FRIDAY, June 3 (HealthDay News) -- Early stage breast cancer
patients can see their chances of the cancer's return drop by 32
percent when the osteoporosis drug Zometa is added to regular
hormone therapy for three years after surgery, Austrian researchers
Women undergoing hormone treatment for breast cancer are prone
to develop osteoporosis, so they are usually given a bisphosphonate
such as Zometa (zoledronic acid), to build bone strength. However,
Zometa appears to have the additional benefit of reducing the risk
of cancer recurrence, according to Dr. Otis Brawley, chief medical
officer for the American Cancer Society.
"Aromatase inhibitors [like Arimidex] cause osteoporosis, and you must put a patient who is being put on an aromatase inhibitor on some type of osteoporosis preventive therapy," Brawley said. "This study says that putting a patient on Zometa may have even a bigger bang for the buck than the prevention of osteoporosis."
Although exactly how Zometa reduces the risk of recurrence isn't
known, lead researcher Dr. Michael Gnant, a professor of surgery at
the Medical University of Vienna, said he thinks "it prohibits
dormant tumor cells in the bone marrow from 'waking up.'"
"Zometa actually hardens the bone and makes it more difficult for the cancer to actually implant," Brawley added.
The report was published in the June 4 online edition of
The Lancet Oncology to coincide with the American Society of
Clinical Oncology's annual meeting in Chicago, where the findings
were to be presented Friday.
For the study, Gnant's team enrolled 1,803 premenopausal women
with early-stage hormone-receptive breast cancer. The trial was
funded by drug makers AstraZeneca and Novartis.
The women were randomly assigned to tamoxifen alone, tamoxifen
plus Zometa, Arimidex (anastrozole) or Arimidex plus Zometa. Zometa
infusions were given every six months during the three years of the
The choice of hormone drugs is important, because while Arimidex
is associated with a risk of developing osteoporosis, tamoxifen
isn't. So women prescribed tamoxifen would not usually be given an
osteoporosis drug, Brawley explained.
In 2009, after four years of follow-up, the researchers reported
women receiving Zometa had a 36 percent reduction in the risk of a
recurrence of breast cancer, compared with women not on the drug.
There were also indications that Zometa extended overall survival,
the researchers said.
The current report looks at more than five years of follow-up,
which is more than two years after treatment with Zometa was
The researchers found that women receiving Zometa had
substantially better disease-free survival (92 percent) than women
receiving hormone therapy alone (88 percent). This is a 32 percent
reduction in the risk of a recurrence of breast cancer among those
who had received Zometa, they noted.
These results were seen among women taking either tamoxifen or
Arimidex plus Zometa. However, overall survival was worse among
women receiving Arimidex, they added.
The effect of Zometa was even more pronounced in women over 40,
where the risk of the cancer's recurrence was cut by 42
In addition, Zometa was associated with a reduction in cancers
developing in bone and other sites as well as breast cancer in the
breast where cancer was found and in the unaffected breast, Gnant's
The researchers added that Zometa was well-tolerated and side
effects, which included joint pain, bone pain and fever, were
relatively mild. There were also no cases of osteonecrosis of the
jaw (death of bone in the jaw), which Zometa has been linked to
when the drug is given for osteoporosis after major dental work,
This study showed that "disease-free survival increased, it's
not powered for overall survival," Brawley said. "There have been
recent studies where disease-free survival was increased, but
ultimately overall survival was not."
"This is something to consider," Brawley said. "I never change my practice based on one trial. But, I see very little harm in giving Zometa along with aromatase inhibitors. Many of the patients I take care of already get this anyway," he added.
In the United States, Zometa is sold to wholesalers for $844.10
per dose, according to Dana Kahn Cooper, a spokeswoman for
"As Zometa is a physician-administered drug by infusion, the cost to the consumer is generally their doctor visit co-pay, which varies based on insurance coverage," Cooper said. "Some patients have drug co-pay as well. We do not set retail prices. Price around the world varies by country."
For more on breast cancer, visit the
American Cancer Society.