Clinical outcomes of patients with resected acinar cell carcinoma of the pancreas: A Korea Tumor Registry System Biliary Pancreas (KOTUS-BP) database analysis

Abstract

Given the rare incidence of the pancreatic acinar cell carcinoma (PACC), the post-resection clinical outcomes remains still unclear, and treatment strategies have relied on that of pancreatic ductal adenocarcinoma (PDAC). The present study retrospectively investigated the clinicopathologic characteristics of resected PACC of 54 patients registered in the Korea Tumor Registry System Biliary Pancreas (KOTUS-BP) database between March 2003 and March 2020. Among 54 patients, with a mean age of 59 years and a male predominance (81.5%), there were 38 pure PACC (70.4%), five ductal differentiations (9.3%), seven mixed neuroendocrine carcinomas (13.0%), and four intraductal and papillary variants (7.4%). A mean tumor size was 4.6 cm consisting of seven at T1, 25 at T2, and 22 at T3 stages. Metastasis to regional lymph node was identified in 13 patients (24.1%). Twenty-eight patients (51.9%) received adjuvant chemotherapy (5-fluorouracil-based [n = 15]; gemcitabine-based [n = 13]). The 5-year survival rate was 54.6% with a median survival of 78.8 months. In survival comparison according to the stages of American Joint Committee on Cancer system, N stage (lymph node metastasis) showed significant differences (p = 0.008), but T stage did not derive any significant difference. The resected PACC appears to have clinical outcomes distinct from the PDAC in this nation-wide study. Therefore, large-scale multinational studies are needed to overcome the rarity of PACC and to establish appropriate treatment strategies and staging system.