The duodenum is in the anatomical part that connects the stomach and small intestine. Early stage duodenal cancer usually has no specific symptoms. For cancer of the duodenal mucosa that grows in the general area. Most of the early cancers are found by chance through gastroscopy. There was a case of early duodenal cancer with a diameter of only 0.6 cm discovered by a patient during a general gastroscopy screening, which was successfully removed under gastroscopy. However, such cases are relatively rare. More often, duodenal polyps are found incidentally by gastroscopy and early cancer is found after removal. And most people with duodenal cancer are diagnosed only after advanced stage of duodenal obstruction or bleeding. Early stage duodenal cancer usually has no specific symptoms, but cancer growing in the duodenal pot belly is likely to be detected relatively early. The bile duct and pancreatic duct open to the duodenum, and this area is called the duodenal jugular. The lumen of the opening of the bile duct and pancreatic duct is relatively small, and the tumor may block the lumen when it is relatively small, which may lead to jaundice, yellow eyes and urine, or induce acute pancreatitis, so there is a possibility of early detection. In conclusion, duodenal cancer is relatively rare compared with gastric cancer, and there are no specific early symptoms or rules for early stage duodenal cancer. Most of them are found during gastroscopy.