Sarcoma

Overview

Sarcoma is a rare cancer type that arises from connective tissues, including muscles, fat, bones, and blood vessels. The National Cancer Institute reports approximately 12,000 new cases of soft tissue sarcomas and 3,000 cases of bone sarcomas annually in the U.S. While bone sarcomas are more common in children, soft tissue sarcomas are often diagnosed in adults.

What is Sarcoma?

A sarcoma is a form of cancer that arises from mesenchymal (connective tissue) cells. Connective tissue includes a variety of structures such as bone, cartilage, fat, muscle, and blood vessels. As a result, sarcomas can develop in any of these tissue types, leading to numerous subtypes of the disease. These subtypes are classified based on the specific tissue and cell type from which the tumour arises.

Sarcomas are classified as primary connective tissue tumours, meaning they originate in connective tissues. This is different from secondary (or "metastatic") connective tissue tumours, which occur when cancer spreads from other parts of the body, such as the lungs, breast, or prostate, to the connective tissue. Sarcomas represent one of five main types of cancer, categorised according to the cell type in which they develop.

Types of Sarcoma

Sarcomas are classified as either soft tissue sarcomas or bone sarcomas, based on their location in the body.

Soft Tissue Sarcomas: They arise in soft tissues and often appear in the limbs, chest, or abdomen. Both children and adults can develop these tumours.

Bone Sarcomas: These are primary tumours of the bone, most commonly diagnosed in children. Osteosarcoma is the most common type.

Sarcoma Symptoms

Sarcoma symptoms can vary significantly based on the tumour’s location, type, and growth rate. In the early stages of sarcoma, it does not cause noticeable symptoms. Some may appear as a painless lump under the skin, while others may only cause discomfort when they grow large enough to press on nearby organs or structures. Bone sarcomas, for example, may result in persistent pain or swelling, often intensifying at night, and can sometimes restrict movement.

Common sarcoma symptoms include pain or discomfort in an arm, leg, abdomen, or pelvis, unexplained weight loss, a new lump or mass, may or may not be painful, persistent back pain, and difficulty moving an affected limb, sometimes resulting in limping or limited range of motion. Because these symptoms overlap with other conditions, it is essential to consult a healthcare provider for an accurate diagnosis if you experience any of these signs.

Sarcoma Causes

The exact causes of most sarcomas still need to be better understood. Generally, cancer develops when mutations occur in the DNA of cells. Inside each cell, DNA is organised into numerous individual genes, which contain the instructions for the cell's functions, including how it should grow and divide.

Mutations can cause cells to grow and divide uncontrollably and to continue surviving when normal cells would typically die. As a result, these abnormal cells can accumulate and form a tumour. Additionally, cells can break away from the original tumour and spread to other parts of the body, a process known as metastasis.

Sarcoma Diagnosis and Tests

Diagnosing sarcoma and assessing its stage involves a series of exams and specialised tests. Here is an overview of the main steps:

Physical Examination: The doctor will begin with a physical exam to understand your symptoms and identify any lumps or abnormalities that could provide clues for diagnosis.

Imaging Tests: The type of imaging used depends on the suspected location and nature of the sarcoma. X-rays help to assess bone abnormalities. MRI scans offer detailed views of soft tissues, making them ideal for identifying connective tissue issues. Other imaging tests may include ultrasound, CT scans, bone scans, and PET scans to evaluate the tumour and check for potential spread.

Biopsy (Tissue Sampling): A biopsy is essential for confirming sarcoma and identifying its specific type. During this procedure, the doctors take a small tissue sample from the affected area and analyse it in a lab. The biopsy sample may be collected through a needle passed through the skin or removed during a surgical procedure. Sometimes, the biopsy is performed at the same time as surgery to remove the tumour.

After confirming sarcoma, your doctor may recommend further tests to determine if the cancer has spread to other areas. Each of these diagnostic steps plays a critical role in choosing the best treatment approach for your situation.

Sarcoma Management and Treatment

Sarcoma treatment typically involves multiple strategies, starting with surgery and supported by other therapies as needed. Here is an overview of each treatment approach:

Surgery: Surgery is the primary treatment for sarcoma and involves removing as much of the cancer as possible. In cases where the tumour is near critical structures, such as nerves or organs, surgeons focus on removing as much of the tumour as they can without causing significant harm. Sometimes, particularly for large or aggressive tumours, amputation may be the only option, though limb-sparing techniques help to maintain function.

Radiation therapy: It employs high-powered energy beams, such as X-rays and protons, to eliminate cancer cells. The radiation can originate from a machine that moves around your body, directing energy beams at the cancer (or external beam radiation). Alternatively, the radiation sources may be placed inside your body temporarily near the tumour (a procedure called brachytherapy). In some cases, radiation is applied during surgery to remove the cancer, which is referred to as intraoperative radiation.

Chemotherapy: Chemotherapy uses drugs that travel throughout the body to target and destroy cancer cells. Some sarcomas respond better to chemotherapy than others, and before surgery, they shrink the tumour or afterwards to help prevent recurrence by eliminating any remaining cancer cells.

Targeted Therapy: Targeted therapy involves drugs designed to attack specific vulnerabilities in cancer cells, often identified through lab tests. Unlike chemotherapy, which affects both healthy and cancerous cells, targeted therapy focuses on the cancer’s unique characteristics, reducing harm to normal cells. This treatment can be particularly effective for sarcomas with specific genetic or molecular profiles.

Immunotherapy: Immunotherapy stimulates the body’s own immune system to fight cancer. Cancer cells sometimes evade detection by producing proteins that “blind” immune cells. Immunotherapy drugs work by disrupting this process, allowing the immune system to recognise and attack the cancer cells more effectively.

Ablation therapy: These therapies eliminate cancer cells by utilising electricity to heat the cells, extremely cold liquid to freeze them, or high-frequency ultrasound waves to damage them.

Preventive Measures for Sarcoma

Since there are no identifiable risk factors associated with sarcoma, prevention is challenging. Avoiding known risks, like radiation exposure, may reduce risk, though often radiation is unavoidable for treating other conditions.

Myths and Facts Related to Sarcoma

Here are some common myths about sarcoma, along with the facts to clarify them:

Myth 1: Biopsies Cause Sarcoma to Spread
Fact: The risk of a proper biopsy spreading cancer cells is extremely low. Biopsies are crucial for accurately diagnosing sarcoma and determining the most effective treatment.

Myth 2: There is No Hope for Patients with Stage 4 Sarcoma
Fact: Advances in treatments such as surgery, chemotherapy, and radiation therapy, along with clinical trials for new medications, gene therapies, and stem cell therapies, are providing new options and hope for patients with Stage 4 sarcoma. Many patients today have better survival chances even with advanced-stage diagnoses.

Myth 3: Amputation is the Only Treatment for Bone Cancer
Fact: In specialised cancer centres, around 90% of bone cancer patients are treated with limb-sparing surgery instead of amputation. Studies show that the survival rates for patients who have limb-sparing surgery are comparable to those who undergo amputation.

Myth 4: It is Possible to Prevent Sarcoma with Superfoods
Fact: A nutritious diet is beneficial for general health, but no single food or "superfood" can prevent sarcoma or other cancers. Sarcomas typically result from complex genetic changes rather than dietary factors. While good nutrition supports overall health, it cannot replace medical treatment for sarcoma.

Myth 5: All Patients with the Same Type of Cancer Receive the Same Treatment
Fact: It is possible to tailor sarcoma treatment depending on the cancer type and stage. For example, myeloma or lymphoma may not require surgery, while osteosarcoma usually requires both surgery and chemotherapy. On the other hand, it is possible to treat Chondrosarcoma with surgery alone. The personalisation in treatment helps to best address each patient’s specific situation.