The MHRA will review its guidance for hormone replacement therapy (HRT) products in light of a study that links their use to an increased risk of cancer.
The medicines watchdog said it would evaluate the findings of the study, published in the Lancet on Friday (February 13), which associated the use of HRT with a “significantly increased” risk of the two most common types of ovarian cancer.
The meta-study, by more than 100 international researchers from the Collaborative Group on Epidemiological Studies of Ovarian Cancer, analysed more than 50 studies covering more than 21,000 post-menopausal women with the disease. The Lancet said the new study showed that HRT use "for just a few years" was linked to a 40 per cent increased chance of developing serous or endometrioid ovarian cancer.
The MHRA said its advice had “always been that the lowest effective dose of HRT should be used for the shortest possible time”. “We will evaluate this study's implications for shorter-term use and update product information as necessary,” it said.
The watchdog advised women on HRT to have regular check-ups and ensure their need to continue treatment was assessed annually.
The researchers said that even using HRT for less than five years starting at around the age of 50 was linked to a "definite risk" of ovarian cancer. Although stopping treatment reduced the risk of cancer over time, women who had used HRT drugs for at least five years still had an increased risk of cancer 10 years later, they said.
Around six million women take HRT in the UK and America, said the researchers, who pointed out that some non-governmental reviews had argued that a few years of HRT use before the age of 60 “should cause no material harm”. But most studies had been too small to reliably assess any risks and a review of all the evidence had been needed, the researchers said.
Although UK guidelines on HRT state that ovarian cancer is linked to long-term use, they were “dominated” by the findings from one large study, the researchers said. The results of this latest study was “directly relevant” to current efforts to revise UK and worldwide guidelines on these products, the researchers added.