Study shows possible benefit of longer Tamoxifen use

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New research is out that may change treatment for women with breast cancer.

The prescription now is to take Tamoxifen for five years, but there is a new study that says it could be more beneficial if it is taken twice as long. It is important to note the study is for women with early-stage breast cancer that is estrogen receptor-positive and pre-menopausal.

The ATLAS Study followed nearly 7,000 breast cancer patients who took Tamoxifen for five years and stopped and compared them with patients who continued taking the drug for five more years. Researchers say patients who completed a 10-year course had a lower recurrence rate and fewer died from breast cancer.

"This particular study seemed to suggest that if women took Tamoxifen for 10 years instead of the standard recommendation for five years, they decrease their risk of death from one-third to one-half, so that is a pretty significant decrease in the risk of dying," said breast surgeon Dr. Gary Dunnington, IU Health at Simon Cancer Center. "It's probably one of the most common questions I'm asked as a breast cancer surgeon was women who have just finished their five years of Tamoxifen and their question is 'If five years is good, wouldn't 10 years be better?'"

Dunnington says the Tamoxifen does have side effects, including a higher risk of deep vein thrombosis - or blood clots in your legs - uterine cancer and stroke. Earlier studies showed if you took Tamoxifen longer than five years, you increase the risk, but not the benefit.

"So this is very different. It is worth watching closely to see if other studies can prove this benefit," Dunnington said. "I believe this is an appropriate time to have a discussion with your physician, 'Is there enough evidence to consider lengthening the time of Tamoxifen?'"

All drugs with significant benefits also have risks and so, with every patient, it's a discussion. Given your situation, do the benefits outweigh the risks of taking the medication?