Facts and figures bone cancers can affect any bone in the body.
Primary bone cancers are very rare, approximately 530 new cases a year in the UK, accounting for only 0.2% of all new cancer cases. (Secondary bone cancer is the spread of cancer to bones from other primary tumours such as breast, prostate and lung cancer).
Although rare in adults, it accounts for 4% of childhood malignancies. Higher incidence in males, male to female ratio of 13:10. Approximately 34% of bone cancers occur in the long bones of the lower limbs.
There are three main types of bone cancer and these tend to occur in different age groups. They are osteosarcomas, chondrosarcomas and Ewing’s sarcoma; the remainder are a mixed group of very rare tumours (spindle cell sarcomas, fibrosarcomas, leiomyosarcomas, bone tumours of vascular origin and Non-Hodgkin’s lymphomas).
Risk factors and causes of bone cancer are not fully understood. Risk factors are known to include previous radiotherapy to the area, some benign bone conditions (e.g. chordroma may develop into chondrosarcoma), certain genetics (those with Li-Fraumeni syndrome have an increased risk of osteosarcoma) and those whose mother was diagnosed with breast cancer before the age of 45 have an increased risk of developing a bone tumour.
These are the most common primary bone tumours and account for approximately 31% of these tumours. The male to female ratio is approximately 1.5:1 and the highest incidence occurs between 15 and-20 years of age and then rises again in the 60+ years age group. Most commonly arise in the femur, tibia and humerus.
These account for approximately 17% of primary bone cancers, primary chondrosarcomas arising from the bone and secondary chondrosarcomas arising in the cartilage.
The male to female ratio is approximately 1.5:1 and the highest incidence is in the 40-60 years age group. Most common sites are pelvis, femur, humerus, scapula and ribs.
These account for 8% of primary bone tumours. The male to female ratio is approximately 1.5:1 and the highest incidence occurs between 10 and 20 years of age, with more than 70% arising in those under 30 years of age. Most common sites are hip bones of the pelvis, femur and tibia (Ewing’s sarcomas can occur in soft tissues).
Bone cancer symptoms
- Pain around the site of the tumour.
- Restricted movement of limb/joint.
- Fever/high temperature.
- Weight loss.
- Pathological fracture – very rare.
Diagnosis of bone cancer
Investigations may include:
- Physical examination.
- X-rays of the affected area.
- Blood tests.
- Chest X-ray.
- Needle biopsy- some bonne tumours are benign, tissue samples will be taken for analysis.
- CT scan.
- MRI scan.
- Bone marrow biopsy (particularly for Ewing’s sarcoma).
Bone cancer treatment
Depends on several factors:
- The type of bone cancer.
- The size of the tumour.
- The position of the tumour.
- The stage of the cancer.
- Age and general health.
Surgery tends to be the main treatment, removing the bone affected with the disease.
If the tumour is in a limb bone, it may be treated by removing the affected part of the bone and a surrounding area of healthy tissue and replacing the bone with a bone graft from somewhere else in the body or a metal prosthesis. This is referred to as limb sparing surgery.
Some bones such as ribs or fibula, will not need to be replaced. However, if the disease has spread into the surrounding tissues and is affecting blood vessels or nerves, limb amputation may be the best option to avoid the risk of recurrence.
Occasionally when bone cancer has spread, it may be possible to remove a metastasis; this is most often performed for lung secondaries and most commonly in the case of osteosarcomas.
Radiotherapy may be used prior to surgery (neoadjuvant) for Ewing’s sarcoma to reduce the tumour and help improve the surgical removal. Also, it may be prescribed post-operatively (adjuvant) for Ewing’s sarcoma to reduce the risk of recurrence.
Radiotherapy in combination with chemotherapy may be used for Ewing’s sarcomas that are surgically unresectable. It is not often used for other bone tumours as they are not radiosensitive.
Palliative radiotherapy may be used in advanced cases for the relief of symptoms such as pain.
Chemotherapy can be effective in some cases, particularly Ewing’s sarcoma, osteosarcoma and spindle cell sarcoma. In all these cases, chemotherapy is usually given prior to surgery to reduce the tumour and improve tumour removal. If the tumour is in a limb, this may enable limb sparing surgery and hence avoid amputation.
Chemotherapy may also be given post-operatively to reduce the risk of recurrence. The combination of chemotherapy drugs will depend on the type of primary bone cancer and may include drugs such as vincristine, ifosfamide, actinomycin C, etoposide, gemcitabine and docetaxel. Palliative chemotherapy may be used in advanced cases for the relief of symptoms such as pain.
Mifamurtide is a drug that stimulates the immune system; it is a relatively new therapy having only been licensed since 2009 but has been found to reduce the risk of recurrence when given post-operatively with chemotherapy for osteosarcoma tumours.