A drug commonly prescribed to treat menopausal symptoms appears to increase the risk of breast cancer recurrence among patients who survive the disease, a new study published in the British medical journal The Lancet Oncology reveals.

 

Livial, generic name tibolone, is a selective tissue estrogenic activity regulator currently used in many breast cancer patients to reduce the symptoms of menopause. It is approved in 55 countries for treating osteoporosis and it is licensed in 90 countries to reduce the effect of menopause.

 

Tibolone acts like estrogen to strengthen bones and prevent hot flashes while avoiding estrogen’s known cancer-promoting effects in the breast.

 

Researchers at VU University Medical Centre, Amsterdam, Netherlands led by Professor Peter Kenemans wanted to find out whether a 2.5 mg daily dose of tibolone in women surgically treated for breast cancer and suffering from menopausal symptoms raised the risk of recurrence.

 

The study involved 3,098 women who were either given tibolone (1,556) or a placebo (1,542). The average age of the women was 53 years old, and mean time since surgery was slightly under three years.

 

The researchers found that women in tibolone group had an increased recurrence risk of 40 percent compared to women in the control group. Moreover, 70 percent of the recurrences among the women given tibolone were distant metastases, which usually end tragically.

 

“The trial findings will provide better basis for gynecologists, oncologists, general practioners and other doctors that counsel patients with breast cancer that are symptomatic with night sweats and hot flushes that interfere with sleep thereby mpairing quality of life,” the researchers wrote.

In fact, the researchers had to halt the study six months earlier because of tibolone’s increased risk of recurrence.

 

“Although the trial was intended to show the non-inferiority of tibolone compared with placebo, the findings clearly show that -- although effective against hot flushes -- tibolone does increase the risk of breast-cancer recurrence,” the researchers concluded.

 

Previous studies on hormone replacement therapy, which is also used to treat menopausal symptoms, have also shown that the therapy increases the risk of breast cancer. The latest study on the issue published in the New England Journal of Medicine in early February found that hormone users’ breast cancer rate fell rapidly in the first two years after halting treatment, even though their mammogram rate didn’t change. Also, women’s risk of contracting breast cancer almost doubled after five years of taking the hormonal drugs.

 

In 2005, about 18 million women were following hormone replacement therapy, a significant decrease from 61 million prescriptions written in 2001. It seems that more and more women choose to experience hot flashes, mood swings and other symptoms of menopause rather than having a stroke, heart attack or breast cancer.