Osteosarcoma is a type of bone cancer which commonly occurs in older children and more often in boys. We rarely see it in children under five. It accounts for about 3% of cancers that happen in children. The most common sites are the arms and the legs, particularly the end of long bones like the knee and shoulder joints. Nonetheless, it can develop in any bone in the body.
What are the causes of Osteosarcoma?
Like most childhood cancers, a definite cause for osteosarcoma is still unknown. However, children who have previously had radiotherapy and chemotherapy are at an increased risk of developing osteosarcoma.
What are the signs and symptoms of Osteosarcoma?
Pain and swelling in the affected bone are the most common presentations of osteosarcoma. This pain may initially come and go, gradually becoming more constant and severe, especially at night.
Doctors often discover osteosarcoma when a bone breaks after your child has had a minor fall or accident. In fact, the reason for breaking bone is due to cancer which weakens the bone.
There are many instances where your child may experience bone pain, apart from cancer. Therefore, parents should not get worried when their child get pain in the hands or legs. Nevertheless, do take your child to the doctor for an assessment if they have persistent bone pains affecting sleep, especially at night.
How is osteosarcoma diagnosed?
We need a variety of tests and investigations to diagnose osteosarcoma.
X-ray and MRI scan
An X-Ray of the painful part of the bone will generally show a tumor, although it is often challenging to see. If there is any suspicion, your doctor may advise you to do an MRI of the affected bone.
Biopsy
A biopsy procedure involves removing a small piece of the tumor and looking at it under a microscope.
What are the staging investigations in bone tumors?
Once osteosarcoma is confirmed, we must find out which other part of the body the tumor has spread. This is crucial in deciding the treatment plan and predicting the treatment results. Various tests are available to check whether the cancer has spread to other body parts, including the lungs and the bones. This is called a staging investigation and involves taking chest x-rays, bone scans, and ‘CT’ scans of the chest.
What are the treatments for Osteosarcoma?
Treatment of bone tumors comprises surgery, chemotherapy and radiotherapy. The treatment plan depends on different factors, including the size, position, and stage of the tumor.
Surgery
Surgery is a decisive mode of treatment and involves either amputation or limb-salvage surgery. The measure of the surgery depends on the bone cancer site.
Limb Sparing surgery
In limb-sparing surgery, the bone and muscles affected by the osteosarcoma are removed, leaving a gap in the bone often filled by a unique metal prosthesis (artificial). This is the type of surgery usually performed on children so that they do not lose their legs.
Amputation
Sometimes amputation of the limb is unavoidable if the cancer is affecting the surrounding blood vessels and nerves. After amputation, a false limb is fitted and it can be regularly adjusted as your child grows. Moreover, false limbs work very well. When osteosarcoma spreads to the lungs, surgery might be done to remove tumors in the lungs.
Chemotherapy
Chemotherapy is a substantial part of the treatment plan for osteosarcoma. Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells which are generally given before surgery to shrink the primary tumor. We also give it after removing the tumor with surgery to help reduce the risk of the cancer recurring (coming back). Usually, in osteosarcoma, a combination of drugs are used.
Radiotherapy
This uses high-energy radiation to destroy the cancer cells.
In some cases, radiotherapy is necessary for treating bone cancer – along with chemotherapy- especially if surgery is not possible because of the unfavorable site of the tumor.
Short-term and long-term effects of Osteosarcoma treatment
Amputation carries its own short-term and long-term outcomes. Therefore, patients need long-term psychological and social rehabilitation. With limb salvage surgery, physiotherapy and rehabilitation after surgery can help a child walk, initially with a walker or crutches and later with no assistive devices.
Metal prosthetic devices which attach to the legs may need to be replaced as the body grows, although we can adjust some prosthetics to fit as a child grows.
Many chemotherapy medicines also carry short-term and long-term risks. This includes anaemia, abnormal bleeding, and an increased risk of infections because of destruction of the bone marrow. Some drugs carry a risk of hearing loss, liver damage, heart and skin problems. In addition, years after chemo, osteosarcoma patients show an increased risk of developing other cancers.
