An Overview of Angiosarcoma of the Breast

Angiosarcoma is an incredibly rare type of breast cancer. This cancer is unlike other breast cancers as it does not start in the lobules or ducts of the breast tissue, but instead starts growing in the blood vessels or the lymphatic vessels in the breast. This type of cancer makes up only about 0.2% of breast cancers. 

Angiosarcoma is divided into two types: primary and secondary. Primary angiosarcoma develops for an unknown reason, while secondary angiosarcoma develops after someone has had radiation to the breast for a previously diagnosed, unrelated breast cancer. 

This article will review angiosarcoma of the breast, including symptoms, diagnosis, and treatment of this disease. 

What Is Angiosarcoma of the Breast?

To understand breast angiosarcoma, it's helpful to know the difference between carcinomas (most breast cancers) and sarcomas.

Most breast cancers that people are familiar with are carcinomas—cancers that begin in epithelial cells, such as those that line the ducts or lobules of the breast.

Sarcomas start in different tissue, called myoepithelial cells. These make up connective tissues such as bones, muscles, and blood and lymphatic vessels.

The term "angio" means blood, and angiosarcomas are tumors that begin in blood or lymph vessels. Angiosarcomas may occur anywhere in the body, and most of these tumors occur in areas other than the breast. In fact, angiosarcoma is even a rare type of sarcoma, with only about 2% of sarcomas being diagnosed as angiosarcomas.

Due to the structure of these tissues, sarcomas do not have a preinvasive stage, such as ductal carcinoma in situ, which is a preinvasive stage of breast carcinoma, when it may be potentially caught early.

Types of Angiosarcomas

There are two types of angiosarcomas of the breast—primary and secondary.

Primary angiosarcoma of the breast accounts for around 80% of breast angiosarcomas and is usually diagnosed in women between the ages of 20 and 40.

Secondary angiosarcoma of the breast is often diagnosed in women over the age of 40. It usually occurs five to 10 years after radiation therapy for breast cancer in a different, unrelated tumor.

Symptoms of Angiosarcoma of the Breast

The symptoms of angiosarcoma can vary depending on whether it is primary or secondary and whether it has spread, or metastasized, to other areas of the body.

Primary angiosarcoma diagnosed in a person who has never had breast cancer may feel like a thickened area of the breast or an ill-defined lump. In some cases, the nearby skin may turn blue or reddish in color, appearing as though it has a rash or a bruise.

Secondary angiosarcoma often shows up as an area of redness or a bluish appearance of the breast. There may also be swelling or a mass in the breast. These lumps, unlike many breast cancers, are often painful.

These tumors have a high rate of recurrence and may recur locally (in the breast) or in distant areas of the body.

What Causes Angiosarcoma of the Breast?

The exact cause of angiosarcoma is not known. With primary angiosarcomas, there aren't any obvious risk factors for the disease.

Secondary angiocarcinomas may occur after radiation, but they have also occurred in women who have developed lymphedema (swelling in soft tissue) as a result of lymph node removal from a previous breast cancer surgery.

Diagnosing Angiosarcoma of the Breast

Several tests may be done to diagnose a breast angiosarcoma, and the choice of initial testing often depends on which symptoms are present. The process usually begins with a careful medical history, to see if there is any previous history of radiation therapy for breast cancer.

Imaging Studies

Radiological imaging studies are often done to look for other types of breast cancer, and they may be performed in this case as well. However, the appearance of angiosarcoma can be somewhat different than a typical breast cancer.

Imaging can include:

• Mammogram: Breast masses seen on mammography often have a fuzzy outline, appearing different than a more common form of breast cancer.
• Ultrasound: Angiosarcomas tend to show up well on ultrasound; masses may have a bumpy appearance.
• Breast magnetic resonance imaging (MRI): An MRI can be used to confirm results of a mammogram or ultrasound and can get a more detailed picture of the suspicious area.

A positron-emission tomography (PET) scan, nuclear medicine bone scan, or computed tomography (CT) scan may also be done to look for distant spread.

Biopsy

A biopsy is the ultimate diagnosis of what type of tissue the suspicious area is. During a biopsy, a piece of tissue is removed to be examined under a microscope to determine what type of cancer it is.

A biopsy can be taken from a tumor deep in the breast, or a punch biopsy of the skin may be done if the outer skin of the breast is affected.

Angiosarcoma of the Breast Treatment

The best treatments for angiosarcoma sometimes differ from those for more common breast cancers.

Surgery

Either breast-conserving surgery (lumpectomy) or aggressive surgery (mastectomy) may be needed. While one 2017 study found that mastectomy was associated with worse overall survival than lumpectomy among people with primary angiosarcoma, another 2017 study published in the New England Journal of Medicine suggests that mastectomy is often the treatment of choice with secondary angiosarcoma.

Unlike more common breast cancers, a sentinel node biopsy, or axillary lymph node dissection, is not usually done, as these tumors are much less likely to spread to nearby lymph nodes.

Chemotherapy

The choice of chemotherapy for an angiosarcoma of the breast is not a straightforward decision. It's a rare type of cancer, and agreement among cancer specialists is difficult. However, as part of the diagnostic process, getting genetic studies of the cancer, the cancer's "genetic fingerprint," may find targeted therapy that might be more effective than traditional chemotherapy.

Radiation Therapy

As with chemotherapy, some people may receive radiation therapy depending on the characteristics of the tumor.

Clinical Trials

Fortunately, studies are looking at systemic therapies (therapies that treat cancer anywhere in the body) for angiosarcoma.

One 2018 study showed that treatment with VEGF (vascular endothelial growth factor) inhibitors looks promising. VEGF inhibitors are a type of targeted therapy aimed at specific molecular abnormalities involved in the growth of cancer, and, in general, have fewer side effects than chemotherapy.

Clinical trials are ongoing to see if immunotherapy, such as Opdivo (nivolumab), as well as different chemotherapy combinations, may be successful at treating this aggressive cancer.

Prognosis of Angiosarcoma of the Breast

While angiosarcomas are usually aggressive tumors, each one is different, and prognosis will depend on the stage at which it is diagnosed, how far it has spread at the time of diagnosis, and how aggressively it is treated.

Survival rates vary significantly among studies, but rates are better when the tumor can be surgically removed.

Coping With Angiosarcoma of the Breast

Coping with a rare type of breast cancer can be challenging, as less is known and there are fewer survivors around to learn from. Fortunately, online support communities now allow people with uncommon and rare cancers the chance to communicate with others facing a similar journey around the globe.

As with any cancer, it's important to learn about your cancer and be your own advocate, but it is even more important with uncommon tumors. Ask questions and seek second opinions if you feel it is necessary to get the care you need.

Summary

Angiosarcoma of the breast is a rare and aggressive type of breast cancer. Though often there is no known cause, it can develop years after someone has had radiation to the breast for a previous breast cancer.

It can have symptoms such as a painful lump or skin discoloration and thickening.

After a biopsy is done to confirm the cancer, treatment options may include surgery, radiation, chemotherapy, targeted therapy, or a clinical trial.