Bone cancers and sarcomas are rare and heterogeneous groups of tumors that arise predominantly from the connective tissues. Globally, they account for less than 1% of all cancers. These cancers usually affect children and young adults more than the older population. According to the National Cancer Registry Programme of the India Council of Medical Research (ICMR), the incidence of bone cancer is below 2 % of all cancers among the Indian population, while sarcomas are the fifth most common solid tumors in children, and account for about 6-7% of all childhood malignancies.
Bones are the supporting framework of our body which facilitates movement, protection of internal organs, and hematopoiesis (formation of blood cellular components). Soft tissues are the extra-skeletal tissues of the body that surround organs and other anatomic structures like tendons, the lining of the joints, muscles, fats, and blood vessels.
Sarcoma and bone cancers arise from the embryonic mesenchymal cells that mature into muscles, adipose tissue, bone, and cartilage among other tissues.
Bone cancer develops when the healthy cells in the bone grow uncontrollably and form a mass called a tumor. As the tumor develops, abnormal cells crowd out the healthy ones. These tumors weaken the bone and make it vulnerable to fracture. The tumors can be malignant (cancerous, spread to other parts of the body) or benign (non-cancerous, do not spread to nearby tissues).
There are mainly two types of bone cancer:
Primary cancers are the true bone cancers; the different kinds of primary bone cancers are:
Other less common bone cancer symptoms are fever, a feeling of being unwell, unintentional weight loss, and anemia (low level of red blood cells).
The exact cause of the bone tumors is unknown. Researchers believe that bone cancer may develop due to sudden changes in the cells of the bone. Additionally, some factors may increase the risk of bone cancer, and include:
If any sign or symptom in a patient raises the suspicion of bone cancer, the following tests are recommended:
The cancer staging is done followed the TNM staging system. It provides detailed information about:
Based on TNM staging, bone cancer can be in any of the following stages:
Treatment options for bone cancer usually depend on several factors, including the type, stage of cancer, possible side effects, and the overall health of the patient.
Treatment modalities available for bone cancer are:
Some side effects of chemotherapy are nausea, hair loss, weight loss, and extreme fatigue.
Radiation Therapy: It involves using high-energy beams like X-rays, gamma rays, and electron beams to shrink and destroy tumors. For bone cancer, radiation therapy can be given alone or in combination with chemotherapy or after surgery to ease the symptoms and prevent the recurrence of cancer.
Side effects from radiation therapy may include mild skin reactions, fatigue, nausea and vomiting, diarrhea, and weight loss.
Targeted Therapy: This therapy involves the use of drugs that interfere with genes or proteins that contribute to the growth and survival of cancer cells, thereby destroying the cancer cells. These are different from chemo drugs and have minimal side effects.
A sarcoma occurs when healthy cells in the soft tissues and other locations undergo a change and start to grow out of control, which slowly forms a mass or lump called a tumor. The tumors can be benign (non-cancerous, do not spread to nearby tissues) or malignant (cancerous, spread to other parts of the body).
The tumors that originate within the soft tissues are called primary cancers while those cancers that start in another part of the body and spread to the soft tissues are called secondary tumors.
Sarcomas are usually asymptomatic during the early stage. As the sarcomas originate in different locations, the signs and symptoms vary depending on the location of the tumor. A lump or swelling which may or may not cause pain is usually the first sign of sarcoma.
Other possible osteosarcoma symptoms include:
The exact cause of soft tissue sarcoma is not clear. Generally, errors in the DNA cause the cell to divide at an uncontrollable rate, forming tumors.
There are no screening tests that can detect sarcomas in their early stages. If a person experiences any possible sign or symptom of sarcoma, the following tests are recommended.
Sarcomas are also staged based on the TNM staging system. Based on this system, the sarcomas can be in the following stages:
The treatment method for soft tissue cancer is based on the location, type, and stage of sarcoma, possible side effects, and overall health of the patient. The major treatment modalities include:
Surgery: Surgery is the mainstay and involves the surgical removal of the entire tumor. In rare cases, where the tumor is large and involves major blood vessels and nerves, the whole tumor is removed to control its spread (amputation). This is common in arms and limbs.
Radiation therapy: Radiation therapy may be used before the surgery (neoadjuvant therapy) to shrink the tumor or after the surgery (adjuvant therapy) to destroy any remaining cancer cells.
Radiations can be given through an external machine or can be delivered by placing a radiation source near the site of the tumor (internally). In some cases, intraoperative radiation is performed during surgery to protect the nearby healthy tissues.
Common side effects of radiation therapy include fatigue, headaches, memory loss, and scalp irritation.
Chemotherapy: Chemotherapy is the use of drugs to destroy rapidly growing cancer cells in the body. Chemo drugs are injected into a vein (IV) or given orally. For sarcomas, chemotherapy is given as the main treatment or after the surgical procedures to enhance its effect.
Common side effects of chemotherapy include nausea, vomiting, fatigue, and hair loss.
Targeted therapy: It involves the use of specific drugs to identify and destroy the specific cancer cells without harming the normal cells. The targeted drugs work differently from standard chemo drugs and offer minimal side effects.
Although there is no way to prevent bone cancer and sarcomas, early diagnosis and timely treatment can help improve mortality and morbidity. For those with a known risk factor, a regular checkup can help in the early detection of cancer. Patients with early-stage tumors have the best chance of long-term survival. Once the active treatment is completed, regular checkups and medications are needed to manage the side effects and maintain overall well-being.