Raised Carbohydrate Antigen 19-9 as an Early Indicator of Advanced Gastric Adenocarcinoma: A Retrospective Study from a University Hospital

Authors
Saravanan K¹, MN Ong¹, GH Loo¹, M Guhan¹, NR Kosai¹

Affiliations

Upper Gastrointestinal and Metabolic Surgery Unit, Department of General Surgery, National University of Malaysia

Introduction
Gastric adenocarcinoma (GA) is one of the leading causes of cancer worldwide, and the identification of reliable biomarkers for its early detection and prognosis is crucial. Carbohydrate antigen 19-9 (CA19-9) has been proposed as a potential biomarker for GA. Elevated CA 19-9 are frequently observed in advanced stages (III/IV) of GA. Furthermore, the normalization of CA 19-9 levels postoperatively in patients with advanced GA who underwent curative resection is associated with better prognostic outcomes. This study aims to investigate the role of CA19-9 in assessing tumour burden, prognosis and response to treatment.

Methods
A retrospective case series was conducted at Hospital Canselor Tuanku Muhriz UKM involving 24 patients diagnosed with advanced GA or gastroesophageal junction adenocarcinoma (GOJC). CA19-9 levels were measured using standardized laboratory techniques. Clinical data, including demographics, staging, tumour characteristics and treatment modalities were collected from electronic medical records.

Results
24 patients diagnosed with advanced gastric or GOJ adenocarcinoma were analysed. This includes 7 GOJC and 17 GA. Out of 24 patients, 23 patients had raised CA 19-9 (95.8%). The mean CA 19-9 of stage III patients (n=5) is 31U/mL (SD 36 U/mL). Stage IV patients (n=19) exhibit significantly higher levels with a mean of 8,173U/mL (SD 21,919 U/mL).

Conclusion
CA 19-9 is a valuable biomarker for advanced GA, in which elevated levels are indicative of advanced disease and correlates with tumour burden, while postoperative normalization is associated with improved prognostic outcomes. Further studies are required to validate the relation between CA 19-9 and GA, and its significance in the impact of clinical management of GA, from early detection to monitoring treatment response and guiding therapeutic strategies.