HER-2
Status Affects Responses to Taxotere ® and Adriamycin ®
in Breast Cancer
According to a recent article published in Breast Cancer
Research and Treatment, the status of the human epidermal
growth factor-2 (HER-2) receptor in patients with breast cancer
affects responses to the two commonly used chemotherapy agents
Taxotere ® (docetaxel) and doxorubicin (Adriamycin ®).
These results provide further evidence that individualized
treatment regimens may provide optimal outcomes for patients
with cancer.
Breast cancer claims the lives of approximately 40,000 women
annually in the United States alone. Chemotherapy is a common
treatment component of nearly all stages of breast cancer,
demonstrating a reduction in cancer recurrences, improvement
in survival and/or improvement in quality of life in patients.
There are several different chemotherapy agents and/or combinations
of agents that are used to treat breast cancer and researchers
have been evaluating reasons to explain why some patients
respond differently than others to certain agents or regimens.
The HER-2 receptor belongs to a family of receptors that
is involved in cellular growth and replication. Some patients
with breast cancer overexpress HER-2, and are referred to
as HER2-positive. All patients should be tested for HER-2
positivity, as the monoclonal antibody Herceptin ® (trastuzumab)
is approved for the treatment of HER-2 breast cancer. Researchers
have been evaluating the possible biologic correlations between
HER-2 overexpression and characteristics of cancer that may
help to provide optimal therapeutic approaches to patients.
Researchers from several institutions including Europe, Canada
and South Africa recently conducted a clinical study to evaluate
a possible relationship between HER-2 status and responses
to the chemotherapy agents Taxotere ® or doxorubicin in
the treatment of breast cancer. This study included 176 patients
with advanced breast cancer who were treated with either Taxotere ®
or doxorubicin alone. Twenty percent of the patients were
HER-2-positive. Patients who were HER-2-positive had approximately
3 times the anti-cancer response rates when treated with Taxotere ®
compared with doxorubicin. However, at the time of the publication
of these results, there was no significant difference between
cancer progression and overall survival between patients treated
with either agent. In addition, there was no difference in
treatment responses between the two agents in patients who
did not overexpress HER-2.
The researchers concluded that breast cancer patients who
are HER-2-positive may have greater anti-cancer responses
to Taxotere ® compared to doxorubicin, providing further
evidence that individualized treatment options may ultimately
improve long-term outcomes. Longer follow-up will reveal if
these results translate into differences in survival. The
researchers stated that further trials need to be conducted
in order to confirm these findings, while ongoing trials are
evaluating HER-2 status in addition to other biologic markers
and possible relations in treatment outcomes. Patients diagnosed
with breast cancer may wish to speak with their physician
about their individual risks and benefits of participating
in a clinical trial further evaluating relationships between
markers and treatment outcomes. Two sources of information
regarding ongoing clinical trials include the National Cancer
Institute (cancer.gov) and www.cancerconsultants.com. Personalized
clinical trial searches are also performed on behalf of the
patient at cancerconsultants.com.
Reference: Di Leo A, Chan S, Paesmans M, et al. HER-2/neu
as a predictive marker in a population of advanced breast
cancer patients randomly treated either with single-agent
doxorubicin or single-agent docetaxel. Breast Cancer Research
and Treatment. 2004;86:197-206.
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