What is the initial lab evaluation for a patient presenting with a suspected uterine mass or uterine cancer?

Initial Lab Evaluation for Suspected Uterine Mass or Cancer

For a patient with suspected uterine mass or cancer, obtain a complete blood count (including platelets) and consider liver function tests, renal function tests, or a chemistry profile as part of the initial laboratory workup. 1

Essential Laboratory Tests

Mandatory Initial Labs

• Complete blood count (CBC) with platelets is required for all patients with known or suspected uterine neoplasms 1

  • This assesses for anemia from chronic bleeding, which occurs in approximately 90% of endometrial cancer presentations 2
  • Platelet count is important for preoperative planning

• Liver function tests (LFTs), renal function tests, or chemistry profile should be considered in the initial workup 1

  • These are particularly important given the typical age group at risk (≥55 years) and presence of comorbid conditions 1

Tumor Markers (Selective Use)

• CA-125 measurement may be helpful but is not routinely indicated for initial diagnosis of uterine cancer 2

  • CA-125 is primarily useful for monitoring clinical response in patients with extrauterine disease (advanced stage) 2
  • Unlike ovarian cancer, CA-125 is not a standard screening or diagnostic marker for uterine malignancies

• Beta-hCG and alpha-fetoprotein (AFP) should be measured if there is concern for germ cell tumors, particularly in younger women or those with mediastinal/retroperitoneal involvement 1

  • This is not routinely needed for typical endometrial cancer presentations

Genetic Testing Considerations

• Genetic counseling and testing should be considered for patients younger than 50 years or those with significant family history of endometrial and/or colorectal cancer 1, 2

  • Approximately 5% of endometrial cancers are caused by hereditary genetic mutations, particularly Lynch syndrome 1
  • Women with Lynch syndrome have up to 60% lifetime risk for endometrial cancer 2

• Immunohistochemistry (IHC) and/or microsatellite instability (MSI) screening of tumor tissue is increasingly implemented to identify individuals at risk for Lynch syndrome 1

  • This requires an infrastructure to handle screening results appropriately 1

Critical Pitfalls to Avoid

• Do not rely solely on laboratory tests for diagnosis - tissue diagnosis via endometrial biopsy remains essential, with imaging (preferably MRI) to characterize the mass 2, 3

  • Office endometrial biopsy has a 10% false-negative rate 2, 3

• Do not order CA-125 routinely for initial uterine cancer evaluation - its role is limited to monitoring advanced disease, not diagnosis 2

• Pregnancy testing should be performed in women of childbearing age presenting with abnormal bleeding 4

• Prothrombin time (PT) and partial thromboplastin time (PTT) should be obtained if bleeding is heavy 4

Additional Workup Beyond Labs

The laboratory evaluation is only one component of the comprehensive initial assessment, which must include 1:

• History and physical examination
• Expert pathology review with endometrial biopsy
• Imaging (MRI preferred for characterizing uterine masses and assessing myometrial invasion) 2
• Chest imaging (chest X-ray) 2