Extracellular Volume Fraction Combined With Pathological Features of α‐SMA and FAP for Predicting the Prognosis of Patients With Pancreatic Ductal Adenocarcinoma After Surgery and Evaluating the Efficacy of Chemotherapy

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.