CT Abnormalities of the Pancreas Associated With the Subsequent Diagnosis of Clinical Stage I Pancreatic Ductal Adenocarcinoma More Than One Year Later: A Case-Control Study
Fumihito Toshima, Ryosuke Watanabe, Dai Inoue, Norihide Yoneda, Tatsuya Yamamoto, Naoki Sasahira, Takashi Sasaki, Masato Matsuyama, Kaori Minehiro, Ukihide Tateishi, Toshifumi Gabata
AJR Am J Roentgenol . 2021 Jun 23. doi: 10.2214/AJR.21.26014. Online ahead of print.
Background: Pancreatic ductal adenocarcinoma (PDAC) is highly lethal, partly due to challenges in early diagnosis. However, the prognosis for earlier stages (carcinoma in situ or stage T1a invasive carcinoma) is relatively favorable.
Objective: To investigate findings of an earlier diagnosis of PDAC on pre-diagnostic CT examinations performed at least one year before the diagnosis of clinical stage I PDAC.
Methods: This retrospective study included 103 patients with clinical stage I PDAC and a pre-diagnostic CT at least one year before the CT that detected PDAC, as well as 103 control patients without PDAC on CT examinations separated by at least 10 years. The frequency and temporal characteristics of focal pancreatic abnormalities (pancreatic mass, main pancreatic duct (MPD) change, parenchymal atrophy, faint parenchymal enhancement, cyst, and parenchymal calcification) on pre-diagnostic CT examinations were determined.
Results: A focal pancreatic abnormality was present on the most recent pre-diagnostic CT in 55/103 (53.4%) patients with PDAC versus 21/103 (20.4%) control patients (p<.001). In patients with PDAC, the most common focal abnormalities on pre-diagnostic CT were atrophy (39/103, 37.9%), faint enhancement (17/65, 26.2%), and MPD change (14/103, 13.6%), which were all more frequent in patients with PDAC than in control patients (p<.05). In 54/55 (98.2%) patients with PDAC, the PDAC corresponded with the site of a focal abnormality (exact location or the abnormality's upstream or downstream edge) on pre-diagnostic CT. Frequency of focal abnormalities decreased with increasing time before the CT that detected PDAC (1-2 years before diagnosis, 64.9%; 2-3 years, 49.2%; 3-5 years, 41.8%; 5-7 years, 29.7%; 7-10 years, 18.5%; over 10 years, 0%). Mean duration from the finding's initial appearance to diagnosis of PDAC was 4.6 years for atrophy, 3.3 years for faint enhancement, and 1.1 years for MPD change.
Conclusion: Most patients with clinical stage I PDAC demonstrated focal pancreatic abnormalities on pre-diagnostic CT obtained at least one year before diagnosis. Focal MPD change exhibited the shortest duration from its development to subsequent diagnosis, where atrophy and faint enhancement exhibited a relatively prolonged course.
Clinical impact: These findings could facilitate earlier PDAC diagnosis and thus improve prognosis.
Read Full Article Here: https://doi.org/10.2214/ajr.21.26014