China is one of the countries with the fastest growing incidence of breast cancer, which is increasing by 3% per year in recent years, and breast cancer has become the number one killer of women’s health. Breast cancer in China is characterized by a younger age of onset and the majority of mid- to late-stage cases.
What are the factors related to the occurrence of breast cancer?
1.Breast cancer and menstruation
It is generally believed that early menarche, late menopause and late age of the first child are the three main risk factors for breast cancer.
(1) Age of menarche: The earlier the age of menarche, the higher the chance of breast cancer in the future. The relative risk of breast cancer increases by 2.2 times when the age of menarche is less than 12 years old compared to more than 17 years old.
Age at menarche is associated with the development of premenopausal breast cancer, but not with postmenopausal breast cancer.
(2) Age at menopause: Those who are menopausal at age 55 or older are 1 times more likely to get breast cancer than those who are menopausal at age 45 or younger. The risk of breast cancer for those who are less than 35 years old at the time of natural menopause is 1/3 of that for women over 50 years old at the time of menopause.
(3) Age at menarche and menopause: It indicates the duration of menstruation. Women who have been menstruating effectively for more than 40 years have a 1-fold increased risk of breast cancer compared to women who have been menstruating for 30 years, and those who have been menstruating for more than 35 years have a 2-fold increased risk compared to those who have been menstruating for less than 25 years. In addition, the incidence of breast cancer is also higher in women who have early menarche and short intermenstrual interval.
2. Breast cancer and marriage and childbirth
In 1713, it was found that the incidence of breast cancer among French nuns who lived alone all their lives was high.
Epidemiological studies have shown that the risk of breast cancer in unmarried people is twice as high as that in married people; the risk of being married without having children or having the first child after the age of 30 is also a negative factor.
The first full-term pregnancy at an appropriate age has a protective effect, but abortion can undermine this effect, especially because it increases the risk of breast cancer.
Studies have concluded that spontaneous abortion does not increase the risk of breast cancer, while induced abortion increases the risk of breast cancer. This is because when a pregnant woman has an abortion, the pregnancy is abruptly interrupted and the body’s hormone levels suddenly drop, the newly developing breast follicles suddenly stop growing and the follicles become smaller, allowing the breast to recover, but this recovery is often incomplete and can induce breast disease.
It is generally believed that women who have had one child have less chance of breast cancer than women who have not had children, and those who have their first child before the age of 18 have four times less chance of breast cancer than those who have their first child at the age of almost 30; those who have their first child above the age of 30 have an increased risk of breast cancer.
The results of a survey on risk factors for breast cancer in women in Tianjin showed that the risk factor for breast cancer increased for late first births and unexplained births. The risk factor for unexplained mothers was lower than that of the age group of 35 years or older at first birth and higher than that of the age group of 34 years or younger.
Using the age group of first births greater than or equal to 19 years, the relative risk factor for nulliparous women was 29 and for the age group of first births over 35 years was 3.5.
Breastfeeding is protective against the development of breast cancer, mainly in premenopausal women.
In 1977, it was reported that Hong Kong boat people used to breastfeed their babies with the right breast in their left hand because they had to operate with their right hand, and it was found that 80% of their breast cancer occurred on the left side.
Eskimos in Canada usually breastfeed for more than 3 years, their breast cancer incidence is very low, breastfeeding can reduce the risk of breast cancer.
3.Breast cancer and heredity
It has been found that women who have a family history of breast cancer and whose mothers had bilateral breast cancer before menopause have 9 times the risk of breast cancer, i.e. half of them are likely to have breast cancer.
The average age of breast cancer in the second generation of breast cancer patients is about 10 years earlier than the general population, mostly before menopause. This predisposition is not only matrilineal but also patrilineal.
If a mother does not have breast cancer, but two of her sisters have breast cancer, the risk of her own disease is three times higher than that of the general population.
4.Breast cancer and living habits
Breast cancer is not an inevitable hereditary disease, but also related to other factors such as fertility, diet, endocrine, etc. Only the combination of multiple factors will lead to breast cancer.
(1) Smoking: The risk of breast cancer is significantly higher in pre-menopausal women who smoke than in non-smokers, while there is no difference after menopause.
(2) Alcohol consumption: The incidence of breast cancer in women who drink alcohol is 40% to 90% higher than that in non-drinkers, and there is also a relationship between the type and amount of alcohol consumed and the incidence. Some reports suggest that alcohol consumption can increase the risk of breast cancer by 145% to 200%. However, alcohol consumption is also related to socioeconomic status, which may only have a mixed effect.
5.Breast cancer and birth control pills
Previous studies have concluded that the use of oral contraceptives by women in the middle of their reproductive years does not increase the risk of breast cancer. Recent studies have demonstrated a mild increase in breast cancer risk among current and recent users of the pill compared to those who have never used the pill.
Breast cancer favors the “six high” groups
According to some data, the incidence of breast cancer is higher in large cities than in medium and small cities, and in medium and small cities than in rural areas. The incidence of breast cancer is higher in large cities than in small cities, and in small cities than in rural areas.
Among white-collar women, there are single women who are called the “Northern Desert” group. They have a high income and are overly pursuing life achievements, and they are under great psychological pressure, resulting in frequent anxiety.
Staying up late disrupts the biological clock of the human body and disrupts the level of hormone secretion controlled by the brain, increasing the risk of breast cancer.
They do not have good eating habits, high fat and high protein intake; they pay too much attention to the perfection of self-image, enjoy life to the fullest, most of them marry late and have children late, even if they have children, they do not breastfeed their children, etc. All these are against the natural reproduction and reproduction law of human beings.
These are the causes that have been proven to cause breast cancer in western developed countries.
Nowadays, there are many fat children in big cities, most of them are only children, they eat KFC and McDonald’s, and their diet is basically high in calories and fat, and they consume too much nutrition.
According to the law in Europe and the United States, they can be seen in more than 20 years, when they are 40-50 years old, and this period will be the high incidence of breast cancer in China.
Therefore, we believe that breast cancer favors people with “six highs”, namely: high education, high income, high living standard, high nutrition, high calorie and high fat diet.
How much cancer can be prevented by lifestyle interventions?
The core of the U.S. Cancer Prevention Guidelines is that poor behavior can lead to cancer. We may reduce cancer rates by more than 20% by correcting poor lifestyle habits, such as poor dietary choices, lack of physical activity, excessive alcohol consumption and obesity.
When tobacco exposure is considered, these correctable problems account for 2/3 of cancer deaths in the United States.
So how much of an association does this lifestyle intervention have with each type of cancer?
On June 23, 2016, the journal Cancer Epidemiology, Biomarkers & Prevention, sponsored by the American Association for Cancer Research (AACR), published online a University of Arizona research paper, Cancer Prevention Guidelines for Adherence to Diet and Physical Activity and the Occurrence of Cancer.
The article analyzed guidelines on diet and physical activity published by the World Cancer Research Fund (WCRF), the American Cancer Society (ACS), the American Institute for Cancer Research (AICR), and other cancer research organization agencies over the past 10 years, and evaluated their role in cancer prevention efforts and the association with overall cancer incidence and mortality.
Twelve prospective cohort studies that met the criteria were ultimately selected for the study, and the results found that
Following cancer prevention guidelines reduced cancer by 10 to 45%.
This included 19% to 60% for female breast cancer, 23% to 60% for endometrial cancer, and 27% to 52% for colorectal cancer. It can also reduce the death of cancer patients by 14% to 61%.
How to prevent breast cancer?
1.Change the bad lifestyle.
From the above information, poor lifestyle is undoubtedly an important cause of breast cancer. Therefore, relieving mental tension, not staying up late, not smoking, avoiding abortion, establishing good dietary habits, and conforming to the natural reproduction and reproduction rules of human beings are all things we can do by ourselves. Changing the bad habits will reduce the harm of breast cancer to our health.
2.Make a good job of breast disease screening.
A girl’s chance of getting breast cancer is 10% since she was born, so screening is the best way to prevent it. Ultrasound and surgical examination should be performed in every screening, and mammography should be considered for women over 35 years old.
3. Preventive treatment.
Short-term prophylactic application of triamcinolone acetonide can be used for benign breast disease.
4, avoid the use of hormone replacement therapy.
The use of hormone replacement therapy leads to an increased risk of breast cancer, and the risk of developing breast cancer increases to 35% after 5 years of use. The risk of developing breast cancer increases to 35% after 5 years of use. After 5 years of discontinuing hormone replacement therapy, the risk of developing breast cancer returns to normal.
Hormone replacement therapy that uses both estrogen and progestin may have a higher incidence of breast cancer than estrogen-only hormone replacement therapy.
5. Prophylactic mastectomy.
It is estimated that prophylactic bilateral mastectomy can reduce the risk of breast cancer in BRCA gene mutation carriers by 85% to 90%.
BPM may be a radical but effective treatment for patients with BRCA1/2 mutation carriers in whom all breast epithelium is likely to be abnormally hyperplastic.
Prophylactic mastectomy may extend life expectancy by 3 to 5 years if performed in patients aged 30 years, but BPM is not relevant in patients > 60 years.