Bone Drug May Prevent Return of Breast Cancer
Study Shows Zometa Reduces the Risk of Breast Cancer Recurrence
A large British trial presented in December at the San Antonio Breast Cancer Symposium found that Zometa treatment did not reduce the risk of recurrence in women with early-stage breast cancers.
Not all of the women in that study received estrogen-suppressing therapy, however, and experts say that may be a key difference.
A subset of women in that study, those who had been postmenopausal for at least five years and thus had naturally lower estrogen levels, did see some survival benefit after taking Zometa compared to those on conventional therapies alone.
Other studies have shown that bisphosphonates improve survival and delay disease progression in patients with lung and bladder cancers and multiple myeloma.
Rowan T. Chlebowski, MD, PhD, chief of medical oncology at the David Geffen School of Medicine at the University of California, Los Angeles, says further studies are needed to sort out which patients may get the most benefits. But he thinks the evidence for using bone drugs is positive, on the whole.
"I'm in the believer group," he says.
"So the concept is, you need a low bone turnover environment for bisphosphonates to have an anti-tumor effect that's mediated through the bone. That seems a viable concept. Maybe we'll get a little bit more data and see where we go from there," Chlebowski tells WebMD.
Other experts, however, say Zometa should be used with caution in premenopausal patients with breast cancer.
"The drug has to be used in the same clinical situation," says Stephanie Bernik, MD, chief of surgical Oncology at Lenox Hill Hospital in New York City.
"We do use ovarian suppression, but it's become less popular in the United States," Bernik says.
"The drug would have to be used in the same way or we need more clinical evidence that we can use bisphosphonates without ovarian suppression," she says.
Rarely, the use of bisphosphonates has been linked to a rare condition called osteonecrosis, or bone death.
There were no cases of osteonecrosis reported in the current study, though patients on Zometa did report bone pain, fatigue, headaches, and muscle pain.
"Drugs do not come without complications," she says. "You really have to be very careful."