US study suggests HRT may make lung cancer more deadly
Women who take combined hormone replacement therapy (HRT) appear to be more likely to die if they develop lung cancer, according to an eight-year study involving more than 16,000 women.
A retrospective analysis published in the Lancet medical journal found that while postmenopausal women who took oestrogen plus progestin did not face an increased risk of lung cancer itself, those who did develop the disease were more likely to die.
The risk of dying was particularly high in women who developed a certain form of the disease called non-small-cell lung cancer.
Researchers from across the US analysed data collected during the Women's Health Initiative (WHI) trial.
They wanted to find out whether there was an association between combined HRT and mortality from lung cancer, as results from the trial appeared to suggest.
The scientists analysed data on 16,608 postmenopausal women between the ages of 50 and 79 years, 8,506 of whom were given combined HRT while the remaining 8,102 received a placebo (dummy treatment).
After around 5.6 years of treatment and 2.4 years of follow-up there were more deaths among women who took HRT than among those who did not - 73 compared with 40 deaths - particularly among those with non-small-cell lung cancer.
Writing in the Lancet, the researchers concluded: "Although treatment with oestrogen plus progestin in postmenopausal women did not increase incidence of lung cancer, it increased the number of deaths from lung cancer, in particular deaths from non-small-cell lung cancer.
"These findings should be incorporated into risk-benefit discussions with women considering combined hormone therapy, especially those with a high risk of lung cancer."
Professor Valerie Beral, director of Cancer Research UK's cancer epidemiology unit, commented: "Many studies have shown that HRT can cause cancers of the breast and ovary.
"This new result for lung cancer is based on small numbers and could be a chance finding. But the government's recommendation that women use HRT for as short a time as possible would still apply."
Chlebowski, R., Schwartz, A., Wakelee, H., Anderson, G., Stefanick, M., Manson, J., Rodabough, R., Chien, J., Wactawski-Wende, J., & Gass, M. (2009). Oestrogen plus progestin and lung cancer in postmenopausal women (Women's Health Initiative trial): a post-hoc analysis of a randomised controlled trial The Lancet DOI: 10.1016/S0140-6736(09)61526-9