CA19-9 as a predictor of recurrence in patients with colorectal cancer.

Abstract

CA19-9 is a cancer-associated carbohydrate antigen that plays a role in the process of tumor progression as an adhesion molecule. We evaluated the prognostic value of CA19-9 tumor expression and CA19-9 preoperative and postoperative serum levels in colorectal cancer patients treated by complete resection. The most powerful discrimination was achieved using the three CA19-9 markers in combination. CA19-9 tumor expression was identified by immunostaining in 71.0% (86/121) of primary carcinomas. Positive CA19-9 serum levels (> or = 37 U/ml) were restricted to cases with positive tumor expression, and CA19-9 was detected more frequently in preoperative serum (20.6%, 25/121) than in 1-month postoperative serum (6.6%, 8/121). Positive tumor expression, positive preoperative serum level, and positive postoperative serum level were all predictive of increased cancer mortality. Patients with three negative parameters had no recurrences and 97.1% 5-year survival, whereas patients with three positive parameters had 62.5% recurrence and 42.8% 5-year survival. CA19-9 detection in tumor tissue and serum identified patients at high risk of cancer recurrence and death and may be useful in selecting patients for adjuvant therapy.