How high is carbohydrate antigen 19-9 in cancer?

Carbohydrate antigen 19-9 is a tumor marker. When its level usually exceeds 37 U/ml, it may indicate an increased risk of cancer; however, cancer cannot be diagnosed based on this marker alone. If abnormal, timely medical consultation is recommended. Detailed analysis is as follows:

The normal reference range for carbohydrate antigen 19-9 is generally between 0 and 37 U/ml. When the level of carbohydrate antigen 19-9 is significantly elevated, i.e., greater than 37 U/ml, it may suggest an increased risk of cancers such as pancreatic cancer, gastric cancer, colon cancer, rectal cancer, and non-small cell lung cancer. Particularly for pancreatic cancer, carbohydrate antigen 19-9 demonstrates relatively high sensitivity, ranging from 70% to 87%. However, its specificity is limited, meaning that elevated levels are not necessarily caused by pancreatic cancer.

In addition to cancer, elevated carbohydrate antigen 19-9 levels may also be associated with other non-neoplastic diseases, such as acute pancreatitis, cholestatic cholangitis, cirrhosis, gastrointestinal inflammation, and gallstones. Therefore, when an elevated carbohydrate antigen 19-9 level is detected, cancer cannot be definitively diagnosed based solely on this marker. Further comprehensive evaluation and analysis are required, incorporating the patient's medical history, symptoms, physical signs, and relevant imaging findings.

Furthermore, the normal reference range for carbohydrate antigen 19-9 may vary slightly among different hospitals and different test kits. Therefore, when interpreting the results, the specific reference range provided by the testing facility should be consulted.