Tamoxifen or Letrozole in Treating Women With Ductal Carcinoma in Situ

DISEASE CHARACTERISTICS:

Diagnosis of ductal carcinoma in situ (DCIS) on core biopsy
No evidence of contralateral breast disease or palpable masses on breast examination
No presence or suspicion of invasive cancer, including contralateral invasive cancer, on core biopsy and MRI
No documented ipsilateral axillary adenopathy
Planning to undergo lumpectomy or mastectomy
Estrogen receptor (ER)-positive tumor by immunohistochemistry

PATIENT CHARACTERISTICS:

Female patient

Premenopausal or postmenopausal

Postmenopausal is defined by any of the following:

No spontaneous menses for >= 1 year
Bilateral oophorectomy
Radiation castration and amenorrheic for >= 3 months
Follicle-stimulating hormone (FSH) > 20 IU/L AND off all hormonal therapy (e.g., hormone replacement therapy or birth control pills) for >= 1 month
Not pregnant or nursing
Negative pregnancy test
Fertile patients must use effective contraception

No co-morbidities contraindicating the use of tamoxifen, including any of the following:

Prior history of thrombotic events
History of hypercoagulable state
History of endometrial hyperplasia
Abnormal vaginal bleeding
No history of contrast dye-related allergies/reactions
No history of metal-containing prostheses or implants

PRIOR CONCURRENT THERAPY:

See Disease Characteristics