DPC4 gene expression in primary pancreatic ductal adenocarcinoma: relationship with CT characteristics

Abstract

Objective:

To investigate the relationship between CT imaging findings and DPC4 gene expression and to determine the prognostic value of DPC4 gene expression to predict overall survival in patients with pancreatic ductal adenocarcinoma.

Methods:

Between January and December 2011, we retrospectively analyzed 163 pancreatic ductal adenocarcinomas in 163 patients who had undergone surgical resection (mean age = 61.8 years; range = 35–81 years). We divided the study patients into two groups according to DPC4 gene expression: DPC4-expression or DPC4-non-expression group. The CT findings were analyzed by two reviewers. The associations between the CT imaging findings and DPC4 gene expression were evaluated using univariate analysis and multivariate logistic regression analysis. Overall survival was compared according to the DPC4 gene expression ( DPC4-expression vs DPC4-non-expression) using Kaplan–Meier analysis and log-rank testing. To avoid bias, subgroup analyses of CT findings in T3 tumour and overall survival in patients with T3 tumour and R0 resection were performed.

Results:

Between DPC4-expression group ( n = 75) and DPC4-non-expression group ( n = 88), three CT findings ( i.e., tumour margin, peripancreatic infiltration, and the presence of background intraductal pancreatic mucinous neoplasm) were significantly different in univariate analysis. Of these, a well-defined tumour margin was significantly associated with DPC4-expression tumour (adjusted odds ratio = 2.06; p = 0.032) in multivariate analysis. Of the total 163 patients, the mean overall survival of the DPC4-expression group was significantly longer than that of the DPC4-non-expression group (30.0 vs 22.0 months; p = 0.049). Of the 150 T3 tumours, the presence of well-defined tumour margins was also a significant CT finding (adjusted odd ratio = 2.00; p = 0.044) in multivariate analysis. However, of 131 patients with T3 tumour and R0 resection, the overall survival period of the DPC4-expression group was not significantly different from that of the DPC4-non-expression group (24.0 vs 22.0 months; p = 0.240).

Conclusion:

The presence of well-defined tumour margins on CT was significantly linked with DPC4-expression tumour.

Advances in knowledge:

A well-defined tumour margin is an independent CT finding associated with DPC4-expression pancreatic ductal adenocarcinoma.