RATIONALE: Timing of breast cancer surgery may improve effectiveness of treatment and may help patients live longer.

PURPOSE: Clinical trial to determine whether timing of primary surgery in relation to menstrual cycle is associated with disease-free survival 5 years after surgery in women who have stage I or stage II breast cancer.

OBJECTIVES:

• Document menstrual phase (follicular vs luteal) by circulating hormones and menstrual history at the time of primary surgery in premenopausal women with stage I or II breast cancer.
• Correlate menstrual phase at primary surgery with 5-year disease-free survival in these patients.
• Compare the menstrual cycle data obtained by hormone levels and study-specific menstrual cycle history with information recorded in the general written record.
• Compare the menstrual cycle data (e.g., hormone levels and cycle history) for these women with the data for the general population.
• Estimate the disease-free survival of women who undergo a 2-stage surgical procedure with cancer found at both stages when the surgery is not confined to the same menstrual cycle phase.

Premenopausal women age 18 to 55 years, who were interviewed for menstrual history and who were surgically treated for stages I to II breast cancer, had serum drawn within 1 day of surgery for estradiol, progesterone, and luteinizing hormone levels. Menstrual history and hormone levels were used to determine menstrual phase: luteal, follicular, and other. Disease-free survival (DFS) and overall survival (OS) rates were determined by Kaplan-Meier method and were compared by using the log-rank test and Cox proportional hazard modeling.

Inclusion Criteria:

1. Women age 18 to 55 years
2. Regular menstrual cycles of 21- to 35-days duration
3. Pathologic stages I to II breast cancer, in whom all gross disease-including ductal carcinoma in situ-was surgically removed either in a one-stage or two-stage procedure.
4. required serum be drawn within 1 calendar day of the lumpectomy/mastectomy for women who underwent a one-stage procedure and within 1 calendar day of each stage for women who underwent a two-stage procedure.

Exclusion Criteria:

1. Lactation within the past 3 months
2. galactorrhea
3. neoadjuvant therapy
4. previous breast cancer, and history of any cancer (except squamous or basal cell skin carcinoma) in which the patient was not disease-free for at least 10 years

This trial enrolled premenopausal women age 18 to 55 years who had regular menstrual cycles of 21- to 35-days duration and pathologic stages I to II breast cancer, in whom all gross disease-including ductal carcinoma in situ-was surgically removed either in a one-stage or two-stage procedure.