Mutant TP53 in duodenal samples of pancreatic juice from patients with pancreatic cancer or high-grade dysplasia

Abstract

Background & aims: Imaging tests can identify patients with pancreatic neoplastic cysts but not microscopic dysplasia. We investigated whether mutant TP53 can be detected in duodenal samples of secretin-stimulated pancreatic juice, and whether this assay can be used to screen for high-grade dysplasia and invasive pancreatic cancer.

Methods: We determined the prevalence of mutant TP53 in microdissected pancreatic intraepithelial neoplasias (PanINs), intraductal papillary mucinous neoplasms (IPMNs), and invasive adenocarcinomas. TP53 mutations were quantified by digital high-resolution melt-curve analysis and sequencing of secretin-stimulated pancreatic juice samples, collected from duodena of 180 subjects enrolled in Cancer of the Pancreas Screening trials; patients were enrolled because of familial and/or inherited predisposition to pancreatic cancer, or as controls.

Results: TP53 mutations were identified in 9.1% of intermediate-grade IPMNs (2 of 22), 17.8% of PanIN-2 (8 of 45), 38.1% of high-grade IPMNs (8 of 21), 47.6% of PanIN-3 (10 of 21), and 75% of invasive pancreatic adenocarcinomas (15 of 20); no TP53 mutations were found in PanIN-1 lesions or low-grade IPMNs. TP53 mutations were detected in duodenal samples of pancreatic juice from 29 of 43 patients with pancreatic ductal adenocarcinoma (67.4% sensitivity; 95% confidence interval, 0.52-0.80) and 4 of 8 patients with high-grade lesions (PanIN-3 and high-grade IPMN). No TP53 mutations were identified in samples from 58 controls or 55 screened individuals without evidence of advanced lesions.

Conclusions: We detected mutant TP53 in secretin-stimulated pancreatic juice samples collected from duodena of patients with high-grade dysplasia or invasive pancreatic cancer. Tests for mutant TP53 might be developed to improve the diagnosis of and screening for pancreatic cancer and high-grade dysplasia. Clinical Trial numbers: NCT00438906 and NCT00714701.

Figure 1

(A) Prevalence of TP53 mutation by diagnostic group. (B, C) Shifted melt curves, difference curves, and Sanger sequencing of digital-HRM-positive PCRs from juice samples from subjects with pancreatic cancer; Arrows indicate mutations. (B) Case 40 (C) Case 29 (Table 2).

Figure 2

(A) Mutant TP53 juice concentrations (mean mutation score) (Y-axis) from subjects with pancreatic cancer and high-grade precursor lesions (x-axis) *P=0.0191. (B) TP53 mutation detected in a pancreatic juice sample from a subject with PanIN-3(Case 4, Table 3). Shifted melt curves, difference curves and sequencing of digital-HRM-PCRs. Arrows indicate mutations.