(CBS News) A new study just out Wednesday has some encouraging news about breast cancer, which kills 40,000 women a year. But now changing a treatment could save lives.
When Carie Capossela finished a five-year course of tamoxifen to prevent her breast cancer from coming back, she was nervous when she finally went off the drug.
"All of a sudden, you're done," she said. "And it's very scary. It's very scary, because you have to then go back and you really have nothing protecting you from the medical standpoint anymore."
Caposella was 33 when she was diagnosed. Estrogen is the main fuel for breast cancer in younger women who have not gone through menopause. Tamoxifen works by blocking the effect of estrogen.
The current recommendation is for women to take the drug for five years, because previous studies showed no benefit to taking it for longer.
But the new study, funded partly by one of the makers of tamoxifen, shows women who took the drug for 10 years were 25 percent less likely to have a recurrence of breast cancer; and 29 percent less likely to die from the disease than those who took it for five.
"I think this will have an effect on practice," said Dr. Judy Garber of Boston's Dana Farber Cancer Institute, "and particularly for my young patients at high risk of recurrence, I think longer tamoxifen now will feel much safer for all of us."
But there are significant side effects. Most women on the drug immediately have symptoms of menopause, including hot flashes and night sweats. Still, Carie Capossela said if her doctor recommends it, she will take tamoxifen again.
"Recurrence is something you live with for your entire life," she said. "All of the sudden you start hearing all these stories about women whose cancers are coming back after 8-9-10 years, and you become obsessed with it again, so it doesn't go away."
Tamoxifen has other rare but serious side effects, including a risk of uterine cancer, strokes and blood clots. But researchers say for younger breast cancer survivors, those risks are outweighed by the drug's benefits.