Diagnostic value of CA 19-9 in patients with pancreatic cancer and nonspecific gastrointestinal symptoms.

Serum expression of the tumor marker CA 19-9 was studied in 2119 patients. The discriminating capacity between benign and malignant disease was high for CA 19-9, especially in patients with pancreatic cancer (n = 347). The sensitivity of CA 19-9 was 85%. In patients who were Lewis blood type positive, the sensitivity increased to 92%. CA 19-9 levels were significantly lower in patients with resectable tumors (n = 126) than in those with unresectable tumors (n = 221, P < 0.0001; sensitivity 74% vs. 90%). CA 19-9 levels dropped sharply after resection but normalized in only 29%, 13%, and 10% of patients with stage I, II, and III tumors, respectively. In unresectable tumors no significant decrease in CA 19-9 levels after laparotomy or bypass surgery was found. Among patients with the same tumor stage, the median survival time in those whose CA 19-9 levels returned to normal after resection was significantly longer than in those who had postoperative CA 19-9 levels that decreased but did not return to normal (stage I, 33 months vs. 11.3 months; stage II, 41 months vs. 8.6 months; and stage III, 28 months vs. 10.8 months). In patients with recurrent disease, 88% had an obvious increase in CA 19-9 levels. CA 19-9 measurement is a simple test that can be used for diagnosis, for evaluation of resectability, and for prediction of survival after surgery and recurrences.