What is Cancer
Cancer Type

Bone cancer (bone sarcoma)

What is primary bone cancer?
Bone cancer is a rare type of cancer that forms as a painful lump (‘tumour') in bone. It's also known as bone sarcoma. When a bone cancer begins to grow, the cancer cells multiply and start to destroy the bone. The affected bone becomes weak and starts to cause problems.

The most common places where bone cancer develops are around the knee, the wrist, the shoulder and the pelvis.
Types of bone cancer
There are over 30 types of bone cancers:
  • Osteosarcoma is the most common type; it's made up of many of abnormal bone-producing cells.
  • Chondrosarcoma is a bone cancer that's made up of many of abnormal cartilage cells.
  • Ewing sarcoma is another type of bone cancer.
Some types of bone cancer affect the soft tissues of the body. These are called soft tissue sarcomas.
How common is it?
According to the National Cancer Registry Report (2007), bone cancer is a rare occurrence in Malaysia. For Malaysian men, it comprises 1.2% of registered cases, with a peak incidence for men in the age group of 10 to 19 years of age. For Malaysian women; it comprises 0.8%, with a peak incidence for in the age group of 10 to 19 years of age.
We don't know exactly what causes most bone cancer. However, there are several risk factors.
  • Age: Bone cancer commonly affects teenagers and young adults, and people over the age of 55. Bone cancer that develops later in life is usually linked to a prior disease of the bone, such as Paget disease.
  • Radiotherapy: there is a very small risk of bone cancer for people who've had radiotherapy. Radiotherapy sometimes affects bone in the treatment area. The risk is higher for people who have high doses of radiotherapy at a very young age. Most people who've had radiotherapy in the past won't develop a bone cancer.
  • Other medical conditions: some people who've had Paget disease of the bone, fibrous dysplasia or multiple enchondromas are at a higher risk of bone cancer. 
Genetic factors
Most bone cancers aren't caused by inheriting a faulty gene. However, some inherited conditions, such as Li-Fraumeni syndrome, put people at higher risk. People who have a strong family history of certain types of cancer are also at risk.
Children who've had a rare type of eye cancer called retinoblastoma are at a higher risk of osteosarcoma.
A small number of people develop bone cancer due to genetic changes that happen during their lifetime, rather than inheriting a faulty gene.
The most common symptom of bone cancer is a painful swelling. Pain may not be constant. It may be much worse at night or during activity. Taking pain-relieving tablets may not help.

As the cancer grows over weeks or months, the pain may get worse and become constant. The pain may cause problems with movement. For example, you may have a limp if the cancer is in the leg. Sometimes you may be able to feel a lump.
Most people who have pain and swelling don't have bone cancer. It's much more likely to be a less serious condition. However, if you have symptoms for more than two weeks, you should see your doctor.
If doctors think you may have bone cancer, they'll carry out blood tests, x-rays and scans. These tests are needed to rule out other conditions. If the results suggest that you may
have bone cancer, your doctor will refer you to a specialist centre.
You may need to have a biopsy. This is the only sure way to diagnose a bone cancer. A biopsy means taking a sample of cells from the lump and examining them under a microscope. Your doctor will use a fine needle to do this. You'll have local anaesthetic to numb the area before the needle is put into the lump.
A bone biopsy should only be carried out by a specialist who does them regularly and has special expertise in this area.
Annie Angle, cancer nurse (Dip. Oncology Nursing, Royal Marsden, London)