Osteosarcoma is a type of bone cancer that most often occurs in the long bones of the arms and legs. It usually starts in the lower part of the femur or tibia near the knee or in the upper arm bone (the humerus) close to the shoulder, but can start in any bone. Most patients are children or teenagers, but it can happen to adults too. It can also spread to other parts of the body, most often to the lungs.
Osteosarcoma symptoms most commonly include pain and swelling. Sometimes the pain is felt in a different area from where the tumor is, and this is called referred pain. It is important to get any unexplained pain checked out by a doctor, especially in children and teens when the bones are growing fast. A doctor will be able to tell if the pain is caused by something that won’t go away with treatment, like an injury, or if it is from something more serious, such as osteosarcoma.
It isn’t known exactly what causes osteosarcoma, but doctors know that it begins when a healthy bone cell develops changes that cause it to grow abnormally and make too much new bone. These cells can then break away from the bone and destroy other healthy tissue. They can also spread (metastasize) to other bones and other parts of the body.
Most people with osteosarcoma need surgery and chemotherapy. Some also need radiation therapy, which is used to kill any cancer cells that might have spread to the lungs. The chances of a person getting cured of osteosarcoma depends on how much of the tumor is removed by surgery and how well the patient responds to chemotherapy.
Symptoms of osteosarcoma usually appear weeks to months before the cancer is diagnosed. This is because the symptoms are similar to many other conditions, and it may take a while for a doctor to find out what the problem is. The most common symptoms are pain and a swelling in the bone or limb. Other symptoms can include a limp, difficulty moving the affected limb, or a feeling that it is stiff or heavier than usual.
A biopsy is needed to confirm a diagnosis of osteosarcoma. This involves taking a small sample of the tumor to be looked at under a microscope. The biopsy may be done with a needle or through an operation. A doctor may need to do several biopsies before a diagnosis is made.
The treatment for osteosarcoma involves a combination of surgery, chemotherapy and radiation therapy. Chemotherapy uses medicines to kill the cancer cells in the bone and any that might have spread. It is given before surgery to shrink the tumor or kill any that might remain, and after surgery to catch any cancer cells that might still be in the body. It takes 10 to 18 weeks to give chemotherapy before surgery, and it may take another 12 to 18 weeks for the remaining cancer cells to die after surgery.
