Inclusion Criteria:

For Premenopausal Women with Early Stage Breast Cancer

- Premenopausal female patients age 18-44 with breast cancer as defined as:

a. AJCC Stage 0-III breast cancer, regardless of hormone-receptor status or
HER2-overexpression, before the start of planned adjuvant or neoadjuvant chemotherapy
and/or hormonal therapy. If chemotherapy is planned, the regimen must be either CMF,
anthracycline containing, or taxane containing. If hormonal therapy is planned, the
regimen must be limited to tamoxifen. All biologics (e.g. bevacizumab, trastuzumab,
lapatinib, etc.) are allowed in addition to the above therapies.

- ECOG performance status 0-1

- Have regular menstrual cycles; patients can have no more than 1 irregular cycle (too
early or too late) within the past year and/or at least 10 spontaneous cycles within
the past year.

Subject Inclusion:

For Unaffected High Risk Premenopausal Women with BRCA mutations

- Premenopausal Women ages 30-45 with known BRCA mutations

- ECOG performance status 0-1

- Have regular menstrual (21-35 days); patients can have no more than 1 irregular cycle
(too early or too late) within the past year and/or at least 10 spontaneous cycles
within the past year.

- No history of breast or ovary cancer.

Exclusion Criteria:

For Cohort of Premenopausal Women with Early Stage Breast Cancer

- Prior therapy for breast cancer or any other cancer, such as chemotherapy, hormonal
therapy or immunotherapy.

- Ovarian resection, unilateral or bilateral oophorectomy, hysterectomy or radiation to
pelvic region.

- Plans for risk-reducing bilateral oophorectomy within one year of completion of
chemotherapy.

- Prior known infertility; infertility is defined as one year of inability to conceive
despite unprotected intercourse and/or the need to use medication (e.g clomiphene) or
assisted reproductive technology (e.g. intrauterine insemination or in vitro
fertilization) to attempt pregnancy.

- Family history of a first-degree relative with non-surgical menopause < age 40

- Current pregnancy.

Subject Exclusion Criteria:

For Unaffected High Risk Premenopausal Women with BRCA mutation

- Prior chemotherapy or immunotherapy for breast cancer or any other cancer

- Ovarian resection, unilateral or bilateral oophorectomy, hysterectomy or radiation to
pelvic region or ovarian disease (e.g. polycystic ovarian syndrome).

- Plans for risk-reducing bilateral oophorectomy within one year

- Prior known infertility; (except women who have undergone voluntary tubal ligation);
infertility is defined as one year of inability to conceive despite unprotected
intercourse and/or the need to use medication (e.g clomiphene) or assisted
reproductive technology (e.g. intrauterine insemination or in vitro fertilization) to
attempt pregnancy.

- Family history of a first-degree relative with non-surgical menopause < age 40

- Current pregnancy