If there is only a slight increase in CA199 and there is no discomfort in the body, and no abnormalities in the body are found in other tests, it is possible that there is no malignant tumor in the body, or there is only some chronic inflammation. However, if a malignant tumor has been diagnosed in the body and CA199 is slightly high, it needs to be reviewed regularly. If CA199 continues to increase during the review process, it means that the tumor in the body has not been effectively controlled but has recurred and progressed. If CA199 remains the same or gradually decreases to normal during the review process, it may indicate that the malignant tumor in the body is under control, but it needs to be combined with CT, ultrasound and other imaging tests to make a comprehensive judgment.