1. Early menarche and late menopause
Compared with menarche at the age of 12, the relative risk of breast cancer is 2.2 times higher when the age of menarche is younger than 17 years old. Compared with menopause at the age of 35, the risk of breast cancer is doubled when the age of menopause is older than 45 years old. Early menarche and late menopause are the two main risk factors for breast cancer.
2. Genetic factors
Studies have found that if a woman’s mother has bilateral breast cancer before menopause, her own risk of breast cancer is 9 times that of other women, and the average age of breast cancer in the second generation of breast cancer patients is about 10 years earlier than others.
Women with sisters who have breast cancer are 3 times more likely to have breast cancer than others. However, breast cancer is not directly inherited, and relatives of breast cancer patients do not necessarily have breast cancer, but they are more likely to have breast cancer than the average person.
3. Marriage and childbearing
Epidemiological studies have shown that even if a woman is married but infertile or has her first child after the age of 30, it is also an unfavorable factor, but the risk of breast cancer in unmarried women is twice that of married women.
Experts believe that childbearing has a protective effect on the breast, and breastfeeding has a protective effect on the occurrence of breast cancer.
4. Ionizing radiation
The breast is a tissue that is more sensitive to the carcinogenic activity of ionizing radiation, and the effects of ionizing radiation are cumulative. Multiple low-dose exposures are as dangerous as a single high-dose exposure.
5. Unhealthy eating habits
The incidence and mortality of breast cancer are strongly correlated with the amount of fat digested per capita. High-calorie, high-fat eating habits will greatly increase the incidence of breast cancer.
What are the causes of breast cancer？
The occurrence of breast cancer is closely related to people’s eating habits. Long-term high-calorie, high-fat diet and genetic factors are the main causes of breast cancer. Women should take active preventive measures to avoid factors that cause breast cancer.