A well-known marker for predicting peritoneal metastasis in gastric cancer: carbohydrate antigen 125

Objectives: Detection of peritoneal metastasis in gastric cancer is still not successful enough despite all the tests performed.In this study, the success of five well-known and commonly used tumor markers in detecting peritoneal metastasis was investigated.Method: A total of 361 patients with 61 peritoneal metastases and 25 distant organ metastasis were included in the study.The relationship between tumor markers and peritoneal metastases was investigated.Results: There was a statistically significant correlation between carbohydrate antigen (CA) 125 and the presence of peritoneal metastasis in gastric cancer (p 22.75 U/mL were significantly associated with peritoneal metastasis (Area under the curve: 0.771, Sensitivity: 73.5%, Specificity: 77.7%, 95% confidence interval: 0.667-0.875).No correlation was found between the presence of peritoneal metastasis and carcinoembryonic antigen, CA 19-9, CA 15-3, and -fetoprotein levels (p = 0.197, p = 0.087, p = 0.497, p = 0.128, respectively).Conclusion: CA 125 is an effective, non-invasive, easily accessible marker for predicting peritoneal metastasis.At levels > 22.75 U/mL, the risk of peritoneal metastasis in gastric cancer can be predicted.