Triptorelin With Either Exemestane or Tamoxifen in Treating Premenopausal Women With Hormone-Responsive Breast Cancer

OBJECTIVES:

- Compare the disease-free survival, breast cancer-free interval, distant recurrence-free
interval and overall survival of premenopausal women with endocrine-responsive breast
cancer when treated with triptorelin and exemestane vs triptorelin and tamoxifen.

- Compare the quality of life, including late side effects of early menopause, of patients
treated with these regimens.

OUTLINE: This is a randomized, international, multicenter study. Patients are stratified
according to planned use of concurrent adjuvant chemotherapy (yes vs no), and number of
positive lymph nodes (0 vs 1 or more). Treatment duration is 5 years. Patients are followed
every 3 months for 1 year, every 6 months for 5 years, and then annually thereafter. Quality
of life is assessed at baseline, every 6 months for 2 years, and annually for 3 years.

DISEASE CHARACTERISTICS:

- Histologically confirmed breast cancer

- Completely resected disease

- No clinically detectable residual loco-regional axillary disease

- Prior surgery for primary breast cancer of 1 of the following types:

- Total mastectomy with or without adjuvant radiotherapy

- Breast-conserving procedure (e.g., lumpectomy, quadrantectomy, or partial
mastectomy with margins negative* for invasive disease and ductal carcinoma
in situ) with planned radiotherapy NOTE: *If all other margins are clear a
positive posterior (deep) margin is permitted, provided the excision was
performed down to the pectoral fascia and all tumor has been removed OR a
positive anterior (superficial; abutting skin) margin is allowed provided
all tumor was removed

- Tumor confined to the breast and axillary nodes

- Tumor detected in internal mammary chain nodes by sentinel node procedure and is
not enlarged is allowed

- Axillary lymph node dissection or a negative axillary sentinel node biopsy required

- Patients with negative or microscopically positive axillary sentinel nodes are
eligible

- Positive sentinel nodes must have either axillary dissection or radiation of
axillary nodes

- No distant metastases

- No locally advanced inoperable breast cancer, including any of the following:

- Inflammatory breast cancer

- Supraclavicular node involvement

- Enlarged internal mammary nodes (unless pathologically negative)

- Bilateral synchronous invasive breast cancer allowed if disease meets all other
eligibility criteria

- No prior ipsilateral or contralateral invasive breast cancer

- Hormone receptor status:

- Estrogen and/or progesterone receptor positive

- At least 10% of the tumor cells positive by immunohistochemistry

- If > 1 breast tumor, each tumor must be hormone receptor positive

PATIENT CHARACTERISTICS:

Age

- Premenopausal

Sex

- Female

Menopausal status

- Premenopausal

- Estradiol in the premenopausal range after prior surgery OR meets the following
criteria:

- Menstruating regularly for the past 6 months

- Has not used any form of hormonal treatment (including hormonal
contraception) within the past 6 months

Performance status

- Not specified

Life expectancy

- Not specified

Hematopoietic

- Not specified

Hepatic

- No systemic hepatic disease that would preclude prolonged follow-up

Renal

- No systemic renal disease that would preclude prolonged follow-up

Cardiovascular

- No systemic cardiovascular disease that would preclude prolonged follow-up

- No prior thrombosis (e.g., deep vein thrombosis) and/or embolism unless patient is
medically suitable

Pulmonary

- No systemic pulmonary disease that would preclude prolonged follow-up

Other

- Not pregnant or nursing

- Fertile patients must use effective nonhormonal contraception

- No history of noncompliance to medical regimens

- No other nonmalignant systemic disease that would preclude prolonged follow-up

- No other malignancy within the past 5 years except adequately treated basal cell or
squamous cell skin cancer, nonbreast carcinoma in situ, contralateral or ipsilateral
carcinoma in situ of the breast, or other nonrecurrent invasive nonbreast malignancy,
including any of the following:

- Stage I papillary thyroid cancer

- Stage IA carcinoma of the cervix

- Stage IA or B endometrioid endometrial cancer

- Borderline or stage I ovarian cancer

- No psychiatric, addictive, or other disorder that would preclude study compliance

PRIOR CONCURRENT THERAPY:

Biologic therapy

- Prior or concurrent neoadjuvant or adjuvant trastuzumab allowed

Chemotherapy

- No prior neoadjuvant or adjuvant chemotherapy

Endocrine therapy

- No prior tamoxifen, other selective estrogen-receptor modulators (SERMs) (e.g.,
raloxifene), or hormone replacement therapy for more than 1 year before breast cancer
diagnosis

- No prior neoadjuvant or adjuvant endocrine therapy since diagnosis of breast cancer

- No concurrent oral or transdermal hormonal therapy

- No other concurrent estrogen, progesterone, or androgens

- No other concurrent aromatase inhibitors

- No concurrent oral or other hormonal contraceptives (i.e., implants or depot
injections)

Radiotherapy

- See Disease Characteristics

- No prior ovarian radiotherapy

Surgery

- See Disease Characteristics

- No prior bilateral oophorectomy

Other

- No concurrent bisphosphonates, except in the following cases:

- Bone density is at least 1.5 standard deviations below the young adult normal
mean

- Participation in a randomized clinical study testing bisphosphonates in the
adjuvant breast cancer setting

- No other concurrent investigational agents