Soft Tissue Sarcoma: Symptoms, Types, Causes, Treatment and Future Directions

What is Soft Tissue Sarcoma?

Vascular tumors are a type of soft tissue sarcoma that can affect the blood vessels or the lymphatic system anywhere in the body. Soft tissue sarcomas are rare cancers that start in the connective tissues that support and surround other body structures, such as muscles, fat, nerves, tendons, and joints. There are more than 70 types of soft tissue sarcoma, each with different characteristics and behaviors.

Vascular tumors are also known as angiosarcomas, hemangioendotheliomas, hemangiopericytomas, or solitary fibrous tumors, depending on the specific type of blood vessel cells involved. They are most often found in children and adolescents, but they can also occur in adults. Vascular tumors can be aggressive and difficult to treat, especially if they spread to other parts of the body.

What are the symptoms of Soft Tissue Sarcoma?

The symptoms of vascular tumors depend on the location and size of the tumor. Some common symptoms include:

• A visible lump or blotch that might or might not hurt
• Bleeding or bruising from the affected area
• Difficulty breathing, swallowing, or speaking if the tumor is in the head and neck region
• Abdominal pain, weight loss, or changes in bowel habits if the tumor is in the digestive tract
• Bone pain or fractures if the tumor is in the bones
• Swelling of the arms or legs if the tumor is in the limbs or causes lymphedema (a buildup of fluid in the tissues)

What are the types of soft tissue sarcoma?

Soft tissue sarcoma is a rare type of cancer that starts as a growth of cells in the body’s soft tissues. The soft tissues connect, support and surround other body structures. Soft tissues include muscle, fat, blood vessels, nerves, tendons and linings of the joints. Soft tissue sarcoma can happen anywhere in the body. It happens most often in the arms, legs and belly.

There are more than 80 types of soft tissue sarcoma or sarcoma-like growths1. Some types are more likely to affect children. Others affect mostly adults. These cancers can be hard to diagnose because they may be mistaken for many other types of growths.

Some of the most common types of soft tissue sarcoma are:

• Leiomyosarcoma: These tumors begin in the smooth muscle tissue that lines hollow organs. The uterus is the most common location among women. Leiomyosarcoma can also begin in organs such as the bladder and stomach.
• Liposarcoma: Tumors that begin in fatty tissue are known as liposarcoma. There are several different forms of liposarcoma. Some are much more aggressive than others so it’s important to know the subtype.
• Gastrointestinal stromal tumor (GIST): GISTs begin in the gastrointestinal tract, usually in the stomach. These tumors tend to be large in size and can spread to other parts of the body.
• Angiosarcoma: These tumors begin in cells in the lining of blood vessels or lymph vessels. They can occur anywhere in the body, but are often found in the skin, breast, liver, spleen, or heart.
• Synovial sarcoma: These tumors start near the joints, such as the knee or elbow. They often affect young adults and can spread to other parts of the body.
• Undifferentiated pleomorphic sarcoma (UPS): UPS can occur anywhere in the body. It usually occurs in the back of the abdomen, in the arms, or in the legs, especially the thighs. These tumors often grow quickly and can spread to other parts of the body, including the lungs.
• Synovial sarcoma: Synovial sarcoma typically occurs in the arms, legs, fingers, and toes. It is more common in children and young adults. The most common sign is a painful lump. Newer therapies such as immunotherapy and epigenetic therapy show great potential for treating these tumors. Learn more about synovial sarcoma. 
• Malignant peripheral nerve sheath tumor (MPNST): MPNSTs are rare, highly aggressive tumors that start in the nerve cells. The most common sign is a painful lump. About one-third of MPNSTs are linked to the genetic condition neurofibromatosis.
• Desmoid tumor: Desmoids are related to soft tissue sarcoma, but they are not a cancer because they do not spread to other parts of the body. Some desmoids can be monitored and don’t need other treatment. Others, however, can be aggressive. Learn more about desmoid tumors.
• Solitary fibrous tumor and hemangiopericytoma: Solitary fibrous tumors and hemangiopericytomas can form anywhere in the body. Some are benign (not cancerous), while others may be highly aggressive. Most often, these tumors grow slowly over many years. Most are not found until they are very large.
• Fibrosarcoma: Fibrosarcoma was once thought to be one of the most common forms of soft tissue sarcoma. Thanks to advances in diagnostic techniques, fibrosarcoma is now considered a rare form of the disease.
• Vascular sarcoma: Vascular tumors start in the blood vessels. They range from benign hemangiomas and low-grade epitheloid hemangioendotheliomas to highly aggressive angiosarcomas. Learn more about angiosarcomas.
• Epithelioid sarcoma: These tumors are more common in young adults. The classic form of the disease grows slowly and occurs in the feet, arms, legs, or forearms of younger men. Epithelioid tumors can also begin in the groin, and these tumors tend to be more aggressive.
• Alveolar soft part sarcoma (ASPS): ASPS is an extremely rare sarcoma that typically starts in the lower extremities of people between the ages of 15 and 40. It is a slow-growing tumor but one that often spreads to other parts of the body, such as the lungs and brain.
• Clear cell sarcoma and melanoma of soft parts: This tumor has features of both soft tissue sarcoma and melanoma (an aggressive form of skin cancer). However, since it starts in the soft tissue and usually does not affect the skin, it is typically classified as sarcoma. The foot and ankle are common locations.
• Extraskeletal myxoid chondrosarcoma (EMC): EMC tumors are painless masses that are soft and gelatinous in consistency. They tend to grow slowly and spread to other parts of the body, particularly the lungs. These tumors typically affect people between the ages of 30 and 60 and most commonly occur in the lower extremities.

What are the causes of Soft Tissue Sarcoma?

The exact causes of vascular tumors are not clear. However, some factors that may increase the risk of developing these cancers include:

• Genetic syndromes that predispose to cancer, such as familial retinoblastoma or neurofibromatosis type 1
• Previous radiation therapy for another cancer
• Exposure to certain chemicals, such as herbicides or industrial solvents
• Infection with human herpesvirus 8 (HHV-8), which is associated with Kaposi’s sarcoma.

What are the Soft Tissue Sarcoma risk factors?

The risk factors for vascular tumors are similar to those for other types of soft tissue sarcoma. Some of these factors include:

• Age: Most soft tissue sarcomas occur in people over 50 years old, but some types, such as vascular tumors, are more common in younger people
• Gender: Men are slightly more likely than women to develop soft tissue sarcomas
• Race: Some types of soft tissue sarcoma, such as Kaposi’s sarcoma, are more common in certain ethnic groups
• Family history: Having a close relative with a soft tissue sarcoma may increase the risk of developing one.

How Soft Tissue Sarcoma diagnosis?

The diagnosis of vascular tumors involves a combination of tests and procedures, such as:

• Physical examination: The doctor will check for any signs of a tumor, such as a lump or swelling
• Imaging tests: X-rays, ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET) scans may be used to locate and measure the tumor and see if it has spread to other organs
• Biopsy: A sample of tissue from the tumor is removed and examined under a microscope to confirm the diagnosis and determine the type and grade of the cancer
• Blood tests: Blood samples may be taken to check for signs of infection or inflammation.

What are the Soft Tissue Sarcoma treatment options?

The treatment options for vascular tumors depend on several factors, such as:

• The type, grade, size, and location of the tumor
• The cancer’s stage (the extent of its dissemination)
• The patient’s age, general health, and preferences

The main treatment options for vascular tumors include:

Surgery In Soft Tissue Sarcoma

Surgery is usually the first and most important treatment for vascular tumors. The goal is to remove the entire tumor along with a margin of healthy tissue around it. This reduces the risk of recurrence (the cancer coming back). Sometimes, surgery may also involve removing nearby lymph nodes or other organs that are affected by the cancer. Depending on the extent of surgery, reconstruction or rehabilitation may be needed to restore function and appearance.

Radiation therapy In Soft Tissue Sarcoma

Radiation therapy uses high-energy beams, such as X-rays or protons, to kill cancer cells or stop them from growing. It may be used before surgery to shrink the tumor and make it easier to remove, or after surgery to destroy any remaining cancer cells and prevent recurrence. It may also be used as the main treatment for tumors that cannot be removed by surgery, or as a palliative treatment to relieve symptoms and improve quality of life. Radiation therapy may cause side effects, such as skin irritation, fatigue, nausea, or hair loss.

Chemotherapy In Soft Tissue Sarcoma

Chemotherapy employs medications to either kill or stop the growth of cancer cells. It can be administered orally, topically, or intravenously. It can be used in conjunction with radiation therapy, before or after surgery, or both. It may also be used as the main treatment for tumors that cannot be removed by surgery, or as a palliative treatment to relieve symptoms and improve quality of life. Chemotherapy may cause side effects, such as hair loss, nausea, vomiting, diarrhea, mouth sores, or low blood cell counts.

Related: Unlocking Hope: Curious Advances In Ewing Sarcoma Cancer Treatment, Paving The Way To Brighter Futures

Approved Targeted Therapy for Soft Tissue Sarcoma

Targeted therapy is a type of treatment that uses drugs to target specific molecules (such as proteins) on cancer cells or inside them. These molecules help send signals that tell cells to grow or divide. By blocking these signals, targeted therapy drugs can stop cancer cells from growing or spreading, or make them die.

There are different types of targeted therapy drugs that may be used to treat soft tissue sarcoma, depending on the subtype of the cancer and the results of molecular tests. Some of the approved targeted therapy drugs for soft tissue sarcoma are:

• Pazopanib (Votrient): This drug is a tyrosine kinase inhibitor that blocks several proteins involved in cell growth and survival, such as VEGF (vascular endothelial growth factor), which helps cells form new blood vessels. It may be used to treat certain advanced soft tissue sarcomas that have not responded to chemotherapy .
• Tazemetostat (Tazverik): This drug works by targeting EZH2, a protein that normally helps some cancer cells grow. It can be used to treat epithelioid sarcomas that cannot be removed completely by surgery .
• Sirolimus albumin-bound nanoparticles (Fyarro): This drug is a form of sirolimus, a drug that blocks a protein called mTOR, which is involved in cell growth and survival. It can be used to treat advanced malignant PEComas, a rare type of soft tissue sarcoma.
• Regorafenib (Stivarga): This drug is another tyrosine kinase inhibitor that blocks several proteins involved in cell growth and survival, such as VEGF, PDGF (platelet-derived growth factor), and RAF (a protein that activates MEK and ERK, which are also involved in cell growth and survival).
• Sorafenib (Nexavar): This drug is similar to regorafenib, but it blocks fewer proteins.
• Sunitinib (Sutent): This drug is also similar to regorafenib and sorafenib, but it blocks different proteins.
• Larotrectinib (Vitrakvi) and Entrectinib (Rozlytrek): These drugs target NTRK genes, which can be mutated or fused with other genes in some cancers, leading to abnormal cell growth and survival. They can be used to treat tumors with an NTRK gene change.
• Atezolizumab (Tecentriq): This drug is a type of immunotherapy that works by blocking a protein called PD-L1, which helps cancer cells evade the immune system. It can be used in combination with doxorubicin for patients with advanced or metastatic STS that cannot be cured by surgery or radiation and have not been treated with chemotherapy.
• Eribulin mesylate (Halaven): This drug is a type of chemotherapy that works by interfering with the process of cell division and causing cell death. It can be used to treat patients with liposarcoma or leiomyosarcoma that have spread to other parts of the body and have received prior chemotherapy .
• Trabectedin (Yondelis): This drug is a type of chemotherapy that works by binding to DNA and disrupting its function. It can be used to treat patients with liposarcoma or leiomyosarcoma that have spread to other parts of the body and have received prior chemotherapy .

Targeted therapy drugs are usually taken as pills or capsules by mouth. The dose and schedule depend on the type of drug and the patient’s response. Targeted therapy drugs can cause different side effects, such as high blood pressure, fatigue, nausea, diarrhea, liver problems, bleeding, clotting, wound healing problems, heart problems, low blood cell counts, and increased risk of developing some types of blood cancers. The side effects vary depending on the drug and the patient’s condition. Your doctor will monitor your health closely while you are on targeted therapy and adjust your treatment as needed.

What are the emerging Soft Tissue Sarcoma treatment options?

There are several new and experimental treatments that are being tested for vascular tumors and other types of soft tissue sarcoma. Some of these include:

• Immunotherapy: This kind of therapy employs the body’s immune system to combat cancer. It may involve stimulating the immune system with substances called cytokines, blocking the immune checkpoints that prevent the immune system from attacking cancer cells, or using genetically modified immune cells (such as CAR T cells) to target specific antigens on cancer cells
• Molecularly targeted therapy: This is a type of treatment that uses drugs that target specific genetic mutations or alterations that are found in some types of soft tissue sarcoma. For example, some drugs target the KIT gene mutation in gastrointestinal stromal tumors (GIST), or the NTRK gene fusion in epithelioid sarcoma
• Nanomedicine: This is a type of treatment that uses tiny particles (such as nanoparticles, nanotubes, or nanorobots) to deliver drugs or other substances directly to the tumor site. This may increase the effectiveness and reduce the toxicity of the treatment
• Gene therapy: This is a type of treatment that uses viruses or other vectors to deliver genes or genetic material into cancer cells. This may correct a defective gene, introduce a new gene, or activate or deactivate a gene that affects the behavior of cancer cells

What are the future directions of Vascular Tumors (Soft Tissue Sarcoma)?

The future directions of vascular tumors and other types of soft tissue sarcoma include:

• Improving the diagnosis and classification of these cancers based on molecular and genetic features
• Developing more effective and less toxic treatments based on personalised medicine and precision oncology
• Identifying new biomarkers and targets for therapy and prevention
• Enhancing the quality of life and survivorship of patients with these cancers

Related: Ewing Sarcoma Pathology Outlines: Essential Insights You Should Know

Conclusion

Vascular tumors are a rare and challenging type of soft tissue sarcoma that can affect the blood vessels or the lymphatic system anywhere in the body. They can be aggressive and difficult to treat, especially if they spread to other parts of the body. Surgery, radiation therapy, chemotherapy, and targeted therapy are the primary forms of treatment. There are also several new and experimental treatments that are being tested for these cancers. The future directions include improving the diagnosis and classification, developing more effective and less toxic treatments, identifying new biomarkers and targets, and enhancing the quality of life and survivorship of patients with these cancers.

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