The goal of this clinical research study is to find out if there is a link between insulin resistance (or pre-diabetes) and endometrial cancer.

Primary Objective:

1. To determine the association between insulin resistance and endometrial cancer in women in Harris County, Texas. 2. To assess the effect of body mass index (BMI) on the association between insulin resistance and endometrial cancer.

Secondary Objectives:

1. To explore the association between polycystic ovarian syndrome (PCOS) and endometrial cancer.
2. To assess the relationship between known reproductive risk factors, menstrual risk factors, family history and endometrial cancer.
3. To explore the molecular changes associated with insulin resistance and PCOS on normal endometrium and tumor tissue.

This study will be comparing women who have had endometrial cancer (cases) to women who have not had endometrial cancer (controls) in Harris County, Texas to better understand the risk factors for getting endometrial cancer. Insulin resistance is a condition of pre-diabetes. Polycystic ovarian syndrome (PCOS) is a condition associated with irregular periods, obesity, infertility, and/or difficulty in getting pregnant. Both insulin resistance and PCOS are believed to increase a woman's risk of getting endometrial cancer.

As part of this study, you will be asked to fill out a questionnaire that asks about your medical history, weight history, family history, reproductive history, and birth control/hormone use. The questionnaire should take about 20 minutes to complete, and you will need to complete it only once. You will have your height and weight measured, and about 4 teaspoons of blood will be drawn to test for insulin resistance (or pre-diabetes). You will be required to fast, not eat or drink anything except water, for 8 hours before having this blood sample drawn. If you are premenopausal and still have both your ovaries, you will have an additional 4 teaspoons of blood drawn to test for PCOS. You will complete the questionnaire during your first visit or at home and will bring it back with you when you come back for your fasting blood test appointment.

If you have been diagnosed with endometrial cancer and have had surgery to remove your uterus, you will also be asked to give permission to use a piece of your leftover tumor and surrounding normal tissue to test for markers of insulin resistance and PCOS. This will be from tissue that was removed during your surgery and will not require another biopsy or surgery.

You will not be required to come back for any follow-up as part of this study. However, you will be asked to fill out a form that asks if you would be willing to be called in the future to participate in other studies.

This is an investigational study. A total of 700 women will take part in this multicenter study, 350 women with endometrial cancer and 350 women without endometrial cancer. A total of up to 350 women will be enrolled at M.D. Anderson.

Inclusion Criteria:

1. Women with histologically confirmed primary endometrial cancer, who will consent to be enrolled in the study no later than 12 weeks after their primary treatment. All stages, grades and histologic subtypes will be eligible.
2. Women who reside in Harris County, Texas. (Cases)
3. Patients must sign an informed consent for the study. (Cases)
4. Women must speak and understand English or Spanish. (Cases)
5. Women who reside in Harris County, Texas. (Controls)
6. No history of prior malignancy with the exception of non-melanoma skin cancer. (Controls)
7. Intact uterus. (Controls)
8. Patients must sign an informed consent for the study. (Controls)
9. Women must speak and understand English or Spanish. (Controls)

Exclusion Criteria:

1. Women who reside outside of Harris County, Texas. (Cases)
2. Patients unwilling or unable to provide informed consent. (Cases)
3. Metastatic cancer to the endometrium from a different primary. (Cases)
4. Women who do not speak and understand English or Spanish. (Cases)
5. Women who reside outside of Harris County, Texas. (Controls)
6. Previous hysterectomy. (Controls)
7. History of prior malignancy with the exception of non-melanoma skin cancer. (Controls)
8. Patients unwilling or unable to provide informed consent. (Controls)
9. Women who do not speak and understand English or Spanish. (Controls)

Participants from Harris County who have had endometrial cancer (cases) and those who have not (controls).