Abstract
AIM: This study aimed to clarify the usefulness of tumor markers from peritoneal lavage in selecting patients with a high risk of recurrence and predicting site-specific recurrence in patients with pancreatic cancer. METHODS: The levels of serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 (sCEA/sCA 19-9) and paired peritoneal lavage CEA and CA 19-9 (pCEA/pCA 19-9) were measured in 90 patients with pancreatic cancer who underwent surgery. Using the cutoff values determined by maximally selected rank statistics for disease-free survival (DFS), the risk of recurrence and its patterns were evaluated in combination with different markers and different test specimens. RESULTS: In univariate and multivariate analysis, an elevated pCA 19-9 level (>1.3 U/mL) was an independent prognostic marker for both DFS (hazard ratio [HR], 2.391; P = .018) and overall survival (HR, 3.194; P = .033). Combination analyses contributed to further stratification of a very high risk of recurrence. Of the 58 patients with resectable pancreatic cancer who underwent curative resection, elevated pCA19-9 was also associated with inferior DFS and overall survival (OS). Patients with elevated pCA 19-9 levels were more likely to have an earlier onset of peritoneal recurrence than those with normal pCA 19-9 levels (P = .048, Gehan-Breslow-Wilcoxon test). CONCLUSION: pCA 19-9 is a reliable marker for predicting postoperative recurrence in patients with pancreatic cancer after surgery. Further risk stratification can be achieved by using combination assays. The combination of pCA 19-9 and sCA19-9 also serves as a predictor of recurrence site-specific recurrence.