Around 5,300 people are diagnosed with sarcoma each year in the UK.
Almost one in three of these people will have waited over six months from their initial appointment to be diagnosed, according to Sarcoma UK.
For every one cm increase in the size of sarcoma, at the point of diagnosis, the chance of a cure is reduced by three to five percent.

Sarcomas make up less than two per cent of all cancers diagnosed in the UK each year, so a full time doctor is unlikely to diagnose more than one bone sarcoma and approximately one soft tissue sarcoma during their career.

However, given the impact that a delayed diagnosis can have on outcomes for patients, the importance of raising awareness among the medical profession and the public is clear.

Medico-legal issues in diagnosis

Over a recent five year period, the MDU opened 85 case files to advise and support members with issues relating to sarcoma. Most cases involved GPs, with a minority involving a range of other medical specialties.

Nearly three quarters of the cases were from members needing support with a range of medico-legal processes, including NHS complaints, Ombudsman complaints, serious incident investigations, coroner's investigations, local disciplinary procedures and GMC complaints.

In just over a third of cases, there was a claim for compensation, with these incidents pre-dating state indemnity being introduced for primary care.

The most common concern was a delayed diagnosis of sarcoma or a failure to investigate or refer in a timely manner. Sarcomas can be difficult to diagnose - not only are they rare but they can occur anywhere in the body and initially can mimic benign conditions.

In its guidelines, Bone and soft tissue sarcoma - recognition and referral, NICE outlines the recommendations for imaging in adults and children presenting with an unexplained lump that is increasing in size or unexplained bone pain. It also recommends timeframes for specialist referral if the imaging suggests the possibility of sarcoma.

The guidance differentiates between children or young people and adults. For children or young people with possible bone or soft tissue sarcoma, the advice is to consider an urgent referral (within 48 hours).

NICE also explains that young people (aged 16-24 years) may be referred using either an adult or children's pathway, depending on their age and local arrangements.

Allegations of delayed diagnosis

There were several common themes that contributed to delays in diagnosis in MDU cases.

Symptoms attributed to wrong cause

In several cases where patients presented with a soft tissue mass that was not only persistent but also increasing in size, the patient provided a history of a possible trigger, such as an injection, injury or insect bite.

For bone sarcomas, bone pain was often attributed, by both patient and doctor, to a relatively minor injury or due to an exacerbation of a pre-existing condition such as osteoarthritis.

Revising the initial diagnosis

In other cases, doctors were reassured by normal imaging and did not revisit an incorrect diagnosis, despite patients continuing to complain of symptoms.

Take the scenario of a deep soft tissue sarcoma in a limb, causing pain for which the patient is sent for a hip X-ray. The hip X-ray demonstrates mild osteoarthritic changes and the symptoms are attributed to this.

The patient then repeatedly contacts the GP with concerns about increasing pain and is given stronger analgesia following telephone consultations. It is only when the patient is seen face-to-face that a mass is found in the thigh and the patient is subsequently diagnosed with a soft tissue sarcoma.

In cases like this, patients may feel they aren't being listened to, that there was a failure to arrange appropriate imaging, or that the doctor failed to reconsider the initial diagnosis despite the symptoms evolving.

Acting outside guidelines

There were several cases where ultrasound findings were uncertain, but the patient wasn't referred for further imaging, or not urgently enough.

NICE guidance states that if an ultrasound suggests the possibility of soft tissue sarcoma or is uncertain and the clinical concern persists then an urgent referral via a suspected cancer pathway should be considered.

Linking symptoms

Clinicians sometimes failed to make a link between the lump and other symptoms such as loss of appetite, weight loss and fatigue. Had all the patient's symptoms been considered together, further investigations for sarcoma may have taken place at an earlier stage.

Safety netting advice

Finally, a lack of safety netting advice was consistently raised as an issue in many of the cases. Patients felt that they were falsely reassured and not advised on red flags to watch for such as rapid growth.

They also felt that once they had been given a diagnosis, it was harder for them to revisit the issue without being deemed as overly anxious.

Managing risks with sarcoma diagnosis

Sarcomas are rare and symptoms can easily be mistaken for common ailments. However, our case analysis reveals lessons that could be helpful to put into action when seeing a patient with an unexplained lump, or bone pain/swelling.

When a patient presents with a mass following a reported trigger, consider whether the size and behaviour of the lump are suspicious, especially if it does not align with a reported injury.
Consider if the level of bone pain or swelling reported by a patient appears excessive, given the mechanism of any reported injury.
If a lump or bone pain has been attributed to a benign cause or an underlying health condition but symptoms don't proceed as expected, such as the lump grows rapidly, then it may be appropriate to reconsider the diagnosis.
If the patient presents with several seemingly unrelated symptoms, it may be worth considering if they are linked.
Make sure you provide safety netting advice and document this if a patient presents with a lump or soft tissue swelling. Providing this advice and making a record of it not only helps to reassure the patient, it will also stand you in good stead if a seemingly minor ailment turns out to be more serious.

In summary

Sarcomas are rare and delayed diagnoses are understandable. However, if that ganglion, lipoma, sebaceous cyst, or abscess aren't behaving as you would expect, especially if they are increasing in size, consider sarcoma as a possible cause and refer the patient accordingly.

The MDU can advise and support you in dealing with any complaints or adverse incidents that arise as a result of a delayed diagnosis.

Learning lessons from MDU cases of sarcoma diagnosis delays

Dr Ellie Mein

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