Name of the Trial
Phase III Randomized Study of Neoadjuvant Therapy Comprising Exemestane Versus Letrozole Versus Anastrozole in Postmenopausal Women with Estrogen Receptor Positive Stage II or III Breast Cancer (ACOSOG-Z1031). See the protocol summary at http://cancer.gov/clinicaltrials/ACOSOG-Z1031.

Principal Investigators
Dr. Matthew Ellis and Dr. John Olson, American College of Surgeons Oncology Group; Dr. Laura Esserman, Cancer and Leukemia Group B  

Why This Trial Is Important
Women with breast cancer that grows in response to the hormone estrogen often benefit from treatment with drugs known as aromatase inhibitors (AIs). AIs block the ability of an enzyme in the body called aromatase to make estrogen.

Researchers want to compare AI therapy and chemotherapy as neoadjuvant (before surgery) treatments for breast cancer, but first they need to determine which AI(s) to use in such a comparison. Neoadjuvant therapy may shrink tumors enough to allow a woman to undergo breast-sparing surgery instead of mastectomy.

In this trial, women with estrogen-responsive (i.e., estrogen receptor-positive) breast cancer will be treated with one of three AIs - exemestane (Aromasin), letrozole (Femara), or anastrozole (Arimidex) - before surgery to determine which AI(s) to use in a future trial that compares neoadjuvant AI therapy and neoadjuvant chemotherapy. If major differences between the AIs cannot be found, more than one AI may be used in the future trial.

"Our long-term aim is to establish AI therapy as a standard neoadjuvant treatment option," said Dr. Ellis. "Another goal of this trial is to help us define a patient population that is likely to benefit from neoadjuvant AI treatment. Through genomic analysis we will determine the molecular basis for differences in aromatase inhibitor response."

Who Can Join This Trial
Researchers seek to enroll 375 postmenopausal women with ER-positive stage II or stage III breast cancer. See the list of eligibility criteria at http://cancer.gov/clinicaltrials/ACOSOG-Z1031

Study Sites and Contact Information
Study sites in the United States and elsewhere are recruiting patients for this trial. See the list of study contacts at http://cancer.gov/clinicaltrials/ACOSOG-Z1031 or call NCI's Cancer Information Service at 1-800-4-CANCER (1-800-422-6237) for more information. The toll-free call is confidential.