CYP1A1 gene mutation increases the risk of lung cancer

New findings point to a “clear association” between the CYP1A1 homozygous Mspl restriction fragment length polymorphism and an increased risk of lung cancer among Caucasians.

CYP1A1 is involved in the metabolism of the suspected lung carcinogen benzopyrene. “It is therefore conceivable that genetically determined variations in its activity modify individual susceptibility to lung cancer,” Dr. Paolo Vineis from Universita di Torino in Italy and colleagues note in the May 1st issue of the International Journal of Cancer. “The role of the CYP1A1 Mspl polymorphism in lung cancer has been widely studied but has not been fully clarified.”Dr. Vineis’ group pooled data from 22 case-control studies on CYP1A1 and lung cancer risk in Caucasian and Asian populations. Among 2451 lung cancer cases and 3358 controls, the age- and gender-adjusted odds ratio for lung cancer was 2.36 in Caucasians with the CYP1A1 homozygous Mspl gene mutation.The association was equally strong for squamous cell carcinoma and adenocarcinoma of the lung, and was stronger in men than in women, a finding that was only partially explained by adjustment for smoking.Analyses on CYP1A1 Mspl polymorphism and lung cancer risk were inconsistent and failed to reach statistical significance in Asians, but the researchers say this might be due to “design specificities or unknown effect modifiers in the Asian studies.”Commenting on the findings, Dr. Vineis said: “Variants of the CYP1A1 gene do increase the risk of lung cancer, confirming that gene-environment interactions are important in cancer, i.e. individual genetic susceptibility modulates the role of carcinogenic exposures.” He cautioned, however, that “very large epidemiological studies are needed to study such issues.”(Source: Int J Cancer 2003;104:650-657: Reuters Health: May 1, 2003: Oncolink)