What is Sarcoma? Types, Symptoms, Causes, and Treatments for Soft Tissue and Bone Sarcomas

Sarcoma is a rare type of cancer that forms tumors in the body’s connective tissues, including blood vessels, muscle, nerves, tendons, body fat, ligaments, and cartilage. Unlike cancers that typically originate in the body organs, sarcomas develop in almost any part of the body, which makes their detection and management more challenging. By definition, sarcomas are broadly classified into two categories: bone sarcomas and soft tissue sarcomas.

Within these categories, there are multiple subtypes of sarcomas, such as Ewing sarcoma, osteosarcoma and chondrosarcoma, which are among the most common types. On the soft tissue sarcomas side, variants include liposarcoma, leiomyosarcoma, synovial sarcoma, and angiosarcoma, along with their rarest forms, such as dermatofibrosarcoma protuberans, epithelioid sarcoma, solitary fibrous tumor, myxofibrosarcoma, and desmoplastic small round cell tumors, which can be challenging for healthcare professionals to detect. The causes of underlying sarcomas often involve genetic changes, environmental exposures and hereditary syndromes, though in most cases, the exact triggers behind the cancer remain unknown.

Because the rare type of cancer can affect a wide range of tissues in the body, the symptoms of sarcoma vary significantly, from painless lumps in soft tissues to painful bodily pains or limited movement in bone sarcomas. Modern sarcoma treatment strategies, including surgery, radiation therapy, chemotherapy and targeted drugs, are continually evolving to improve outcomes.

What is a Sarcoma?

In medical terms, sarcoma is defined as a rare and diverse group of cancers that arise from the bones or soft, connective tissue of the body. While sarcomas account for less than 1% of all adult cancers, the types of sarcoma are relatively more common among children and young adults. The sarcomas’ ability to originate in multiple tissue types makes them distinct from carcinomas, which typically form in epithelial tissues, such as the skin or the linings of organs.

The diversity of sarcomas means that diagnosis often requires a combination of testing methods, such as biopsy, imaging, and molecular testing, to determine the exact subtype of sarcoma and its stage.

Types of Sarcomas

Sarcomas are broadly classified into two types, which are further subdivided into multiple subtypes.

Bone Sarcomas

The type of sarcoma that develops in the bones is identified by its specific name. It is rare compared to other bone cancers, such as metastatic cancers that spread from other organs.

The most common subtypes of bone sarcomas include:

• Osteosarcoma

The most prevalent type of bone sarcoma, which often affects adolescents and young adults, typically forms in the long bones.

• Ewing Sarcoma

The type of sarcoma is frequently diagnosed in children and teenagers, which generally develops in the pelvis, chest wall or thigh.

• Chondrosarcoma

The type of bone sarcoma is commonly observed in middle-aged and older adults, which begins in cartilage-producing cells. Chondrosarcoma is more resistant to chemotherapy.

Soft Tissue Sarcomas

As denoted by the name, soft tissue sarcomas refer to a group of malignant cancers that develop in the soft tissues of the body, including muscles, blood vessels, fat, tendons, nerves and the joint linings.

The most common subtypes of soft tissue sarcomas include:

• Rhabdomyosarcoma

The type of sarcoma originates in the skeletal muscle tissues and is most commonly found in adolescents and children. It often develops in skeletal muscle tissues of the head, neck, bladder or reproductive organs.

• Leiomyosarcoma

Leiomyosarcoma forms in the smooth muscle cells, which are found in the uterus, stomach and blood vessels. The subtype of soft tissue sarcoma commonly affects adults and can sometimes be aggressive.

• Liposarcoma

The type of sarcoma arises from the fat cells and usually develops in the deep soft tissues of the area behind the abdomen, thighs or arms. It can range from a slow-growing tumor to more aggressive forms.

• Synovial Sarcoma

Though the type of cancer does not arise from the synovial tissues, it typically forms near joints, particularly the ankles, knees or elbows. Synovial sarcoma is most often diagnosed in young adults.

• Angiosarcoma

It is a rare subtype of soft tissue sarcoma that begins in the blood vessels or lymphatic vessels. Angiosarcoma may affect the skin, liver, breast or heart and often grows at a quicker rate than other types of sarcomas.

• Dermatofibrosarcoma Protuberans (DFSP)

DFSP is a slow-growing type of sarcoma that develops in the connective tissue of the skin. While it grows slowly, the type of sarcoma can invade surrounding tissues if left untreated.

• Epithelioid Sarcoma

It is a rare type of cancer that often develops in the hands, feet or forearms. Epithelioid sarcomas typically grow slowly but have a tendency to spread to other lymph nodes.

• Myxofibrosarcoma

The type of sarcoma is commonly diagnosed in elderly individuals, which affects the arms and legs. It has a tendency to recur locally after treatment.

• Solitary Fibrous Tumor

The type of sarcoma can occur in various parts of the body, but is commonly found in the lining of the lungs or the pleura. Some solitary fibrous tumors are benign, while others may be difficult to treat.

• Desmoplastic Small Round Cell Tumor

It is a rare and aggressive type of sarcoma that typically forms in the abdomen or pelvis and is most commonly found in young males.

• Gastrointestinal Stromal Tumor

A distinct subtype of soft tissue sarcoma, gastrointestinal stromal tumor, develops in the digestive tract, most often in the small intestine or stomach. It arises from special cells called interstitial cells of Cajal and often responds well to targeted corrective therapies.

Symptoms of Sarcomas

The symptoms of sarcomas depend primarily on their type and the area of the body affected. Some tumors may not cause noticeable symptoms until they grow large. The common symptoms of soft tissue and bone sarcomas include:

Soft Tissue Sarcoma

• Painless lump or swelling that increases in size gradually
• Pain or soreness if the tumor presses on muscles or nerves
• Restricted movement in the affected area
• Bleeding or ulceration in surface tumors in rare cases

Bone Sarcoma

• Persistent bone pain, which becomes more painful at night
• Swelling or tenderness near bones or joints
• Difficulty moving a joint or limb
• Increased risk of bone fractures

Causes of Sarcomas

The causes of sarcoma are complex and not always fully understood. However, over time, several causes of sarcomas have been identified, which include:

Genetic Mutations

Changes in DNA that affect cell growth and repair may trigger the development of sarcomas.

Inherited Syndromes

Conditions such as Li-Fraumeni syndrome, familial retinoblastoma and neurofibromatosis are suspected of developing sarcomas.

Radiation Exposure

Prior radiation therapy for other cancers can increase the risk of developing sarcomas later in life.

Environmental Factors

Prolonged exposure to certain environmental factors, such as vinyl chloride or herbicides, has been linked to the development of sarcomas in most cases.

Chronic Inflammation or Lymphedema

Long-term swelling or inflammation in tissues may contribute to the formation of sarcoma in bones or soft tissues.

Treatments for Sarcomas

The suitable treatment for sarcoma depends mainly on its type, severity, location in the body, and the overall health of the affected individual. Treatment usually involves a multidisciplinary approach:

Surgery

Surgery is the primary treatment for most sarcomas, which is aimed at obliterating the tumor while preserving function.

Radiation Therapy

Another common sarcoma removal technique is radiation therapy, which is often used before or after surgery to shrink tumors or destroy remaining cancer cells.

Chemotherapy

The type of treatment is effective for certain sarcomas, particularly aggressive types such as Ewing sarcoma and rhabdomyosarcoma.

Targeted Therapy

The sarcoma is treated through specific drugs designed to block specific molecules involved in the tumor growth. The technique is commonly used in gastrointestinal stromal tumors (GISTs).

Immunotherapy

An emerging corrective treatment of sarcoma that uses the body’s immune system to recognise and fight sarcoma cells.

Sarcomas represent a diverse and complex group of malignant tumors that can develop in connective tissues around the body. Although the type of cancer is rare, its wide range of subtypes makes early recognition and accurate diagnosis crucial. Understanding the definition of sarcoma, its types, common symptoms, potential causes and treatment options is key to ensuring effective management of the condition.

With ongoing research and development in targeted therapies, the outlook for individuals diagnosed with these rare types of cancers continues to evolve, highlighting the importance of awareness and timely medical intervention.