AFP and hCG Testing in Patients with Testicular Mass
Alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) should be ordered for all patients with a testicular mass as they are critical tumor markers that aid in diagnosis, staging, prognosis, and treatment planning for testicular cancer. 1
Diagnostic Value
- AFP and hCG are essential serum tumor markers that help distinguish between seminomatous and nonseminomatous germ cell tumors (GCTs) 1
- These markers should be drawn before any treatment, including orchiectomy, to establish baseline values 1
- Pure seminoma can have elevated hCG but never elevated AFP; any AFP elevation indicates nonseminoma components and changes management 1
- Elevated tumor markers may be sufficient for diagnosis in rare, medically unstable patients with metastatic disease requiring urgent treatment 1
Staging and Risk Assessment
- Post-orchiectomy marker levels are used for formal risk stratification according to the International Germ Cell Cancer Collaborative Group (IGCCCG) prognostic index 1
- The magnitude of marker elevations influences risk classification and subsequent treatment decisions 1
- Serial measurements determine if markers are rising or falling at appropriate rates based on their biological half-lives (24-36 hours for hCG, 7 days for AFP) 1
- Persistent marker elevation after orchiectomy may indicate residual disease requiring more aggressive therapy 1
Clinical Interpretation
- Normal AFP with elevated hCG may indicate pure seminoma 1
- Elevated AFP always indicates nonseminomatous elements, even if histology shows pure seminoma 1
- hCG levels up to 200 IU/L may be seen with pure seminoma, but higher levels suggest nonseminomatous components 2
- False positive hCG elevations can occur with marijuana use and hypogonadism, requiring careful interpretation 1
Management Implications
- Marker levels guide treatment selection between surveillance, radiation therapy, or chemotherapy 1
- For patients with low-stage disease, persistent marker elevation after orchiectomy suggests the need for systemic chemotherapy rather than retroperitoneal lymph node dissection (RPLND) 1
- Marker normalization does not guarantee complete tumor eradication, highlighting the importance of appropriate follow-up 3
Common Pitfalls
- Failing to obtain markers before orchiectomy, which can make it difficult to establish baseline values and interpret post-surgical changes 1
- Misinterpreting mildly elevated hCG in pure seminoma as indicating nonseminoma 1, 2
- Not repeating marker tests at appropriate intervals (at least 7 days after orchiectomy) to determine half-life kinetics 1
- Overlooking that approximately 23% of nonseminomatous tumors may have neither AFP nor hCG elevation, requiring histological confirmation 4
By ordering AFP and hCG for patients with testicular masses, clinicians can make more accurate diagnoses, determine appropriate staging, guide treatment decisions, and monitor for recurrence during follow-up.