Angiosarcoma

Angiosarcoma is a rare and aggressive cancer that starts in the lining of blood vessels or lymph vessels, most often appearing on the skin of the head and neck but capable of developing almost anywhere in the body.

Table of contents

• What is angiosarcoma?
• Where angiosarcoma develops
• Causes and risk factors
• Signs and symptoms
• How angiosarcoma is diagnosed
• Treatment options
• Outlook and survival

What is angiosarcoma?

Angiosarcoma is a rare type of cancer that forms in the lining of blood vessels and lymph vessels^[1]. The lymph vessels are part of the immune system that collects bacteria, viruses, and waste products from the body and disposes of them^[1].

This cancer is very rare, occurring in approximately one person per million people each year in the United States^[2]. Angiosarcoma makes up only 1 to 2 percent of all soft tissue sarcomas^[3]. It is most commonly found in elderly white men and can occur at any age, though people aged 60 and older are more likely to develop it^[3].

Angiosarcoma is considered aggressive because it grows quickly and often spreads to other parts of the body before diagnosis. Because these cancers arise from the cells lining blood or lymphatic vessels, they can easily spread to distant sites, particularly the liver and lungs^[2]. This makes early diagnosis especially important for survival.

Where angiosarcoma develops

Angiosarcoma can develop anywhere in the body, but it most often occurs in specific locations. About 60 percent of angiosarcoma cases affect the skin, with the scalp alone accounting for approximately 50 percent of all cases^[2]. The skin of the head and neck region is the most common site overall^[1].

When angiosarcoma affects the skin, it is called cutaneous angiosarcoma. This form typically appears as reddish or blue small lumps that eventually spread, grow bigger, and bleed easily, or as a purplish area of skin that looks like a rash or bruise^[14].

Less commonly, angiosarcoma can form in deeper tissues and internal organs. It may develop in the breast, particularly in women who have received radiation therapy for breast cancer treatment^[7]. The liver and spleen can also be affected, though symptoms may not appear until the tumor grows large enough to impact how the organ works^[14].

In very rare cases, angiosarcoma can occur in the heart, most often in the right upper heart chamber^[9]. Cardiac angiosarcoma is particularly aggressive and invasive, making it difficult to remove with surgery^[9]. Angiosarcoma can also develop in bones and other deep soft tissues throughout the body^[2].

Causes and risk factors

The exact cause of angiosarcoma is not clear in most cases^[1]. However, several definite risk factors have been identified that increase the likelihood of developing this cancer.

Radiation therapy is a well-established risk factor. Angiosarcoma can develop in areas that were previously treated with radiation, typically appearing several years after treatment. For breast cancer survivors who received radiation to the chest wall, angiosarcoma may develop approximately eight to ten years later^[14].

Chronic lymphedema is another significant risk factor. This condition involves long-term swelling caused by damage to lymph vessels. Approximately 5 percent of all angiosarcomas are linked to chronic lymphedema^[14]. When angiosarcoma develops in the setting of chronic lymphedema, it is called Stewart-Treves syndrome^[13].

Chemical exposure has been associated with certain types of angiosarcoma. Liver angiosarcoma, in particular, is linked to exposure to vinyl chloride, arsenic, and thorium dioxide. Sometimes, angiosarcomas related to chemical exposure don’t appear until 10 to 40 years after the exposure occurred^[14].

Genetic factors may also play a role. People with certain mutations in their DNA, such as changes in the POT1 gene, may be more likely to develop cardiac angiosarcoma^[9]. Several genetic syndromes, including neurofibromatosis, Klippel-Trenaunay syndrome, and Maffucci syndrome, are associated with an increased risk^[13].

It is important to note that angiosarcoma can also appear spontaneously without any identifiable cause, underscoring the complexity of this disease^[21].

Signs and symptoms

The symptoms of angiosarcoma vary greatly depending on where the tumor develops in the body. Many symptoms may be non-specific, making early detection challenging^[2].

When angiosarcoma affects the skin on the head, neck, or scalp, the most common signs include a raised area of skin that looks like a bruise or a bruise-like lesion that grows larger over time. The area may bleed when scratched or bumped, and swelling may develop in the skin around the lesion^[1]. Some people describe a rapidly growing lump or bump under the skin, which may be painful^[7].

For angiosarcoma of the breast, symptoms can include a purple area that looks like a bruise, a sore that doesn’t heal and continues to grow, or a soft lump that can be felt^[8].

When angiosarcoma develops in internal organs like the liver or heart, symptoms are often less obvious initially. Patients may not notice symptoms until the tumor grows large enough to affect organ function or create pressure on nearby structures^[14]. Common symptoms for internal angiosarcoma include fatigue, pain near the affected area, malaise, and unexplained weight loss^[14].

Cardiac angiosarcoma commonly causes shortness of breath as the most frequent symptom. Other symptoms may include chest pain, heart palpitations, and passing out^[9]. Liver angiosarcoma may cause jaundice, which is yellowing of the skin and eyes, along with persistent pain in the upper left part of the abdomen^[14].

Angiosarcoma is known for being an aggressive cancer that can quickly spread to other parts of the body^[7]. If the cancer spreads beyond its original site, additional symptoms may develop depending on where it has metastasized.

How angiosarcoma is diagnosed

Diagnosing angiosarcoma typically involves several steps and different types of tests. The process usually begins with a thorough physical examination, during which the healthcare provider examines the affected area and evaluates any symptoms^[11].

Imaging tests play a crucial role in diagnosis. These tests help doctors see the size and location of the tumor and determine whether the cancer has spread. Common imaging tests include MRI (magnetic resonance imaging), CT (computed tomography) scans, and PET (positron emission tomography) scans^[1]. Ultrasound may also be used, particularly for examining tumors close to the skin surface^[4].

The definitive diagnosis of angiosarcoma requires a biopsy. During this procedure, a small sample of the suspicious tissue is removed and sent to a laboratory for examination. A specialist called a pathologist studies the cells from the sample under a microscope to determine if they are cancerous and what type of cancer is present^[8].

Immunohistochemical analysis is often performed on the biopsy sample. This special testing helps provide more detailed information about the cancer cells and confirms the diagnosis of angiosarcoma^[2].

For angiosarcoma in specific locations, additional specialized tests may be needed. For example, cardiac catheterization or echocardiograms may be used when heart involvement is suspected^[9].

Blood and urine tests may also be ordered as part of the diagnostic process, though these tests alone cannot diagnose angiosarcoma^[4]. These tests help assess overall health and organ function.

Treatment options

The treatment of angiosarcoma depends on several factors, including the location of the cancer, its size, and whether it has spread to other parts of the body. Most patients benefit from a combination of different treatment approaches^[3].

Surgery is often the main treatment for localized angiosarcoma. The goal is to remove all of the cancer along with some surrounding healthy tissue. This margin of healthy tissue helps ensure that all cancer cells have been removed^[11]. For angiosarcoma affecting the arms or legs, surgeons typically perform limb-sparing surgery so the limb can continue to function well^[7]. However, in rare cases where cancer has spread throughout the limb, partial or full amputation may be necessary.

For breast angiosarcoma, particularly when it develops after radiation therapy for breast cancer, the typical treatment involves removal of the breast, known as a mastectomy, combined with chemotherapy^[7]. Heart angiosarcoma requires specialized cardiovascular surgery, though complete tumor removal can be challenging because of the tumor’s invasive nature^[9].

Radiation therapy uses high-energy beams, such as X-rays and protons, to kill cancer cells. It is often used after surgery to destroy any remaining cancer cells^[11]. Radiation may also be an option when surgery is not possible, such as when the cancer is very large or has spread to other areas. Sometimes radiation is combined with chemotherapy for patients who cannot undergo surgery^[8].

Chemotherapy uses drugs or chemicals to kill cancer cells or slow their growth. It may be recommended if the angiosarcoma has spread to other areas of the body^[11]. Paclitaxel is particularly effective for angiosarcoma and is usually administered weekly^[12]. Other chemotherapy regimens include anthracycline-based drugs like doxorubicin and gemcitabine-based combinations^[12].

Targeted drug therapy attacks specific chemicals present within cancer cells. By blocking these chemicals, targeted treatments can cause cancer cells to die^[11]. Because angiosarcomas develop from blood vessel cells and involve vascular signaling, drugs that target vascular endothelial growth factor (VEGF) have shown promise^[10]. Pazopanib is one such targeted therapy that has been studied in angiosarcoma patients^[12].

Immunotherapy is a newer treatment approach that helps the immune system become more effective at attacking cancer cells. It is sometimes used when angiosarcoma is advanced^[11].

A multidisciplinary approach that combines surgery, radiation therapy, chemotherapy, or immunotherapy typically offers the best chance for favorable outcomes^[3].

Outlook and survival

Angiosarcoma carries a poor prognosis overall, even with treatment^[3]. The five-year survival rate ranges from approximately 30 to 38 percent^[2]. However, survival varies significantly depending on several factors.

The earlier angiosarcoma is diagnosed, the better the chances of survival. People with small tumors that can be completely removed with surgery have the best outlook^[8]. Patients with low-grade breast angiosarcoma tend to survive longer than those with other types of this cancer^[16].

Unfortunately, many people with angiosarcoma are not diagnosed until the cancer has already spread to other parts of the body, which often results in a worse prognosis^[16]. The reported rates of advanced or metastatic disease at the time of diagnosis vary from 16 to 44 percent, with overall survival ranging from six to sixteen months for these patients^[10].

The location of the tumor significantly impacts prognosis. Cardiac angiosarcoma and liver angiosarcoma have particularly poor outcomes, with survival sometimes measured in months rather than years^[2].

Angiosarcoma has a high rate of local recurrence, meaning the tumor can return after treatment^[9]. Because of this risk, continuing to follow up with healthcare providers after treatment is essential for monitoring and early detection of any recurrence.

While these statistics provide general information, every person’s situation is unique. Prognosis depends on many individual factors, including where the tumor is located in the body, whether cancer has spread, how much of the tumor could be removed during surgery, and the person’s overall health. Newer treatments continue to be developed, which may improve outcomes for future patients^[16].