Focal Parenchymal Atrophy of the Pancreas Is Frequently Observed on Pre-Diagnostic Computed Tomography in Patients with Pancreatic Cancer: A Case-Control Study

SIMPLE SUMMARY: Pancreatic ductal adenocarcinoma (PDAC), which accounts for the majority of pancreatic cancers, is highly lethal, and its early diagnosis is difficult. Focal parenchymal atrophy (FPA) observed on computed tomography (CT) has been reported as a characteristic imaging finding of early PDAC without identifiable masses. However, it remains unclear whether FPA is frequently observed on pre-diagnostic CT. In this study, 76 patients with PDAC in whom CT was performed between 6 months and 3 years before PDAC diagnosis, and 76 sex- and age-matched controls without PDAC were reviewed. FPA was observed corresponding to the location of the subsequent tumor detected in 26/76 (34.2%) patients on pre-diagnostic CT, whereas it was observed in 3/76 (3.9%) controls without PDAC (p < 0.001). FPA was less frequently found in tumors in the pancreatic head than in those in the pancreatic body or tail. FPA may predict the subsequent diagnosis of PDAC, thus serving as an important imaging sign for the early diagnosis of PDAC. ABSTRACT: Pancreatic ductal adenocarcinoma (PDAC) accounts for the majority of all pancreatic cancers and is highly lethal. Focal parenchymal atrophy (FPA) of the pancreas has been reported as a characteristic imaging finding of early PDAC. Here, we reviewed 76 patients with PDAC who underwent computed tomography (CT) between 6 months and 3 years before PDAC diagnosis, as well as 76 sex- and age-matched controls without PDAC on CT examinations separated by at least 5 years. FPA was observed corresponding to the location of the subsequent tumor on pre-diagnostic CT in 14/44 (31.8%) patients between 6 months and 1 year, 14/51 (27.5%) patients between 1 and 2 years, and 9/41 (22.0%) patients between 2 and 3 years before PDAC diagnosis. Overall, FPA was more frequently observed in patients with PDAC (26/76; 34.2%) on pre-diagnostic CT than that in controls (3/76; 3.9%) (p < 0.001). FPA was observed before the appearance of cut-off/dilatation of the main pancreatic duct, suggesting that FPA might be the earliest sign of PDAC. FPA was less frequently found in tumors in the pancreatic head (3/27; 11.1%) than in those in the body (14/30; 46.7%) or tail (9/19; 47.4%). FPA may predict the subsequent PDAC diagnosis, serving as an important imaging sign for the early diagnosis of pancreatic cancer.