What laboratory tests and imaging studies are recommended for a patient with suspected bone cancer?

Laboratory Tests for Suspected Bone Cancer

For any patient with suspected bone cancer, obtain a complete blood count (CBC), comprehensive metabolic panel with calcium, lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) before definitive treatment—these are essential baseline prognostic markers and monitoring parameters mandated by NCCN guidelines. 1, 2

Essential Laboratory Panel

Prognostic Markers (Required)

• Alkaline phosphatase (ALP): Elevated levels correlate with adverse outcomes in osteosarcoma and indicate higher disease burden; this must be measured at baseline and monitored periodically during treatment and surveillance 1, 2
• Lactate dehydrogenase (LDH): Elevated levels are associated with higher disease burden, poorer outcomes in bone sarcomas, and are predictive of skeletal metastases in osteosarcoma patients 1, 2

Comprehensive Baseline Assessment

• Complete blood count (CBC) with differential: Required to assess baseline hematologic status before chemotherapy and surgery 1, 2
• Comprehensive metabolic panel with calcium: Essential for detecting hypercalcemia and establishing baseline renal and hepatic function, as chemotherapy can cause renal and hepatic dysfunction 1, 2
• Coagulation profile: Must be evaluated to assess bleeding risk before biopsy and surgical procedures 2
• Blood group typing: Required for potential transfusions during surgery 2

Additional Laboratory Studies

• Serum electrolytes (including magnesium and phosphate): Needed for baseline monitoring before chemotherapy administration 2
• Molecular studies: Should be considered to delineate potential therapeutic options 1

Critical Timing and Sequencing

All staging investigations, including laboratory tests, must be completed before biopsy to avoid contamination of tissue planes and ensure accurate baseline assessment. 1, 2

Age-Specific Approach

• Patients <40 years: An aggressive, symptomatic bone lesion has significant risk of being a malignant primary bone tumor; refer to an orthopedic oncologist before further workup 1
• Patients ≥40 years: Workup for potential bone metastasis is recommended, including serum protein electrophoresis, prostate-specific antigen test, or mammogram as clinically indicated 1

Imaging Studies (Complementary to Labs)

While the question focuses on laboratory tests, NCCN guidelines mandate specific imaging as part of the complete staging workup:

• Plain radiographs: Initial diagnostic test when bone malignancy is suspected 1, 3
• Chest imaging: CT chest with contrast to detect pulmonary metastases (most common site) 1
• MRI of primary site: Contrast-enhanced MRI of the entire bone for local staging 1
• CT chest/abdomen/pelvis with contrast: Standard staging for most bone cancers 1
• Bone scan or FDG-PET/CT: Consider if clinically indicated for detecting skeletal metastases 1

Common Pitfalls to Avoid

• Do not delay referral: Any patient with radiographic suspicion of bone malignancy should be quickly referred to a cancer center or bone sarcoma reference center for multidisciplinary evaluation before further workup 2
• Do not perform biopsy before staging: Complete all laboratory and imaging studies first to avoid tissue contamination and ensure accurate baseline values 1, 2
• Do not overlook fertility counseling: Fertility consultation should be offered to individuals of child-bearing potential before cytotoxic chemotherapy 1
• Distinguish ALP elevation: Carefully evaluate elevated ALP to distinguish between benign bone turnover and malignant processes 2

Ongoing Monitoring

Laboratory studies should be performed periodically during treatment and surveillance, with life-long follow-up recommended for monitoring late effects of surgery, radiation therapy, and systemic therapy in long-term survivors. 1