Letrozole After Tamoxifen in Treating Women With Breast Cancer

• Status: Completed
• Trial end date: 2003-10-01
• Target enrollment: 0
• Participant gender: Female

Summary

RATIONALE: Estrogen can stimulate the growth of breast cancer cells. Hormone therapy using letrozole may fight breast cancer by reducing the production of estrogen.

PURPOSE: This randomized phase III trial is studying letrozole to see how well it works in treating women with breast cancer who have received tamoxifen for at least 5 years.

• Phase: Phase 3
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: NCIC Clinical Trials Group
• Collaborators: Cancer and Leukemia Group B; Eastern Cooperative Oncology Group; European Organisation for Research and Treatment of Cancer - EORTC; International Breast Cancer Study Group; National Cancer Institute (NCI); North Central Cancer Treatment Group; Southwest Oncology Group
• Treatments: Letrozole; Tamoxifen

Criteria

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed primary invasive breast carcinoma resected at time of original diagnosis

• No ductal carcinoma in situ

• Axillary lymph node negative, positive, or unknown

• No evidence of metastases

• No localized or distant breast cancer recurrence

• Not registered on protocol NCCTG-893052, any other IBCSG protocol, or protocol SWOG-S9623

• Hormone receptor status:

• Estrogen or progesterone receptor positive as defined by tumor receptor content at least 10 fmol/mg protein or receptor positive by ERICA or PgRICA

• Unknown status allowed if effort to determine status has been made by immunocytochemistry

• No contralateral breast cancer

PATIENT CHARACTERISTICS:

Age:

• Postmenopausal

Sex:

• Female

Menopausal status:

• Postmenopausal defined by one of the following:

• Age 50 or over at start of adjuvant tamoxifen

• Under age 50 and considered postmenopausal by treating physician at start of adjuvant tamoxifen

• Under age 50 at start of adjuvant tamoxifen and had bilateral oophorectomy (surgical or radiation)

• Under age 50 and premenopausal at start of adjuvant tamoxifen, but became amenorrheic during tamoxifen and remained amenorrheic for at least 1 year

• Considered postmenopausal by physician with LH/FSH levels under the treatment center's postmenopausal limits

Performance status:

• ECOG 0-2

Life expectancy:

• At least 5 years

Hematopoietic:

• WBC ≥ 3,000/mm^3 OR

• Granulocyte count ≥ 1,500/mm^3

• Platelet count ≥ 100,000/mm^3

Hepatic:

• AST and/or ALT < 2 times upper limit of normal (ULN) (unless imaging examinations have ruled out metastatic disease)

• Alkaline phosphatase < 2 times ULN (unless imaging examinations have ruled out metastatic disease)

Renal:

• Not specified

Other:

• No concurrent medical or psychiatric condition that would preclude study participation

• No other malignancy within the past 5 years except adequately treated superficial squamous cell or basal cell skin cancer or carcinoma in situ of the cervix

• Able to swallow study drug

• Adequate oral intake

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• Prior adjuvant chemotherapy allowed

• No concurrent chemotherapy

Endocrine therapy:

• Completed at least 4.5 but no more than 6 years of adjuvant tamoxifen after resection

• Completed at least 4.5-6 years of adjuvant aromatase inhibitor as initial therapy or after tamoxifen

• No more than 3 months since prior adjuvant tamoxifen

• No concurrent hormone replacement therapy (e.g., megestrol)

• No concurrent selective estrogen-receptor modulators (e.g., raloxifene or idoxifene)

• Concurrent intermittent vaginal estrogens (e.g., Estring) allowed if other local measures for intractable vaginal atrophy are insufficient

• No other concurrent aromatase inhibitors

• No more than 2 years since prior aromatase inhibitor therapy (re-randomization)

Radiotherapy:

• Prior radiotherapy allowed

Surgery:

• See Disease Characteristics

Other:

• At least 1 month since prior investigational drugs

• Prior treatment on a clinical trial for breast cancer allowed if permission has been obtained from the sponsors of the original study for their patient to participate on MA.17/JMA.17/BIG-97-01

• No prior placebo on core protocol

• No concurrent anticancer therapy

• Concurrent thyroid medication, calcium, vitamin D, and bisphosphonates allowed