Sarcoma cancer

Sarcoma is a complex and diverse category of cancer that can manifest in various tissues throughout the body, primarily within the bones and soft tissues. The term “sarcoma” encompasses more than 70 distinct types, broadly classified into bone sarcomas and soft tissue sarcomas. Soft tissue sarcomas originate in connective tissues, which include muscles, fat, blood vessels, nerves, tendons, and the linings of joints.

Due to the wide variety in types, the treatment for sarcoma is highly individualized and dependent on factors such as the specific type of sarcoma, its anatomical location, and the patient’s overall health.

Epidemiology of Sarcomas

Sarcomas are versatile malignancies that can arise in various parts of the body. Their distributions include:

• Lower Extremities: Approximately 40% of sarcomas are found in the legs, ankles, and feet.
• Upper Extremities: About 15% manifest in the shoulders, arms, wrists, and hands.
• Trunk and Pelvic Regions: Around 30% occur in the chest wall, abdomen, and pelvis.
• Head and Neck: The remaining 15% are located in the head and neck regions.

The American Cancer Society estimates that approximately 17,560 individuals in the United States will be diagnosed with some form of Sarcoma in 2024.

Types of Sarcoma

The term sarcoma encompasses a diverse array of cancers arising from bone and soft tissues, with over 70 recognized subtypes.

Bone Sarcomas

Primary bone sarcomas originate within the bones themselves. Notably, over one-third of these cases are diagnosed in individuals under 35 years of age, with a significant number of them occurring in children. There are five key types of primary bone sarcoma:

• Osteosarcoma: The most prevalent form, often occurring in the long bones.
• Chondrosarcoma: Arises from cartilage cells. It’s typically found in older adults.
• Chordoma: Develops from the remnants of the notochord, and is commonly found at the base of the skull or spine.
• Ewing’s Sarcoma: Primarily affects children and adolescents. It is often located in the pelvis or long bones.
• Fibrosarcoma: Originates from fibroblasts, connective tissue cells.

In contrast, metastatic bone cancer starts in other organs (such as the thyroid, lung, kidney, breast, or prostate) and spreads to the bones. This process can lead to significant structural damage and pain in the skeletal system.

Soft Tissue Sarcomas

Soft tissue sarcomas originate in connective tissues, including muscle, fat, blood vessels, and nerves. These sarcomas predominantly affect adults, though certain types, like rhabdomyosarcoma, are primarily found in children. Common types of soft tissue sarcomas are as follows:

• Angiosarcoma: Arises from blood vessels, known for its aggressive behavior.
• Desmoplastic Small Round Cell Tumors: A rare and aggressive tumor often affecting young adults.
• Gastrointestinal Stromal Tumor (GIST): Typically found in the digestive tract.
• Leiomyosarcoma: Develops in smooth muscle tissue.
• Liposarcoma: Originates from fat cells.
• Malignant Peripheral Nerve Sheath Tumor: Arises from the protective lining of nerves.
• Malignant Schwannoma: A type of tumor that affects Schwann cells in the nerves.
• Myxofibrosarcoma: Typically appears in older adults and can present as a soft tissue mass.
• Rhabdomyosarcoma: Affects striated muscle tissue, common in children.
• Synovial Sarcoma: Often located near joints, affecting soft tissues.
• Undifferentiated Pleomorphic Sarcoma: A highly aggressive form of soft tissue sarcoma.

Who is affected by sarcoma?

Sarcomas affect individuals across all age groups, including both children and adults. Generally, soft tissue sarcomas are more prevalent in adults, while bone sarcomas are more frequently diagnosed in children, adolescents, and individuals over 65 years of age. Certain demographics, including those assigned male at birth, as well as individuals in Black or Hispanic demographics, have a higher incidence of bone sarcoma.

Symptoms of Sarcoma

Sarcoma can inflict a range of symptoms, which may consist of:

• A palpable lump that may or may not be tender.
• Persistent bone pain or discomfort.
• Bone fractures that occur without significant trauma.
• Unexplained abdominal pain.
• Unintentional weight loss.

Causes of Sarcoma

The etiological factors underlying most sarcomas remain largely unclear. Generally, cancer arises from mutations in cellular DNA, leading to uncontrolled cell growth and division. These mutations disrupt normal cellular functions, allowing abnormal cells to proliferate, accumulate, and form tumors. Furthermore, malignant cells can metastasize, spreading to other bodily regions.

Risk Factors for Sarcoma

Several factors may elevate the risk of developing sarcomas:

• Inherited syndromes: Genetic conditions such as familial retinoblastoma and neurofibromatosis type 1 can predispose individuals to various cancers, including sarcoma.
• Radiation therapy: Previous radiation treatments for other cancers can increase the likelihood of developing sarcoma later in life.
• Chronic swelling (lymphedema): This condition can heighten the risk for angiosarcoma.
• Chemical exposure: Prolonged contact with certain industrial chemicals and herbicides may raise the risk of sarcomas, particularly those affecting the liver.
• Viral infections: Human herpesvirus 8 (HHV-8) is known to increase the risk of Kaposi sarcoma, particularly in immunocompromised individuals.

Diagnosis of Sarcoma

The diagnosis of sarcoma begins with a comprehensive evaluation by a healthcare provider, which includes a thorough medical history and physical examination. To confirm the diagnosis and determine the specific type of sarcoma, various diagnostic tests may be employed, particularly involving tissue sampling through biopsy.

Diagnostic Tests

• X-ray: Utilizes low doses of radiation to create images of bones and soft tissues, providing initial insight into abnormalities.
• Computed Tomography (CT) Scan: Combines multiple X-ray images to produce detailed cross-sectional views of internal structures, aiding in tumor localization.
• Magnetic Resonance Imaging (MRI): Employs strong magnets and radio waves to generate high-resolution images, offering clearer detail than X-rays, especially when abnormalities are detected.
• Bone Scan: Involves the injection of a small amount of radioactive material to identify bone disorders, such as bone sarcoma, by highlighting areas of increased metabolic activity.
• Positron Emission Tomography (PET) Scan: Utilizes a glucose tracer to reveal areas of high glucose metabolism, which often indicates tumor presence.
• Biopsy: The definitive test for diagnosing sarcoma, involving the extraction of tissue from the tumor. A pathologist examines the sample microscopically to confirm the presence of sarcoma and to classify its specific subtype, guiding treatment options.

Staging of Sarcoma

Staging provides essential information about the extent and severity of sarcoma, facilitating treatment decisions. Most sarcomas are staged using the TNM classification system:

• T: Indicates the size and local extent of the primary tumor.
• N: Assesses the involvement of nearby lymph nodes.
• M: Identifies whether the cancer has metastasized to distant organs.

Additionally, the grade (G) of the tumor is determined based on how much the cancer cells resemble normal cells. Lower grades typically correlate with a better prognosis. Staging is quantified on a scale from I to IV, with higher numbers indicating more extensive disease progression. 

Each sarcoma subtype may have distinct staging criteria, which your healthcare provider can clarify regarding your specific diagnosis and its implications for treatment and prognosis.

Management and Treatment

The optimum management of sarcoma typically involves a multidisciplinary team:

• Surgeons
• Radiologists
• Medical oncologists
• Radiation oncologists
• Pathologists
• Geneticists

Treatment Options for Sarcoma

Surgery:

• The primary treatment approach for localized sarcoma, aiming to completely excise the tumor while preserving surrounding healthy tissue. 
• Strategies may include wide local excision or limb-salvage procedures, using grafts or replacements as necessary. 
• In some cases, amputation may be considered to ensure all cancerous cells are removed.

Radiation Therapy: 

• Utilizes high-energy X-rays to target and kill cancer cells. 
• Techniques include external beam radiation and internal radiation (brachytherapy), which can be administered during or after surgery to manage remaining cancer cells or metastasis.

Chemotherapy: 

• Involves the systemic use of cytotoxic drugs to inhibit the growth of rapidly dividing cancer cells. 
• Chemotherapy may be employed as neoadjuvant therapy (prior to surgery) to shrink tumors or adjuvant therapy (following surgery) to eliminate residual disease.

Targeted Therapy: 

• Focuses on specific molecular targets associated with cancer cells, minimizing effects on healthy tissues. 
• This approach may be utilized alone or in conjunction with other therapeutic modalities.

Immunotherapy: 

• Enhances the body’s immune response against cancer cells, counteracting their ability to evade immune detection. 
• This innovative treatment may be particularly beneficial in specific sarcoma subtypes.

Thermal Ablation: 

A minimally invasive procedure that uses extreme temperatures to destroy tumor tissue, guided by imaging techniques to ensure precision.

Palliative Care: 

• Aimed at enhancing quality of life for patients with advanced illness, palliative care focuses on symptom management and support. 
• This holistic approach ensures comprehensive care, addressing physical, emotional, and psychological needs.

Clinical Trials: 

Participation in clinical trials may be recommended as a means to access new and evolving treatment options that are currently under investigation.

Survival Rates

In general, survival rates for sarcoma vary significantly depending on the stage at which it is diagnosed. 

For localized sarcoma, where the cancer has not spread, the five-year survival rate is approximately 81%. In contrast, for those diagnosed with locally advanced sarcoma, the five-year survival rate drops to about 56%. Unfortunately, for metastatic sarcoma, where the cancer has spread to distant parts of the body, the five-year survival rate is only around 16%. 

These statistics highlight the critical importance of early detection and personalized treatment plans. Consultations with an oncologist can produce a clearer understanding of an individual’s prognosis.