Papillary breast cancer is a rare type of breast cancer accounting for less than 1% of all breast cancers.
There are different types of papillary breast cancer, and they are often seen mixed with other types of breast cancer. Papillary cancer cells can also be found in ductal carcinoma in situ (DCIS), a non-invasive breast cancer.
Papillary breast cancer is usually a low grade (well-differentiated), slow-growing breast cancer. Although each case is different, the outlook for papillary breast cancer is generally better than most other types of invasive breast cancer.
Papillary breast cancer is not the same as the benign (not cancer) condition intraductal papilloma.
The symptoms of papillary breast cancer are similar to those of invasive ductal breast cancer. These can include a change in the size of the breast, a lump or thickening of the skin and changes to the nipple such as nipple discharge and the nipple being pulled in (inverted nipple).
Routine breast screening can often pick up cancer before there are any symptoms. Therefore, some women will be diagnosed with papillary breast cancer after attending breast screening without having any of the symptoms described above.
Papillary breast cancer is diagnosed in the same way as other breast cancers. A range of tests will be done to make the diagnosis. They include a mammogram (breast x-ray), ultrasound scan, fine needle aspiration and/or needle core biopsy.
The features of your papillary breast cancer will affect what treatments you are offered.
Breast surgery is usually the first treatment for papillary breast cancer.
This may be:
- breast-conserving surgery, usually referred to as wide local excision or lumpectomy, which is the removal of the cancer with a margin (border) of normal breast tissue around it
- mastectomy, which is the removal of all the breast tissue including the nipple area.
The type of surgery recommended depends on the area of the breast affected, the size of the cancer relative to the size of your breast and whether more than one area in the breast is affected. Your breast surgeon will discuss this with you.
If you have breast-conserving surgery, it’s important that a clear margin of tissue is taken from around the cancer. If a clear margin of tissue is not seen when the area removed is examined under the microscope, sometimes a second operation is needed.
If you’re going to have a mastectomy, you’ll usually be able to have breast reconstruction either at the same time as your mastectomy (immediate reconstruction) or at a later date (delayed reconstruction).
Surgery to the lymph nodes
If you have invasive papillary breast cancer, your specialist team will want to check if any of the lymph nodes (glands) under the arm (the axilla) contain cancer cells. This helps them decide whether or not you will benefit from any additional treatment after surgery. To do this, your surgeon is likely to recommend an operation to remove either some (a lymph node sample or biopsy) or all of the lymph nodes (a lymph node clearance).
Sentinel lymph node biopsy is widely used for people with breast cancer whose tests before surgery show no evidence of the lymph nodes containing cancer cells. It identifies whether or not the first lymph node (or nodes) is clear of cancer cells. If it is, this usually means the other nodes are clear too, so no more will need to be removed.
If the results of the sentinel lymph node biopsy show that the first node or nodes are affected, you may be recommended to have further surgery or radiotherapy to the remaining lymph nodes.
Sentinel lymph node biopsy is not suitable if tests before your operation show that your lymph nodes contain cancer cells. In this case it is likely that your surgeon will recommend a lymph node clearance.
What are the adjuvant (additional) treatments?
After surgery, you may need further treatment. This is called adjuvant (additional) therapy and can include:
- hormone therapy
- targeted therapy.
The aim of these treatments is to reduce the risk of breast cancer returning in the same breast or developing in the other breast, or spreading somewhere else in the body.
If you have breast-conserving surgery, you will usually be offered radiotherapy to the breast to reduce the risk of the cancer coming back in the same breast. Sometimes you may be offered radiotherapy to the nodes under your arm.
In some circumstances, you may be recommended to have radiotherapy to the chest wall after a mastectomy, for example if some lymph nodes under the arm are affected.
Hormone (endocrine) therapy
Hormone therapy will only be prescribed if your breast cancer has receptors within the cell that bind to the female hormone oestrogen and stimulate the cancer to grow (known as oestrogen receptor positive or ER+ breast cancer).
All breast cancers are tested for oestrogen receptors using tissue from a biopsy or after surgery. Most papillary breast cancers are oestrogen receptor positive.
Depending on various features of the cancer, chemotherapy may be recommended for some people. Because it’s less common for invasive papillary breast cancer to spread to the lymph nodes under the arm, and it’s more likely than other types of breast cancer to grow slowly, chemotherapy is not often used.
Targeted therapies (sometimes called biological therapies)
This is a group of drugs that block the growth and spread of cancer. They target and interfere with processes in the cells that cause cancer to grow.
The most widely used targeted therapy is trastuzumab (Herceptin). Only people whose cancer has high levels of HER2 (HER2 positive), a protein that makes cancer cells grow, will benefit from having trastuzumab.
There are various tests to measure HER2 levels which are done on breast tissue removed during a biopsy or surgery. Invasive papillary breast cancer is usually HER2 negative, meaning that trastuzumab will not be of any benefit.
Intracystic papillary breast cancer
Intracystic papillary breast cancer is a type of papillary breast cancer. It is sometimes called ‘encapsulated papillary carcinoma’. It’s difficult to know exactly how many people are diagnosed with this particular type of breast cancer as papillary breast cancer itself is rare. It's sometimes found alongside DCIS or invasive breast cancer. The treatment of intracystic papillary breast cancer will depend on whether either DCIS or invasive breast cancer is also present.
Micropapillary breast cancer is another rare type of breast cancer that is often found mixed with other types of invasive breast cancer or DCIS.
As with all types of breast cancer, the treatment of micropapillary breast cancer will depend on various features such as the size, grade, ER status and HER2 status. Because micropapillary breast cancer is more likely than some other types of breast cancer to have spread to the lymph nodes, treatment usually includes chemotherapy.