Serum Estradiol Levels In Postmenopausal Women With Breast Cancer Receiving Adjuvant Aromatase Inhibitors and Vaginal Estrogen

Inclusion Criteria:

- History of breast cancer, stages I-III with pathology confirmed at MSKCC

- Women who have completed all of their primary treatment (surgery, radiation therapy,
adjuvant chemotherapy) with the exception of endocrine therapy and currently have no
clinical evidence of disease.

- Women who are currently on aromatase inhibitors for at least three months--either
letrozole or anastrozole

- Women with symptomatic urogenital atrophy: vaginal dryness, irritation, pruritus,
dyspareunia, urinary frequency and/or urinary incontinence

- Menopausal at study entry defined as:

- Bilateral salpingo-oophorectomy independent of age

- If natural menopause, age ≥ 50 with cessation of menses for at least 12 months

- If menopause induced by chemotherapy, age ≥ 50 with no menstrual period at
least 12 months after chemotherapy finished

- At least 18 years of age

- Able to participate in the informed consent process

- Gynecology examination within six months

- Able to read/speak English

Exclusion Criteria:

- Inability to give informed consent

- Vaginal bleeding of unknown etiology within 12 months of study entry

- History of prior vaginal 17-β estradiol or other topical estrogen use within the past
six months