Breast cancer is one of common malignant tumors in women, all malignant tumors in China ranks the third place, ranking second in female cancer. 40-49 years of age is the best hair age of breast cancer.
Based on years of clinical observation, breast cancer issued the following main reasons:
Breast cancer etiology (1) 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.
Cause breast cancer (2) familial aggregation of breast cancer in family members and relatives who, the risk of breast cancer 2-3 times higher than normal.
(3) The occurrence of benign breast disease, benign breast tumor higher than normal chance of breast cancer. 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.
(4) single women in childbirth and breastfeeding women with breast cancer more than the married, 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.
(5) radiation and ionizing radiation on breast cancer, the risk increases with radiation dose. Atomic bombing of Nagasaki and Hiroshima at the time of the survivors, breast cancer incidence increasing trend.
Cause breast cancer (6) diet and weight gain in obese middle-aged women 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.