CHICAGO
— A study in which women with breast cancer were given two
chemotherapy drugs simultaneously was cut short after the
combination contributed to the deaths of two patients and
caused life-threatening complications in an alarming number
of others.
The
problems developed in women given the standard intravenous
drug doxorubicin along with a newer drug called docetaxel.
The two drugs are frequently used alone to treat breast cancer.
Scientists have been exploring the effects of combining them,
with mixed results so far.
Docetaxel, or Taxotere, belongs to a class of cancer drugs
that also includes Taxol. These drugs are derived from the
yew tree and have shown promise in improving cancer survival.
French researchers set out to compare five-year, disease-free
survival rates in 627 women treated with either doxorubicin
plus Taxotere or the more conventional combination of doxorubicin
plus cyclophosphamide. But they stopped the study after a
little over three years, in 2003.
The patients who died had developed low white blood cell counts,
fever and severe intestinal problems. A third woman became
severely ill with similar symptoms.
Low white-cell counts with fever developed in nearly 41% of
the doxorubicin-Taxotere women, compared with 7% of the other
patients. The condition is a potential side effect of chemotherapy
and can be life-threatening because it means the drugs have
weakened the body's ability to fight infection.
The high rate of complications indicated the two-drug combination
was too toxic, said the researchers, led by Dr. Etienne Brain
of the Rene Huguenin Cancer Center in Saint-Cloud, France.
The study appears in Wednesday's Journal of the American Medical
Association.
Dr. Carolyn Runowicz, president-elect of the American Cancer
Society and an oncologist at the University of Connecticut,
said the combination should not be abandoned because there
is still a chance that it could improve survival. But it should
be used with drugs to boost white-cell counts as a precaution,
she said.
In a study presented over the weekend, Dr. Lori Goldstein
of Fox Chase Cancer Center in Philadelphia compared the same
two-drug combinations for treating early breast cancer.
There were four treatment-related deaths among the nearly
3,000 women studied — all in women on the Taxotere combination
— but Goldstein said that rate was acceptably low. She found
no difference in survival rates over nearly five years, but
low white-cell counts with fever were more common in patients
on the Taxotere combination.
Participants in the French study had a high chance of cancer
recurrence because the cancer had reached their lymph nodes
or because they had other risk factors.
