According to the National Cancer Institute, 1 in 8 American women will be diagnosed with breast cancer at some point in her life. It is much less common in men, and only 1 in 800 men are likely to develop it during their lifetime.
Your breast is made up of lobules and ducts surrounded by fat and connective tissue. Glandular lobules produce milk that is transported to the nipple through the ducts.
Breast cancer occurs when normal cells in the lobules, ducts, or other breast tissue are damaged and grow out of control. The abnormal cells grow rapidly and accumulate, forming a mass called a tumor.
If a tumor grows but does not spread to nearby breast tissue, it is considered benign and not considered cancer. A malignant tumor spreads, invades surrounding tissue, and is considered cancerous.
There are many different types of breast cancer, as it can start in the lobules, ducts, or other tissues.
Breast cancer can be classified in several ways. It is often classified according to where it originates and whether it moves from that point.
An easily identifiable feature of breast cancer is the type of cell in which it occurs.
Another important feature of breast cancer is that it invades the surrounding tissue or stays where it first formed.
Combining these classifications gives the type of breast cancer a descriptive name as outlined below.
The symptoms of breast cancer can vary widely, and some types of breast cancer may not have obvious symptoms.
Sometimes a lump may be too small to be felt, or it may cause any changes in or around your breast. In these cases, cancerous cells are usually first detected by screening techniques such as mammograms.
When there are symptoms, they may include:
- a lump or thickening of breast tissue that you can feel with your fingers
- breast swelling or changes in your breast size or shape
- changes in the skin on your chest, such as pitting, redness, or skin irritation
- nipple inversion or nipple pain
- a lump in your armpit area
- nipple discharge other than breast milk
It’s important to know how your breasts usually look and feel. This will help you notice any changes and contact your healthcare provider immediately if anything looks or feels different.
Noninvasive breast cancer develops in the cells of a duct or lobule and stays in that location. It is also referred to as “in situ” meaning “in its original place”.
There are two types of noninvasive breast cancer:
- ductal carcinoma in situ (DCIS)
- Lobular carcinoma in situ (LCIS)
Let’s take a closer look at each type.
DCIS is usually treatable. It is usually treated with a lumpectomy followed by radiation therapy or mastectomy.
If the cancer is hormone receptor positive, it can be treated with tamoxifen or an aromatase inhibitor (for postmenopausal patients) for 5 years after surgery. This treatment is thought to reduce the risk of DCIS recurrence or invasive cancer in both breasts.
LCIS treatment requires close follow-up with your doctor due to the high risk of developing invasive breast cancer. Your LCIS may not need treatment, or your doctor may recommend removal with breast-conserving surgery, such as an excisional biopsy.
Invasive breast cancer also develops in the cells of a duct or lobule, but does not stay where it arises. Instead, it spreads and invades the surrounding tissue. Another name for this is “penetration”.
There are two types of invasive breast cancer:
- invasive (infiltrating) ductal carcinoma (IDC)
- invasive (infiltrating) lobular carcinoma (ILC)
Breast cancer is typically classified according to the surface proteins found in cancer cells.
When breast cancer tissue is removed from your body, it is tested for these proteins. Cancer cells are then divided into subtypes based on the presence or absence of surface proteins. Knowing the subtype can help your doctor determine the best course of treatment for your cancer.
Let’s look at the three most common subtypes for breast cancer.
Hormone receptor positive
This subtype has estrogen and/or progesterone receptors. “ER positive” tumor has estrogen receptors while “PR positive” tumor has progesterone receptors. This subtype usually needs hormones corresponding to its receptors in order to grow.
It is estimated to be around.
Treatment with anti-estrogen or anti-progesterone hormone therapy can inhibit tumor growth and kill cancer cells. If the receptor is absent, it is called a “hormone receptor negative” tumor.
This subtype has extra copies of the HER2 gene, so it produces too much growth hormone called HER2. This hormone makes the cancer grow faster.
Treatment typically includes drugs that can slow the production of this hormone and kill cancer cells.
Cancers that do not have ER, PR, or HER2 receptors are called “triple negative.”
more common in women with BRCA1 gene mutation, so your doctor would recommend that you be tested for this mutation if your cancer is triple negative.
About 10 to 15 percent of invasive breast cancers are triple negative.
Less common types of breast cancer are often named for how they look under the microscope. Here’s a closer look at a few less common types.
Inflammatory breast cancer (IBC)
Inflammatory breast cancer accounts for about 1 to 5 percent of all breast cancers. It is a fast-growing, aggressive form of breast cancer that has different symptoms than most other types of breast cancer. Because it is not present as a lump, IBC is often confused with other conditions.
Some of the most common symptoms of IBC include:
- swollen, hot, red breast
- thickened or dimpled breast skin
- a breast that feels larger or heavier than normal
- pain or tenderness in the breast or the area around it
- itching on or around the breast
- inverted nipple
IBC symptoms are caused by a blockage of the lymphatic system within the breast. These symptoms tend to develop quickly, usually within 3 to 6 months.
Paget’s disease of the breast
Paget’s disease only
Paget’s disease is a rare cancer that occurs in the milk ducts and spreads to the skin of the nipple and the skin around the nipple. According to the National Cancer Institute, this type of breast cancer is often accompanied by DCIS, or an invasive tumor within the breast.
The symptoms of Paget’s disease are often mistaken for skin conditions such as eczema or dermatitis at first. However, the symptoms do not respond to topical treatments.
Typical symptoms of Paget’s disease include:
- redness, scaling, or crusting around the nipple and areola
- tingling or itching sensation around the nipple
- thickened skin at or near the nipple
- flattened nipple
- bloody or yellowish discharge from the nipple
Phyllodes tumors of the breast
A phyllodes tumor is a very rare type of breast cancer.
In about 75 percent of cases, phyllodes tumors are not cancerous, so they don’t usually spread beyond the breast. But they can grow quickly, and some can be considered “borderline”, meaning they have properties that can make them cancerous at a later stage.
Phyllodes tumors form in the connective tissue of the breast. The most common symptoms include:
- a smooth lump in or around the breast
- a lump that grows rapidly and stretches the skin
- chest skin that looks red and feels hot
Tubular carcinoma of the breast
Tubular carcinoma is a subtype of invasive ductal carcinoma (IDC). This type of breast cancer gets its name because of the tube-shaped structures that can be seen under the microscope that make up the tumor. Tumors are usually small (about 1 centimeter or less) and tend to grow slowly.
Tubular carcinoma is rare,
Because these tumors are small, they are most often detected during a routine mammogram. They tend to be low grade with a good prognosis.
Mucinous (colloid) carcinoma of the breast
Mucinous carcinoma, also known as colloid carcinoma, is a rare form of invasive ductal carcinoma (IDC). About 2 percent of breast cancers are “pure” mucinous carcinomas, while up to 7 percent of breast cancers have a component of mucinous carcinoma cells.
In this type of cancer, the tumor consists of abnormal cells that appear to “swim” in pools of mucus when viewed under the microscope.
It is a typically less aggressive type of cancer that is less likely than some other types of IDC to spread to the axillary (armpit) lymph nodes.
Mucinous carcinoma tends to be more common in postmenopausal women, with an average age of diagnosis between 60 and 70.
Medullary carcinoma of the breast
Medullary carcinoma of the breast is another rare subtype of invasive ductal carcinoma (IDC). Takes into account those around
The tumor is typically a soft, fleshy mass rather than a lump in the breast tissue. The mass most commonly develops in the middle of the breast and is most common. BRCA1 mutation.
Although these cancer cells often have an aggressive appearance, they do not grow quickly and usually do not spread to the lymph nodes. This makes it easier to treat than some other types of breast cancer.
Breast cancer treatment varies depending on many factors, such as:
Possible treatment options for breast cancer include:
- Lumpectomy. This breast-conserving surgery is often used for smaller, less invasive tumors. It just involves removing the tumor and some surrounding tissue.
- mastectomy. With mastectomy, the entire breast is removed. The type of mastectomy can vary depending on how invasive the cancer is.
- Radiation therapy. Radiation therapy is often used to destroy cancer cells that remain in the breast or surrounding tissue after the cancer has been surgically removed.
- Chemotherapy. Chemotherapy drugs are often used to destroy cancer cells that have spread to distant parts of the body.
- Hormone therapy. Anti-estrogen and anti-progesterone therapy can be used to slow the growth of hormone receptor-positive tumors.
- Immunotherapy. Immunotherapy is a way to stimulate your immune system so that it can recognize and attack cancer cells. This is a growing area of research that continues to find new ways to treat cancer.
- Other targeted therapy. For HER2-positive breast cancer, some types of targeted therapy can detect and disrupt growth-promoting proteins on the surface of cancer cells. This may help slow the growth of HER2-positive tumors.
Regular breast self-exams and mammograms help detect breast cancer in its early stages. Finding breast cancer that has not yet spread gives you the best chance of staying healthy and cancer-free for many years.
According to the American Cancer Society, on average, when your breast cancer is treated before it has spread, you are 99 percent more likely to survive 5 years than someone without breast cancer.
Other steps you can take to reduce your risk of getting breast cancer include:
- Limit alcohol to no more than one drink per day.
- Stay at a healthy weight throughout your life.
- Stay physically active.
- Breastfeed if possible.
- Avoid hormone therapy for postmenopausal symptoms.
- Avoid breast implants.
- If you’re at high risk, talk to your doctor about medication or surgical treatments to reduce your chances of getting breast cancer.
There are many types of breast cancer. Some types of breast cancer develop in the milk-producing lobes of your breast, while others grow in the cells lining the milk ducts. Some tumors are benign and non-invasive, but others can be malignant and invade nearby breast tissue.
Breast cancer can be treated with surgery, chemotherapy, radiation therapy, targeted drugs, and hormone therapy. However, you will need less treatment if breast cancer is detected early through breast self-exams or routine mammograms.