Adjuvant Post-Tamoxifen Exemestane Trial

A Phase III Randomized Parallel-Group Multicenter Trial, Designed to Compare 5 Years of Adjuvant Exemestane Versus 5 Years of Observation in Postmenopausal Women With Operable Breast Cancer Who Have Received 5-7 Years of Adjuvant Tamoxifen.

The ATENA phase III randomized parallel-group multicenter trial is designed to compare 5 years of adjuvant exemestane versus 5 years of observation in postmenopausal women with operable breast cancer who have received 5-7 years of adjuvant tamoxifen. The primary endpoint for the core protocol is disease-free survival (DFS). Exemestane treatment is planned for 5 years unless disease relapse or excessive toxicity is documented, the patient refuses further treatment or any new anti-cancer therapy is initiated.

• Patients must have completed at least 5 years and not more than 7 years of continued treatment with tamoxifen (20 mg/day), while tamoxifen could have been discontinued up to 6 months prior to study entry.
• A substudy (ATENA lipid substudy)is designed to evaluate changes in the patients' serum lipid profile during study treatment.

Inclusion Criteria:

• postmenopausal women only
• histologically confirmed stage I-IIIA primary adenocarcinoma of the breast
• estrogen and/or progesterone receptors positive or unknown
• patients should have undergone surgery with a curative intent
• patients must have completed at least 5 years and not more than 7 years of continued treatment with tamoxifen (20 mg/day), while tamoxifen could have been discontinued up to 6 months prior to study entry
• Absence of any evidence of local or distant metastatic disease was required prior to randomization

Exclusion Criteria:

• DCIS, bilateral breast cancer, evidence of metastasis, ER and Pgr negative