SAN ANTONIOResults of two randomized International Breast Cancer Study
Group (IBCSG) trials of chemoendocrine therapy for node-negative breast cancer
suggest that adjuvant chemotherapy may provide additional benefit over
endocrine therapy alone for patients with estrogen-receptor (ER)-negative, but
not ER-positive, tumors.
Endocrine responsiveness is an important determinant of treatment response
for both premenopausal and postmenopausal patients, according to the studies
presented at the 25th Annual San Antonio Breast Cancer Symposium (abstract 11).
The two trialsIBCSG VIII and IBCSG IXwere conducted between 1988 and 1998.
Patients in both trials had histologically proven unilateral breast cancer,
stage T1a, 1b, 2a, T2, or T3, with negative nodes and no metastases. Tumors
could be either ER positive or negative; an unknown designation was permitted
only in the absence of material.
The trial results were reported by Monica M. Castiglione-Gertsch, MD,
director of the Swiss Institute for Applied Cancer Research Coordinating Center
in Bern, Switzerland, and chief executive officer of the IBCSG.
For IBCSG VIII, 1,109 premenopausal or perimenopausal women were randomized
to goserelin (Zoladex) 3.6 mg subcutaneously monthly for 24 months; classical
CMF (oral cyclophosphamide at 100 mg/m2 on days 1 to 14; IV
metho-trexate at 40 mg/m2 on days 1 and 8; and IV fluorouracil at
600 mg/m2 on days 1 and 8) for six courses; or classical CMF for six
courses followed by goserelin for 18 months. Median follow-up was 5.7 years.
IBCSG IX randomized 1,669 postmenopausal women to tamoxifen (Nol-vadex)
alone (20 mg/d for 60 months) or classical CMF followed by tamoxifen (20 mg/d)
for 57 months. Median follow-up was 6 years.