Acinar cell carcinoma of the pancreas in the United States: prognostic factors and comparison to ductal adenocarcinoma.

INTRODUCTION

Pancreatic acinar cell carcinoma (ACC) is a rare tumor with poorly defined prognosis.

OBJECTIVE

Our objective was to compare a large population of patients with ACC to pancreatic ductal cell adenocarcinoma (DCC) in order to determine distinguishing characteristics and to assess survival.

METHODS

Patients were identified from the National Cancer Database. Regression methods were used to identify differences between ACC and DCC and to identify predictors of survival for resected ACC. Eight hundred sixty-five patients with ACC were identified.

RESULTS

Median tumor size was 6.9 cm (vs. 4.6 cm DCC); 32.1% had nodal metastases (vs. 48.0% DCC); and 47% had high-grade tumors (vs. 37.3% DCC). Resection margins were R0 77.3%, R1 13.7%, and R2 9.0%. Patients with ACC were more likely to be male, white, and have larger tumor size, no nodal involvement, or pancreatic tail tumors. Stage-specific 5-year survival was significantly better for resected ACC vs. DCC Stage I: 52.4% vs. 28.4%, II: 40.2% vs. 9.8%, III: 22.8% vs. 6.8%, and IV: 17.2% vs. 2.8%. On multivariable analysis, age < 65, well-differentiated tumors, and negative resection margins were independent prognostic factors for ACC.

DISCUSSION

ACC carries a better prognosis than DCC. Aggressive surgical resection with negative margins is associated with long-term survival in these more favorable pancreatic cancers.