February
2004
Risk
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Tailoring
Adjuvant Therapy for Early-stage Breast Cancer Studied
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Tailoring
Adjuvant Therapy for Early-stage Breast Cancer Studied
Although
chemotherapy and ovarian function suppression are both effective adjuvant
therapies for patients with early-stage breast cancer, little is known
of the efficacy of their sequential combination (how well the treatment
works when given in a certain order), state researchers in a new study
report.
Adjuvant
therapy is a term used to describe when physicians choose more than
one therapy in treating a patient, specifically the therapy is given
after the primary cancer treatment is completed in order to improve
the chance of a cure.
A
new study by the International Breast Cancer Study Group (IBCSG)
concludes that premenopausal women with lymph node-negative breast
cancer should receive adjuvant therapy tailored according to the estrogen
receptor status of the primary tumor.
The
study was reported in the Journal of the National Cancer
Institute (JNCI).
Patients
with estrogen receptor (ER)-negative, or endocrine nonresponsive,
breast cancer should receive adjuvant chemotherapy, according to the
study, whereas for patients with ER-positive, or endocrine responsive,
tumors, the use of endocrine therapy alone or in combination with
adjuvant chemotherapy requires further study.
Some
studies have suggested that cytotoxic chemotherapy benefits premenopausal
women with breast cancer because it causes premature menopause.
The
new study addresses whether adjuvant ovarian function suppression
can be used as a replacement for or as a supplement to cytotoxic adjuvant
chemotherapy for premenopausal women with early-stage breast cancer.
In
an editorial commenting of this study in the JNCI,
the authors said, "These findings support the idea that ovarian suppression
"is a viable treatment alternative for at least some premenopausal
women with breast cancer." The authors, Dr. Joseph L. Pater and Dr.
Wendy R. Parulekar, are physicians at the National Cancer
Institute of Canada Clinical Trials Group at Queen's University
in Kingston, Ontario.
In
the study, Dr. Monica Castiglione-Gertsch, a member of the IBCSG,
compared outcomes of 1,063 pre- and perimenopausal women who were
previously treated for lymph-node negative (early-stage) breast cancer
and randomly assigned to receive adjuvant chemotherapy, adjuvant therapy
with the ovarian function suppression drug goserelin, or adjuvant
chemotherapy followed by goserelin.
The
women were tested to determine the estrogen receptor status of their
tumors.
After
a median follow-up of seven years, there was no difference in
disease-free survival or overall survival among patients in the three
treatment groups.
However,
a subgroup analysis showed that patients with ER-negative tumors
who received chemotherapy alone or followed by goserelin had better
disease-free survival than patients who received goserelin alone.
By
contrast, among patients with ER-positive tumors, results were similar
after chemotherapy alone or goserelin alone. Sequential use of chemotherapy
followed by goserelin resulted in a statistically nonsignificant benefit
that was limited to younger women.
The
study authors caution that the study findings "should not alter
current patient care, but rather emphasize the relevance of current
studies of chemotherapy and endocrine agents."
Drs.
Pater and Parulekar agree, recommending that future studies examine
the selective use of ovarian suppression in women who are not rendered
menopausal by chemotherapy.
Always
consult your physician for more information.
