What biochemistry and hematology tests are routinely ordered for cancer patients to assess organ function, detect treatment‑related toxicities, stage disease, and monitor response?

Biochemistry and Hematology Tests for Cancer Patients

Cancer patients require routine monitoring with complete blood count with differential, comprehensive metabolic panel including liver and renal function tests, and bone biochemistry tests before and during treatment to detect organ dysfunction, treatment-related toxicities, and guide therapy modifications. 1

Core Hematology Panel

Complete Blood Count (CBC) with Differential

• Absolute neutrophil count (ANC) to detect myelosuppression and neutropenia risk, which can lead to life-threatening infections 1, 2, 3
• Lymphocyte count as lymphopenia is a risk factor for hematological toxicity and treatment complications 3, 4
• Platelet count to monitor for thrombocytopenia, particularly in patients receiving pelvic radiation or myelosuppressive chemotherapy 3, 4
• Hemoglobin and hematocrit to assess for anemia requiring intervention 1, 3
• White blood cell count to evaluate overall bone marrow function 1, 4

Blood Smear Examination

• Evaluate for monocytosis, eosinophilia, and dysplasia in specific malignancies like systemic mastocytosis 1

Essential Biochemistry Tests

Comprehensive Metabolic Panel

• Serum creatinine and blood urea nitrogen to assess renal function before and after each chemotherapy cycle, particularly with nephrotoxic agents like cisplatin 1, 2
• Liver function tests (AST, ALT, alkaline phosphatase, bilirubin) to detect hepatotoxicity and guide dose modifications 1, 2
• Electrolytes (sodium, potassium, chloride, bicarbonate) to identify metabolic derangements 1, 2

Additional Biochemistry Markers

• Lactate dehydrogenase (LDH) as a prognostic marker in multiple cancer types 1
• Uric acid to monitor for tumor lysis syndrome risk 1
• Albumin level as hypoalbuminemia is a risk factor for chemotherapy toxicity and predicts need for treatment schedule changes 1, 4
• Bone biochemistry tests (calcium, phosphate, magnesium) to detect metabolic bone disease and electrolyte abnormalities that increase cardiac arrhythmia risk 1, 2

Specialized Monitoring Based on Treatment

Cardiac Monitoring

• Creatine kinase levels when using targeted therapies with known cardiac toxicity 1
• Cardiac troponin I to identify patients at risk for developing cardiac dysfunction, particularly with anthracyclines or trastuzumab 1, 2
• BNP or NT-proBNP may be useful but not established for routine surveillance 1
• Electrocardiogram required for agents causing QT prolongation or cardiac arrhythmias 1, 2

Lipid Monitoring

• Lipid spectrum depending on the specific targeted therapy being used 1

Tumor Markers: Limited Role

Not Recommended for Routine Use

• CEA (carcinoembryonic antigen) is explicitly not recommended for routine staging, risk assessment, or surveillance in lung cancer despite its use in colorectal cancer 1, 5
• Serum tryptase is specific for systemic mastocytosis but not routinely used in other cancers 1

Monitoring Frequency and Timing

Baseline Assessment

• Perform all core hematology and biochemistry tests before initiating any cancer treatment 1, 2

During Active Treatment

• Every 6-12 months for indolent diseases like indolent systemic mastocytosis 1
• Before and after each chemotherapy cycle for patients receiving myelosuppressive or nephrotoxic agents 2, 4
• Every 8-12 weeks during targeted therapy to assess response and toxicity 1

Critical Thresholds Requiring Immediate Action

• Fever ≥38°C (100.4°F) with neutropenia requires immediate evaluation for neutropenic sepsis 2
• QTc >500 ms mandates treatment discontinuation 2
• Severe electrolyte abnormalities (hypokalemia, hypomagnesemia) require correction before continuing treatment 2

Common Pitfalls to Avoid

• Do not rely on tumor markers like CEA for lung cancer monitoring as they lack sensitivity and specificity in this population 1, 5
• Albumin and creatinine clearance should be routinely monitored at baseline as they predict chemotherapy toxicity and need for schedule modifications 4
• Lymphopenia at baseline is an independent risk factor for hematological toxicity and should trigger closer monitoring 3, 4
• Performance status ≥1 combined with laboratory abnormalities (hypoalbuminemia, renal dysfunction) significantly increases toxicity risk 4