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.