Abstract
OBJECTIVES: This study aimed to evaluate the extracellular matrix of pancreatic ductal adenocarcinoma (PDAC) using the extracellular volume fraction (fECV) derived from enhanced CT images, integrating fECV with α-SMA-positive cancer-associated fibroblasts (CAFs) and FAP-positive CAFs to investigate their relationship with clinicopathological characteristics and prognosis of patients with PDAC. METHODS: A retrospective analysis of 124 patients who underwent surgical resection for PDAC was conducted. Immunohistochemistry was applied to determine the expression of α-SMA and FAP. fECV was calculated by attenuation values of PDAC and aorta. The Kaplan-Meier method was used to plot the postoperative overall survival (OS) and disease-free survival (DFS) curves. A Cox proportional hazards regression model was used to develop a predictive model. RESULTS: High α-SMA (OS: p < 0.001; DFS: p = 0.065) and FAP (OS: p < 0.001; DFS: p < 0.001) expressions and low fECV (OS: p < 0.001; DFS: p < 0.001) predict poor prognosis. Patients with co-high expression of α-SMA and FAP had worse OS and DFS. Multivariable analysis identified α-SMA (OS: hazard ratio [HR], 2.34 [95% CI, 1.30-4.21], p = 0.005), FAP (OS: HR, 4.43 [95% CI, 2.72-7.19], p < 0.001), and fECV (OS: HR, 0.58 [95% CI, 0.37-0.90], p = 0.015) as independent predictors of prognosis. The predictive model established by combining fECV with α-SMA and FAP in this study cohort demonstrated the best predictive value. CONCLUSIONS: The integration of fECV with α-SMA and FAP expressions offers a robust method for predicting clinical outcomes in PDAC patients, potentially guiding treatment strategies.