RATIONALE: Estrogen replacement therapy may improve quality-of-life in postmenopausal women with endometrial cancer. It is not yet known whether estrogen replacement therapy will affect cancer recurrence.

PURPOSE: Randomized double-blinded phase III trial to determine the effectiveness of estrogen replacement therapy in treating women who have stage I or stage II endometrial cancer.

OBJECTIVES:

• Determine the effect of estrogen replacement therapy on recurrence free and overall survival in women with a history of stage I or II endometrial adenocarcinoma.

OUTLINE: This is a randomized, double blind study. Patients are stratified according to stage of endometrial cancer (IA vs IB/IC vs II). Patients are randomized to one of two treatment arms:

• Arm I: Patients receive oral conjugated estrogens (Premarin) daily for 3 years.
• Arm II: Patients receive oral placebo daily for 3 years. Patients are followed every 6 months for 3 years and then annually for 2 years.

PROJECTED ACCRUAL: Approximately 2,108 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically confirmed grade I, II or III endometrial adenocarcinoma (endometrioid, villoglandular, mucinous, adenosquamous, papillary serous, clear cell, or not otherwise specified)

• Must have had total hysterectomy and bilateral salpingo-oophorectomy within past 20 weeks

  • Surgical stage IA, IB, IC, IIA (occult), or IIB (occult) disease

• Must have had normal mammogram, or a negative breast biopsy after an abnormal mammogram, within past year

PATIENT CHARACTERISTICS:

Age:

• Not specified

Performance status:

• Not specified

Life expectancy:

• Not specified

Hematopoietic:

• Not specified

Hepatic:

• Bilirubin no greater than 1.5 times normal
• SGOT no greater than 3 times normal
• No acute liver disease

Renal:

• Not specified

Cardiovascular:

• No prior thromboembolic disease

Other:

• No prior or current carcinoma of the breast
• No other prior invasive malignancy within the past 5 years except nonmelanoma skin cancer

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• Not specified

Endocrine therapy:

• No concurrent hormonal therapy

Radiotherapy:

• Not specified

Surgery:

• See Disease Characteristics
• Recovered from prior surgery

Other:

• No prior cancer treatment that would preclude study therapy
• Concurrent participation on GOG Lap-1 or GOG Lap-2 allowed