PREDICTIVE VALUE OF PREOPERATIVE SERUM SIALYL TN ANTIGEN LEVELS IN PROGNOSIS OF PATIENTS WITH GASTRIC-CANCER

Background. Expression of sialyl Tn antigen (STN) or serum STN levels were reported to be the independent prognostic factors of colon and ov arian cancers, respectively. The clinical significance of serum STN wa s evaluated as a tumor marker in gastric cancer. Methods. Preoperative STN levels were examined in 350 patients with gastric cancer, surgica lly treated in the Department of Surgery II, Kyushu University Hospita l, and in the National Kyushu Cancer Center, between April, 1981 and A pril, 1986. The patients were divided into two groups: a high STN grou p (n = 304), with over 45 U/ml of STN, and a low STN group (n = 46), w ith less than or equal to 45 U/ml. Results. In the high STN group, the patients were older and the tumors were larger, compared to the low S TN group. Histologically, tumors in the high STN group were deeply pen etrating and the rates of lymphatic involvement, vascular involvement, and lymph node and hepatic metastases were higher. Infiltrative growt h patterns dominated. Thus, the tumors were in an advanced stage. The 5-year survival rate for patients in the high STN group was significan tly less than that of patients in the low STN group (44.8% +/- 7.9% ve rsus 75.1% +/- 2.6%, P < 0.05). Conclusions. Because a high STN level correlates with an advanced tumor stage and a poorer prognosis, close follow-up and aggressive therapy are recommended.