Lung Function Test May Not Point to Cancer in Women
New research shows that many women newly diagnosed with lung cancer have normal lung function, according to a report in the medical journal Chest.
Women perform better on lung function tests compared with their male counterparts, the researchers state.
The American College of Chest Physicians (ACCP) journal states that a significant proportion of women with newly diagnosed lung cancer had normal lung function on pulmonary function tests.
In addition, among patients with lung cancer, significantly more men than women had the condition called COPD, a risk factor for lung cancer that progressively and permanently reduces lung function.
According to the American Lung Association, COPD refers to two lung diseases, chronic bronchitis and emphysema. They are characterized by obstruction to airflow that interferes with normal breathing.
The Association states that both of these conditions frequently co-exist, and that physicians prefer the term COPD.
The American Academy of Family Physicians states that about 14 million people in the US have COPD. The disease develops over many years.
Dr. Raghu Loganathan, who conducted the study with colleagues from Memorial Sloan-Kettering Cancer Center, says, "Using the presence of COPD alone as a criterion to determine a patient's risk may miss women with lung cancer.”
Dr. Loganathan used pulmonary function testing to compare the prevalence of COPD in 151 men and 143 women who were newly diagnosed with lung cancer.
Spirometry testing was used to determine pulmonary function. This test measures the amount of air breathed in and out. It also measures how quickly air is inhaled and expelled from the lungs while one breathes through a mouthpiece.
At the time of diagnosis, 72.8 percent of men presented with COPD compared with 52.4 percent of women.
Among patients who smoked (87 percent), COPD occurred in 74.8 percent in men and 57.3 percent in women.
Overall, smoking status and older age were strongly associated with COPD. Both former and current smokers were about 10 times more likely to have COPD compared with nonsmokers.
"The absence of COPD should not lower the risk in a female patient who is otherwise considered to be at increased likelihood for developing lung cancer," says Dr. Loganathan.
"Physicians must consider additional (and well-established) risk factors, such as smoking history and age of the patient, when contemplating lung cancer screening," he notes.
The researchers also suggest that gender-based differences in spirometry should be considered when looking at strategies for screening for lung cancer.
Although screening for lung cancer is currently not a standard level of care, persons considered suitable candidates for lung cancer screening include those with a heavy smoking history, age greater than 50 years, presence of COPD, occupational exposure to asbestos, or history of exposure to radiation.
Currently, most screening programs and clinical trials choose patients for lung cancer screening based on smoking history and not on the presence or absence of COPD.
"Understanding the role that gender has in the development of lung cancer may help identify more advanced screening methods and new approaches to preventive care," says Dr. W. Michael Alberts, ACCP president.
Always consult your physician for more information.
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According to the American Lung Association, chronic obstructive pulmonary disease, or COPD, is the fourth leading cause of death in America, claiming the lives of 120,000 Americans in 2002.
Beginning in 2000, women have exceeded men in the number of deaths attributable to COPD.
In 2002, over 61,000 females died compared to 59,000 males.
Smoking is the primary risk factor for COPD. About 80 percent to 90 percent of COPD deaths are caused by smoking.
Female smokers are nearly 13 times as likely to die from COPD as women who have never smoked.
Male smokers are nearly 12 times as likely to die from COPD as men who have never smoked.
The Association states that other risk factors of COPD include air pollution, second-hand smoke, history of childhood respiratory infections, and heredity.
Occupational exposure to certain industrial pollutants also increases the risk for COPD.
A recent study found that the fraction of COPD attributed to work was estimated as about 19 percent overall and 31 percent among never smokers, says the Association.
In 2003, 10.7 million U.S. adults were estimated to have COPD. However, close to 24 million US adults have evidence of impaired lung function, indicating an under-diagnosis of COPD.
Always consult your physician for more information.
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