Tamoxifen side effects could be down to menopause

WOMEN TAKING a drug to help prevent breast cancer may believe it causes side effects which are in fact due to the menopause, research suggests.

A new study found that side effects such as hot flushes, sweats, nausea and low libido may not be down to the drug.

The study echoes research published last December which found that women taking the drug to stop breast cancer recurring also mistakenly thought it caused side effects.

Tamoxifen helps stop cancer returning if taken over the long term and is widely used among women with hormone-positive breast cancers.

It is also taken by women known to be at high risk of developing breast cancer in the future. Among these women, it cuts the risk of breast cancer by at least 30 per cent and the effects can last 20 years.

But only one in six high-risk women opt to take the drug when it is offered.

Tamoxifen does have known side effects, which include hot flushes, sweats, nausea and low libido. In the latest study, led by Queen Mary University of London (QMUL), almost 4,000 women were split into two groups, with one group receiving a placebo and the other tamoxifen for five years.

Overall, 69.7 per cent of women managed to adhere to their treatment for at least 4.5 years.

Symptoms that were reported included nausea or vomiting, headaches, hot flushes and gynaecological symptoms, such as irregular bleeding, vaginal dryness and vaginal discharge.

Drop-out rates were highest in the first 12 to 18 months (7.4 per cent on placebo compared with 12.2 per cent on tamoxifen), the research found.

After six months, just over 40 per cent of women reporting nausea and vomiting were not adhering to treatment, regardless of whether they were receiving placebo or tamoxifen.

Co-author of the paper Dr Ivana Sestak from QMUL said: “We found that the association between nausea, vomiting, headaches, hot flushes and gynaecological symptoms and non-adherence to treatment was largely similar between women taking placebo or tamoxifen.”