Pretreatment Contrast-Enhanced Harmonic EUS Predicts Pathological Response and Recurrence-Free Survival After Multimodal Treatment in Resectable Pancreatic Cancer.

OBJECTIVES: Recurrence remains common in resectable pancreatic cancer (PC) despite multimodal treatment. We evaluated whether pretreatment contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) predicts pathological response and recurrence-free survival (RFS). METHODS: We retrospectively analyzed 52 patients with resectable PC who underwent CH-EUS before standardized multimodal treatment (neoadjuvant chemotherapy, surgery, and adjuvant chemotherapy). Associations between CH-EUS enhancement patterns (iso- or hypoenhancement) at 20, 40, and 60 s and pathological response were assessed. Associations with RFS were analyzed using Kaplan-Meier and Cox regression analyses. RESULTS: Hypoenhancement was associated with significantly lower pathological response rates at all phases. Median RFS was significantly shorter in the hypoenhancement group at 20 s (560 vs. 1296 days; p = 0.018), 40 s (683 days vs. not reached; p = 0.013), and 60 s (779 days vs. not reached; p = 0.034). In multivariate analysis, hypoenhancement at 20 s independently predicted shorter RFS (HR 2.49, 95% CI 1.01-6.09; p = 0.047). CONCLUSIONS: Pretreatment CH-EUS predicts pathological response and recurrence risk in resectable PC. In particular, 20-s enhancement provides a simple, reproducible imaging biomarker that may support pre-treatment risk stratification and potentially guide individualized management strategies.