Letrozole Versus Observation in Patients With Newly Diagnosed Uterine Leiomyosarcoma

Inclusion Criteria:

1. Patients must have signed an approved informed consent.
2. Histologically confirmed uterine leiomyosarcoma with disease limited to the uterus (determined by surgical staging or radiologic imaging).
3. Tumors must express ER positivity by immunohistochemistry (ER expression \>10% by immunohistochemistry).
4. Patients must have a hysterectomy and bilateral oophorectomy prior to initiation of therapy.
5. All patients must have no measurable disease. Measurable disease is defined as lesions that can be measured by physical examination or by means of imaging techniques. Imaging must be done within 6 weeks of study entry.
6. Patients must have a Zubrod performance status of 0, 1, or 2.
7. Patients must have a pretreatment granulocyte count (i.e., segmented neutrophils + bands) of greater than 1,000/Fl, a hemoglobin level of greater than or equal to 9.0 gm/dL and a platelet count of greater than 75,000/dL.
8. Patients must have an adequate renal function as documented by serum creatinine less than or equal to 2.0 mg/dL.
9. Patients must have adequate hepatic function as documented by a serum bilirubin less than or equal to 2.5 mg/dL.
10. Aspartate transaminase (SGOT) must be less than 3x institutional upper limit of normal.
11. Patients must have recovered from the effects of prior surgery.
12. No more than 12 weeks must have elapsed from hysterectomy.
13. Patients must be 18 years or older.

Exclusion Criteria:

1. Patients who do not have pure uterine sarcomas (i.e., no mixed malignant Mullerian tumors).
2. Patients with any other severe concurrent disease, which would make the patient inappropriate for entry into this study, including significant hepatic, renal, or gastrointestinal diseases.
3. Patients with a history of prior malignancy except for adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, or other cancer for which the patient has been disease-free for at least five years.
4. Patients who were taking or have a history of taking letrozole or another aromatase inhibitor.
5. Patients with active or uncontrolled systemic infection.
6. Patients with history of uncontrolled cardiac disease; i.e., uncontrolled hypertension, unstable angina, recent myocardial infarction (within prior 6 months), uncontrolled congestive heart failure, and cardiomyopathy with an ejection fraction under 40%.
7. Patients who are pregnant or breast-feeding.
8. Presence of clinically apparent untreated central nervous system metastases.
9. Presence of carcinomatous meningitis.
10. Patients currently receiving chemotherapy or radiation therapy.