Elevated serum CA 19-9 at screening tests: underlying conditions and role of abdominopelvic CT

To investigate underlying conditions of patients with elevated CA 19-9 at screening tests and to evaluate diagnostic performance of abdominopelvic CT.

One hundred and thirteen patients with elevated CA 19-9 (>37 U/ml) who underwent abdominopelvic CT in a screening program were selected. Underlying conditions were determined by reviewing all available data and follow-up records. Patients were categorized into malignancy, benign, and normal/non-related disease groups. Their mean CA 19-9 and percent of patients with CA 19-9 ≥ 100 U/ml were compared. Diagnostic sensitivity of CT for detecting underlying conditions of elevated CA 19-9 was analysed.

Seventeen patients (17/113, 15 %) had 17 elevated CA 19-9-related malignancies, and 55 patients (55/113, 48.7 %) had 70 benign diseases. Mean CA 19-9 and percent of patients with CA 19-9 ≥ 100 U/ml in the malignancy group were significantly higher than in the two other groups. CT detected all except one malignant lesion with a detection sensitivity of 94.1 % (16/17). Of 70 CA 19-9-related benign diseases, CT detected 34 benign diseases (48.6 %) providing an alternative diagnosis for elevated CA 19-9.

Abdominopelvic CT is not only useful in detecting malignancies, but can also diagnose alternative benign causes of elevated CA 19-9 in asymptomatic screening tests.

• Fifteen percent of asymptomatic patients with elevated CA19-9 may have intra-abdominal malignancies. • Mean value of CA19-9 is different among malignant, benign, and non-related groups. • CT shows excellent sensitivity for intra-abdominal malignancies as causatives of elevated CA19-9. • CT provides alternative benign diagnoses as causatives of elevated CA19-9. • Detection of causatives of elevated CA19-9 using CT alleviates concerns and uncertainty.