The purpose of this study is to clarify the diagnostic significance of AKR1B10 in patients with pancreatic ductal adenocarcinoma, and to combine with CA19-9 to improve the diagnosis rate of pancreatic ductal adenocarcinoma.

General Inclusion Criteria

1. Age ≥ 18 years old;
2. Sign the informed consent form voluntarily;
3. Not a patient in the intensive care unit;

2. Patients with pancreatic ductal adenocarcinoma (PDAC group)

1. Two or more imaging studies (ultrasound, CT, MRI) found pancreatic tumors before operation, after surgical resection, intraoperative frozen pathology and postoperative pathology were clearly diagnosed as PDAC by 2 experienced pathologists, or diagnosed as pancreatic ductal adenocarcinoma by preoperative needle biopsy；
2. No other treatments such as radiotherapy or chemotherapy have been taken before the operation.

3. Benign disease group (Benign group)

1. Diagnosis of pancreatic intraductal papillary mucinous tumor (IPMN), mucinous cystadenoma or pancreas cyst based on clinical manifestations, clinical examinations, medical imagings (ultrasound/CT/MRI/ERCP), biopsy, and pathology
2. No relevant surgical treatment;

4. Healthy donors (Healthy group)

1. Healthy donors undergoing medical examinations at the above research centers;
2. Healthy donors of similar age without any benign or malignant diseases.

Exclusion Criteria:

1. PDAC group:

1. Patients who have undergone radiotherapy, chemotherapy and other tumor-related treatments before surgery;
2. Patients with non-primary pancreatic cancer;
3. Patients undergoing secondary operations;
4. Infected with HIV or AIDS related diseases;
5. Diagnosed as chronic or acute gastroenteritis;
6. Pregnant women;
7. Other situations that are not suitable for this research; 2. Benign group

(1) Patients who have undergone related surgical treatment in other hospitals; (2) Patients with a history of malignant tumors; 3. Healthy group:

1. Patients with a history of tumor;
2. Tumors found in medical examinations;
3. History of hepatitis B or C;
4. A history of acute or chronic gastroenteritis, cholecystitis, and cholangitis.

The population included in the case group was patients with clinically and pathologically clear pancreatic ductal adenocarcinoma; and the population included in the benign group was patients with clinically and pathologically clear IPMN, mucinous cystadenoma, or pancreas cyst; and the population included in the control group was a healthy population without any benign or malignant diseases.