Clinical Utility of the Combined Use of CA19-9 and DUPAN-2 in Pancreatic Adenocarcinoma.

ABSTRACT

PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) patients with normal carbohydrate antigen (CA) 19-9 levels can have early-stage cancer or advanced cancer without elevation of CA19-9 level; estimating their malignant potential is difficult. This study investigated the clinical utility of the combined use of preoperative CA 19-9 and Duke pancreatic monoclonal antigen type 2 (DUPAN-2) levels in patients with PDAC. METHODS: Patients who underwent curative-intent surgery for PDAC between November 2005 and December 2021 were investigated. Eligible patients were classified into four groups based on these two markers. Among patients with normal CA19-9 levels, those with normal and high DUPAN-2 levels were classified into normal/normal (N/N) and normal/high (N/H) groups, respectively. Among patients with high CA19-9 levels, those with normal and high DUPAN-2 levels were classified into high/normal (H/N) and high/high (H/H) groups, respectively. Survival rates were compared between the groups. RESULTS: Among 521 patients, the N/N, N/H, H/N, and H/H groups accounted for 25.0%, 10.6%, 35.1%, and 29.4% of patients, respectively. The proportions of resectable PDAC in the N/N and H/N groups (71.5% and 66.7%) were significantly higher than those in the N/H and H/H groups (49.1% and 54.9%) (P < 0.01). The 5-year survival rates in the N/N, N/H, H/N, and H/H groups were 66.0%, 31.1%, 34.9%, and 29.7%, respectively; the rate in the N/N group was significantly better than those in the other three groups (P < 0.0001, P < 0.0001, and P < 0.0001, respectively). CONCLUSIONS: Only patients with normal CA19-9 and DUPNA-2 values should be diagnosed with early-stage PDAC.