This study investigates whether molecular testing can help to predict the risk of endometrial cancer coming back (recurrence) after treatment in patients diagnosed with low risk endometrial cancer and scheduled to have surgery to remove the uterus and/or cervix (hysterectomy). Having sentinel lymph node mapping performed may help researchers to see if the cancer has spread in patients with low risk endometrial cancer.

PRIMARY OBJECTIVE:

I. Validate the use of a molecular panel of estrogen-induced genes to predict recurrence in low risk endometrial cancer.

SECONDARY OBJECTIVES:

I. Calculate the positive predictive value (PPV)/negative predictive value (NPV)/sensitivity (Sens)/specificity (Spec) of lymph node mapping to predict pelvic lymph node involvement.

II. Correlate CA125 and HE4 levels with recurrence and to explore the use of other serum biomarkers to predict recurrence.

III. Describe patterns of recurrence in a low risk patient population. IV. Determine if molecular panel can predict lymph node involvement in low risk endometrial cancer patients who undergo pelvic and para-aortic lymphadenectomy.

V. Compare performance of molecular panel to the Mayo low risk criteria for prediction of lymph node involvement.

VI. Compare performance of molecular panel to the high intermediate risk criteria from Gynecologic Oncology Group, trial 99 (GOG 99) for prediction of recurrence.

VII. Determine the feasibility of lymph node mapping in this patient population.

VIII. Determine the morbidity and mortality of lymph node dissection and mapping.

OUTLINE:

Patients undergo hysterectomy and sentinel lymph node mapping. Patients may also undergo bilateral salpingo-oophorectomy at the direction of the treating physician. If peritoneal disease or other contraindications to lymphatic mapping are detected at the time of surgery, mapping and sentinel node biopsy are performed at the surgeon's discretion. At the time of hysterectomy, patients undergo collection of tissue for molecular testing. Before and after surgery, patients also undergo collection of blood samples for tumor marker analysis.

Inclusion Criteria:

• Histologically confirmed low grade (grade 1-2) endometrioid type adenocarcinoma
• Candidate for surgery
• No evidence of deep invasion or peritoneal disease in patients that have undergone preoperative imaging
• Patients may have had prior hormonal treatment for the treatment of early endometrial neoplasia. Patients may not have had prior radiation or chemotherapy for treatment of endometrial cancer
• Patients must have a negative pregnancy if of childbearing potential

Exclusion Criteria:

• Histologically confirmed high grade endometrioid or non-endometrioid type endometrial cancer (including serous, clear cell, carcinosarcoma or any mixed tumor containing these cell types)
• Medical co-morbidities making surgery unsafe, as determined by the primary treating physician
• Evidence of deep myometrial invasion, cervical involvement or peritoneal disease on preoperative imaging
• Prior treatment with radiation or chemotherapy for endometrial cancer
• Any contraindication to lymph node mapping

Patients diagnosed with low risk endometrial cancer who are scheduled to have a hysterectomy