Early diagnosis of pancreatic cancer

Early diagnosis of pancreatic cancer is often achieved with the help of the following examination methods:

(1) Ultrasound examination: It is the preferred method for diagnosing pancreatic cancer and a screening method in general surveys. It can show irregularities in the shape of the pancreas, detect tumors larger than 2 cm, dilate the pancreatic duct, dilate the bile duct (intrahepatic or/and extrahepatic), enlarge the gallbladder, and metastatic lesions in the liver. The positive rate for pancreatic cancer of about 3 cm can reach 80%.

(2) Ultrasound examination with fiberscope: An ultrasound probe is installed at the top of the gastroscope and placed close to the posterior wall of the stomach to perform a comprehensive examination of the pancreas. This examination is not affected by gas, greatly improves the diagnosis rate of pancreatic cancer, and can clearly show the pancreatic structure and detect early lesions.

(3) CT scan: It can show the correct location and size of pancreatic tumors and their relationship with surrounding blood vessels, and can detect tumors with a diameter of about 1 cm. If the scan is enhanced, some lesions that are difficult to identify with plain scans can be displayed more clearly. Low-density irregular lesions can be seen in the enhanced pancreatic parenchyma for examination. Clinical staging of pancreatic cancer can be performed to help determine surgical methods and prognosis. Currently, CT has become the main method for diagnosing pancreatic cancer. The accuracy rate of CT in diagnosing pancreatic cancer can reach 98%.

(4) Magnetic resonance imaging (MRI): It can show abnormal pancreatic contours. The signal level of T1-weighted images can be used to determine the extent of early local invasion. MRI is superior to CT scanning in determining pancreatic cancer, especially small pancreatic cancer confined to the pancreas, and the presence or absence of peripancreatic metastasis and vascular invasion. Magnetic resonance imaging is a good method for predicting pancreatic cancer before surgery.

(5) Endoscopic retrograde cholangiopancreatography (ERCP): It has a high specificity for the diagnosis of pancreatic cancer. In addition to showing the filling defect and occlusion of the main pancreatic duct, it can also clearly observe the morphological changes of pancreatic duct stenosis and detect pancreatic duct lesions with a tumor size of less than 2 cm. Therefore, ERCP is an effective method for diagnosing small pancreatic cancers.

(6) Selective angiography (SAG): It is a lesion examination, but it can make a diagnosis when the tumor is 1 cm. It can show the morphology of the arteries around the pancreas, which is important for determining whether the tumor has vascular invasion. If the artery is irregularly narrowed or occluded, the size of the tumor can be estimated based on the abnormal vascular area. The possibility of tumor surgery and the choice of surgical method can also be determined based on SAG findings, and whether the tumor can be removed by surgery. It is very important that when there is blocked artery infiltration, the usual imaging results cannot make a clear diagnosis, and the accuracy of selective angiography is higher than 90%.

(7) Mother-and-daughter pancreaticoduodenoscope examination: This is a new method that has been recently developed and implemented. The diameter of the daughter scope (pancreaticoduodenoscope) is only 1 mm. This operation does not require a duodenal papillary incision. The mother scope is inserted into the pancreatic duct to directly observe the situation inside the duct. It can observe mucosal bulges, redness, stenosis, occlusion, etc. in pancreatic cancer. However, this scope currently has some shortcomings, such as the tube diameter is too thin, it is easy to break, the front end cannot change direction, and it cannot take biopsies. However, after several years, it may become the main means of diagnosing pancreatic cancer.