Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically proven adenocarcinoma of the breast that is
potentially curable Prior treatment with one of the following therapies required:
Segmental mastectomy (lumpectomy) followed by radiotherapy Chest wall irradiation allowed
only in patients with T4 dermal involvement on pathologic diagnosis Further excision or
boost radiotherapy to the tumor bed recommended if microscopic disease found at mastectomy
margins Total mastectomy Chest wall irradiation required if microscopic disease found at
mastectomy margins Clinical stage T1-3a N0-2 M0 disease prior to surgery The following T4
features exclude: Chest wall extension Edema (including peau d'orange) Skin ulceration
Satellite skin nodules confined to same breast Inflammatory carcinoma Pathologic stage
T1-4 NX-2 M0 disease following surgery Eligible T4 tumors are those with dermal
involvement on pathology assessment only Pathologic assessment of axillary lymph nodes
required May be omitted in patients with clinical N0 status provided other entry criteria
are met No bilateral breast cancer without complete resection of both sides Hormone
receptor status: Estrogen and progesterone receptor status determined from primary tumor
when possible by quantitative biochemical methods or immunohistochemistry Results recorded
as positive or negative if immunohistochemistry used Unknown status does not exclude
provided other entry criteria are met

PATIENT CHARACTERISTICS: Age: Postmenopausal Sex: Women only Menopausal status:
Postmenopausal by one or more of the following: Amenorrhea lasting more than 1 year in
women under 50 years of age with no prior hysterectomy No menses for 6 months prior to
breast surgery in women 50 years of age and over with no prior hysterectomy Documented
oophorectomy prior to breast cancer diagnosis Luteinizing hormone and follicle-stimulating
hormone values diagnostic of postmenopausal status by local laboratory criteria Women 50
years of age and over with prior hysterectomy Performance status: ECOG 0-2 Life
expectancy: At least 5 years Hematopoietic: WBC at least 3,000/mm3 Platelet count at least
100,000/mm3 Hepatic: (unless metastatic disease ruled out by radiologic exam) AST or ALT
less than twice normal Alkaline phosphatase less than twice normal Renal: Not specified
Other: No symptomatic gallbladder disease or cholecystitis No intercurrent illness that
reduces life expectancy to less than 5 years No other major medical or psychiatric illness
that precludes study treatment or follow-up No second malignancy within 5 years except:
Adequately treated basal cell skin carcinoma Adequately treated cancer of the cervix,
endometrium, colon, or thyroid Able and willing to complete quality-of-life questionnaires
in English or French Illiteracy, loss of sight, or other inability to complete
questionnaires does not exclude Accessible for treatment and follow-up

PRIOR CONCURRENT THERAPY: Biologic therapy: No prior biologic therapy Chemotherapy: Prior
or concurrent adjuvant chemotherapy allowed at investigator's discretion Recommended
regimens: CMF (cyclophosphamide/methotrexate/fluorouracil) CEF
(cyclophosphamide/etoposide/fluorouracil) AC (doxorubicin/cyclophosphamide) Choice of
adjuvant chemotherapy regimen defined prior to randomization if given concurrently with
protocol therapy Endocrine therapy: No estrogen, progestins, or androgen therapy for a
period of more than 30 days following pathologic diagnosis of breast cancer Prior
tamoxifen allowed All hormonal therapy discontinued prior to randomization Radiotherapy:
See Disease Characteristics Surgery: See Disease Characteristics