Certain SNPs may indicate a greater lung cancer risk in African Americans than in Caucasians, despite occurring less frequently in African Americans. Researchers from the Karmanos Cancer Institute and the University of Texas M. D. Anderson Cancer Center found that the genes CHRNA3 and CHRNA5 may contribute to lung cancer risk due directly to or through their association with nicotine dependence. The study appears in the October issue of the Journal of Thoracic Oncology.
The investigators evaluated data on 1,508 non-small-cell lung cancer (NSCLC) patients (38% of which were African American) and 1,314 corresponding control patients matched based on age, sex, and race. The three case-controlled studies examined family history of lung cancer, smoking history, and age.
Using unconditional logistical regression, the scientists identified associations between SNPs and lung cancer risk. Despite reporting lower levels of smoking, lung cancer incidence remains higher for African Americans than for Caucasians.
Previous conclusions from genome-wide association studies identified links between NSCLC risk, smoking behavior, and SNPs on chromosome 15q25.1. The present study concentrated on the genes CHRNA3 and CHRNA5, confirming a stronger association with the risk of lung cancer than with nicotine dependence in African Americans.