This study was performed to evaluate the effectiveness of the serum tumor markers CEA, CA 19-9, and CA 72-4 in monitoring the recurrence of gastric cancer and in its preoperative assessment.

Two hundred fifty-five patients who underwent potentially curative surgery during period from January 1995 to December 2000 at the Department of Surgery were assessed. Serum samples were obtained preoperatively, 2 weeks after the surgery, and at 6-month intervals. The cut-off levels were established as 5 ng/ml for CEA, 36 U/ml for CA 19-9, and 4 U/ml for CA 72-4. The tumor stage was described according to the 5th edition of the Union Internationale Contra la Cancer (UICC) TNM classification in 1997.

The preoperative positivities were 10.5% for CEA, 9.7% for CA 19-9, and 12.4% for CA 72-4. The serum levels of the three tumor markers decreased after curative surgery. The preoperative serum levels of the three tumor markers were significantly related to the depth of invasion, the tumor size, lymph-node metastasis, the pathologic stage, and recurrence, except that CEA was not associated with tumor size. The marker sensitivities in recurrent cases were 43.3% for CEA, 41.8% for CA 19-9, and 50.0% for CA 72-4, and the marker specificities were 85.1% for CEA, 96.8% for CA 19-9, and 87.8% for CA 72-4.

The preoperative serum levels of CEA, CA 19-9, and CA 72-4 are not useful for the initial diagnosis of gastric cancer because of their low positivity. However, we should consider their relationship with depth of invasion, lymph-node metastasis, tumor size, pathologic stage, and recurrence. Also, the follow-up levels of the three markers have a statistical relationship with recurrence of gastric cancer even though their sensitivities are low.