The occurrence of breast cancer is the result of a combination of factors. Studies over the years have shown that only 3-5% of breast cancers are hereditary, and the main reason for the increased incidence of breast cancer is the poor lifestyle of modern people.
Sitting more, moving less An important susceptibility factor
Dozens of cohort studies have explored the relationship between exercise and breast cancer risk. Recently, Friedenreich et al. summarized the results of 34 case-control studies and 28 cohort studies, of which 47 studies concluded that exercise reduced the risk of breast cancer by an average of 25% to 30%. The main forms of exercise that reduced the risk of breast cancer were recreational exercise (mean reduction of 20%), walking or cycling for transportation purposes (mean reduction of 14%), housework (mean reduction of 14%) and occupational exercise (mean reduction of 13%). Most of the literature shows a dose-dependence of this effect, i.e. a moderate amount of exercise (<4>4 MET of exercise energy consumption per day) leads to an average risk reduction of 26%. Also, exercise reduces the risk of breast cancer in women of any age and is more beneficial when it is continued for many years. New research suggests that the preventive effect of exercise on breast cancer is more pronounced in young women aged 12 to 22 years and in postmenopausal women aged 50 years and older.
Fat and obesity are not negligible contributors
More than 100 studies have confirmed that excessive fat intake and obesity are additional factors that contribute to the increased risk of breast cancer in postmenopausal women. Postmenopausal women who are overweight or obese have a 30 to 50 percent increased risk of breast cancer compared to those who are in proportionate shape. Among those who have not used hormone replacement therapy, the risk of breast cancer in postmenopausal women with a body mass index (BMI) of 31.1 kg/m2 is 2.5 times higher than that of women with a BMI of 22.6 kg/m2, and this effect is particularly pronounced in women who have gained weight in adulthood. Also, centripetal obesity increases the risk of breast cancer, but the effect is not dependent on BMI.
Alcohol A catalyst for breast cancer development
Several studies have demonstrated that alcohol consumption may increase the risk of breast cancer. Previously, a study was published on the relationship between alcohol intake and breast cancer risk among women in the United States, which began in 1992. The study investigated 38,454 women, and after 10 years of follow-up, 1,484 cases were diagnosed with breast cancer, 1,190 of which were invasive and 294 were in situ cancers. The results showed that those who consumed more than 30 g of alcohol per day had 1.32 times the overall risk of breast cancer than non-drinkers, including 1.43 times the risk of invasive cancer. Women who consumed more than 10 g of alcohol per day and were on estrogen replacement therapy had 1.84 times the risk of breast cancer compared to women who did neither. Deandrea et al. recently published the results of a controlled study conducted in Italy from 1991-1994, in which the relative risk of breast cancer in women with ER(+) was 1.13 for those who consumed 10 g of alcohol per day compared to those who did not drink alcohol, and 1.13 for those who consumed more than 13.8 g of alcohol per day. The relative risk increased to 2.16 if the daily alcohol consumption exceeded 13.8g.
Depressed mood Cumulative risk up to 62%
Peled et al. recently published the results of a controlled study that concluded that adverse social events (e.g., death or divorce of a parent at an early age, death of a loved one or spouse in adulthood) and depression increase the risk of breast cancer, with the cumulative effect (i.e., experiencing multiple adverse events) being more pronounced, with a risk of up to 62%. The WHO has also shown that adverse social events in the two years prior to breast cancer diagnosis may have a more important effect on the risk of developing breast cancer.
A “preference” for “dinky” and advanced maternal age
Early, full-term pregnancy is the only factor known to consistently reduce the lifetime risk of breast cancer. Compared to nulliparity, a first full-term pregnancy before age 20 is associated with a 50 percent lower risk of breast cancer, while an older first-time mother has a 27 percent increased risk of breast cancer. A Meta-analysis by Ma et al. showed that this effect was mainly limited to ER(+)/PR(+) breast cancer, with each pregnancy reducing the risk of ER(+)/PR(+) breast cancer by 11%.
Whether hormone replacement therapy causes cancer is controversial
Whether hormone replacement therapy (HRT) increases the risk of breast cancer in postmenopausal women is controversial. Recently, Biglia et al. summarized the literature and concluded that HRT may increase the risk of invasive lobular carcinoma and mixed ductal lobular carcinoma, while the effect on invasive ductal carcinoma is not significant. At the same time, not all HRT causes an increased risk of breast cancer, and the results of a large cohort trial showed that 7 years of replacement therapy with progesterone combined with estrogen in postmenopausal women after hysterectomy did not increase the risk of breast cancer. Another study showed that the risk of ER(+)/PR(+) breast cancer increased only after 15 years of estrogen replacement therapy (ERT), and that the overall risk of breast cancer would increase with 20 years of use. Additional studies have shown that combined estrogen-progestin replacement therapy (CHRT) increases the risk of breast cancer by approximately 30% compared to estrogen alone. These results suggest that progesterone replacement therapy may be a major factor in the increased risk of breast cancer.
Promote healthy life and actively prevent breast cancer
1.Strengthening exercise, especially for professional women, advocating long-term adherence to running, fast walking, hiking, cycling and other forms of exercise.
2. Establish a reasonable and healthy dietary structure, reduce fat intake, consume more vegetables and fruits with high fiber and vitamin content, and control weight, which is especially important for postmenopausal women.
3.Do not drink alcohol or drink less alcohol, especially reduce the intake of beer, liquor and beverage alcohol.
4, maintain an optimistic and positive attitude towards life, learn to reduce stress on their own.
5.Early full-term pregnancy and breastfeeding, strengthen self-protection and avoid abortion.
6.If there is no special need, reduce the use of long-term hormone replacement therapy, especially avoid the use of progesterone replacement therapy.