Association of serum alpha-fetoprotein (AFP) with indirect prognosis in gastric cancer

Aims: Alpha-fetoprotein (AFP) is a glycoprotein secreted from the yolk sac and hepatocytes during fetal life. Elevated levels in adults are considered markers for yolk sac tumors, hepatocellular carcinoma and gastric cancer. There is still no consensus on the definition of AFP-secreting gastric cancers, but AFP-secreting gastric cancers have been reported to have a worse prognosis. In this study, AFP levels in gastric cancers with high AFP were compared with pathology results and evaluated in terms of indirect prognosis. Methods: Patients with gastric cancer operated in the General Surgery Clinic of Ankara Bilkent City Hospital between 2019 and 2023 were retrospectively screened. Among the screened patients, those whose information could not be reached and those with incomplete information were excluded and 126 patients were included in the study. Serum AFP levels of these patients were compared with pathology results, stages and tumor sizes. Results: The mean age of the patients in our study was 66±11 years, 42 (33.6%) were female and 84 (66.7%) were male. Of the 126 patients analyzed in the study, 107 (84.9%) were AFP-negative and 19 (15.1%) were AFP-positive. There was no significant difference in AFP levels between all patients in terms of liver metastasis, peritoneal metastasis, disease stage, perineural invasion and tumor location. However, serum AFP levels were significantly higher in patients with lymphovascular invasion and lung metastases (p=0.042; p=0.024). In the analysis for serum AFP level in the presence of lymphovascular invasion, ROC value was 2.35 ng/ml, sensitivity 58.2%, specificity 55.9%, area under the curve (AUC) 0.618, 95% confidence interval (95% CI) 0.512-0.723 and p=0.028. Conclusion: Lymphovascular invasion is a poor prognostic factor in gastric cancer. In this study, a significant correlation was found between serum AFP value and lymphovascular invasion. In gastric cancers without AFP secretion, a serum AFP value above 2.35 ng/ml may be indirectly associated with poor prognosis because it predicts lymphovascular invasion.