New research shows that many women recently diagnosed with lung cancer have normal lung function and perform better on lung function tests compared with their male counterparts.
A study published in the May issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians (ACCP), shows a significant proportion of women with newly diagnosed lung cancer presented with normal lung function on pulmonary function tests. Furthermore, among patients with lung cancer, significantly more men than women presented with COPD, a well-known independent risk factor for lung cancer that progressively and permanently reduces lung function.
"These findings suggest that the susceptibility patterns among women may be different compared with men," said Raghu Loganathan, MD, FCCP, Lincoln Medical and Mental Health Center, Bronx, NY. "Using the presence of COPD alone as a criterion to determine a patient's risk may miss women with lung cancer."
Dr. Loganathan and colleagues from Memorial Sloan-Kettering Cancer Center in New York used pulmonary function testing to compare the prevalence of COPD in 151 men vs 143 women who were newly diagnosed with lung cancer. Spirometry testing was used to determine pulmonary function. Patients were considered to have COPD when the FEV1/FVC ratio was lower than 70 percent; an FEV1/FVC ratio of greater than 70 was considered normal lung function. 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," said 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." The researchers also suggest that gender-based differences in spirometry should be considered in constructing 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 heavy smoking history (30 pack years), 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," said W. Michael Alberts, MD, FCCP, President of the American College of Chest Physicians.