Study: HRT puts women at greater risk for lung cancer

The reports of health problems associated with hormone replacement therapy (HRT) keep coming. First, the Women’s Health Initiative identified women who took the combined estrogen-plus-progestin therapy were at a much greater risk of developing breast cancer. It later showed these women were at an increased risk of heart disease and other serious health problems. Now, an article published online in the Journal of Clinical Oncology suggests that women who took combined HRT are at an increased risk of lung cancer by as much as 50 percent.

The level of risk seemed to increase with the duration of therapy. Women who took combined therapy for 10 years or more were at the greatest risk for lung cancer. The study also indicated that the risk was limited to the combined therapy as opposed to the estrogen-only HRT. Smoking also didn’t affect the influence of HRT on lung cancer risk.

“Although HRT use has declined and is not recommended except for short-term treatment of menopausal symptoms, our results indicate millions of women remain at risk of developing lung cancer,” Christopher G. Slatore, MD, of Oregon Health and Sciences University in Portland, and colleagues wrote.

The study involved data from a prospective cohort of 36,588 peri- and postmenopausal women ages 50 to 76 who had participated in the Vitamins and Lifestyles (VITAL) study that examined associations between use of supplements and cancer risk. Two-thirds of the study’s participants either took or had taken HRT. A similar number had a family history of lung cancer, and another two-thirds smoked.

During the six years of follow-up in the study, 344 women, including some from both the HRT and the non-HRT group, developed lung cancer. The study showed that women who took combined HRT for nine years or less had a 1.27 risk for lung caner, something not considered statistically significant. However, women who took the combined therapy for 10 years or longer had a 1.48 hazard ratio for lung cancer, considered a much more notable increase.

“These findings may be helpful for informing women of their risk of developing lung cancer and delineating important pathways involved in hormone metabolism and lung cancer,” the authors wrote in conclusion.

Source: MedPage Today