Endometrial Cancer Diagnostics

Laboratory Tests and Ancillaries

Tumor Markers

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Examples of tumor markers are CA-125, carcinoembryonic antigen (CEA), vimentin, estrogen receptor (ER), progesterone receptor (PgR), p16, p53 by immunohistochemistry (IHC), polymerase epsilon (POLE) mutations, microsatellite instability high (MSI-H) or mismatch repair deficient (dMMR), no specific molecular profile (NSMP). CA-125 may be used to assess therapeutic response, but false positive results in the presence of peritoneal inflammation, radiation injury, and normal levels in vaginal metastasis render this test unreliable. The hormone receptor status (eg PgR, ER) may help with treatment decision-making especially if considering initiation of hormone therapy. Testing for ER status is recommended in stage III, IV or recurrent endometrioid carcinoma. Testing for HER2 immunohistochemistry is recommended for advanced-stage or recurrent serous endometrial carcinoma or carcinosarcoma. Evaluation of the tumor for dMMR with the use of immunohistochemistry or microsatellite instability (MSI) is recommended. Tumor mutational burden (TMB) testing should be considered by using an approved assay or a validated test performed in a certified laboratory.

Others

Pregnancy tests should be conducted on all patients of childbearing age. A full blood count, liver function tests and renal function profiles should be obtained. CBC and prothrombin time should be done in patients experiencing heavy vaginal bleeding. A PAP smear may be considered to rule out other abnormal histologies.

Surgical Diagnostic Procedures

Endometrial Biopsy

Endometrial biopsy is the gold standard in evaluating endometrial neoplasia. This is used as an initial diagnostic study to help determine an appropriate management strategy. This is recommended for patients with ovarian cancer undergoing fertility-sparing treatment.

Dilation and Curettage (D and C)

Dilation and curettage are used to obtain an endometrial sample to evaluate the endometrial lining.

Hysteroscopy

Hysteroscopy is used to evaluate the endometrial lining for lesions causing vaginal bleeding. This procedure is often done together with dilation and curettage or for biopsy.

Lymph Node (LN) Biopsy

LN biopsy is not routinely used but may be useful in disease staging.

Imaging

Initial studies depend on symptomatology and risk for metastatic disease. This is highly recommended for patients suspected of having extrauterine disease.

Magnetic Resonance Imaging (MRI)

A contrast-enhanced pelvic MRI is used to establish the origin and extent of the tumor, and to evaluate for myometrial invasion and cervical involvement. The sensitivity for myometrial invasion is 80-90% and for cervical invasion, it is 57-100%. This is the best radiologic modality compared to CT scans or PET scans for the detection of LN metastases. This is the preferred imaging modality in patients who wish to preserve their fertility.

Pelvic Ultrasound

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A pelvic ultrasound is the first-line imaging study used to evaluate the etiology of vaginal bleeding in women suspected to have endometrial cancer or hyperplasia. This is an imaging study option if MRI is contraindicated in patients still desiring pregnancy. Pelvic transvaginal ultrasound (TVUS) is preferred in evaluating myoinvasion and disease extent in patients with contraindications to MRI.

Positron Emission Tomography (PET) Scan

A positron emission tomography scan is a confirmatory test in patients suspected of metastatic disease.

Chest Radiography

A chest radiogram should be performed in all patients as part of the initial assessment. This prompts the need for a chest CT scan if with positive findings.

Computed Tomography (CT) Scan

A computed tomography scan may be used to confirm the presence of metastasis especially if with positive findings in a chest X-ray. A CT scan of the chest, abdomen and pelvis is the preferred modality to evaluate for metastatic disease in patients undergoing non-fertility sparing treatment and with high-grade carcinoma (eg poorly differentiated endometrioid, serous, clear cell, undifferentiated carcinoma and carcinosarcoma). This may be used to evaluate for metastatic disease in post-hysterectomy patients with incidental findings of endometrial cancer or with incomplete staging with uterine risk factors (eg >2 cm tumor, high-grade carcinoma, >50% myoinvasion, lymphovascular space invasion (LVSI), and cervical stromal involvement). CT scan of the abdomen, pelvis and/or chest is also recommended in patients with suspected recurrence or metastasis based on detection of abnormal findings on physical exam, which includes vaginal tumor, palpable mass or adenopathy and new pelvic, abdominal or pulmonary symptoms.