With the improvement of life, diabetes is a “disease of affluence” that is eating away at our health. The worst thing about diabetes is its complications, but did you know? Diabetes and cancer are also inextricably linked. According to the World Health Organization in 2012, there were 14.1 million new cases and 8.2 million deaths from cancer worldwide, which is a staggering statistic. Research data shows that the incidence of tumors among diabetic patients can be as high as 28.35%, which is much higher than the highest incidence rate of 1.16% for all age groups in the general population. Why is the incidence of malignant tumors so high in diabetic patients, is it a coincidence or is there an inevitable connection? At present, the exact pathogenesis of the increased incidence of malignant tumors due to diabetes is still unclear, and there are different opinions, but the more agreed view is that it is related to high glucose itself and insulin resistance. 1. Hyperglycemia Glucose is the only source of energy for tumor cells, and long-term hyperglycemia can be used as a nutritional base to promote the growth of tumor cells. Diabetes first and malignant tumor later may be related to the chronic stimulation of normal organs by long-term hyperglycemia. In addition, long-term hyperglycemia may lead to impaired cellular respiration and increased anaerobic enzymes, which can fully compensate for the damage of respiratory enzyme system through the enhancement of glycolysis, thus turning normal cells into tumor cells. 2.Insulin resistance It has been confirmed that insulin resistance plays a pivotal role in the occurrence and development of type 2 diabetes. Insulin resistance refers to a decrease in the effectiveness of insulin in promoting glucose uptake and utilization, resulting in compensatory hyperinsulinemia. Insulin is a major anabolic hormone in humans and animals and is extremely closely associated with malignancy. Insulin affects cellular metabolism and growth and regulates the metabolism of carbohydrates, amino acids and fats. Excessive insulin can promote the proliferation of intestinal cells through many ways, which eventually induces tumors. 3, genetic factors Malignant tumors and diabetes have a certain genetic basis, related to gene deletion or gene mutation, the onset of which is more in middle-aged and elderly people. 4.Immune function disorder Malignant tumor and diabetes have common points in cellular and humoral immune changes. The occurrence and prognosis of malignant tumors are directly related to cellular and humoral immune disorders. Long-term hyperglycemia can lead to cellular immune regulation disorder and T-lymphocyte ratio disorder. Selenium has insulin-like effects, which can promote glucose transport, activate cAMP phosphodiesterase and stimulate the phosphorylation of ribosomal proteins, and can play a direct role in scavenging free radicals through glutathione peroxidase to ensure the structural integrity and function of insulin molecules. and function of the insulin molecule. The decrease of selenium reduces the activity of selenium-containing glutathione peroxidase, strengthens the damage of free radicals to mitochondrial DNA, reduces insulin activity, leads to disorder of glucose metabolism and hyperglycemia, so proper supplementation of malt selenium and other high conversion and high retention of bio-organic selenium is beneficial to patients to stabilize blood sugar and reduce the risk of cancer. 6.Related to vascular endothelial growth factor Diabetic retinopathy research shows that vascular endothelial growth factor is significantly higher in diabetic patients than in non-diabetic patients. Another study shows that the level of vascular endothelial growth factor in breast cancer, gastrointestinal tumors and other tumor tissues have different levels of elevation. 7.The role of endothelin Diabetic vascular complications are related to endothelin. In the mechanism of tumorigenesis, endothelin is involved in the induction of cell proliferation and has a role in the formation of tumors due to abnormal tissue proliferation. 8.Obesity Obesity is a good factor for endometrial cancer and diabetes respectively. In addition, long-term hyperglycemia can cause autonomic neuropathy, slow down gastrointestinal motility and increase the incidence of gastrointestinal tumors. Insulin deficiency makes liver cells suffer from the toxic effect of free fatty acid for a long time, leading to liver cell necrosis and fibrosis, which may be one of the mechanisms of liver cancer in diabetic patients.