African-Americans have unique lung cancer risks from chronic obstructive pulmonary disease

Scientists at the M.D. Anderson Cancer Center have developed a risk prediction assessment for lung cancer specifically for African Americans that suggests a greater risk from chronic obstructive pulmonary disease (COPD), according to a report published in the September issue of Cancer Prevention Research, a journal of the American Association for Cancer Research. Etzel and colleagues analyzed data from 491 African Americans with lung cancer and 497 African Americans without lung cancer to identify risk factors for the disease. They then compared these risk factors with a previously established risk prediction model for whites.

What was unique to African Americans was the risk associated with chronic obstructive pulmonary disease. African American men with a prior history of chronic obstructive pulmonary disease had a more than sixfold increased risk of lung cancer, similar to that seen with smoking. This is approximately two-fold higher than the risk typically seen from chronic obstructive pulmonary disease among whites.

"The one size fits all risk prediction clearly does not work," said Carol Etzel, Ph.D., assistant professor of epidemiology at the University of Texas M.D. Anderson Cancer Center.

As with whites, smoking was a significant risk factor for lung cancer. Current smokers had a more than sixfold increased risk of lung cancer, and former smokers had a more than threefold increased risk. This decreased risk was confined to those who had quit smoking more than ten years prior to diagnosis; these patients had a 58 percent decreased risk compared with patients who had quit within the previous ten years.

Researchers also found that hay fever, previously shown to be protective among whites, was also protective among African Americans. Specifically, African Americans with hay fever were 44 percent less likely to develop lung cancer, a rate that had been previously seen among whites.

African American males have a higher risk of lung cancer incidence at 110.6 per 100,000 compared with 81 per 100,000 among white males. Mortality is also higher among African American men at 95.8 per 100,000 compared with 72.6 among whites. Lung cancer incidence and mortality rates among women are comparable.

Etzel said the risk prediction model detailed in Cancer Prevention Research is part of an ongoing project to establish risk models among different ethnic groups; a model for Hispanics is currently under development.

"What we hope is that a doctor can use these models to encourage their patients to take steps to prevent lung cancer. Even if they are never smokers, they can be at risk," said Etzel.

Source: American Association for Cancer Research