Endoscopic ultrasound improves the early diagnosis rate of pancreatic cancer

With the progress of digestive endoscopy technology in recent years, the early diagnosis rate of pancreatic cancer is gradually increasing. Ordinary ultrasound is difficult to diagnose pancreatic cancer due to the interference of gastrointestinal gas. Endoscopic ultrasound (EUS) combines ultrasound with endoscopy, allowing the high-frequency probe to pass through the endoscope channel and close to the gastric and duodenal wall, avoiding echo attenuation and interference from intestinal gas, and improving the diagnosis rate of early pancreatic cancer.

Clinical statistics show that the positive diagnostic rate of EUS for small pancreatic cancers with a diameter of ≤2 cm is 73.7% to 100%. Some scholars have also reported that EUS is more accurate than CT and MRI in examining small pancreatic cancers, and can detect pancreatic masses with a diameter of only 5 mm that cannot be detected by other methods. However, it should be noted that the larger the tumor diameter, the lower the accuracy of EUS in identifying its performance characteristics. For example, the accuracy of EUS in evaluating pancreatic cancers with a diameter of ≤3 cm is 90%, but the accuracy for those with a diameter of >3 cm is only 30%.

EUS can also detect the depth and range of tumor infiltration and lymph node metastasis, which is helpful for determining the stage of pancreatic cancer. The application of small probe intraductal ultrasound (IDUS) has further improved the accuracy of pancreatic cancer diagnosis.

In addition, studies have found that quantitative endoscopic ultrasound elasticity description can be shown by calculating the elasticity quotient value (B/A, where B and A represent the ultrasound elasticity values ​​of the control and pancreatic lesions, respectively). This value is significantly higher in pancreatic cancer than in inflammatory masses. The sensitivity and specificity for the diagnosis of pancreatic cancer are 100% and 92%, respectively, which is helpful for the identification of solid pancreatic masses and the evaluation of hardness.