Cases of “pancreatic ductal adenocarcinoma (PDAC) concomitant with intraductal papillary mucinous neoplasm” (IPMN) have multiple PDAC lesions more frequently than cases of “PDAC without IPMN”. However, the mechanism of carcinogenesis in this former disease category remains unknown. The main objective of this work was thus to investigate the effects of chronic inflammation on carcinogenesis in PDAC cases. We selected 31 “PDAC concomitant with IPMN” patients and 58 “PDAC without IPMN” patients and pathologically evaluated their background pancreatic parenchyma. Fibrosis and inflammation scores of background pancreas were higher in “PDAC concomitant with IPMN” than in “PDAC without IPMN” (P < 0.0001 and P < 0.0001, respectively), whereas the fatty infiltration score of background pancreas was high in “PDAC without IPMN” (P = 0.0024). Immunohistochemically, the expression of 8-hydroxy-2′-deoxyguanosine (8-OHDG), an oxidative stress marker, in the background pancreas was high in “PDAC concomitant with IPMN” compared with that in “PDAC without IPMN” (P < 0.0001). Chronic inflammation activates oxidative stress in tissue throughout the pancreas and probably confers susceptibility to tumorigenesis in “PDAC concomitant with IPMN”.

“胰腺导管腺癌（PDAC）伴有导管内乳头状粘液性肿瘤”（IPMN）的病例比“无 IPMN 的 PDAC”病例更频繁地出现多个 PDAC 病变。然而，这一前一类疾病的致癌机制仍不清楚。因此，这项工作的主要目的是研究慢性炎症对 PDAC 病例致癌的影响。我们选择了 31 名“PDAC 伴有 IPMN”患者和 58 名“PDAC 不伴有 IPMN”患者，并对他们的背景胰腺实质进行了病理学评估。 “PDAC 合并 IPMN”组的背景胰腺纤维化和炎症评分高于“PDAC 无 IPMN”组（分别为P < 0.0001 和P < 0.0001），而背景胰腺的脂肪浸润评分在“PDAC 无 IPMN”组中较高”（ P = 0.0024）。免疫组织化学结果显示，与“无 IPMN 的 PDAC”相比，“伴有 IPMN 的 PDAC”背景胰腺中氧化应激标记物 8-羟基-2'-脱氧鸟苷 (8-OHDG) 的表达较高（ P < 0.0001） ）。慢性炎症会激活整个胰腺组织中的氧化应激，并可能导致“PDAC 与 IPMN 相伴”对肿瘤发生的易感性。