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