Every cell in the body has the potential, under the appropriate circumstances, to become cancerous. In a normal cell, a series of precise and orderly mechanisms dictate the speed and timing of cell growth, division and death. But sometimes, this cell cycle can go awry. External factors, such as carcinogens, toxins and UV rays, can damage the cells’ DNA, triggering the loss of the control mechanisms that dictate when and how fast certain cells divide and/or die. Heredity can also play a role in some types of cancers, particularly when combined with these external triggers.
Structure of the breast
The breast is made up of lobes and ducts. Each breast has 15 to 20 sections called lobes, which have many smaller sections called lobules. Lobules end in dozens of tiny bulbs that can produce milk. The lobes, lobules, and bulbs are linked by thin tubes called ducts.
Each breast also has blood vessels and lymph vessels. The lymph vessels carry an almost colorless fluid called lymph. Lymph vessels lead to organs called lymph nodes. Lymph nodes are small bean-shaped structures that are found throughout the body. They filter substances in lymph and help fight infection and disease. Clusters of lymph nodes are found near the breast in the axilla (under the arm), above the collarbone and in the chest.
What Is Breast Cancer?
Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.
The most common type of breast cancer is ductal carcinoma, which begins in the cells of the ducts. Cancer that begins in the lobes or lobules is called lobular carcinoma and is more often found in both breasts than are other types of breast cancer. Inflammatory breast cancer is an uncommon type of breast cancer in which the breast is warm, red, and swollen. Cancer cells have the ability to invade the surrounding tissues and blood and lymphatic vessels. By doing so they can seed new cancer lesions in other distant organs like bone, lung or liver.
What are the risk factors for breast cancer?
Anything that increases your chances of getting a disease is called a risk factor. Risk factors for breast cancer include the following:
- Older age
- Menstruating at an early age
- Older age at first birth or never having given birth
- A personal history of breast cancer or benign (non-cancerous) breast disease
- A mother or sister with breast cancer
- Treatment with radiation therapy to the breast/chest
- Breast tissue that is dense on a mammogram
- Hormone use (such as estrogen and progesterone)
- High alcoholic consumption
Breast cancer is sometimes caused by inherited gene mutations. The genes in cells carry the hereditary information that is received from the person’s parents. Hereditary breast cancer makes up approximately 5% to 10% of all breast cancer. Some altered genes related to breast cancer are more common in certain ethnic groups.
Women who have an altered gene related to breast cancer and who have had breast cancer in one breast have an increased risk of developing breast cancer in the other breast. These women also have an increased risk of developing ovarian cancer, and may have an increased risk of developing other cancers. Men who have an altered gene related to breast cancer also have an increased risk of developing this disease.
Tests have been developed that can detect altered genes. These genetic tests are sometimes done for members of families with a high risk of cancer.
How is Breast Cancer Diagnosed?
Early diagnosis of breast cancer is key when it comes to increasing a patient's odds for survival. A doctor should be seen if changes in the breast are noticed. The following tests and procedures may be used:
- Mammogram: an x-ray of the breast.
- Biopsy: the removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.
- Estrogen and progesterone receptor test: a test to measure the amount of estrogen and progesterone (hormones) receptors in cancer tissue. If cancer is found in the breast, tissue from the tumor is examined in the laboratory to find out whether estrogen and progesterone could affect the way the cancer grows. The test results indicate whether hormone therapy may help stop the cancer from growing.
- MRI (magnetic resonance imaging): a procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI).
How Is Breast Cancer Treated?
The earlier breast cancer is diagnosed and an effective treatment initiated, the better the outcome is likely to be for the patient. The primary treatment objectives are cure, extension of life and improvement in the patient's quality of life.
Neo-adjuvant therapy is the delivery of treatment prior to surgery to shrink the tumor and facilitate more complete surgical removal. And in some cases, it allows breast-conserving surgery instead of removal of the entire breast.
Four types of standard treatment are used:
Surgery: Most patients with breast cancer have surgery to remove the cancer from the breast as their first therapy. Some of the lymph nodes under the arm are usually taken out and looked at under a microscope to see if they contain cancer cells.
Breast-conserving surgery, an operation to remove the cancer but not the breast itself, includes:
- Lumpectomy (surgical procedure to remove a tumor (lump) and a small amount of normal tissue around it), or
- Partial mastectomy – a surgical procedure to remove the part of the breast that contains cancer and some normal tissue around it. This procedure is also called a segmental mastectomy.
Patients who are treated with breast-conserving surgery may also have some of the lymph nodes under the arm removed for biopsy, which determines if and how far the cancer has spread.
Other types of surgery include the total mastectomy. This is a surgical procedure to remove the whole breast that contains cancer. This procedure is also called a simple mastectomy. Some of the lymph nodes under the arm may be removed for biopsy at the same time as the breast surgery or after.
Even if the doctor removes all the cancer that can be seen at the time of surgery, some patients may be given radiation therapy, chemotherapy, or hormone therapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, to increase the chances of a cure, is called adjuvant therapy.
Radiation therapy: It is a treatment that uses high-energy x-ray or other types of radiation to kill cancer cells or keep them from growing. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
Chemotherapy: It is a treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). The way the radiation therapy is given depends on the type and stage of the cancer being treated.
Hormone therapy: It is a treatment that removes hormones or blocks their action and stops cancer cells from growing. Hormones are substances produced by glands in the body and circulated in the bloodstream. Some hormones can cause certain cancers to grow.
Where is Breast Cancer Research Headed?
In recent years, significant advances have been made in scientific understanding of molecular biology and genetics. These advances have had a major impact on improving treatment of all types of cancer. As researchers look more closely at the mechanisms leading to the formation and growth of tumors, it is likely that the array of better and more effective cancer treatments will expand. Clarification regarding optimal sequencing of breast cancer therapies and extended adjuvant care for breast cancer have already opened doors for potential new paradigms in cancer treatment, paving the way for a brighter future for patients.