Tumors of the bone can be benign or malignant, with the malignant variety being more challenging to treat. Furthermore, malignant tumors could either be primary tumors (originating from bone) of the bone or secondary deposits from tumors elsewhere in the body.
The most commonly encountered bone cancers are osteosarcomas. The classic osteosarcoma is a rare (0.2% of all malignant tumors) highly malignant cancer, with an incidence of 3 cases/million population/year. Keep reading to get an outlook on osteosarcoma.
What is osteosarcoma?
Osteosarcoma is a bone tumor that primarily affects the long bones-shinbone (tibia) near the knee, the thighbone (femur) near the knee, or the upper arm bone (humerus) near the shoulder.
It is a type of malignant tumor of bones characterized by the tumor cells’ direct formation of immature bone or osteoid tissue. Rarely, osteosarcoma may also arise in the soft tissue.
It can happen in the second decade of life and late adulthood. The age at presentation ranges from 10 to 25 years of age, but it can also occur in adults over 60.
Types of Osteosarcoma
It can be classified as:
- Localized – only present in the bone it started in.
- Metastatic – present in other areas, such as the lung or unconnected bones.
Causes of osteosarcoma
The exact cause of osteosarcoma is yet unknown, but studies suggest that you could be at a high risk of developing it if you have:
- Previous history of bone cancer.
- Exposure to radiation therapy as part of treating your previous cancer.
- Family history or genetic predisposition of osteosarcoma or hereditary retinoblastoma (cancer of the retina of eyes).
- Genetic diseases such as Paget’s disease or Li-Fraumeni syndrome.
Signs and symptoms
- Most patients with osteosarcoma at the extremities complain of pain and soft tissue swelling. Because of the stretching of the periosteum (outer layer of bone), this primary bone tumor usually causes pain before the tumor is discernible.
- Weakening of the bone with the development of minute stress fractures. Fracture – Up to 15% of pediatric patients present with pathological fractures.
- Swelling related to the soft tissue mass if osteosarcoma shows soft tissue extension.
- Other uncommon symptoms include weight loss, redness on the affected bone region, fever, weight loss, and reduced appetite.
Diagnosis of Osteosarcoma
Your doctor may do a simple blood test to check for tumor markers that would show the possibility of osteosarcoma. Besides this, other tests used to diagnose osteosarcoma include:
- CT scan: a 3-D X-ray for examining bones and soft organs.
- MRI uses sound waves and powerful magnets to create visuals and images of internal organs.
- X-ray: creates images of dense tissue inside the body, including bone.
- PET scan: a full-body scan for the detection of cancer.
- Biopsy: removal of a tissue sample from the bone to test cancer cells under a microscope.
The management of osteosarcoma aims to eradicate the disease, keep the integrity of the skeletal system, and preserve a limb with useful function. Chemotherapy and surgery are preferred for treating this condition.
In most cases, surgeons save the cancerous limb with surgical interventions. They surgically remove the tumor and surrounding bone and replace the missing bone with an artificial or prosthetic part.
These dramatic changes in events, from amputation to limb salvage surgeries, have heralded new hope for patients who have this form of cancer.
Chemotherapy is a method that uses drugs that help shrink and kill cancerous cells. The chemotherapy treatment duration varies and may depend on whether cancer has spread to other parts of the body. After chemotherapy, surgery can be used to remove any remaining tumors.
Chemotherapeutic drugs used in the treatment of osteosarcoma include:
- High-dose Methotrexate (HDMTX)
- Cisplatin (CDP), Adriamycin (ADM)
- Ifosfamide (IF)
These drugs are mostly injected through veins.
To know more about the early detection and treatment of osteosarcoma, watch this video by Dr Kurt Weiss, professor of Musculoskeletal Oncology at UPMC, Pittsburgh, USA.
Osteosarcoma is malignant but can show a good prognosis if the tumor is confined to the original bone. In fact, 3 out of 4 people can be successfully treated if their tumors haven’t spread elsewhere.
Unfortunately, the survival rate is reduced to almost 30 percent if cancer has spread to other body parts. But over 85% of patients can be treated with limb-sparing surgery without decreasing the long-term survival rates.