Longitudinal analysis of serum alpha-fetoprotein in stable and progressive metastatic pancreatic neuroendocrine tumours

Background Neuroendocrine tumours (NETs) are a heterogeneous group of rare neoplasms arising from neuroendocrine cells, most commonly found in the gastrointestinal tract and pancreas. Despite novel diagnostic techniques, identifying reliable biomarkers for NETs still remains a challenge. Objectives Our study explores the diagnostic, monitoring and prognostic value of alpha-fetoprotein (AFP) in pancreatic NETs. Materials and methods We recruited 41 adult patients diagnosed with liver metastatic non-functioning pancreatic NETs. Serum AFP levels were assessed at three-month intervals over a span of four years. For comparative purposes, we analysed data in relation to sex, age, liver tumour burden (LTB; <10%, 10–25%), tumour grade based on the WHO 2022 classification (G1, G2), and treatment response on baseline as defined by RECIST 1.1 criteria (SD – stable disease, PD – progressive disease). Every patient underwent treatment with somatostatin analogues during the study period. Results Elevated AFP concentrations showed a continuous upward trend across all participants and were significantly associated with indicators of more aggressive disease: greater liver tumour burden (10–25%, p < 0.001), higher tumour grade (G2, p < 0.001), and progression of disease (PD, p < 0.001). No statistically significant differences in AFP levels were observed in relation to age or sex. Conclusion AFP consistently increases in patients with progressive pancreatic NETs compared to patients with stable disease on baseline. Potential utility of AFP measurements requires further follow-up studies, especially as a prognostic biomarker.