Hormone replacement therapy (HRT) increases the risk of developing ovarian cancer, a meta-analysis published in The Lancet has found.
The study, performed by researchers at the University of Oxford, analysed 52 epidemiological studies of 21,488 women with ovarian cancer. They found that taking HRT drugs increased the incidence of ovarian cancer from 20 in every 1000 cases to 21 in every 1000 cases in women over the age of 50.
Katherine Taylor, chief executive of charity Ovarian Cancer Action, said: 'It's important to remember that every woman is different and they may each have different risk factors. For example, we know that a woman's genetic make-up can have a significant impact on her likelihood of developing ovarian cancer.
The risk was evident in women who take HRT drugs for more than five years. The study also noted that when women stopped taking the HRT drugs, the risk dropped, going down further as time passed.
HRT drugs, which are commonly prescribed to women to alleviate the effects of menopause, have a well documented link to breast cancer, but other studies have suggested that it cuts the risk of developing bowel cancer.
Ms Taylor added: 'At Ovarian Cancer Action, we believe all women with ovarian cancer should be BRCA tested at the point of diagnosis to ensure they get the best treatment available and can inform their families, who can then take action to reduce their own risk of developing ovarian and breast cancer.'