Hormone Replacement Therapy May Increase the Risk of Lung Cancer

Hormone replacement therapy (HRT), although its use has diminished in recent years, can still carry risks.  One of these is an increased likelihood of contracting lung cancer, according to a study posted in the journal Lancet.

The Women’s Health Initiative (WHI) study was a large double-blind trial across the USA that enrolled 16,500 postmenopausal women to take estrogen-plus-progestin or a placebo.  It was stopped prematurely after an average of 5.6 years, because the HRT recipients had a higher rate of cardiovascular disease, coronary heart disease, stroke, venous thromboembolism, and breast cancer; they also had a lesser rate of fractures and colorectal cancer than those taking the placebo.  These findings helped almost virtual abandonment of long-term HRT for treating postmenopausal symptoms.

An analysis on after a further 2.4 years of follow-up found that 109 women in the HRT group had been diagnosed with lung cancer, compared with 85 women in the placebo group.  There were 73 deaths from lung cancer in the HRT group vs. 40 in the placebo group; those in the HRT group were more likely to have non-small-cell lung cancer, while small-cell lung cancer numbers were similar in the two groups. 

This finding adds to the reasons why HRT should only be used in women with exceptionally severe postmenopausal symptoms, for as short a period as possible.  In particular, the patient should not smoke!