Trial Information

The CORE Study (Chemotherapy OR Endocrine Treatment First?) A Randomized Study by the Scandinavian Breast Group [CORE]

OBJECTIVES:

- Determine the optimal sequence of chemotherapy and endocrine therapy as first-line
therapy in postmenopausal women with metastatic or locally advanced breast cancer that
is potentially sensitive to both modalities.

OUTLINE: This is an open-label, randomized, crossover, multicenter study. Patients are
stratified according to participating center. Patients are randomized to 1 of 2 treatment
arms.

- Arm I (chemotherapy first): Beginning within 4 weeks after randomization, patients
receive chemotherapy* comprising either an anthracycline- or a taxane-based regimen, or
a combination of both drugs, according to local institutional guidelines. Treatment
continues for 6 months or longer, in the absence of disease progression or unacceptable
toxicity. After discontinuation of chemotherapy, patients receive endocrine therapy
comprising oral letrozole once daily in the absence of disease progression or
unacceptable toxicity. Patients with immediately life-threatening disease (e.g.,
lymphangitis carcinomatosa or liver involvement exceeding 1/3 of the liver) are
recommended for second-line chemotherapy.

NOTE: *Patients may receive chemotherapy on a separate clinical chemotherapy trial but must
first undergo randomization in this study.

- Arm II (endocrine therapy first):Beginning immediately after randomization, patients
receive oral letrozole once daily in the absence of disease progression or unacceptable
toxicity. Patients who demonstrate progressive disease then receive chemotherapy as in
arm I.

Quality of life and pain are assessed at baseline and then periodically for 5 years.

After completion of study therapy, patients are followed periodically.

PROJECTED ACCRUAL: A total of 1,500 patients will be accrued for this study.