THURSDAY, Feb. 24 (HealthDay News) -- The cancer drug Herceptin
produces significantly longer disease-free survival in women with
an aggressive type of early-stage breast cancer who take the drug
for a year after standard chemotherapy, a new study suggests.
After analyzing more than 5,000 women from 39 countries between
December 2001 and June 2005, Herceptin appeared to reduce the
likelihood of a cancer recurrence by 24 percent, the Italian
Herceptin (trastuzumab) is a monoclonal antibody that suppresses
the HER2/neu protein, which fuels 20 percent to 30 percent of
breast cancers. These so-called HER2-positive cancers tend to be
aggressive and fast-growing.
"We were inclined to consider the possibility that long-term exposure to trastuzumab deserved a proper test and might be useful," said study author Dr. Luca Gianni, a researcher at Fondazione San Raffaele in Milan.
But while Herceptin patients in the four-year study experienced
longer disease-free survival times than patients in an observation
group taking chemotherapy alone, the overall risk of death was
similar between the two groups.
Gianni attributed this to the fact that 52 percent of patients
from the observation group crossed over to receive Herceptin
treatment midway through the research because of the drug's
impressive early results.
The study received funding from Hoffman-La Roche, the maker of
Herceptin, and is published in the Feb. 25 issue of
The Lancet Oncology.
"It is very difficult to account for the bias introduced by the late introduction of trastuzumab in more than half of the patients originally randomized to no therapy," Gianni said. "However, it is reasonable to think that the lack of a measurable improvement of survival in the current analysis was due to the effect of the introduction of trastuzumab therapy in a large proportion of women who selected to cross over to the antibody."
While Herceptin has become standard treatment for women with
HER2-positive malignancies, the timing of its use is still much in
debate. Editorials accompanying Gianni's study took opposing views,
with Finnish researcher Heikki Joensuu contending that
administering Herceptin simultaneously with chemotherapy might be
Belgian researcher Evandro de Azambuja, however, argued that the
simultaneous treatments would significantly increase the risk of
heart damage, which can be a side effect of both Herceptin and a
class of standard chemotherapy drugs called anthracyclines.
"I think that both views are respectable, but not necessarily so diverging as they look at first glance," Gianni said. "One should simply consider that the ideal approach can well be that of combining administration of trastuzumab with chemotherapy . . . but avoiding anthracyclines does not mean to avoid combined chemotherapy. Anthracyclines contribute an added benefit that should be thoroughly weighted against the risk of cardiac events before dismissing the combination just as too toxic."
Dr. Lauren Cassell, chief of breast surgery at Lenox Hill
Hospital in New York City, said the study's results met her
"It's confirmation of the fact that Herceptin is extremely effective in patients who show this protein," said Cassell, who noted that oncologists at her hospital typically administer Herceptin for one year after chemotherapy ends. "It is something routinely being used."
Gianni and Cassell agreed that more research needs to focus on
whether Herceptin use should be extended to further improve its
"For how long the trastuzumab should be given is really unclear and difficult to test, but in my view will need to be addressed," Gianni said. "The most important message is that we still are and will continue to learn from continuous follow up of studies . . . about [its] optimal use."
There's more on Herceptin at the
U.S. National Library of Medicine.
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