Benign persistent elevation of alphafoetoprotein (AFP) after curative treatment for germ-cell tumors.

598 Background: Follow-up of patients with germ-cell tumours (GCT) relies on monitoring serum markers (SM) including alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), and lactate dehydrogenase (LDH). Instances of benign, non-GCT related elevation of AFP have been reported as case reports. Identifying such occurrences is crucial to prevent misdiagnosis of residual disease and subsequent overtreatment, which may lead to increased morbidity. Methods: We conducted a national retrospective study in nine GETUG institutions. Patients with isolated persistent elevation of AFP levels above the normal range after receiving curative treatment for GCT without detectable disease on CT scan imaging were identified. Data on patient characteristics, treatment response, changes in SM values over time, and serum AFP levels from first- and second-degree relatives were collected. Familial AFP elevation was defined as AFP levels above the normal range in at least one first- or second-degree relative. Results: From June 1990 to April 2024, 31 patients were identified. Median age was 35 years (range, 19 to 49 years). 15 patients (48%) had pure seminoma, and 16 (52%) had non-seminomatous GCT. Overall, 19 patients (61%) had a clinical stage I disease, 17 (23%) had stage II, and 5 (16%) had stage III. No patient had a history of chronic alcoholism or consumption of medications with hepatic toxicity. Median AFP level after curative treatment was 12 ng/mL (range, 8.8 to 36 ng/mL). No evidence of disease was found on CT scan. An ultrasound examination of the contralateral testis and an FDG-PET/CT were performed in 15 (48%) and 7 patients (23%), respectively, also showing no evidence of disease. Serum AFP levels from family relatives were obtained for 14 patients (45%), with a family elevation identified for 10/14 patients (71%). After a median follow-up of 35 months (range: 7-253 months), AFP levels remained elevated in all 31 patients without documented disease relapse. Conclusions: Benign and often familial elevations of serum AFP levels are rare occurrences, which can be a chance finding following curative treatment for GCT. Ultrasound examination of the contralateral testis and AFP measurement in family members are recommended. Surveillance alone is appropriate.