Breast cancer is a disease in which malignant (cancerous) cells form in the breast tissue.
The breast consists of glandular lobes and ducts. Each breast has 15 to 20 lobes. Each lobe has many lobules. The lobules end in dozens of vesicles that make milk. The lobes, lobules, and follicles are connected by thin ducts called ducts.
An anatomical view of the female breast. The nipple and areola are on the outside of the breast. The lymph nodes, lobes, lobules, ducts, and other parts of the interior of the breast are also shown.
Each breast also has blood vessels and lymphatic vessels. The lymphatic vessels carry an almost colorless, watery fluid called lymph. Lymphatic vessels carry lymph between lymph nodes. Lymph nodes are bean-sized structures that are spread throughout the body. They filter lymph and store white blood cells that help fight infection and disease. Multiple sets of lymph nodes are found in the armpits (underarms), above the collarbone, and near the breast in the chest.
Sometimes breast cancer occurs in women who are pregnant or have just given birth.
Breast cancer occurs about once every 3,000 pregnancies. It is most common in women between the ages of 32 and 38. As many women choose to delay childbirth, the number of new cases of breast cancer during pregnancy will increase.
Symptoms of breast cancer include breast lumps or other changes in the breast.
These and other symptoms may be caused by breast cancer or other diseases. Talk to your doctor if you have:
A lump or a thickening in your breast or armpit.
Change in the size or shape of the breast.
Depressions or folds in the skin of the breast.
A nipple that is recessed inward into the breast.
Fluid coming from the nipple that is not breast milk, especially bloody fluid.
Scaly, red, or swollen skin on the breast, nipple, or areola (the dark area of skin around the nipple).
Dents in the breasts that look like orange peels are called orange peel-like changes.
It may be difficult to detect breast cancer early in pregnant or breastfeeding women.
In women who are pregnant, breastfeeding, or have just given birth, the breasts often become larger, softer, or lumpy. This is because normal hormonal changes occur during pregnancy. These changes can make small lumps difficult to detect. Breasts may also become more dense. In women with dense breasts, it is more difficult to detect breast cancer with a mammogram. Because these breast changes can delay diagnosis, these women usually find breast cancer at a later stage.
Mammography should be part of prenatal and postnatal care.
To detect breast cancer, pregnant and breastfeeding women should examine their own breasts. Women should also receive regular clinical breast exams before and after giving birth. Tell your doctor promptly if you notice any changes in your breasts that you don’t expect or are concerned about.
Tests to examine the breasts are used to detect (find) and diagnose breast cancer.
The following tests and procedures may be used:
General examination: An examination of the body to check the general health of the body, including checking for disease conditions such as lumps or any other areas that look abnormal. The patient’s health habits, previous illnesses and treatment history will also be recorded.
Clinical breast examination (CBE): An examination of the breasts by a doctor or other health professional. The doctor will carefully touch the breast and underarm for lumps or anything abnormal.
B ultrasound: A procedure in which high-energy sound waves (ultrasound) are reflected from internal tissues or organs and produce echoes. These echoes form an image of the body’s tissues called a sonogram. This picture can be printed out to look at later.
Mammograms: Having a mammogram poses little risk to the unborn baby. Even if there is cancer, a mammogram of a pregnant woman may be negative.
Mammogram. The breast is pressed between two flat plates. x-rays are used to take pictures of the breast tissue.
Pathology: Cells or tissue are removed so that a pathologist can look at them under a microscope to check for signs of cancer. If a lump is found in the breast, a biopsy may be done.
There are three types of breast biopsies:
Local excision: removal of the entire mass of tissue
Coarse needle aspiration: removing the tissue with a coarse needle
Fine needle puncture: tissue or fluid is removed with a fine needle.
If cancer is found, tests are done to study the cancer cells.
Decisions about the best treatment are based on the results of these tests and the age of the unborn baby in months. The tests provide information about:
How fast the cancer is growing.
How likely the cancer is to spread to other parts of the body.
How well certain treatments work.
How likely the cancer is to come back.
Tests may include the following:
Hormone testing: A test that detects the number of estrogen and progesterone receptors in the cancer tissue. If there are more estrogen or progesterone receptors than normal, the cancer is said to be estrogen receptor-positive or progesterone receptor-positive. This type of breast cancer may grow more quickly. Test results show whether treatment to block estrogen and progestin given after the baby is born can stop the growth of the cancer.
FISH test: A laboratory test that measures how many HER2/neu genes are present in a tissue sample and how much HER2/neu protein is present. If there are more HER2/neu genes or higher-than-normal levels of HER2/neu protein than usual, it is called HER2/neu-positive. This type of breast cancer may grow more quickly and spread more easily to other parts of the body. After the baby is born, it can be treated with drugs that target the HER2/neu protein, such as trastuzumab and pertuzumab.
Multigene tests: Tests that look at tissue samples to see the activity of many genes at the same time. These tests may help predict whether the cancer will spread to other parts of the body or recur. This test helps predict whether estrogen receptor-positive and lymph node-negative stage 1 or stage 2 breast cancer will spread to other parts of the body. If the risk of cancer spreading is high, chemotherapy can reduce the risk. A laboratory study that looked at the activity of 70 different genes in breast cancer tissue from women with early invasive breast cancer that had not spread to lymph nodes or had spread to three or fewer lymph nodes. The activity levels of these genes help predict whether breast cancer will spread to other parts of the body or will recur. If testing shows a high risk of cancer spreading or recurring, chemotherapy can be used to reduce the risk.
Some factors affect prognosis (chance of recovery) and treatment choices.
Prognosis (chance of recovery) and treatment options depend on the following factors:
The stage of the cancer (how big the tumor is and whether it is in the breast or has spread to other parts of the body).
The type of breast cancer.
The age of the unborn baby in months.
The presence or absence of symptoms or signs.
The patient’s general health status.