What is a commonly used tumor marker for Non-Hodgkin's (NHL) lymphoma?

Tumor Markers for Non-Hodgkin's Lymphoma

Lactate dehydrogenase (LDH) is the most commonly used and clinically significant tumor marker for Non-Hodgkin's lymphoma (NHL). 1

Diagnostic Workup for NHL

The NCCN Guidelines recommend a comprehensive diagnostic workup for NHL that includes several essential laboratory tests:

Essential Laboratory Tests:

• Complete blood count (CBC) with differential and platelets
• Lactate dehydrogenase (LDH)
• Comprehensive metabolic panel
• Beta-2-microglobulin
• Hepatitis B testing 1

Role of LDH in NHL

LDH serves multiple important functions in NHL management:

1. Prognostic indicator:

   • Elevated LDH correlates with more aggressive disease and poorer outcomes
   • Forms a key component of the International Prognostic Index (IPI) 2
   • Higher LDH levels are associated with decreased survival time, particularly in advanced stages 3

2. Disease monitoring:

   • LDH levels typically decrease with successful treatment
   • Rising LDH may indicate disease progression or relapse 3
   • Normalizes in complete remission 4

3. Correlation with disease characteristics:

   • Higher LDH levels are more frequent in high-grade and intermediate-grade NHL compared to low-grade NHL 4
   • Associated with advanced disease stage, bulky disease, large mediastinal tumors, hepatosplenomegaly, bone marrow involvement, and leukemic presentation 4

Other Relevant Markers

While LDH is the primary tumor marker, other tests are important in the workup:

• Beta-2-microglobulin: Another important prognostic marker 1
• Immunophenotyping markers: Essential for diagnosis and classification, not for monitoring
  • CD20, CD3, CD5, CD10, BCL2, BCL6, cyclin D1, CD21, CD23 (immunohistochemistry)
  • Kappa/lambda, CD19, CD20, CD5, CD23, CD10 (flow cytometry) 1

Clinical Application

In clinical practice, LDH should be measured:

• At initial diagnosis
• Before starting treatment
• During treatment to monitor response
• During follow-up to detect early relapse

Prognostic Significance

Patients with NHL who have elevated LDH levels have significantly worse outcomes:

• In one study, patients with advanced disease and LDH >8.0 μkat/L had a 2-year survival rate of only 30%, compared to 80% for those with lower levels 3
• In elderly NHL patients, those with elevated LDH had 13.1 times higher odds of not responding to chemotherapy compared to those with normal LDH (OR: 13.1; 95% CI: 1.36-126.30) 5

Common Pitfalls

• Relying solely on LDH without considering other clinical factors
• Not obtaining baseline LDH before treatment initiation
• Failing to interpret LDH changes in context of clinical findings
• Not recognizing that LDH may be elevated due to other conditions (liver disease, hemolysis, myocardial infarction)

LDH remains the single most important and widely used tumor marker in NHL, providing valuable information for diagnosis, prognosis, and monitoring of treatment response.