Tamoxifen or Letrozole in Treating Women With Ductal Carcinoma in Situ

OBJECTIVES:

- Determine the clinical response in women with estrogen receptor-positive ductal
carcinoma in situ (DCIS) treated with neoadjuvant hormonal therapy comprising tamoxifen
or letrozole, by evaluating the maximal change in tumor diameter on mammography and MRI
following treatment.

- Identify those cellular antigens which are altered by hormonal therapy.

- Determine which cellular antigens are predictive of clinical response to hormonal
therapy.

- Evaluate whether genomic changes or gene expression in DCIS are altered by hormonal
therapy and find candidate genes which are correlated with response to treatment.

OUTLINE: This is a pilot study.

Patients who are premenopausal receive oral tamoxifen once daily for 3 months in the absence
of unacceptable toxicity. Patients who are post menopausal receive oral letrozole once daily
for 3 months in the absence of unacceptable toxicity.

After 3 months of hormonal therapy, patients undergo lumpectomy or mastectomy.

After completion of study treatment, patients are followed every 6 months for 5 years and
then annually thereafter.

PROJECTED ACCRUAL: A total of 40 patients will be accrued for this study.

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