on January 20th, 2016 No Comments
Although the relationship between smoking and lung cancer has been established beyond any doubt, it’s still difficult to know how a patient’s ethnicity might play into risk assessment. But it’s clear that it has a role. Lung cancer is the leading cause of cancer death in this country, and it disproportionately affects African Americans. Doctors are struggling to understand the interactions between genes and environment that contribute to lung cancer risk in all populations.
Physician scientist Sean David, MD, DPhil, and a multidisciplinary team of colleagues recently published in EBioMedicine the results of a study suggesting that African Americans who carry a panel of risky genetic sequences may be at higher risk for the disease, even if they are light smokers.
The study involved analyses of more than 7,000 Women’s Health Initiative participants and nearly 2,000 participants in a lung cancer case-control study with collaborators from multiple institutions in the United States.
As David explained to me in an email:
All smokers are at heightened risk for lung cancer, particularly those possessing high-risk genotypes. Our study suggests that African American light smokers are not at lower risk than heavy smokers if they possess certain genotypes, but that smoking more cigarettes does markedly increase lung cancer risk in individuals without these high-risk genotypes. These conclusions reinforce the message that light or heavy smoking is a risky proposition for African Americans, who can benefit from smoking cessation and evidence-based lung cancer screening services.
The researchers identified six nucleotide changes that appeared to affect the relationship between cigarettes smoked per day and lung cancer risk in African American smokers – all on chromosome 15. Although the nucleotide changes, called single nucleotide polymorphisms, or SNPs, had been associated with lung cancer risk in previous studies, this is the first time the risk has been tied to daily cigarette exposure in African Americans.