Not all the bone tumor turns to cancer because some are benign. Malignant tumors in bone tissue cause bone cancer (primary bone cancer). Sometimes, metastatic tumors that develop another part of the body and spread to the bone can also cause bone cancer. However, the incidence of primary bone cancer is low compared with benign primary bone tumors. Almost 1% of new primary bone cancer cases are diagnosed every year. This indicates bone cancer is a rare type of cancer.
Growth of primary bone tumors (either benign or malignant) can compress surrounding healthy bone tissue. But benign tumors are unable to spread or destroy bone tissue and rarely cause life-threatening outcomes.
Primary bone cancers are clinically categorized as sarcomas. Sarcomas are further classified as soft-tissue sarcomas that involve muscles, fibrous tissue, blood vessels, fat, and other supporting tissue that helps to hold the bone. Synovial sarcoma is another type of bone cancer that primarily impacts synovial fluid cavities present in the bone.
Secondary bone cancer or cancer that spreads (metastasizes) to the bone from other parts of the body is clinically categorized as metastatic bone cancer. The organ or tissue from where secondary bone cancer began is referred on that fashion. For instance, breast cancer can be metastasized to the bone and cause secondary bone cancer. The incidence of secondary bone cancer is higher than primary bone cancer. Breast cancer and prostate cancer often spread to the bone. Metastatic tumors in the bone can cause fractures, pain, and hypercalcemia (abnormally high levels of calcium in the blood).
Symptoms of bone cancer
Following are some noticeable symptoms of bone cancer:
Pain is one of the most common symptoms of all types of bone cancer, but in some cases, bone cancer does not cause pain.
Lump formation occurs in the affected parts like in the legs, arms, chest, and pelvis. The nature of the lump is usually soft and warm.
Fracture of bone without significant cause
Unusual chronic pain or inflammation near a bone can occur due to cancer or other condition. It is always better to consult with a doctor to determine the cause of any bone symptoms.
Types of primary bone cancer
Following are four primary bone cancers:
Osteosarcoma: osteoblasts, the bone-forming cells are affected. The arm near the shoulder and the leg near the knee are typically affected with osteosarcoma. It can occur at any age. However, children and adolescents are more likely to develop such cancer. Males are more susceptible than females.
Chondrosarcoma: Cartilaginous tissue is the origin of chondrosarcoma. The rate of growth of this cancer is usually slow, but sometimes it causes rapid growth. Pelvis, upper leg, and shoulder are the parts from where chondrosarcoma is usually started.
Ewing sarcoma: The origin of this cancer usually starts from the bone. But sometimes, muscle, fat, fibrous tissue, blood vessels, or other supporting tissue can also involve. The rate of growth of this tumor is very quick and spread to other organs including the lungs.
Chordoma: This is a rare type of spine bone cancer. The base of the spine and the base of the skull is usually the site of origin of this type of cancer. Men are more susceptible than females. Young adults and children can develop this type of bone cancer.
The treatment plan varies depending upon the size, stage, location of the cancer. The doctor also considers the patient’s age and general health before suggesting treatment options. In general, surgery, chemotherapy, radiation therapy, cryosurgery, and targeted therapy are the available treatment options for bone cancer.
The complete removal of the entire tumor along with clearing edging is the usual treatment recommendation for bone cancer. Special surgical intervention can minimize the healthy tissue removal tendency along with the tumor. Improvement of surgical techniques and post-operative tumor treatment made it possible to remove bone cancer in the arms and legs without the entire removal of the limb. However, reconstructive surgery requires patients who undergo limb-sparing surgery to regain limb function.
Chemotherapy is a group of medicines that kills cancer cells. Patients with newly diagnosed or recurrent Ewing sarcoma or osteosarcoma usually receive a combination of chemotherapy before undergoing surgery. Chemotherapy is not a preferable treatment for chondrosarcoma or chordoma.
Radiotherapy uses high-energy x-rays to kill cancer cells. The doctor usually prescribes radiation therapy in combination with surgical intervention. Radiation therapy is often recommended for Ewing sarcoma. But radiation therapy may also be preferred as a combination therapy for osteosarcoma, chondrosarcoma, and chordoma, mostly when a small part of cancerous growth remains after surgery. However, radiation therapy can also be used without surgery or in combination with stem cell transplant to treat osteosarcoma that has to reoccur after treatment in a different bone.
In cryosurgery, liquid nitrogen is used to freeze and kill cancer cells. In some cases, doctors prefer to use this technique instead of using conventional surgery to destroy tumors in bone.
Targeted therapy is a type of medication that is formulated to interact with a specific molecule involved in the growth and spread of cancer cells. The monoclonal antibody denosumab is an approved targeted medication used to treat adults and skeletally mature adolescents who have giant cell bone tumors that cannot be removed with surgery. It prevents the bone damage caused by osteoclast.