Hormone replacement therapy links to higher lung cancer risk

Hormone replacement therapy (HRT) used by post menopausal women is now linked to increased risk for lung cancer. Women age 50 to 76 who take estrogen plus progestin for 10 years or more were found to have a 50 percent greater chance of developing lung cancer compared to women not using hormone replacement therapy.

Even though the risk of lung cancer is small compared to smoking, Chris Slatore, M.D., who led the study says, "Although HRT use has declined and is not recommended except for short-term treatment of menopausal symptoms, our results indicate millions of women may remain at risk of developing lung cancer."

The link between hormone replacement and lung cancer was found in a review of data from the Vitamins and Lifestyle Study in Washington State from 2000 to 2002.

Researchers followed 36,588 perimenopausal and postmenopausal participants aged 50 to 76 for six years. At the end of the observation period 344 of the participants had developed lung cancer. The results linked longer years of HRT with more advanced stages of lung cancer at time of diagnosis.

The reasons that hormone replacement therapy might increase lung cancer risk are not clear. HRT is already associated with increased risk of breast cancer, stroke, and blood clots. The researchers say it may be a combination of genetic and environment interactions responsible for the association between hormone replacement therapy and lung cancer.

Oregon Health and Science University