Musculoskeletal & Soft Tissue Cancers
Musculoskeletal and soft tissue cancers are a rare and diverse group of malignancies that arise from the body's connective tissues. They are collectively known as sarcomas.
Bone cancers (osseous sarcomas) form in the bones and are more common in children and adolescents. The most frequent types are osteosarcoma and Ewing sarcoma.
Soft tissue cancers (soft tissue sarcomas) develop in tissues like fat, muscle, nerves, and blood vessels. These can occur in any part of the body but are most often found in the limbs.
Key Risk Factors
Unlike many other cancers, the exact cause of most musculoskeletal and soft tissue sarcomas is unknown. However, certain factors can increase a person's risk.
Genetics: A small number of sarcomas are linked to inherited genetic syndromes, such as Li-Fraumeni syndrome and retinoblastoma.
Radiation Exposure: Prior radiation therapy for another cancer can increase the risk of developing a bone or soft tissue sarcoma years later.
Chemical Exposure: Exposure to certain industrial chemicals, like vinyl chloride and herbicides, has been linked to an increased risk of soft tissue sarcomas.
Chronic Swelling: Certain chronic conditions involving swelling, like lymphedema, can increase the risk of developing a sarcoma.
Epidemiology
In India, the epidemiology of musculoskeletal and soft tissue cancers is distinct due to a younger age of onset and challenges in diagnosis.
Rarity: These cancers are rare, accounting for less than 1% of all cancers in adults, but a higher proportion of cancers in children and adolescents.
Younger Age of Onset: A significant number of bone and soft tissue sarcomas in India are diagnosed in children and young adults, often a decade or more younger than in Western countries.
Late-Stage Diagnosis: A major challenge in India is the late-stage presentation of patients. This is often due to a lack of awareness, misdiagnosis, or a delay in seeking specialised medical attention, which can lead to larger tumours and a higher likelihood of metastasis.
Regional Differences: Studies show variations in incidence across different regions of India. For example, some bone cancers like Ewing sarcoma are prevalent in younger age groups and have been noted to be more common in certain areas.
Typical Symptoms
The symptoms of musculoskeletal and soft tissue cancers can be vague, but some specific signs should prompt medical evaluation, especially if they are persistent.
Painless Lump or Swelling: This is the most common symptom of soft tissue sarcoma. The lump may grow rapidly, which should raise suspicion.
Persistent Pain: A chronic, unexplained pain in a bone or a joint that worsens at night and is not relieved by rest.
Fractures: A bone fracture that occurs after a minor injury or without any clear cause can be a sign of an underlying bone cancer that has weakened the bone.
Limitation of Movement: A growing tumour near a joint can cause swelling and pain, leading to a limited range of motion.
Systemic Symptoms: In advanced cases, patients may experience unexplained weight loss, fatigue, or fever.
Treatment Approaches
Treatment for musculoskeletal and soft tissue cancers is highly specialised and requires a multidisciplinary team. The goal is often to salvage the affected limb, rather than amputate it.
Surgery: This is the primary and most important treatment. The surgeon removes the tumour with a wide margin of surrounding healthy tissue. Advances in surgical techniques now allow for limb-sparing surgeries in many cases, where the tumour is removed and the bone and joint are reconstructed with a prosthesis or bone graft.
Chemotherapy: Chemotherapy is often used in combination with surgery, especially for highly aggressive bone cancers like osteosarcoma and Ewing sarcoma. It may be given before surgery (neoadjuvant therapy) to shrink the tumour and kill micrometastases, or after surgery (adjuvant therapy) to reduce the risk of recurrence.
Radiation Therapy: High-energy rays are used to kill cancer cells. It may be used before or after surgery to shrink the tumour or eliminate any remaining cancer cells. It is particularly effective for certain types of soft tissue sarcomas.
Targeted Therapy: These newer drugs are used for specific types of sarcomas with certain genetic mutations. They are less common but are a promising area of research.