Enhancing the Diagnostic Performance of Repeated Endoscopic Ultrasound-Guided Tissue Acquisition Combined with Surrogate Repeated Endoscopic Retrograde Pancreatography for Small Pancreatic Cancer.

[PURPOSE] Diagnosing pancreatic tumors ≤ 10 mm is challenging due to limited visualization and low sampling sensitivity. This study aimed to evaluate the cumulative diagnostic performance of repeated endoscopic ultrasound-guided tissue acquisition (EUS-TA) and surrogate repeated endoscopic retrograde pancreatography (ERP).

[METHODS] This study analyzed 40 patients with suspected pancreatic tumors ≤ 10 mm who underwent EUS-TA and/or ERP retrospectively. When a diagnosis could not be determined based on the initial EUS-TA or ERP procedure, EUS-TA or ERP was repeated as necessary. The cumulative diagnostic performance of EUS-TA and ERP for pancreatic tumors was evaluated.

[RESULTS] EUS-TA was performed once for 35 cases, twice for seven cases, and three times for one case. ERP was performed for 15 cases, and the median number of ERP attempts was two (range, 1-8). The cumulative sensitivity of EUS-TA increased from 56.7% to 70.0% after three attempts, while ERP sensitivity increased from 54.5% to 72.7% after two attempts. The cumulative diagnostic performance of repeated EUS-TA and ERP combined by case included sensitivity and accuracy rates of 87.9% and 90.0%. When limited to pancreatic cancer, the sensitivity and accuracy rates were 95.8% and 96.8%, respectively. No severe adverse events occurred.

[CONCLUSION] Repeated EUS-TA and ERP showed good diagnostic sensitivity for small pancreatic cancers ≤ 10 mm. When malignancy is suspected but not confirmed by a single procedure, repeating both may be an option in selected cases. Performing EUS-TA and ERP at least twice may be reasonable when small pancreatic cancer is suspected.