An updated report on the benefits and harms of HRT (hormone replacement therapy) has found that estrogen plus progestin and estrogen alone reduce fracture risk but raise the risk of stroke, gallbladder disease, urinary incontinence and thromboembolism events. Estrogen plus progestin raise the chances of developing breast cancer and probably dementia, while estrogen alone decreases breast cancer risk.

This review, written by researchers from Oregon Health & Science University, and Providence Cancer Center, and published in Annals of Internal Medicine, was conducted to help USPSTF (US Preventive Services Task Force) issue its new recommendations on hormone therapy.

As background information, the researchers explained that menopausal hormone therapy to prevent chronic diseases is not recommended today, because of the high risk of serious adverse events.

The researchers set out to update evidence regarding how effective hormone therapy is in reducing the risk of developing chronic conditions, as well as studying the impact and severity of adverse effects. They also wanted to see what the outcomes might be among females in different subgroups.

They gathered and analyzed data from MEDLINE (Jan 2002 – Nov 2011), the Cochrane Central Register for Controlled Database of Systematic Reviews (up to September 2011), Scopus and some other reference lists. They also looked at randomized, placebo-controlled trials of HRT (hormone replacement therapy) that had been published in the English language since 2002 – the trials were all focused on preventing chronic conditions.

They studied a short-list of 9 trials which met their inclusion criteria – the trials were assessed as being of fair-quality.

Below are some of the findings from this study:

  • Estrogen plus progestin therapy
    reduced fractures (46 fewer per 10,000 woman-years)
    increased invasive breast cancer (8 more per 10,000 woman-years)
    increased deep venous thrombosis (12 more per 10,000 woman-years)
    increased dementia (22 more per 10,000 woman-years)
    increased gallbladder disease (20 more per 10,000 woman-years)
    increased lung cancer death (5 more per 10,000 woman-years)
    increased pulmonary embolism (9 more per 10,000 woman-years)
    increased stroke (9 more per 10,000 woman-years)
    increased urinary incontinence (872 more per 10,000 woman-years)

  • Estrogen-only therapy
    reduced fractures (56 fewer per 10,000 woman-years)
    reduced invasive breast cancer incidence (8 fewer per 10,000 woman-years)
    reduced death (2 fewer per 10,000 woman-years)
    increased stroke (11 more per 10,000 woman-years)
    increased deep venous thrombosis (7 more per 10,000 woman-years)
    increased gallbladder disease (33 more per 10,000 woman-years)
    increased urinary incontinence (1271 more per 10,000 woman-years)

There were no consistent differences in outcomes related to comorbid conditions or age.

The study did not look into compliance (adherence), some outcome risks, and some other regimens.

In an abstract in the same journal, the authors concluded:

“Estrogen plus progestin and estrogen alone decreased risk for fractures but increased risk for stroke, thromboembolic events, gallbladder disease, and urinary incontinence. Estrogen plus progestin increased risk for breast cancer and probable dementia, whereas estrogen alone decreased risk for breast cancer. “

Written by Christian Nordqvist