The combination of CA125, CA199, CEA, and AFP is an effective diagnostic biomarker for gastric cancer in elderly individuals.

[BACKGROUND] Serum tumour markers (TMs) such as alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA199) and CA125 have been established as prognostic indicators for gastric cancer (GC); however, the diagnostic value of these markers for GC in older adults has yet to be examined. Therefore, this study aimed to explore the diagnostic and prognostic significance of AFP, CEA, CA199 and CA125 for GC in elderly individuals.

[METHODS] A total of 188 patients who visited The Sixth Affiliated Hospital, School of Medicine, South China University of Technology, from May 2021 to March 2024 were selected for this study. TMs, namely, CA199, CA125, CEA, and AFP, were examined in all patients. Comparisons of these TMs were conducted among the three groups, and TM levels were compared in patients with GC at various TNM stages. The diagnostic value of these TMs for GC was evaluated by calculating the area under the curve (AUC).

[RESULTS] We selected 89 patients diagnosed with GC: 52 patients with benign gastric diseases and 47 healthy individuals for our study. The positivity rates of AFP, CA125, CEA and CA199 were significantly greater in the GC group (31.46%, 31.46%, 43.82% and 23.60%, respectively) than in the benign gastric disease group and healthy control group. The diagnostic sensitivities of CEA, CA125, CA199 and AFP for GC were 31.46%, 29.21%, 44.90% and 24.72%, respectively. The combination of these markers yielded a sensitivity of 65.17%, which was significantly greater than the sensitivity of each marker alone (P < 0.05). Additionally, patients with stage I-II disease had significantly lower serum levels of CEA, CA199, CA125, and AFP than did those with stage III-IV disease.

[CONCLUSIONS] The levels of serum TMs, including CA12-5, CEA, CA199 and AFP, are elevated in elderly individuals with GC, indicating a higher TNM stage. The combination of CEA, CA12-5, CA199 and AFP has enhanced diagnostic value for GC, thereby offering significant clinical guidance. However, this study is limited by its retrospective design and lack of external validation, which should be addressed in future prospective trials.