Osteosarcoma, sometimes called osteogenic sarcoma. Though it is a rare disease, it is the most common kind of bone cancer which begins in cells that form bones. In very rare instances, it occurs in soft tissue outside the bone. Osteosarcoma is most often found in the long bones – more often the legs, but sometimes the arms – but it can start in any bone. It is mostly found in children and teens. It can affect adults, too, but teenage boys are most likely to get it.
Osteosarcoma happens when the cells that grow new bone form a cancerous tumour. In children and teens, osteosarcoma often happens at the ends of long bones, where bone grows quickest. Often tumours develop around the knee, either in the lower part of the thighbone or the upper part of the shinbone. They may also grow in the upper arm bone close to the shoulder. However, osteosarcoma can develop in any bone in your body, especially in older adults.
Treatment for osteosarcoma usually involves chemotherapy and surgery. Typically, radiation therapy is not effective in treating osteosarcoma, though the use of new improved radiation techniques, such as proton beam therapy, is being studied.
- Symptoms for osteosarcoma include:
- Swelling or lumps around bones or the ends of bones.
- Bone or joint pain or soreness. This pain may come and go for months.
- Broken bones that don’t seem to be caused by normal events like a fall.
The patient may have pain at night or after he/she plays or exercises. There may be a limp if the osteosarcoma affects the legs. Initially, the pain may not be very constant, but it tends to worsen overnight, usually increasing with activity.
Telangiectatic osteosarcomas are a rare type of sarcoma that tends to weaken bones more than other forms of osteosarcomas. These are more likely to cause fractures at the location of the tumour.
The cause of osteosarcoma is not clear and most cases appear to occur sporadically. The condition seems to stem from an error in the child’s DNA, or genetic code. Bone-growing cells make osteosarcoma tumours by mistake. Teenagers who have a “growth spurt” are most likely to get it, and taller kids could have higher risks. A possible link between the speed of the growth spurt and the development of osteosarcoma is also being studied.
Treatments like radiation therapy for other types of cancer, or cancer medicines called alkylating agents, can could put the patient at a higher risk of getting osteosarcoma. Certain illnesses, like Paget’s disease of the bone or a type of eye cancer called hereditary retinoblastoma, may also raise the risk.
Some of the other risk factors are inherited genetic conditions such as Bloom syndrome, Li-Fraumeni syndrome, Rothmund-Thomson syndrome and Diamond-Blackfan anaemia.
After taking the medical history and family health background the doctor may check the patient’s body for unusual lumps around bones, or to figure out what’s causing the pain. Imaging tests like X-rays, CT scans, MRIs, or bone scans may be recommended. These can show unusual changes in bones that may be signs of osteosarcoma. They can also show areas where the tumour may have spread.
If there are signs of the disease on imaging tests, a biopsy maybe recommended. In a biopsy, a small sample of bone or tissue from a painful or swollen area is taken. The biopsy can show whether the tissue is cancerous and also reveals the cancer’s grade, which helps doctors understand how aggressive the cancer may be. Types of biopsy procedures used to diagnose osteosarcoma include:
- Needle biopsy: The doctor inserts a thin needle through the skin and guides it into the tumour. The needle is used to remove small pieces of tissue from the tumour.
- Surgical biopsy: The doctor makes an incision through the skin and removes either the entire tumour (excisional biopsy) or a portion of the tumour (incisional biopsy).
There are different kinds of treatment for osteosarcoma. The treatment for osteosarcoma depends on several things, such as the tumour’s location, how aggressive it is and whether it has spread. Age and overall health of the patient is also factored in.
Most people with osteosarcoma need both surgery and chemotherapy. In some cases radiation therapy is also administered.
Surgery: The goal of surgery is to remove the cancer cells, but surgeons also perform operations to maintain function and minimize disability. The extent of surgery for osteosarcoma depends on several factors, such as the tumour size, location and the person’s age.
- Limb-sparing surgery: In most cases, surgery for osteosarcoma focuses on removing the tumour and sparing the limb so that function can be maintained. Its feasibility depends, in part, on the extent of the cancer and how much muscle and tissue need to be removed.
- Amputation: With advancements in limb-sparing surgery, amputation has greatly reduced over the years. If amputation is necessary, advances in prosthetic joints can significantly improve outcomes and function.
- Rotationplasty: In this surgery, sometimes used for children who are still growing, the surgeon removes the tumour and surrounding area, including the knee joint. The foot and ankle are then rotated and the ankle functions as a knee. A prosthesis is used for the lower leg and foot. Results typically enable the person to function very well in physical activities, sports and daily living.
Chemotherapy: Doctors treat most osteosarcomas with chemotherapy. It helps in shrinking the tumour, which in turn makes surgery easier. It also gets rid of small clusters of cancer cells in the body that doctors may not be able to see on medical scans.
Children tend to have less severe side effects from chemo than adults. Due to this, the doctor may use higher doses of chemo to try to kill the tumour. Some side effects may include nausea and vomiting, lack of hunger and diarrhoea.
Radiation Therapy: Usually radiation is not used to treat osteosarcoma. However, the doctor may recommend this option in certain circumstances. During radiation therapy, doctors can use high-energy X-rays to kill cancer cells. It doesn’t work as well on osteosarcoma cells as it may with the cells of other cancers but the doctor might consider what’s called external beam radiation therapy if surgery can’t remove all the cancer. That often happens when the tumour is in the hip or jaw bone. This type of therapy focuses high-energy beams on the tumour from a machine outside the body to kill the remaining cancer cells.