What are the different types of breast cancer?
Breast cancers are distinguished by where they start.
There are several different types of cancers that can form in the breast. Doctors
generally group the types together based on where in the breast they start, meaning
in what type of cells they’re found.
The main cells in the breast that can become cancerous are those of the lobes (glands
that make milk, also called lobules) and the
ducts (tiny tubes that carry milk from the lobules to the nipples).
Hormones can affect the growth of breast cancer.
Many types of breast cancer cells have what are called estrogen and/or progesterone
“receptors,” or proteins on the outsides of the cells that can attach to hormones.
Women with receptor-positive cancers tend to have better outlooks for treatment
with hormone therapy.
Common types of breast cancer
Most breast cancers start in either the ducts or the lobules.
So the two main types of breast cancer are called ductal carcinomas (cancers that
start in the ducts) and lobular carcinomas (cancers that start in the lobules).
Each of these types has further subtypes, such as carcinoma in situ and invasive
carcinoma.
Ductal carcinoma is the most common type of breast cancer.
Often an early form of breast cancer, this cancer begins in the cells that line
the breast’s milk ducts. Here are the main types of ductal carcinoma:
- Ductal carcinoma in situ, or DCIS, is cancer that has not spread to other tissues
from the ducts
- The most common type of ductal carcinoma and the most common type of breast cancer
overall is
invasive or infiltrating ductal carcinoma, or IDC. On mammograms, IDC lesions
can show up as star-like or rounded. This cancer can spread into the other parts
of the breast tissue and to other parts of the body
Lobular carcinoma is less common than ductal carcinoma.
This type of cancer begins in the cells of the breast’s lobes, or lobules. Lobules
are glands that make milk. Here are some of the main types of lobular
carcinoma:
- With lobular carcinoma in situ (LCIS), cancer is found only in the lobules. This
type of lobular carcinoma does not spread to other tissues very often
-
Invasive or Infiltrating lobular carcinoma, or ILC, accounts for about 5% of
all breast cancer diagnoses and often starts with a subtle thickening in the upper-outer
quadrant of the breast. Infiltrating lobular carcinomas often respond well to hormone
therapy. This cancer can spread to nearby breast tissues and other parts of the
body
Uncommon types of breast cancer
There are several other, less common types of breast cancer.
These include a condition called Paget’s disease of the nipple, inflammatory breast
cancer (IBC), male breast cancer, and several other types.
- Paget’s disease is a rare condition in which cancer cells collect in the
nipple: The cancer can then spread from the ducts of the nipple to the
nipple’s surface. The nipple and areola (the dark circle of skin around the nipple)
can then become red, itchy, and irritated. Paget’s disease accounts for fewer than
5% of breast cancer cases in the U.S. But 97% of people with Paget’s disease also
have another cancer, somewhere else in the breast
- Inflammatory breast cancer (IBC) is very aggressive: This rare
type of breast cancer causes the lymph vessels in the skin of the breast to become
blocked. This cancer is called “inflammatory” because it often makes the breast
look swollen and red—“inflamed.” IBC accounts for 1% to 5% of all breast cancer
cases in the United States
- Men can develop breast cancer—but they’re very unlikely to: Less
than 1% of all breast cancers occur in men. For the most part, men don’t produce
a lot of female hormones, so they don’t develop breast gland tissue. Sometimes,
however, men can have abnormal levels of certain hormones, or they take certain
medicines that raise these levels. As a result, these men have increased amounts
of breast tissue and can develop breast cancer
These are just a few of the rare cancers of the breast.
Still others—each accounting for no more than 1% to 3% of breast cancer diagnoses—include
medullary carcinoma, tubular carcinoma, mucinous or colloid carcinoma, papillary
carcinoma, adenocystic carcinoma, and sarcomas of the breast (cancers of the connective
tissues, like muscle).
Learn about the stages of breast
cancer
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