobacco smoked was not different among lung cancer patients with three different genotypes (A, MspI site-absent, homozygous; B, heteroz ygote; and C). The background frequency of the MspI polymorphism C gen otype is a little less than 10%, similar to that of the Japanese healt hy population. The CypIA1 MspI polymorphism itself does not seem to be related to susceptibility to bronchial carcinogenesis in this area.