Gender clearly plays a role in the survival rate of people with lung cancer, a new study has found.

Among patients receiving treatment for lung cancer, women had significantly better survival rates than men, researchers found.

Women also had a decreased risk of death -- 21 percent lower -- compared to men in a group of patients who received no treatment, leading researchers to believe that lung cancer has a different biologic behavior and natural history in women than in men.

Biological Basis for Progression

"In patients with lung cancer receiving treatment, women have shown a better response to therapy, resulting in better survival rates," says Juan Wisnivesky, MD, MPH, FCCP, Mount Sinai School of Medicine, New York, NY.

"Yet, new data suggest that even in untreated patients, women with lung cancer still live longer than men, despite the presence of other medical conditions or gender differences in life expectancy," he adds. "This suggests that the progression of lung cancer has a biological basis, with the disease being more aggressive in men than women."

Significantly Better Survival

Researchers from Mount Sinai School of Medicine reviewed 18,967 cases of stage I and II non-small cell lung cancer diagnosed between 1991 and 1999 from the Surveillance, Epidemiology, and End Results registry linked to Medicare records.

Patients were grouped into three categories according to treatment received: surgery, radiation or chemotherapy, and untreated.

Women in the three groups had significantly better cancer specific, overall, and relative survival than men, researchers found, after making adjustments for comorbidities and general life expectancy.

Controlling for Other Factors

Lung cancer specific five-year survival for women was 54 percent compared with 40 percent for men among patients who received treatment, and women had a 30 percent decreased risk of death compared with men in this group.

Among untreated patients, women had a 21 percent decreased risk of lung cancer deaths compared to men, after adjusting for differences in age, race, socioeconomic status, access to care and cancer histology.

Women lived longer than men after controlling for age, race, disease stage at diagnosis, histology, median income, geographic area, access to care, and type of treatment, researchers found.

May Influence Course of Treatment

"It is clear that gender plays a role in the survival rate of men and women," says W. Michael Alberts, MD, FCCP, President of the American College of Chest Physicians.

"Physicians caring for patients with lung cancer should consider the inherent progression of lung cancer among men and women when deciding on a patient's course of treatment," he recommends.