Serum Tumor Markers in Testicular Cancer

Introduction to Tumor Markers

• The National Comprehensive Cancer Network recommends measuring alpha-fetoprotein (AFP), beta-human chorionic gonadotropin (β-HCG), and lactate dehydrogenase (LDH) before orchiectomy, during treatment, and throughout follow-up for testicular cancer patients 1, 2, 3

Primary Tumor Markers

• Alpha-fetoprotein (AFP) is produced exclusively by nonseminomatous germ cell tumors and is never elevated in pure seminoma, with a half-life of 5-7 days 1, 4
• Any elevation of AFP in a histologically "pure" seminoma indicates an undetected focus of nonseminoma, and the patient must be treated as having nonseminomatous disease 1, 4
• Beta-human chorionic gonadotropin (β-HCG) may be elevated in both seminomas and nonseminomas, with a half-life of 1-3 days 1, 3, 5
• Lactate dehydrogenase (LDH) is the least specific marker but still clinically important, with elevated levels indicating worse prognosis in seminoma patients 1, 4, 7

Clinical Interpretation Guidelines

• The European Association of Urology and the National Comprehensive Cancer Network recommend that pure seminoma patients have β-HCG and LDH measured, while AFP must be negative 1, 3
• Nonseminoma patients may have any combination of AFP, β-HCG, and LDH elevated 1, 4
• The International Germ Cell Cancer Collaborative Group (IGCCCG) classification system is used for prognostic stratification, with good prognosis nonseminoma requiring AFP <1,000 ng/mL, β-HCG <5,000 IU/L, and LDH <1.5 × ULN 2, 7, 8

Timing of Marker Assessment

• Baseline AFP, β-HCG, and LDH should be obtained before any therapeutic intervention, and repeated after orchiectomy to assess for normalization based on half-lives 1, 3, 5
• Markers should be monitored before, during, and after chemotherapy or radiation, and measured at every follow-up visit to detect early signs of relapse 1, 2, 4

Critical Pitfalls to Avoid

• False positives for β-HCG can occur due to hypogonadism, marijuana use, or heterophilic antibodies, and should be considered when interpreting results 6
• Normal marker levels do not exclude testicular cancer, and persistent or rising markers after orchiectomy indicate metastatic disease requiring immediate staging with CT imaging 3, 5