A Phase III Prospective, Randomized, Double-Blind Clinical Trial of Hormone Replacement Therapy In Postmenopausal Women With A History Of Node-Negative Or Ductal Carcinoma In Situ Who Are Receiving Adjuvant Tamoxifen

Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed node-negative invasive carcinoma or ductal carcinoma in situ
of the breast

- No contralateral breast cancer

- No recurrent or metastatic disease

- Completion of active non-hormonal therapy for breast cancer

- Receiving tamoxifen (20 mg/day) for at least 3 months prior to study and plan to
continue drug while on study

- Hot flashes severe enough to seek medical intervention (at least 7-8 moderate to
severe hot flashes per day or 60 per week at baseline) AND/OR

- Vaginal symptoms, including dyspareunia, vaginal dryness, irritation, or thinning due
to estrogen deficiency

- If uterus present, no prior histologically confirmed adenomatous or atypical
endometrial hyperplasia or endometrial carcinoma AND no concurrent endometrial cancer
confirmed by pelvic exam within the past year

- No active endometriosis

- No unexplained vaginal bleeding

- Hormone receptor status:

- Estrogen and progesterone receptor status known for patients with invasive
breast cancer

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Sex:

- Female

Menopausal status:

- Postmenopausal

- No menstrual period for more than 12 months OR prior bilateral oophorectomy

- Must be over 55 years of age OR have documented follicle-stimulating hormone levels
in postmenopausal range if one or both ovaries remain after prior hysterectomy

Performance status:

- ECOG 0-1

Life expectancy:

- Not specified

Hematopoietic:

- Not specified

Hepatic:

- Not specified

Renal:

- Not specified

Cardiovascular:

- No prior superficial or deep venous or arterial thrombosis

- No serious venous stasis disease

Pulmonary:

- No pulmonary embolus

Other:

- Must be able to read and speak English

- No lower extremity trauma, swelling, or tenderness within the past 4 weeks

- No active gallbladder disease

- No migraine headaches

- No other prior malignancy unless curatively treated with no evidence of recurrence

- No concurrent seizure disorder requiring anti-seizure medication

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Not specified

Chemotherapy:

- Not specified

Endocrine therapy:

- See Disease Characteristics

- No other concurrent estrogen or hormone replacement therapy

- No concurrent clonidine, bellergal, progestational agent, or methyldopa for hot
flashes

- No concurrent topical vaginal estrogen cream (e.g., Estring or Vagifem) for patients
with vaginal symptoms only

Radiotherapy:

- Not specified

Surgery:

- At least 4 weeks since prior surgery

Other:

- At least 12 months since prior treatment for congestive heart failure

- Concurrent selective serotonin reuptake inhibitors (SSRI) or antidepressants with
SSRI activity allowed if begun at least 3 months prior to study and continue during
study