By Admin at 13 Oct 2016, 15:39 PM
About 5 percent of breast cancer patients develop cancer in the other breast (contralateral breast cancer) within 10 years of their initial diagnosis. Drugs including tamoxifen and aromatase inhibitors are often prescribed to patients to reduce this risk, but researchers from the U.S. National Institutes of Health wanted to find out just how beneficial the drugs were in real-life settings.
The study involved nearly 7,500 women diagnosed with invasive breast cancer at an average age of 61. Fifty-two percent of the women used tamoxifen while close to 26 percent used aromatase inhibitors.
Tamoxifen interferes with the activity of estrogen in the breast. It’s primarily used to treat hormone receptor-positive breast cancer, which relies on estrogen to grow. Past studies have found tamoxifen may lower the chance of breast cancer recurrence in those already diagnosed as well as reduce the risk of developing breast cancer in women at high risk by up to half.
Aromatase inhibitors, such as anastrozole, work by stopping the production of estrogen in fat tissue. It, along with tamoxifen, may be prescribed to some breast cancer survivors to help prevent recurrence, and the featured study suggests this may be a beneficial strategy.
The risk of developing cancer in the previously cancer-free breast decreased the longer patients used tamoxifen. Women who took tamoxifen for at least four years had a 66 percent lower risk of contralateral breast cancer compared to women who did not take the drug.
The researchers concluded that among women with estrogen receptor-positive tumors, three cases of contralateral breast cancer could be prevented for every 100 women taking tamoxifen for four years or more.
Aromatase inhibitors were also associated with a lower risk of contralateral breast cancer. Such drugs are often prescribed for long periods (five or 10 years) and may be associated with side effects, including hot flashes, night sweats and mood swings, which cause some women to question whether or not to continue their use.
Dr. Stephanie Bernik, chief of surgical oncology at Lenox Hill Hospital in New York City, told U.S. News & World Report:
"Many women have side effects from the drugs and although these side effects are often minor, they need encouragement to continue using the drug … With more evidence showing that in real-life settings tamoxifen and aromatase inhibitors help prevent recurrences, more women will continue to take the drug for longer periods of time."
The new findings may ultimately help women prescribed such drugs to make a more informed decision and weigh the benefits of using such drugs against the risks. Your health care providers can also help you or your family member with this important decision.
Sources
JAMA Oncology October 6, 2016
U.S. News & World Report October 6, 2016
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