Etiology of breast cancer, breast cancer is one of common malignant tumors in women, all malignant tumors in our ranks third, the second ranking female malignancy. 40-49 years of age is breast cancer the best hair age.
1. Benign breast disease, benign breast tumor occurrence of breast cancer higher than normal chance. Lobular hyperplasia or breast fibroadenoma in patients with increased risk of breast cancer, some benign diseases can increase susceptibility to cancer or cancer-promoting substances.
Etiology of breast cancer 2. Breast ovarian function by ovarian hormones in the physiological regulation of estrogen to stimulate breast development is the basic condition is one of the prerequisites for cancer. Some studies that menarche less than 12 years of age, the relatively high incidence of breast cancer; underwent bilateral oophorectomy in women with breast cancer rare, indicating the occurrence of ovarian function and breast cancer causation.
3. Childbearing and breastfeeding single women than married women with breast cancer for many, marriage is not fertile, birth or breast-feeding breast-feeding but not too short, a higher incidence of breast cancer. Breast-feeding may delay the reconstruction of post-partum ovulation and menstruation, and to improve the development of breast tissue.
4. Diet and obesity in older women, weight gain increased incidence of breast cancer. Recent studies have pointed out that changes in diet, especially fat diet, can change the endocrine environment, strengthen or extend the estrogen stimulation of mammary epithelial cells and increase the risk of breast cancer. Generally believed that human malignant tumors, 1 / 3 of diet-related weight gain in women after menopause may be important risk factors for breast cancer.
5. Familial aggregation of family members and relatives who have breast cancer, the risk of breast cancer 2-3 times higher than normal.
Etiology of breast cancer 6. Radiotherapy and breast cancer related to ionizing radiation, the risk increases with radiation dose. Atomic bombing of Nagasaki and Hiroshima at the time of the survivors, breast cancer incidence increasing trend.