Breast cancer (mammary carcinoma) is a malignant tumor in the human mammary gland. It is one of the most common types of cancer in women. The earlier breast cancer is detected, the greater the chances of recovery. For treatment, doctors mainly have surgical tumor removal, chemotherapy, radiation and anti-hormone therapy available.
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| Breast Cancer |
Causes, risk factors and frequency
The exact causes for the development of breast cancer have not yet been clarified. Most people get it accidentally. However, there are some risk factors that favor the disease.
Women are at higher risk of developing breast cancer if they
- are older than 50 years old.
- have no children.
- become pregnant for the first time after the age of 30.
- had their first period before the age of 12 or
- late menopause.
- have several women in the family who were diagnosed with breast or ovarian cancer before the age of 50.
- take hormone replacement therapy for menopausal symptoms.
- long-term use of female sex hormones (birth control pills).
In rare cases, breast cancer is hereditary. The risk of developing hereditary breast cancer is particularly high in women who carry a mutation in the breast cancer genes BRCA1 or BRCA2. The probability that these women will actually get breast cancer in their lifetime is said to be up to 65%. There are also other genes that can increase the risk of the disease slightly to moderately if they are modified. Overall, however, no more than 5% of breast cancer cases have genetic causes.
Women who have at least two cases of breast or ovarian cancer in the family are recommended to seek tumor genetic counseling. This is especially true if one of the sick relatives was diagnosed before the age of 51. A genetic test is also useful if there is at least one female relative who developed breast cancer before the age of 35.
In women who have a proven increased genetic risk of developing breast cancer, both breasts can be amputated as a precautionary measure (mastectomy). By removing the ovaries, the production of the sex hormone estrogen is largely stopped and a certain protection against breast cancer is achieved. According to studies, if there is a family burden, this measure can reduce the risk of illness by up to two thirds (almost 70%).
A healthy lifestyle has a positive effect on the risk of breast cancer, while lack of exercise and a high-fat diet increase the risk of developing the disease. In addition to being significantly overweight, heavy smoking and the daily consumption of alcohol in the amount of a glass of wine also increase the risk of developing breast cancer. Other factors and their influence on the development of breast cancer are currently still being discussed in specialist circles. These include vitamin D deficiency, consumption of a lot of red meat in young adulthood, insufficient iodine intake and chemicals.
According to the World Health Organization (WHO), breast cancer is the most common cause of cancer-related death in women worldwide. More than a million women are diagnosed with this annually. While the disease is rather rare in Asia and Africa, breast cancer is the most common type of cancer in western countries.
Symptoms
Do you feel a hardening in your chest that wasn't there before?
Does a nipple secrete clear or bloody discharge?
Do your breasts suddenly seem different in size?
These could be signs of a malignant change in the breast tissue. Breast cancer usually develops over many years and is initially not recognizable from the outside. The first signs of breast cancer can be palpable or visible lumps in the breast or armpit. Dents that appear suddenly in the nipple or breast skin also require clarification. Other symptoms may include nipple discharge or persistent redness or flaking of the skin.
Changes in the breast should always be examined by a specialist. In most cases they are benign, especially in young women.
In the early stages, breast cancer is usually not painful. In the advanced stage, affected women usually suffer from exhaustion and unwanted weight loss. If there are already secondary tumors (metastases) in the bones, back or joint pain can occur. X-rays (mammography) are used by the doctor to clarify the situation. If tiny calcium deposits, so-called microcalcifications, become visible in the milk ducts, this can be an indication of cancer. However, microcalcification also occurs during harmless remodeling processes in the tissue. A biopsy provides certainty here (see «Treatment»).
Malignant tumors in the mammary gland are divided into those that grow in the milk ducts (ductal carcinomas) and those that grow in the mammary glands or lobules of the glands (lobular or lobular carcinomas). Preliminary stages of breast cancer or a very early form of cancer can occur both in the milk ducts and in the mammary glands. The doctor then diagnoses ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS).
A rare special form of breast cancer is inflammatory carcinoma. This inflammatory form of the tumor spreads particularly quickly and should be treated quickly.
When to the doctor?
See a specialist if you see or feel any abnormal changes in or on any of your breasts.
Treatment
If a woman notices a change in or on one of her breasts, this must be clarified by a doctor. First, the doctor examines the breasts, armpits and clavicles with palpation and possibly also with ultrasound (sonography). If there is a suspicion of breast cancer, further tests follow. The two most common ways to diagnose breast cancer are an X-ray of the breast (mammography) and a tissue sample (biopsy). X-rays show how big a lump is and where it is. They help distinguish benign from malignant changes in the mammary gland tissue. To ensure that not too many benign breast tumors are removed unnecessarily, a second or third opinion is often obtained and the findings are backed up with an ultrasound examination. A weak point of mammography is the poor detection of tumors in extremely dense glandular tissue. This is especially the case with younger women. It is also advisable to repeat the examination with a second procedure such as ultrasound or possibly also a magnetic resonance mammography. For example, cysts (sacs filled with fluid) can be distinguished from tumors. If a nipple secretes secretion, in individual cases the milk ducts can also be visualized (galactography) or mirrored (ductoscopy) by injecting a contrast medium.
The definitive diagnosis is made using a tissue sample. To do this, the doctor removes a tiny piece of tissue from the knot in question using a hollow needle or a punch. This is examined under the microscope for cancer cells. If it is a malignant change, the tissue sample also provides information about the type of tumor and its aggressiveness
.If breast cancer has been diagnosed and the breast cancer is already advanced, further examinations may be appropriate. The lungs, liver, and bones are checked for secondary growths (metastases).
Mammary tumors are divided into different stages according to an international scheme. The decisive factors for the TNM system are the tumor size (T), the involvement of the lymph nodes (N) and any metastases (M). The classification is crucial for the disease prognosis and the type of therapy.
The doctors' therapy suggestions are based on various factors: How big is the tumor? How far has it spread? Are there daughter tumors? What are the properties of the tumor tissue? Has the patient already had her menopause or not yet? Does the tumor respond to hormones? The needs of the affected woman are also included in the therapy. The patient should inform herself comprehensively about all options and make her decision for or against a proposed therapy.
In most cases, different forms of therapy are combined in the treatment. These include surgery, radiation therapy, chemotherapy, anti-hormone therapy and antibody therapy.
Surgery
Surgery removes as much of the tumor as possible to prevent the cancer from spreading to surrounding tissues and other parts of the body. In a good two-thirds of the women affected, the breast can be preserved. If a lot of tissue has to be removed, an attempt is made during the operation to balance the shape of the breast by moving the tissue that is still there. If that doesn't work, breast reconstruction is an option.
While previously removal of the breast (mastectomy) often seemed unavoidable, we now know that a breast-conserving operation in combination with radiation following the operation yields similarly good results.
Nevertheless, it may be necessary for the affected breast to be completely removed. This is the case, for example, if the tumor is more than three centimeters in size, if it cannot be removed completely and with sufficient distance from the healthy tissue, if there are several lumps in the breast, or if the lymphatic vessels or milk ducts are massively affected or it is itself is an inflammatory carcinoma. However, it is often possible to operate in a manner that is gentle on the breast. Here the doctors decide individually and for the benefit of the patient. If she asks for a breast removal because she feels safer that way, this wish is also respected.
If secondary tumors form, this usually happens first in the lymph nodes in the armpit. Therefore, depending on the stage of the cancer, the lymph nodes are often also examined during the operation. If they are infected by tumor cells, they are removed.
If the entire breast had to be removed, there are many different breast reconstruction options today. This can happen either during the same intervention (immediate reconstruction) or in a second operation (interval reconstruction). Interval reconstruction is mainly used when therapy with medication or radiation is to be carried out first. The breast can be built up using implants or prostheses made of silicone or with the body's own tissue from the stomach, buttocks, back or thighs. Once the newly constructed breast has healed completely, the nipple and areola can also be reconstructed.
Radiotherapy
Radiation therapy is often used after breast-conserving surgery. Any remaining cancer cells are destroyed with high-energy radiation. Studies have shown that this so-called radiotherapy after the operation significantly reduces the risk of recurrence. If the cancer was very large or if it also affected the pectoral muscle, radiation therapy makes sense even after a complete breast removal.
The patient is irradiated four to five times a week for six to eight weeks. The individual sessions only last a few minutes, and the entire breast is usually irradiated. The site where the tumor was located usually receives an additional dose of radiation. Some residual tumors can also be treated during the operation: the doctor places a radiation source in the wound cavity, which emits radiation for about half an hour.
If there is a suspicion or evidence that there are tumor cells in the lymph nodes in the armpit, these are also irradiated.
Chemotherapy
In order to fight any remaining tumor cells intensively and to reduce the risk of recurrence, chemotherapy is also recommended for many patients. This can be done after or before the operation. Chemotherapy is particularly recommended for women who are at high risk of recurrence. The risk of recurrence is measured by the type of tumor, the stage, the involvement of the lymph nodes, the age of the patient and the hormone dependency of the tumor.
So-called cytostatics are used for therapy, which inhibit the division of the cancer cells and destroy them. The drug groups that are preferred for use in breast cancer include anthracyclines (doxorubicin, epirubicin) and taxanes (docetaxel, paclitaxel). The disadvantage of these substances: they also affect healthy cells. This often leads to side effects such as hair loss, susceptibility to infections and gastrointestinal problems. However, these can be alleviated with medication.
The doctor usually administers the cytostatics via an infusion directly into the vein, or the patient swallows them in tablet form. The therapy is carried out cyclically with breaks to allow the body to recover. For example, chemotherapy may consist of eight cycles occurring every three weeks.
Today, neoadjuvant chemotherapy is considered to be just as effective as adjuvant. If the drugs are given before the operation, they can shrink the tumor and thus make it operable. Sometimes it is even possible to save the breast.
Whether a tumor will respond to chemotherapy and whether this is appropriate at all can usually be checked in patients with early-stage disease and a hormone-dependent tumor using so-called gene expression tests before the start of treatment. This is used to determine the activity of individual genes in the tumor tissue (gene expression).
Anti-Hormone Therapy
According to estimates, around two thirds of all breast cancer tumors are hormone-dependent: endogenous hormones such as the female sex hormone estrogen promote the growth of cancer cells. Anti-hormone therapy takes advantage of this: it blocks the effect of hormones and thus slows down tumor growth. Anti-hormone therapy should only be started after surgery and after chemotherapy.
Theoretically, the ovaries, in which the estrogen is mainly produced, can also be removed or irradiated. However, this is rarely done nowadays, as the same effect can be achieved with drug treatment.
A very common drug is tamoxifen. This active ingredient is a so-called selective estrogen receptor modulator (SERM). The cancer cells have certain receptors on their surface to which the estrogen docks. This is where the tamoxifen binds, so the estrogen can't get to the cancer cells. Doctors call this principle competitive inhibition. Women going through the menopause are usually treated with tamoxifen for five years. The therapy is well tolerated by most patients, but it also has possible side effects such as hot flashes and an increased risk of blood clots (thrombosis) and cancer of the lining of the uterus (endometrial cancer).
In order to block the body's own estrogen production, the ovaries can also be switched off in women before menopause. So-called GnRH agonists stop hormone production. Accordingly, the growth of cancer cells is no longer stimulated. The doctor injects the GnRH agonists under the skin once a month. Alternatively, an implant can be used, which is renewed every three months. The therapy usually lasts two years. After that, the ovaries normally work as usual.
So-called aromatase inhibitors are suitable for breast cancer patients after menopause. They block the enzyme aromatase, which is responsible for the production of estrogen in the body. Today, the third-generation aromatase inhibitors are used, these are the active ingredients letrozole, anastrozole and exemestane. The therapy is initially designed for five years and is often combined with tamoxifen. Then two or three years of tamoxifen follows for two or three years of the aromatase inhibitor. It is important that the therapy does not last less than five years in total. For some patients it may make sense if they only receive an aromatase inhibitor after five years of tamoxifen. The anti-hormone therapy can then last up to ten years.
In rare cases, aromatase inhibitors can also be used before menopause. Then, however, estrogen production in the ovaries must also be blocked.
Antibody therapy
A good quarter of all breast cancer tumors have a very specific type of docking sites on their cell surfaces: the so-called HER2 receptors. In this case, the patient can be treated with antibodies such as trastuzumab. This binds to the receptors and thus prevents the tumor from growing further. At the same time, the immune system is alerted and attacks the malignant cells. Antibody therapy can be used both alongside and after chemotherapy. It is injected under the skin every three weeks and can last up to a year. During the treatment, the doctor regularly checks the lungs and heart, as these can be stressed by the therapy.
According to studies, the combination of antibody therapy with trastuzumab and chemotherapy before surgery, i.e. neoadjuvant, can even completely destroy the tumors in some women.
Antibody therapy can be combined with anti-hormone therapy if the tumor is hormone-dependent.
Therapy for advanced breast cancer
If secondary tumors have already formed in other organs such as the bones, brain or liver, experts speak of metastatic breast cancer. Here, too, cytostatics are used that inhibit cell growth. A highly effective cytostatic drug that has only been approved in Europe since 2011 is eribulin. In the case of advanced breast cancer, the goal of treatment is to prolong life and maintain the best possible quality of life. Various forms of therapy are combined for this purpose.
Although some metastases can be surgically removed or irradiated, breast cancer often forms secondary tumors in the bones. They disrupt bone metabolism and accelerate bone breakdown, which can lead to brittle bones and the resulting fractures. Women with bone metastases are therefore often given so-called bisphosphonates, which reduce the breakdown of bone mass, as an infusion through a vein or in tablet form.
Angiogenesis inhibitors are drugs that prevent the tumor from forming its own blood vessels. He is thus undersupplied and dies from it. As an angiogenesis inhibitor, the active substance bevacizumab is given in addition to chemotherapy with taxanes.
The enzymes tyrosine kinases, which are dysfunctional in this disease, are responsible for the rapid, uncontrolled spread of cancer cells. Tyrosine kinase inhibitors such as lapatinib are given as tablets in addition to chemotherapy.
When the cancer can no longer be stopped from progressing, the focus of treatment shifts to reducing pain and other symptoms caused by the disease. The women affected are also given psychological care.