The female breast is a nursing organ, a second sex organ, the most perfect and sublime artwork in the world, a priceless and noble gift from nature to mankind. The breast is great, yet fragile. It is the source of life and strength, but it is also enough to put life at risk. The incidence of breast cancer in Beijing has increased from 21.0 per 100,000 in the 1980s to 61.82 per 100,000 in 2008, a twofold increase in the last 30 years, making it the number one malignant tumor threatening women’s health, according to a health bulletin released by the Beijing Municipal Health Bureau in 2011. While its incidence has been gradually increasing worldwide for half a century, the mortality rate of breast cancer in Europe and the United States has been decreasing in recent years, thanks to early detection and standardized treatment of breast cancer. Since the pathogenesis of breast cancer is still unclear, it is impossible to achieve complete primary prevention (etiological prevention). Secondary prevention (i.e. early detection and treatment) is the only way to reduce the mortality rate of breast cancer today. According to several domestic surveys and studies, less than 10% of women over 30 years old in China pay attention to breast health and have regular breast examinations, which is a very serious situation. Therefore, the whole society should increase the publicity of breast disease and call on women to know and care for their breasts. Wang Yajun, General Surgery Department, Xuanwu Hospital, Capital Medical University
1. What is the breast?
If you knead it gently, you will find that inside the breast, there is something other than fat, which is the breast gland tissue. It consists of 15-20 glandular lobes, each of which is divided into several lobules. The lobules are where the milk is secreted, concentrating the milk-producing glandular compartments, and the milk produced is carried out through the milk ducts. Together, the lobules and ducts form the mammary gland (Figure 1).
Figure 1. Anatomy of the breast
2. How does breast cancer occur?
The pathogenesis of breast cancer is not clear. If there is an increase in the number of cells without morphological changes, it is called simple hyperplasia; if there is an increase in the number of cells and abnormal changes in morphology and structure, it is called atypical hyperplasia, and only in the middle stage of atypical hyperplasia is there a tendency to become cancerous; in the advanced stage of atypical hyperplasia, there are very abnormal changes in the morphology and structure of cells and it becomes cancer. The whole process of breast cancer development varies greatly from several years to several decades, and it may develop suddenly without any precancerous stage to be detected. Most breast cancers arise from the most predominant tissues of the breast, namely ductal and lobular cancers. Tumor cells that have not yet invaded the basement membrane and have not progressed deeper are called carcinoma in situ (Figure 2), which is also an early stage cancer with a 5-year survival rate of over 95%; conversely, if they destroy the lobular or ductal structures, they are invasive carcinoma (Figure 3). If the tumor continues to develop, local axillary and supraclavicular lymphatic metastases occur (Figure 4), and even distant metastases.
Figure 2. Carcinoma in situ of the breast. The tumor originates from the lobules and is confined within the lobular tissue (left), and the tumor originates from the ducts and is confined within the ducts (right).
Figure 3. Infiltrating carcinoma of the breast. Tumor cells break through the lobular basement membrane (left) and tumor cells break through the ductal basement membrane (right).
Figure 4. Common lymph node metastasis of breast cancer
3. Breast Cancer Risk Factors
First of all, it is important to clarify that risk factors are not the cause of the disease (the cause of breast cancer is currently unknown), and women should not be burdened with the thought of having a certain risk factor, which is totally unnecessary. For example, a certain risk factor only increases the incidence rate from 20/100,000 to 100/100,000 in the general population, and only 10 out of 10,000 people with risk factors may have breast cancer, which is an increase of 8 patients, which is still a relatively low probability. This is still a relatively low probability. It is more meaningful only if a woman’s risk factors are analyzed and evaluated comprehensively, so that the patient’s risk of developing breast cancer in the future can be graded, and then targeted screening and prevention measures can be taken.
(1) Major risk factors: ① Age. Age is the most important but easily neglected risk factor for breast cancer. Statistics of breast cancer patients in Beijing show that the incidence of the disease gradually increases from the age of 30, with the peak age being around 48. Family history of first-degree blood relatives with breast cancer is the main risk factor for breast cancer, and the lifetime risk of breast cancer for BRAC-1 and BRAC-2 gene mutation carriers is 60%-85%; ③ atypical hyperplasia or papillomatosis. The risk of breast cancer increases 4-5 times in those with ductal and lobular epithelial atypical hyperplasia or papillomatosis; ④ Mental depression. A case-control study of risk factors for breast cancer in Beijing showed that the relative risk of mental depression for breast cancer was 4.74 times higher.
(2) Secondary risk factors: ① Prolonged estrogen exposure. Age at menarche <12 years, age at menopause >50 years, and estrogen replacement therapy during menopause have a mildly increased risk of breast cancer; (2) Marital status. Late childbearing and not breastfeeding have a mildly increased risk of breast cancer; ③ Previous breast cancer. The risk of contralateral breast cancer may occur in 1% of patients each year; ④ obesity or high-fat diet. Fat intake has the effect of directly increasing serum estrogen levels. ⑤ Other. The relative risk is also mildly increased by long-term smoking and alcohol consumption, family members with other malignancies, and long-term oral contraceptive use.
In the United States, there is Gail model to predict the risk of breast cancer in the next 5, 10 and 20 years (interested friends can visit http://www.cancer.gov/bcrisktool/ and enter their data according to the article to get an analysis report, which is suitable for westerners for reference only), but there is no uniform assessment model in China yet.
4. Early detection of breast cancer
Most early stage breast cancers can be completely cured and the breast can be retained, so early detection becomes the key to breast cancer prevention and treatment. Unlike countries in Europe and the United States that have the conditions for universal medical checkups, most of the breast cancer patients in China come to the clinic only when they find a lump on their own. Although it is still controversial whether breast self-examination can improve the survival rate, it is still worth advocating in China, as reasonable breast self-examination can make tumors be detected at a younger age. The examination method: once a month, within 7-10 days after menstruation is appropriate, when the breast is relatively soft and easy to find abnormalities; women who have stopped menstruation can choose a fixed time every month for examination. ①Visual examination: Take a sitting or standing position and carefully observe the development of bilateral breast in front of a mirror, whether the shape, size and position are symmetrical, whether the nipples are at the same level, whether there is retraction and depression, epidermal erosion and desquamation, etc. Then check the breast skin for redness, varicose veins, rupture, local depression or bulge, and whether it has become orange peel-like. ② palpation: sitting or supine position, finger flattened to touch, using the finger belly rather than the fingertips to lightly press the breast tissue on the chest wall, starting from around the areola to expand in a spiral clockwise direction until the entire breast tissue and axillary lymph nodes, and finally squeeze the nipple is there is overflow. It should not be missed and should not be grasped and pinched so as not to scratch up the gland and cause false sensation. When a lump is found, its location, size, texture, mobility, presence of pressure pain and other characteristics should be noted and go to the hospital for further examination. Also compare both sides for examination (Figure 5). If any abnormality is found, consult a breast specialist promptly.
Figure 5. Breast self-examination method. Standing microscopic observation (left), lying down sequential palpation (middle), squeezing the nipple for fluid overflow (right).
When breast cancer is very early, it is clinically asymptomatic and lumpless, which is very difficult to detect, so regular adjuvant examinations are necessary. Color Doppler ultrasound and mammography are the most commonly used and valuable diagnostic imaging methods with a sensitivity and diagnostic compliance rate of over 85%, and combined examination can improve the diagnostic rate. The World Health Organization and the American Cancer Society recommend that women over the age of 50 should have a mammogram every year, women between the ages of 40 and 49 every 1-2 years, and women between the ages of 35 and 40 should have a mammogram as basic information to be kept for later use as a control. Ultrasound is an economical, easy, non-invasive and painless screening method that is more suitable for young women, especially pregnant and lactating women, but is not as sensitive as mammography in detecting microcalcifications. The two methods can complement each other and improve the early detection rate of breast cancer. It is hoped that breast cancer screening can be fully realized in China as soon as possible. Finally, it is important to remind people that relying on physical examination, infrared examination or simple palpation by a non-oncologist is not equivalent to breast examination, which often delays the diagnosis and treatment; once a problem is detected, go to a breast specialist for consultation.
5. Prevention of breast cancer
Prevention of breast cancer in terms of its cause is still a worldwide problem. Despite this, some progress has been made in recent years in the prevention of breast cancer with drugs. For example, the estrogen receptor modulator tamoxifen can reduce the risk of breast cancer by 50% in high-risk individuals, but it also has side effects such as blood clots and an increased risk of endometrial cancer. In a high-risk individual, the risk of breast cancer, possible benefits, and drug side effects need to be carefully evaluated before making a decision about chemoprevention. Women who have more than one first-degree relative with breast cancer and who are also positive for BCRA 1 or 2 should be followed up and, if necessary, undergo preventive surgery to reduce the incidence of breast cancer.
A proper diet and a good lifestyle are important factors to ensure good health. Epidemiological studies have found that a high-fat diet can increase the incidence of breast cancer. Low-fat and high-fiber foods such as fruits and vegetables have a preventive effect on breast cancer because they can lower the level of estrogen in the blood. The preventive effect of soy milk and the phytoestrogen soy isoflavones on breast cancer is still controversial. Maintain a healthy weight, body mass index = weight (Kg)/height (m)2, reference standard: 18.2-23.9 is appropriate. Quitting smoking, alcohol and proper exercise are all helpful to reduce the incidence of breast cancer. Breast cancer is also related to endocrine disorders and menstrual disorders, and breastfeeding is a protective factor, so breastfeeding should be actively promoted. Estrogen has been shown to be a specific promoter in the development of breast cancer. In terms of prevention for women at risk, the use of estrogen-containing cosmetics and health products should be minimized. It is an indisputable fact that environmental pollution has led to an increase in cancer incidence. Therefore it is extremely important to care about your work, life, living environment and diet and water. The decrease of immune system defense ability promotes the occurrence of tumor, so improving immunity is an important way to prevent tumor. It is important to pay attention to exercise, develop healthy living habits and avoid the occurrence of undesirable factors such as malnutrition, long-term overwork, mental depression or mental tension.
Finally, let each of us tie the pink ribbon, one more person to promote breast disease, one less possibility of breast cancer patients – breast cancer can be easily detected at an early stage; one more point to pay attention to breast health, one less tragic fate – early breast cancer Let us all take action to care for our breasts and health.