Routine CA-125 Testing for Endometrial Cancer Surveillance
Routine CA-125 testing should NOT be performed for surveillance in this patient with endometrial carcinoma in complete remission. 1
Guideline-Based Recommendation
The Society of Gynecologic Oncologists explicitly states there is insufficient data to support routine use of CA-125 at any surveillance timepoint (0-12 months, 12-24 months, 24-36 months, 3-5 years, or >5 years) for endometrial cancer surveillance. 1
Why CA-125 Should Not Be Used Routinely
Limited Detection Capability
- CA-125 detects only 15% of endometrial cancer recurrences during routine surveillance visits, making it one of the least effective surveillance modalities. 1
- In comparison, symptoms detect 41-83% of recurrences and physical examination detects 35-68%. 1
Negligible Utility in Most Endometrial Cancers
- The role of CA-125 for detecting recurrence is negligible in patients with low-risk disease (which comprises the majority of endometrial cancer cases). 1
- CA-125 elevation occurs in more than half of patients with advanced-stage and/or high-grade histology, but most of these patients had elevated pretreatment levels. 1
When CA-125 MAY Be Considered (Select Cases Only)
CA-125 may be appropriate only in highly select patients with:
- Advanced disease (stage III/IV) 1
- Serous histology 1
- Clear cell histology 1
- AND an elevated CA-125 level before treatment 1
Even in high-risk endometrial cancer populations, CA-125 detected only 10% of recurrences in one multi-institutional study. 2
What Should Be Done Instead
Recommended Surveillance Strategy
The cornerstone of endometrial cancer surveillance is thorough history and physical examination (including speculum, bimanual pelvic, and rectovaginal examination) at scheduled intervals based on risk stratification. 1
Risk-Stratified Examination Schedule
- Low risk (stage IA grade 1-2): Every 6 months for years 0-1, then yearly 1
- Intermediate risk (stage IB-II): Every 3 months for year 1, every 6 months for years 2-5, then yearly 1
- High risk (stage III/IV, serous, clear cell): Every 3 months for years 1-2, every 6 months for years 3-5, then yearly 1
When to Order Imaging
Imaging (CT and/or PET scan) should be reserved for when recurrence is suspected based on symptoms or examination findings—not for routine surveillance. 1
Critical Clinical Context for This Patient
At nearly 2 years post-treatment with a normal PET scan at 21 months, this patient has already demonstrated no evidence of disease on advanced imaging. Adding routine CA-125 testing would not improve outcomes and could lead to:
- False-positive elevations from benign conditions (endometriosis, pelvic inflammatory disease, prior radiotherapy) 1, 3
- Unnecessary anxiety and additional testing
- Increased healthcare costs without survival benefit
Common Pitfalls to Avoid
- Do not order CA-125 "just to be safe" in patients without the specific high-risk features and elevated pretreatment levels noted above. 1
- Do not use CA-125 as a substitute for thorough physical examination, which remains essential for detecting the 26-50% of recurrences that occur within the pelvis. 1
- Be aware that elevated CA-125 can occur from multiple benign causes, including prior radiotherapy, which could apply to this patient depending on her treatment history. 1
Patient Education Priority
Counsel this patient to immediately report any symptoms including vaginal bleeding, pelvic/abdominal pain, unexplained weight loss, or persistent cough, as more than half of all endometrial cancer recurrences are detected through symptoms rather than surveillance testing. 1