In laymans terms, a malignant tumour is one that grows destructively, spreads to remote areas of the body (metastasizes), is resistant to treatment, and can kill you.
The treatment of malignant tumours is quite complex, and the surgeon is part of a team of oncologists (both chemo- and radiotherapy), radiologists and pathologists (help to diagnose), and often other specialists, including Plastic Surgeons, Palliative Care specialists and Pain Management specialists. One of the vital members of this team is actually your general practitioner; and the most important member of the team, along with family and friends, is the patient themselves.
Generally speaking, diagnosis will start with a suspicion by your general practitioner, followed by a series of radiological investigations looking for local and systemic spread of tumour eg plain xrays, MRI and CT scans, and sometimes whole-body bone scans.
It is often possible to determine the type of tumour at this stage, but it is usually confirmed by a biopsy (taking a sample of the tissue). It may be possible to do this with just a needle in the Radiology Department, but more often is a formal operation with an overnight stay in hospital.
Depending on the type of the tumour, first-line treatment will be a number of cycles of chemotherapy and/or radiotherapy, followed by surgery, followed by more chemo- or radiotherapy.
Primary malignant bone, cartilage and muscle tumours are actually quite rare. The examples listed below are perhaps the better-known varieties.
Example malignant tumours
The most common primary malignant bone tumour. The bone cells have lost their normal regulatory controls, and grow wildly, invading local tissue with the possibility of distant metastasis (10% of patients have a metastasis at diagnosis). High rate of micrometastasis (mets present but not diagnosable) meaning almost all should have chemotherapy. Peak incidence in teens; second peak in the elderly. Fifty per cent occur around the knee; 15% in the shoulder. Treatment is usually chemotherapy, followed by surgery (see below – limb salvage vs amputation). Survival rate has been steadily improving; currently between 70-80% 10 year survival. Please be aware this is a statistical calculation; the patient is more than a number in a textbook!
Malignant tumour of cartilage (usually arises from bone; rarely in soft tissue). Second most common primary malignant bone tumour. Commonest in pelvis but can occur in any bone. Most are low grade ie slow growing, low metastatic potential, up to 90% long term survival. Higher grade tumours are much more aggressive, with survival rates dropping down to 45-50%, and sometimes less. Resistant to chemo- and radiotherapy. Curettage for low grade lesions, excision for high grade.
Rare but dangerous tumour. Occurs most commonly in 10-30yo with bulk in early teens. Twenty per cent occur in femur, 10% in pelvis. Majority have micrometastases so all should have chemotherapy. If a good response to chemo is achieved, proceed to surgery. Around 70% or better 5yr-survival.