Sarcomas: early diagnosis is crucial

ONE OF THE most frequent types of compensation claim seen by medical negligence solicitors in the UK is the failure to diagnose cancer when it presents. Delayed diagnosis permits the tumour to advance and an advanced tumour will demand more aggressive treatment with the probability of additional complications.

Late diagnosis may also result in the tumour spreading into the rest of the body – known as metastases. These metastases are typically impossible to eradicate and frequently prove fatal.

Sarcomas are malignant tumours which arise from the connective tissues of the body: bone and cartilage or soft tissue and muscle. Unlike cancer of the breast, prostate or lung, sarcomas are rare. However, their rarity tends to lead to late diagnosis, so many patients present with a long history and a large mass.

Soft tissue sarcoma
There are many different sub-types of soft tissue sarcoma, some of which resemble the normal tissues of the body such as fat, muscle, nerve, or fibrous tissue. Patients present with a swelling, which is often painless, that increases in size slowly and can become surprisingly large, especially if it is in the thigh or buttock. Delay in diagnosis is common and usually involves the failure to investigate enlarging lesions or persistent pain in the absence of trauma.

A general practitioner may see only a handful of sarcoma patients during his entire professional lifetime. However, he should refer for further investigation any patient who presents with key suspicious features. These include any soft tissue mass that is enlarging, especially if it is painless. If he is suspicious of malignancy he should request that the patient be seen under the two-week-wait rule.

In the hospital clinic imaging is undertaken to visualise the mass, usually by ultrasound. More detailed scanning with either computed tomography (CT) or magnetic resonance imaging (MRI) will be required later. The diagnosis is made by a cutting needle or trucut biopsy and the pathology should be reviewed by an expert.

Once the diagnosis has been established, urgent referral should be made to an expert sarcoma multi-disciplinary team, often at a tertiary centre. Wide excisional surgery, usually with radiotherapy, offers the best chance of local cure. Amputation is rarely necessary. For the majority of soft tissue sarcomas treated by surgical removal, recurrence, if it is going to appear, will do so within a period of three years (80% probability). In patients who are destined to develop wide-spread metastases, 80% will do so within a period of two years.

Illustrative case
A young man attended the accident and emergency department at his local hospital complaining of what appeared to be a boil. This was excised and sent for histology. The diagnosis was of soft tissue sarcoma but this report was never acted upon. A recurrent 5cm tumour eventually had to be excised two years later.

If the original small tumour had been correctly managed the patient would have been cured. Definitive treatment delayed for the larger tumour recurring two years later may still have achieved local control but was likely to be associated with metastases. Both breach of duty and causation were alleged.

Sarcoma of bone
Osteosarcoma is the most common bone tumour and principally affects the long bones in adolescents. Other bone tumours include chondrosarcoma (which arises from cartilage) and giant cell tumours (which are usually benign but which can be locally destructive and occasionally metastasise).

Osteosarcoma presents with bone pain, especially on weight bearing, often associated with soft tissue swelling. Bony swelling and a limp are usually late features. Most can be diagnosed on a plain x-ray which shows destruction of the bone.

The initial management of osteosarcoma is with chemotherapy. That has been shown to reduce dramatically the incidence of death from metastatic disease and also serves to shrink the tumour preoperatively. Limb conserving surgery is generally possible and the bone removed is replaced by a metal prosthesis.

Patients who present with metastatic spread have a poor outlook and prognosis. The late occurrence of isolated lung metastases may be managed by removing a wedge of affected lung. Salvage chemotherapy may provide effective palliation but is rarely curative.

Illustrative case
A young patient attended the local casualty department complaining of pain following a road traffic accident. Xrays were taken and assurance given that there was no fracture. The subsequent report on this x-ray suggested a bone tumour but no further action was taken. One year later amputation was necessary for a 7cm osteosarcoma. Correct initial management would have comprised chemotherapy and possibly amputation, but would likely have resulted in cure. However, with a 7cm tumour the risk of metastases was far higher on the balance of probabilities and could result in death. Both breach of duty and causation were alleged.

Dr Clive Harmer MB FRCR FRCP is a clinical oncologist and cancer specialist. He established the Sarcoma Clinic at The Royal Marsden Hospital, London, in 1974 and treated sarcoma patients until 2005. Since retirement he remains both registered and licensed with the GMC. He has extensive medico-legal experience in the diagnosis and management of all types of cancer, with High Court appearances in London and Belfast.