S9630, Medroxyprogesterone in Treating Women With Breast Cancer

DISEASE CHARACTERISTICS:

One of the following histologically proven diagnoses:

Primary invasive adenocarcinoma of the unilateral or bilateral breast

Stage I, IIA, or IIB (T1-3, N0-1, M0)
No recurrent invasive breast cancer
Ductal carcinoma in situ (DCIS)
Lobular carcinoma in situ (LCIS) with microinvasion
Paget's disease of the nipple
No sarcoma, lymphoma, or apocrine, adenocystic, or squamous cell cancer of the breast

Currently free of breast cancer (no evidence of disease)

No evidence of distant disease on chest x-ray or chest CT scan and mammogram of the opposite breast within the past year

Prior definitive local treatment of primary lesion (mastectomy or breast-sparing procedure with radiotherapy) and either axillary node or sentinel node biopsy

Surgical margins clear of both infiltrating carcinoma (any type) and DCIS

No gross or microscopically positive margins except:

Invasive cancer or DCIS at the focal margin treated with definitive radiotherapy
Gross or LCIS at the final margin
Biopsy requirement waived for DCIS or LCIS with minimal microinvasion
Patients with breast-sparing procedure must have received or be planning to receive radiotherapy at start of tamoxifen treatment
No endometrial simple or cystic hyperplasia, proliferative changes, complex (adenomatous) or atypical hyperplasia, or carcinoma

Patients must be planning one of the following:

Starting adjuvant tamoxifen for five years OR
Started tamoxifen within 28 days prior to study and planning to receive adjuvant tamoxifen for five years

Hormone receptor status:

Candidate for adjuvant tamoxifen therapy

PATIENT CHARACTERISTICS:

Age:

Adult

Sex:

Female

Menopausal status:

Postmenopausal defined as:

At least 1 year since last menstrual period
At least 2 months since bilateral oophorectomy prior to breast cancer diagnosis
4-12 months since last menstrual period and FSH elevated to postmenopausal range
Postmenopausal estrogen therapy and 55 years of age or older

Performance status:

Not specified

Life expectancy:

Not specified

Hematopoietic:

Not specified

Hepatic:

Not specified

Renal:

Not specified

Other:

Fertile patients must use effective contraception during and for at least 2 months after study
No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or stage I or II cancer currently in complete remission
No concurrent nonmalignant-related illness that would preclude study

PRIOR CONCURRENT THERAPY:

Biologic therapy:

Not specified

Chemotherapy:

Adjuvant chemotherapy allowed
No concurrent chemotherapy

Endocrine therapy:

See Disease Characteristics
No prior hormonal treatment for breast cancer (except tamoxifen)
No concurrent postmenopausal estrogen therapy

Radiotherapy:

See Disease Characteristics

Surgery:

See Disease Characteristics
No prior or concurrent hysterectomy

Other:

No prior or current participation in an adjuvant intergroup trial