When is a Seminoma not a Seminoma? The Incidence, Risk Factors and Management of Patients With Testicular Seminoma With Discordant Elevated Serum Alpha-fetoprotein.

OBJECTIVE

To describe the incidence, clinical and demographic factors, and treatment patterns associated with discordant elevated alpha-fetoprotein (AFP) findings in patients with pure seminomatous histology.

METHODS

We queried the National Cancer Database to identify patients with testicular germ cell tumors (GCT) diagnosed in 2011-2015. Patients were grouped based on histologic diagnosis and pre-operative serum AFP level.

RESULTS

Of 18,616 patients diagnosed with testicular GCT, 53% (N = 9,849) had pure seminomatous histology, of whom 8.3% (N = 821) had an elevated serum AFP pre-operatively. Non-white patients with seminoma were more likely to have a pre-op elevated AFP (OR 1.42; 95% CI: 1.10-1.83); patients treated at higher volume centers were less likely to have a pre-op elevated AFP (0.66, 95% CI: 0.53-0.83). Patients with seminoma with elevated AFP received adjuvant radiation more frequently than those with NSGCT (Stage I: 15% vs 0.2%, P <.01; Stage II: 21.9% vs 0.1%, P <.01) and less frequently underwent retroperitoneal lymph node dissection (RPLND) (Stage 1: 1.9% vs 11.1% P <.01; Stage II: 8.8% vs 17.4%, P <.01).

CONCLUSION

The detection of elevated serum alpha-fetoprotein (AFP) in patients with pure seminomatous testicular germ cell tumors (GCT) is a discordant finding that implies the presence of occult non-seminomatous GCT (NSGCT) elements. 8% of patients with pure seminomatous GCTs had diagnostically discordant elevated pre-operative AFP levels. Despite recommendations to manage these patients as NSGCT, patients with seminoma and elevated AFP were managed in a fashion comparable to those with seminoma and normal AFP levels.