Breast cancer is the most common form of cancer in the UK. The most common type is invasive breast cancer, non-special type (NST).
There are other rare types of breast cancer. Learn more about some of them and how they are treated.
Breast cancer clustering
Doctors have developed ways to group breast cancer into different types. It is sometimes called a rarer breast cancerspecial kindand more common breast cancerthere is no special type.
Most breast cancers are invasive, without a specific type. About 70 out of 100 (about 70%) breast cancers are of this type. You may see it written as NST or NOS (not otherwise specified).
A special type of breast cancerthey have cells with special functions. They are visible when the doctor observes the cells under a microscope.
Medullary carcinoma of the breast
Less than 1 in 5 out of 100 breast cancers (less than 5%) is medullary breast cancer. They are more common in younger women and in women who have inherited a defective BRCA 1 gene.
Cancer cells are usually larger than in other forms of breast cancer. When doctors look at these tumors under a microscope, they see a clear border between the tumor and normal tissue. This type of breast tumor is also unusual in that it contains white blood cells.
Doctors treat medullary breast cancer in the same way as other forms of invasive breast cancer, with surgery, radiation therapy, and drug therapy. The outlook is generally very good.
Mucinous (mucinous or colloid) breast cancer
1 to 2 out of 100 breast cancers (1 to 2%) are mucinous cancers. This type of cancer grows more slowly than other types and is more common in older women. It is less likely to spread to the lymph nodes.
Mucinous breast cancer got this name because the cancer consists of a large amount of mucin. It can be pure mucosal cancer or it can be a mixture of mucosal cancer and other types.
Doctors usually treat mucosal cancer in the same way as other types of breast cancer. Cancer is removed surgically by removing the entire breast (mastectomy) or part of the breast (breast surgery). You may have a sentinel node biopsy to see if the cancer has spread to your lymph nodes.
The outlook for mucinous breast cancer is generally very good.
Tubular breast cancer
About 2 out of 100 breast cancers (about 2%) are tubular cancers. Cancer cells look like tubes under a microscope. This type is more common in older women, and the tumor is usually very small at diagnosis. Sometimes it spreads to nearby lymph nodes.
Treatment is the same as for other types of invasive breast cancer. Tubal breast cancer is less likely to return after treatment than some other types. So the outlook is generally good.
Adenocystic breast cancer
Less than 1 in 100 breast cancers (less than 1%) is adenoid cystic cancer. This type of cancer is sometimes called sieve cancer. This is a type of cancer that is more often diagnosed in the salivary glands, but some develop in the breast tissue.
It usually occurs in the elderly, but it has also been observed in people as young as 25 years old.
Adenocystic breast cancer tends to grow slowly. Doctors usually recommend surgery. Most women do not need to have their entire breast removed (mastectomy). Instead, your doctor will simply remove the cancerous area. This surgery is called breast conserving surgery.
Cancer rarely spreads to other parts of the body. Therefore, lymph nodes usually do not need to be removed. The risk of recurrence of this type of tumor is low, so the outlook is good.
Metaplastic breast cancer
This type of breast cancer is very rare and occurs in less than 5 out of 100 breast cancer cases (less than 5%). It usually occurs between the ages of 47 and 61 and is relatively more common in Hispanic or black women.
Doctors treat metaplastic cell cancer in the same way as other types of breast cancer. You may have surgery, chemotherapy and radiation.
Some metaplastic breast tumors are triple negative. This means that the tumors have no receptors for estrogen, progesterone or HER2. Therefore, hormone therapy or targeted therapy is not helpful for these types of cancer.
Metaplastic breast cancer usually does not spread to the lymph nodes. But it is more likely to spread to other parts of the body than other types of breast cancer.
Lymphoma in the breast
Non-Hodgkin lymphoma (NHL) of the breast is rare and occurs in less than 1 in 100 breast cancers (less than 1%).
The most common types are B-cell lymphomas, such as diffuse large B-cell lymphomas and extranodal marginal zone lymphomas. A rarer type is peripheral T-cell lymphoma (PTCL).
There is a rare type of NHL called breast implant-associated anaplastic large cell lymphoma (BIA-ALCL). This can develop in a small number of women who have breast implants. The first symptom is usually swelling (seroma) around the breast implant. Very rarely, a lump can be felt near the implant.
Most people experience these symptoms many years after their implant surgery, but it can happen earlier. BIA-ALCL in situ is when the lymphoma has not spread to other areas of the breast. The implant is removed and usually no further treatment is needed, but sometimes the patient may be treated with medication. The outlook is excellent for this species.
In some women, lymphoma may look like a lump in the breast. This type is called infiltrative i-ALCL and can also spread to the lymph nodes. After the implant is removed, treatment is usually chemotherapy or sometimes radiation therapy. The outlook for this species is not very good.
The main type of breast cancer
A primary type of breast cancer has specific genetic changes in the cells. The cells produce large amounts of a protein called cytokeratin 5/6.
Primary breast cancers are often triple negative. This means they don't have many receptors for estrogen, progesterone or HER2. Therefore, hormone therapy and targeted drugs do not work for most basal-like cancers.
Instead, doctors use other treatments, such as surgery, chemotherapy, and radiation.
Phyllodes lub cystosarcoma phyllodes
Phyllodes is pronounced fill-oy-dees. This type of breast cancer occurs in less than 1 in 100 breast cancer cases (less than 1%). Also called cystosarcoma phyllodes. The first symptom is usually a lump in the breast.
Phyllodes can be cancerous (malignant) or non-cancerous (benign). It usually occurs in middle-aged or elderly women. If it is cancer, it can spread to the lymph nodes, but this is rare.
The main treatment is surgery. Sometimes you may also receive radiation or chemotherapy.
Papillary breast cancer
Papillary breast cancer occurs in less than 1 in 100 breast cancer cases (less than 1%). Papillary tumors affect older women.
There are different types of papillary breast cancer:
- in situ, these are early-stage cancers that have not spread
- invasive, they have spread into the surrounding breast tissue or beyond it
- non-cancerous (benign) are also called papillomas
Treatment depends on the type of papillary breast cancer. You may have surgery on your chest and sometimes on your lymph nodes. You may also receive radiation therapy and drug treatment.
Treatment of a rare form of breast cancer
Coping with a cancer diagnosis can be difficult, both practically and emotionally. This can be especially difficult if you have a rare cancer. Being well informed about your cancer and its treatment can make it easier for you to make decisions and cope with what is happening.
Talking to other people who are going through the same thing can help. But finding people who have had a rare form of cancer can be difficult.
Cancer Chat is a forum for discussing cancer research in the UK. This is a place for anyone suffering from cancer. You can share experiences, stories and information with other people who know what you are going through.
- Check out the cancer chat
Support and information
The Rare Cancers Alliance provides support and information to people with rare cancers.
Nurses from Cancer Research UK
For support and information, call the Cancer Research UK information nurses. They can advise you on who can help you and what support is available. Freephone: 0808 800 4040 - from Monday to Friday from 9 am to 5 pm
Experiments and research
There may be fewer clinical trials for rare cancers than for more common types. Research into rare types of cancer is difficult to organize and carry out. Obtaining a sufficient number of patients is critical to the success of the trial. The results will not be strong enough to prove that one type of treatment is better than the other if the sample size is too small.
The International Rare Cancer Initiative (IRCI) aims to advance further research into new treatments for rare cancers. They design trials in multiple countries so that more people can participate in the trials.
- Learn more about research and trials