Pancreatic cancer and tumor markers: role of the newly identified CAR-3 antigen.

BACKGROUND AND AIM

The aim of this study is to assess the clinical usefulness of the serum assay for CAR-3 in the diagnosis and follow-up of pancreatic cancer.

MATERIALS AND METHODS

Serum levels of tumor markers (CAR-3, Ca 19.9, Ca 195 and CEA) were measured in a total of 238 patients with various diseases of the gastrointestinal (GI) tract, including 61 pancreatic cancers. Cut-off levels were calculated on the basis of a non-parametric estimate of 90% specificity. After surgery, patients with pancreatic cancer underwent a combined serological and radiological (CT-scan) follow-up.

RESULTS

At the cut-off level of 6.15 U/L, the sensitivity of CAR-3 was 62.3% (CA 19.9: 77%; Ca 195: 75.4%; CEA: 24.5%). In the differential diagnosis between pancreatic cancer and other GI diseases, significant differences were found. No association was discovered either between serum level of tumor markers and tumor stage or between short- and long-term survivors. In the follow-up, CT-scan was superior to serologic tests (sensitivity: 94.2%). Among tumor markers, CAR-3 achieved a sensitivity of 62.5% (Ca 19.9: 83.3%; Ca 195: 75%).

DISCUSSION

CAR-3 is shed in the circulating stream in a much lower proportion of cases than that observed for antigen expression at immunohistochemistry. During the follow-up CT-scan was the most accurate diagnostic tool. However, the meagre therapeutical options for recurrent pancreatic cancer, do not justify such an aggressive follow-up.

CONCLUSIONS

Ca 19.9 remains the tumor marker of choice for either the pre-operative work-up or the post-surgical follow-up of patients with pancreatic cancer.