Serological analysis of tumor markers has emerged as a non-invasive method for monitoring cancer patients, including tumor recurrence and response to treatment. Tumor markers have the potential to aid in both the diagnosis and prognosis of cancer, but their most important role currently lies in the monitoring of tumor progression. Tumor markers can also provide valuable information on treatment effectiveness, with changes in plasma values indicating tumor regression or progression. This research aimed to investigate the correlation between the serum detection values of three tumor markers – CEA, CA 19-9, and CA 72-4 – and their utility in the diagnosis and prognosis of patients with gastric cancer. The study seeks to uncover the relationship between these tumor markers and the evolution of gastric cancer, providing insights into their potential use in clinical practice.