What blood tests are recommended for cancer surveillance in patients with a history of cancer?

Blood Tests for Cancer Surveillance

Routine blood tests, including tumor markers, are NOT recommended for cancer surveillance in asymptomatic patients with a history of cancer, as they have not been shown to improve survival or quality of life. 1

Evidence-Based Surveillance Approach

What NOT to Order

The strongest guideline evidence consistently recommends AGAINST routine laboratory testing for cancer surveillance:

• No tumor markers (CEA, CA 15-3, CA 27.29) should be ordered routinely in asymptomatic breast cancer survivors 1, 2
• No routine CBC, chemistry panels, or liver function tests for breast cancer follow-up 1
• No routine CEA testing for colorectal cancer surveillance in asymptomatic patients 1
• These tests have not demonstrated survival benefit and lead to false-positive results requiring additional unnecessary testing 1

The Cornerstone of Surveillance

History and physical examination remain the gold standard for cancer surveillance, as 41-83% of recurrences are detected by patient-reported symptoms 2:

• Breast cancer survivors: History and physical every 3-6 months for first 3 years, then every 6-12 months for years 4-5, then annually 1, 2
• Colorectal cancer survivors: Similar schedule with focus on symptoms of recurrence 1
• Physical examination alone detects 35-68% of recurrences 2

When Blood Tests ARE Indicated

Blood tests should only be ordered when clinically indicated by symptoms or examination findings 2:

• New bone pain, chest pain, abdominal pain, persistent cough, or neurological symptoms warrant investigation 2
• Abnormal physical examination findings (hepatomegaly, lymphadenopathy) justify targeted testing 2
• Symptomatic patients may benefit from CEA, liver enzymes, or other tests to guide diagnostic imaging 1

Cancer-Specific Imaging Surveillance

Breast Cancer

• Annual mammography is the only recommended routine test 1, 2
• No routine CT, MRI, PET scans, bone scans, or chest x-rays in asymptomatic patients 1

Colorectal Cancer

• Colonoscopy at 1 year post-resection, then per guidelines based on findings 1
• CT imaging only for symptomatic patients or abnormal findings 1

Critical Pitfalls to Avoid

Ordering routine tumor markers creates more harm than benefit through:

• False-positive results leading to unnecessary anxiety and additional testing 1
• No demonstrated improvement in survival outcomes 1
• Increased healthcare costs without clinical benefit 1
• Risk of overdiagnosis and overtreatment 3, 4

The 0.22% rate of futile invasive procedures from false-positive screening tests demonstrates real patient harm 5

Emerging Technologies

Multi-cancer early detection (MCED) blood tests are investigational and NOT recommended for routine surveillance 4, 6:

• Sensitivity ranges from 27-95% but is lower for early-stage cancers 4
• Prospective trials are needed to demonstrate mortality benefit 4, 6
• Current evidence shows feasibility but not clinical utility for surveillance 5, 7
• These tests may complement but not replace standard screening 6

Patient Education Priority

Educate patients about symptoms of recurrence rather than relying on blood tests 1:

• New lumps in breast, underarm, or neck 1
• Bone pain, persistent cough, abdominal symptoms 2
• Neurological changes, unexplained weight loss 2
• Patient-reported symptoms detect the majority of clinically significant recurrences 2