To detect invasive lung cancer in its early stages, researchers urge current and former smokers who have a strong family history of the disease to take a lung function test and undergo screening with spiral computed tomography. The test is especially important should the previously diagnosed relative be young (around 50).
These findings appear in an article on familial lung cancer in the first issue for January 2006 of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.
Ann G. Schwartz, Ph.D., of the Karmanos Cancer Institute in Detroit, Mich., along with an associate, emphasized that 85 to 95 percent of all lung cancers are attributable to cigarette smoking. The rate of lung cancer in the United States has dropped over the past two decades as a result of extraordinary personal and public health smoking cessation efforts. Yet, an estimated 46 million former smokers in America remain at risk for the disease, along with almost 49 million who continue to smoke. Consequently, further efforts need to be made to identify high-risk populations.
“Because cigarette smoking is such an overwhelming risk factor and preventable, the importance of family history and genetic susceptibility to lung cancer risk has been overlooked,” said Dr. Schwartz.
She pointed out that people with a family history of lung cancer are at approximately a two- to threefold increased risk of developing the illness.
The authors noted that the median age of onset for younger family members affected by lung cancer was around 50, showing a trend toward an earlier age at onset.
“Although evidence pointing to a gene for lung cancer is substantial, the problems associated with the conduct of a linkage study in lung cancer are even greater,” said Dr. Schwarz. “The average age of lung cancer diagnosis is 70 years and five-year survival after diagnosis continues to be poor, at 15 percent, so affected family members are typically deceased, as are their parents, siblings and spouses.”
One way the authors suggest to identify high risk groups is to routinely collect data on family history of lung cancer in patients who have chronic obstructive pulmonary disease (COPD), an illness that is also strongly associated with cigarette smoking. In addition, data on family history of COPD should be gathered from those already diagnosed with lung cancer.
Finally, the investigators encouraged the funding of larger linkage and association studies to identify genes for both lung cancer and COPD.
