There are different types of breast cancer. Breast cancer is also called breast carcinoma: a malignant tumor in the breast. Mamma is the Latin word for breast.
There are different types of breast cancer. The difference is due to:
• tumors that are not yet breast cancer, but may become breast cancer (preliminary stage).
• the place where it originates: in a milk duct (ductal) or mammary gland (lobular).
• characteristics of the breast cancer
The treatment of the types of breast cancer can be different.
Pre-stage of breast cancer
Breast cancer is sometimes detected so early that the wrong cells are only in the milk ducts or mammary glands. The cells have not (yet) grown further into the breast. Also metastases are not possible. Usually this is a ductal carcinoma in situ (DCIS): the wrong cells are in a milk duct.
DCIS is often discovered during population screening. About 2,200 women receive a DCIS every year. A small proportion of women with DCIS will develop breast cancer that continues to grow in the breast (invasive breast cancer). It is impossible to say with whom this will happen and with whom not. That’s why all women with DCIS get treatment just to be safe.
This usually consists of a mastectomy or breast-conserving treatment with radiation or hormone therapy.
Sometimes it is a lobular carcinoma in situ (LCIS): the wrong cells are in a mammary gland. LCIS almost never gives complaints. It is therefore usually discovered by chance. LCIS can become breast cancer. It is not known how often this happens. People with LCIS are more likely to have a check-up of the breasts.
Sometimes LCIS behaves the same as DCIS. The doctor can then suggest treatment.
Do the cancer cells in the milk ducts or mammary glands continue to grow in the breast? Then this is (invasive) breast cancer. The tumor can also spread to other organs.
Tumor in the milk duct
This is the most common form of breast cancer. It may feel like a hard lump in the breast. But sometimes you don’t feel it or hardly at all. A tumor in the milk duct is called invasive carcinoma NST. NST stands for: non-special type.
Tumor in the mammary gland
This is less common than a tumor in the milk duct. About 10% of women with breast cancer have a tumor in the mammary gland. You often only feel swelling of the breast. This tumor is not always clearly visible on a photo or scan.
Breast cancer is further divided into:
• hormone sensitive
• triple negative
Hormone-sensitive breast cancer
Hormone sensitive means that the tumor grows through hormones. Hormones are substances that the body makes itself. They give off signals with which they influence organs or direct processes in the body. Breast cancer involves the female sex hormones estrogen and progesterone.
Do more than 10% of breast cancer cells grow due to estrogen or progesterone? Then the tumor is hormone sensitive. This is the case in about three quarters of breast tumors. Hormone-sensitive breast cancer can be treated with hormone therapy (see chapter Hormone therapy).
Hormone-sensitive breast cancer spreads less quickly and has a better chance of survival than other types of breast cancer.
HER2-positive breast cancer
HER2 is a protein that regulates the growth and division of normal breast cells. In HER2-positive breast cancer, much of the protein HER2 is on the tumor. This gives the cancer cells many signals to grow and divide. 10% of breast cancers are HER2-positive.
This strain is more common in pre-menopausal women. HER2-positive breast cancer can be treated with targeted therapy (see chapter Targeted therapy). HER2-positive breast cancer often grows faster and more aggressively than hormone-sensitive breast cancer. Targeted therapy has greatly improved the outlook.
Triple negative breast cancer
Triple negative breast cancer is 3 times negative:
• the tumor does not grow under the influence of the hormone estrogen
• the tumor does not grow under the influence of the hormone progesterone
• the tumor is not HER2-positive
About 15% of breast cancers are triple negative. This species is more common in women of reproductive age.
Treatment often consists of chemotherapy, surgery and radiation.
Hormone therapy and most targeted therapies do not work in triple negative breast cancer.
A triple negative tumor often grows rapidly and is aggressive.
It also spreads more often and faster than other types of breast cancer. The chance that this breast cancer will come back is also greater. Has the tumor not come back or metastasized after 7 years? Then there is a very good chance that it will not come back or metastasize.
Rare Forms of Breast Cancer
There are a number of rare forms of breast cancer:
• Inflammatory carcinoma (Mastitis Carcinomatosa)
• Paget’s disease
• Phyllode’s tumor
• Medullary carcinoma
• Tubular carcinoma