The etiology of pancreatic cancer is not well understood. The incidence of pancreatic cancer is related to smoking, alcohol consumption, high-fat and high-protein diet, excessive coffee consumption, environmental pollution and genetic factors; recent survey reports found that the incidence of pancreatic cancer in diabetic population is significantly higher than that in the general population; it has also been noted that there is a relationship between patients with chronic pancreatitis and the development of pancreatic cancer, and it is found that the proportion of pancreatic cancer in patients with chronic pancreatitis is significantly higher; in addition, there are many other factors There are also many factors related to the occurrence of this disease, such as occupation, environment, geography, etc. 1, smoking animal test: it has been proved that feeding animals with tobacco acid water can cause pancreatic cancer, a large sample of survey results show that smokers have a 1.5 times higher chance of pancreatic cancer than nonsmokers, the greater the amount of smoking the higher the chance of pancreatic cancer, such as smoking a pack a day pancreatic cancer occurs in both sexes 4 and 2 times higher than nonsmokers. The above information shows that smoking can induce the occurrence of pancreatic cancer in some people. 2.Inappropriate diet: In recent years, some scholars attribute the increase of pancreatic cancer to improper diet structure. Animal tests have shown that animals fed with high protein and high fat diet can accelerate the renewal of pancreatic duct cells and increase their sensitivity to carcinogenic substances. Domestic scholars such as Shen Kui clearly proposed that the dietary structure is closely related to the occurrence of pancreatic cancer, and those who eat more meat are prone to this disease. Japanese scholars pointed out that the increase in the incidence of pancreatic cancer in Japan in recent years is related to the Europeanization of the Japanese diet. That is, eating too much high protein and high fat. There are also scholars who believe that coffee eaters have a higher chance of pancreatic cancer, but this has not been further confirmed. Diabetes and pancreatic cancer: It has been known for a long time that people with diabetes are prone to pancreatic cancer; however, studies in recent years have pointed out that the incidence of pancreatic cancer in patients with diabetes is one times that of patients without diabetes, and the trend is increasing; some people think that it is two to four times that of the normal population, and some data even report that its incidence can reach 12.4% of malignant tumors of the digestive system, but the real relationship between the two is not clear. 4, chronic pancreatitis and pancreatic cancer: as early as 1950 Mikal et al. noted the relationship between chronic pancreatitis and pancreatic cancer, and in 1960 Panlino-Netto pointed out that only patients with chronic pancreatitis with pancreatic calcification and pancreatic cancer existed at the same time, and in 1977 White further pointed out that there were only 3 cases of chronic pancreatitis with primary calcification combined with pancreatic cancer, accounting for 2.2%. Chronic pancreatitis and diabetes mellitus may have a relationship with the development of pancreatic cancer. Chronic pancreatitis often coexists with pancreatic cancer, and according to Mikal et al. (1950), who reported data from 100 autopsies, 49% showed chronic pancreatitis under the microscope and 84% had interstitial fibrosis of the pancreas. Since pancreatic cancer can cause obstruction of the pancreatic duct, which can lead to the development of pancreatitis, it is difficult to determine which of the two is causal. Panlino-Netto (1960) reported that pancreatitis and pancreatic cancer coexisted only in patients with pancreatic calcification. However, in White’s (1977) case of pancreatitis, only 3% of those with primary calcification were combined with cancer, and in addition, pancreatic cancer can occasionally develop calcification. As for the relationship between pancreatic cancer and diabetes mellitus, it is not very clear. About 5%-20% of patients with pancreatic cancer have diabetes, and 80% of them are found to have diabetes and pancreatic cancer in the same year. Sommers et al. (1954) reported that 28% of diabetic patients had pancreatic ductal hyperplasia, while only 9% of controls had pancreatic ductal hyperplasia, and it is assumed that cancer can occur on the basis of pancreatic ductal hyperplasia. Bell (1957) reported a total of 32,508 autopsies in men over 40 years of age, and the incidence of pancreatic cancer was more than twice as high in diabetic patients compared to non-diabetic patients. However, there is some evidence that there is no significant relationship between the development of pancreatic cancer and diabetes mellitus. According to Lemass (1960), patients with pancreatic cancer combined with diabetes did not have pathological changes in which islet cells were destroyed. Some patients with pancreatic cancer can have some degree of impairment of glucose metabolism, which may be due to some disturbance of insulin release from pancreatic islet cells despite the absence of pathological changes. It is also believed that pancreatic cancer in combination with diabetes is not unique. The incidence of diabetes mellitus also reaches 10% in the general population. 5, abnormal gene expression and pancreatic cancer: Recently, there are more genetic studies on the occurrence of pancreatic cancer, abnormal gene expression is closely related to the occurrence of pancreatic cancer, the relationship between the occurrence of various tumors and cellular genes is currently a hot spot in the study of the causes of cancer, in each gene family, the mutation of the K-ras gene 12 loci and the occurrence of pancreatic cancer is closely related, and the oncogene P53, as well as the recently cloned MTSl The inactivation of oncogenes such as P53 and the recently cloned MTSl also has an effect. Since carcinogenesis is a multifactorial process, there may be activation and inactivation of multiple oncogenes or oncogenes, and it is not unrelated to family inheritance.