When is a seminoma not a seminoma? The incidence, risk factors and management of patients with testicular seminoma with discordant elevated serum alpha-fetoprotein.

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

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

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 < 0.01; Stage II: 21.9% vs 0.1%, p <0.01) and less frequently underwent retroperitoneal lymph node dissection (RPLND) (Stage 1: 1.9% vs 11.1% p <0.01; Stage II: 8.8% vs 17.4%, p <0.01).

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.

Urology. 2021 Aug 10 [Epub ahead of print]

Katherine E Fero, Patrick M Lec, Vidit Sharma, Andrew T Lenis, Josiah Low, Mark S Litwin, Michael S Leapman, Karim Chamie

Department of Urology, David Geffen School of Medicine at UCLA. Electronic address: ., Department of Urology, David Geffen School of Medicine at UCLA., Department of Urology, David Geffen School of Medicine at UCLA; Greater Los Angeles Veteran's Affairs, Health Services Research and Development Program., Department of Urology, David Geffen School of Medicine at UCLA; Division of Urology, Memorial Sloan Kettering Cancer Center, New York, New York., Department of Urology, David Geffen School of Medicine at UCLA; Department of Health Policy & Management, UCLA Fielding School of Public Health., Department of Urology, Yale School of Medicine, New Haven, Connecticut.