SATURDAY, Sept. 19, 2009 (HealthDay News) -- Taking a combination form of hormone replacement therapy, which includes both estrogen and progestin, increases a woman's risk for dying from lung cancer, a new study has found.
The finding stems from an analysis of data from the Women's Health Initiative trial on 16,608 postmenopausal women, aged 50 to 79, in the United States who had been randomly assigned to take either a once-daily tablet of 0.625 milligrams conjugated equine estrogen plus 2.5 mg medroxyprogesterone acetate or a placebo.
After eight years, 73 women taking the hormone therapy and 40 women in the placebo group had died of lung cancer. That meant, according to the researchers, that women who took the drug were 71 percent more likely to die from the disease.
The study also found that women taking the hormone therapy were 28 percent more likely to be diagnosed with lung cancer, although the study noted that the finding was not statistically significant.
"Treatment with estrogen plus progestin in postmenopausal women ... increased the number of deaths from lung cancer, in particular deaths from non-small-cell lung cancer," concluded Rowan Chlebowski, of the Los Angeles Biomedical Research Institute at Harbour-UCLA Medical Center, and his colleagues.
The researchers urged that the findings "be incorporated into risk-benefit discussions with women considering combined hormone therapy, especially those with a high risk of lung cancer ... such as current smokers or long-term past smokers."
Dr. Apar Kishor Ganti, from the University of Nebraska Medical Center in Omaha, wrote in an accompanying editorial that "because the optimum safe duration of hormone-replacement therapy in terms of lung cancer survival is unclear, such therapy should probably be avoided in women at a high risk of developing lung cancer, especially those with a history of smoking."
In fact, Ganti questioned whether hormone therapy should be used at all.
"These results, along with the findings showing no protection against coronary heart disease, seriously question whether hormone-replacement therapy has any role in medicine today," he wrote. "It is difficult to presume that the benefits of routine use of such therapy for menopausal symptoms outweigh the increased risks of mortality, especially in the absence of improvement in the quality of life."
The study, which appears online and in an upcoming print issue of The Lancet, was released Sept. 19 to coincide with the European Cancer Organization meeting.
The U.S. National Institute on Aging has more on hormones and menopause.