This phase II trial studies how well levonorgestrel-releasing intrauterine system works in treating patients with complex atypical hyperplasia or grade I endometrial cancer. High levels of estrogen can cause the growth of endometrial cancer cells. Progesterone can help balance the amount of estrogen present. Hormone therapy using levonorgestrel, a type of progesterone, may fight endometrial cancer by helping regulate hormone levels.

PRIMARY OBJECTIVES:

I. To determine the efficacy of the levonorgestrel intrauterine device (IUD) (levonorgestrel-releasing intrauterine system) to treat complex atypical hyperplasia (CAH) and grade 1 endometrioid endometrial carcinoma (G1 EEC).

II. To determine if response to therapy can be predicted based on the molecular profile of the tumor or by change in gene expression after therapy.

SECONDARY OBJECTIVES:

I. To assess quality of life outcomes in patients treated with levonorgestrel IUD.

II. To document the toxicity profile of the levonorgestrel IUD in the treatment of complex atypical hyperplasia and grade 1 endometrioid endometrial cancer.

III. To evaluate the molecular profile of the hysterectomy specimen of patients treated with the levonorgestrel IUD. Compare molecular profile in pretreatment tissue to hysterectomy tissue between responders and non-responders to levonorgestrel IUD therapy.

IV. To evaluate long-term survival, disease status, and fertility outcomes in patients with levonorgestrel IUD.

OUTLINE:

Patients undergo placement of a levonorgestrel-releasing intrauterine system.

After completion of study treatment, patients are followed up every 3 months for 1 year, and then periodically for up to 5 years.

Inclusion Criteria:

• All patients with a diagnosis of complex atypical hyperplasia or endometrial biopsy within three months of study enrollment OR patients with a diagnosis of grade 1 endometrioid endometrial carcinoma on endometrial biopsy within three months of study enrollment in the presence of one or more of the following: 1)desire for future fertility 2)morbid obesity (body mass index > 40) 3)multiple co-morbidities (ASA Class 3 or 4)
• No prior treatment for diagnoses in inclusion criteria 1.
• Women of any racial or ethnic group.
• Ability to comply with endometrial biopsies every 3 months.
• Willing and able to sign informed consent.
• Age greater than 18 years.

Exclusion Criteria:

• Diagnosis of grade 1 endometrioid endometrial carcinoma without the presence of one of the 3 criteria mentioned in inclusion criteria 1.
• Diagnosis of grade 2 endometrioid endometrial carcinoma or higher on endometrial biopsy or on dilation and curettage specimen.
• Evidence of extrauterine spread of disease on imaging or during surgical evaluation.
• Congenital or acquired uterine anomaly which distorts the uterine cavity.
• Acute pelvic inflammatory disease.
• Acute liver disease or previously diagnosed liver tumor (benign or malignant).
• Conditions associated with increased susceptibility to infections with microorganisms. Such conditions include, but are not limited to, AIDS, leukemia and IV drug abuse.
• Genital actinomycosis.
• Current carcinoma of the breast.
• Current pregnancy.
• Breastfeeding mothers.