There are many risk factors for breast cancer. Although a lot of studies have been done by domestic and foreign scholars, the main causative factors have not been clearly identified so far, but it is certain that the superposition of several risk factors will inevitably lead to an increase in the risk of breast cancer. At present, the main risk factors for breast cancer development in China are, in order, benign breast disease, mental stimulation, breastfeeding, family history of tumor, menstrual cycle, age at menarche, number of births, age at first birth, age at first marriage and weight. Studying the risk factors of breast cancer can help people to understand the causes of breast cancer and then formulate measures to prevent breast cancer. Li Yanxin, Department of General Surgery, Tongliao Hospital
I. Family history of breast cancer or ovarian cancer
(1) American women with first-degree relatives (parents, siblings, children) who have breast cancer are 2-3 times more likely to develop breast cancer than those without a family history. The relative risk is up to 9 times higher if the first-degree relative had bilateral breast cancer before menopause.
(2) The relative risk of breast cancer in women with a family history of breast cancer is 4.5.
(3) Sometimes breast cancer can also be characterized by family clustering, that is, at least three relatives in the paternal or maternal line have breast cancer, a family history of both breast and ovarian cancer, and a family history of bilateral or early breast cancer.
(2) Early menarche (menstruation before the age of 12) and late menopause (menopause after the age of 55)
(1) Women with a younger age of menarche have a higher probability of breast cancer and are associated with both pre-menopausal and post-menopausal breast cancer.
(2) The risk of breast cancer decreases with each year of delay in age at menarche.
(3) Women of childbearing age who have a young menarche have higher hormone levels and shorter menstrual cycles. Therefore, they are more likely to be exposed to endogenous estrogen, which is the main cause of breast cancer in these women.
(4) The risk of breast cancer is lower in those who undergo artificial menopause before the age of 45 than in those who undergo natural menopause after the age of 55.
(5) The probability of breast cancer increases with each year of delayed menopause.
(3) Women who are infertile or infertile and whose first child is older than 35 years old
(1) Women who have never been pregnant or have never given birth, or have their first child older than 35 years old, have a higher risk of breast cancer than women who have given birth.
(2) The younger a woman’s first normal gestational age (after the age of 18 years), the lower her lifetime probability of developing breast cancer.
(3) These differences in risk are mainly seen in women diagnosed with breast cancer after the age of 40, not in younger breast cancer patients.
IV. Not breastfeeding despite childbirth, or breastfeeding for a short period of time
(1) The prevalence of breastfeeding is lower among people in areas with high incidence of breast cancer than those in areas with low incidence.
(2) Prolonged breastfeeding can reduce the risk of breast cancer.
V. Weight gain after middle age, especially after menopause
(1) Weight gain is associated with breast cancer, especially after menopause.
(2) The relative risk of breast cancer increases in women who gradually gain weight, especially in women around 60 years old, and the risk of breast cancer increases by 80% for every 10 kg increase in body weight.
(3) High-calorie diet during adolescence accelerates growth and menstruation, which leads to weight gain after middle age and eventually increases the risk of breast cancer.
History of atypical hyperplasia of the breast
(1) The risk of breast cancer is not high for purely hyperplastic lesions.
(2) The relative risk of breast cancer is slightly increased with moderate or severe hyperplasia and papillary fibrovascular core.
(3) The presence of lobular or ductal atypical hyperplasia predicts a 1.5 to 4 times higher risk of breast cancer than the general population.
(4) This risk may increase to 11 times if combined with a history of breast cancer in a relative.
VII. High fat diet such as meat, fried egg, butter, cheese, animal fat, etc., and drinking white wine more than 3 times a day (more than 15 grams)
(1) Adipose tissue may contribute to the development of breast cancer.
(2) The mortality rate of breast cancer in each country is positively correlated with the average fat consumption in each country, i.e., the more fat consumption, the higher the mortality rate of breast cancer.
(3) The risk of breast cancer increases by 50%-70% for women who drink alcohol more than 3 times a day.
Mental depression, introversion and work stress
(1) Introversion, long-term depression and unhappy early life are important factors leading to cancer.
(2) Long-term mental depression and long-term tension, superimposed with poor lifestyle, can cause further damage to the breast.
(3) More urban women suffer from breast diseases and have an increased incidence of breast cancer.
In conclusion, women with one or more of the above risk factors are statistically at a higher risk of breast cancer than other women, but it does not mean that these women will definitely develop breast cancer. And women who do not have these risk factors clinically are not less likely to develop breast cancer. Therefore, breast cancer risk factors should be viewed scientifically, i.e. do not be overly nervous and do not let down your guard. Only regular checkups and striving for early detection and diagnosis can win time and opportunities for early treatment of breast cancer.