Medicolegal Aspects of Brain Tumours: Breach of Duty and Causation in Delayed Diagnosis Claims.

Brain tumour cases often feature in clinical negligence claims particularly when the diagnosis or referral has been delayed.   

Building the chronology of a delayed diagnosis

For solicitors investigating a potential delayed diagnosis claim, an important starting point is to establish a clear chronology. This should identify the nature and progression of the patient’s symptoms, each presentation to primary or secondary care, the advice given, any investigations requested and the timing of subsequent referral, imaging and specialist review. This chronology can help identify the point at which it may be argued that further investigation or referral should reasonably have occurred. 

Recognising the clinical presentation

The presentation of brain tumours varies depending on their location, size and growth pattern.  Frequent symptoms include progressive or persistent headache particularly in the morning, seizures (present in up to 50% of new cases), focal neurological deficits such as weakness, visual disturbance and sensory disturbance, cognitive deficits and nausea and vomiting. 

One of the main difficulties in diagnosing a brain tumour occurs because of the non-specific nature of early symptoms.  Headaches are among the most frequent early complaints, however, they are also very common in the general population and as such rarely indicate a serious intracranial pathology.  There is thus a dilemma for general practitioners who, on one hand don't want to miss a serious pathology but on the other hand want to avoid the risk of over-investigation. 

When does a delay become a breach of duty?

This distinction is particularly important when considering breach of duty. The question is not whether the tumour could have been diagnosed with the benefit of hindsight, but whether the information available to the clinician at the relevant time should reasonably have prompted further investigation, safety-netting, referral or follow-up. Repeated attendances, an evolving symptom pattern and the development of neurological signs may therefore be particularly important when reviewing the records. 

A further issue is that the most common brain tumours differ between adults and children in both their pathology and location.   

Metastases, often from the lung, breast and melanoma are the most seen brain tumours in adults.  The most common primary tumours are meningiomas and malignant gliomas.  Most primary tumours are in the cerebral hemispheres. 

Paediatric brain tumours are the most common solid tumours in children.  The most frequently seen are pilocytic astrocytoma, medulloblastoma and ependymoma.  Around 60% occur in the posterior fossa (cerebellum or brainstem)  

Delays in diagnosis can result in serious consequences.  As a tumour grows it causes an increase in intracranial pressure worsening symptoms such as headache and nausea but may also cause damage to adjacent parts of the brain.   Deficits such as paralysis, visual loss and cognitive impairment may become irreversible if treatment is not initiated quickly. 

In a clinical negligence claim, however, identifying deterioration during the period of delay is only part of the analysis. It is also necessary to consider whether that deterioration would probably have been avoided had diagnosis occurred at the appropriate time. Establishing this counterfactual position is often central to the causation evidence. 

The standard of care requires the recognition of red-flag symptoms and the organisation of appropriate investigations in a reasonable time frame.  Failure to recognise persistent or worsening neurological symptoms; organise appropriate imaging studies when clinically indicated, and following up abnormal test results with an appropriate referral may all constitute a breach of duty. 

Potential allegations may therefore arise at several stages of the diagnostic pathway. These may include failure to recognise an evolving pattern of symptoms, failure to investigate appropriately, inadequate safety-netting, delay in arranging or reporting imaging, failure to act upon an abnormal result, or delay in referring the patient for specialist assessment. Identifying precisely where the alleged failure occurred is important when determining which expert discipline is required to address breach of duty.

Brain tumours are relatively rare.  In the UK they account for about 3% of all new tumour cases with around 12000 diagnoses annually.  The incidence is approximately 26 per 100000 population per year.  A typical general practitioner with a patient list of around 2000, on average, is likely to see one new brain tumour case every two years and only a few malignant cases in his or her career.  This low incidence creates a further issue as clinicians often have limited experience with such conditions. 

For breach of duty purposes, rarity alone does not determine whether care was reasonable. The factual circumstances of the individual presentation remain crucial. Solicitors will therefore often need expert evidence addressing what a reasonably competent clinician should have done when faced with the combination, duration and progression of symptoms documented in the medical records. 

Guidelines, imaging and referral pathways

To address these challenges, clinical guideline such as NICE NG99 (Brain tumours(primary) and brain metastases in the over 16s) attempt to provide a structured approach to the assessment, investigation and referral of brain tumours.  It deals with who to suspect, such as people with new or progressive neurological symptoms, papilloedema, new onset seizures, or certain headache patterns.  The recommended first line imaging is MRI brain with contrast followed by an urgent referral to an appropriate specialist/neurosurgical or neuro-oncology service if the examination confirms a tumour.  NICE also has a quality standard (QS203) that reinforces timely imaging and specialist assessment. 

In practice, any new intracranial lesion reported as a possible tumour (glioma, meningioma, metastasis, etc.) should trigger a neuro-oncology MDT referral rather than being managed in isolation by a single clinician. 

Where imaging has identified an abnormality, the subsequent pathway can create a separate area for investigation. The records should establish when the scan was performed, when it was reported, when the result was reviewed, when the patient was informed and when the appropriate specialist referral or MDT discussion took place. A delay at any one of these stages may need to be considered separately from an earlier alleged delay in obtaining the scan itself. 

Even with advanced imaging techniques, diagnostic uncertainty can still be present.  MRI imaging with techniques such as diffusion-weighting, perfusion imaging and spectroscopy have improved diagnostic accuracy but these investigations require expert interpretation.  Misinterpretation can lead to incorrect diagnosis, delays in treatment and unnecessary interventions which carry medicolegal implications. 

Why earlier diagnosis does not always change the outcome

Whilst delayed treatment is often associated with poorer outcomes, some slow-growing or low-grade brain tumours are unlikely to show a clear survival benefit from earlier management.  Some tumours can't be managed optimally for several reasons such as location in a vital area or the toxicity of treatment.  In such cases, earlier diagnosis would not affect the outcome.  Incidental, asymptomatic meningiomas for example are often managed with a "wait and watch" approach because they may never cause any symptoms or significantly increase in size with time. 

This is where causation can become substantially more complex than breach. Even if it is accepted that diagnosis should have occurred earlier, the claimant must still establish what would probably have happened following that earlier diagnosis and whether the ultimate outcome would have been materially different. The existence of a diagnostic delay does not, by itself, establish that the delay caused additional injury. 

In some cases where a low-grade tumour is diagnosed, treatment is deliberately deferred in favour of monitoring because early treatment may not improve survival and could cause disability and a worsening of quality of life.  A notable exception to this is with low grade gliomas where earlier intervention has been shown to improve 10-year mortality significantly. 

Establishing the counterfactual

The relevant counterfactual questions may therefore include the likely size and characteristics of the tumour at an earlier date, whether treatment would have been offered at that point, whether surgery would have been technically possible, whether the extent of resection would have differed and whether earlier treatment would probably have altered survival, neurological function or quality of life. These questions will depend heavily on the tumour type and the individual circumstances of the patient. 

Malignant tumours such as glioblastoma often present when they have reached a diameter of over 3cm.  The prognosis although generally very poor is better with smaller tumours.  Nonetheless, two patients with identical tumour sizes can have very different outcomes depending on age, tumour genetics, performance status, and how much tumour can safely be removed. 

For solicitors, this means that causation should not necessarily be approached solely by comparing the date of actual diagnosis with the proposed earlier date. Prognostic factors, tumour biology, operability and the likely treatment pathway at each point may all be relevant to determining whether the delay made a material difference to the patient’s outcome. 

The key challenge: proving causation

Demonstrating a breach of duty in the management of brain tumours is often straightforward particularly if red flag symptoms are ignored.  The challenge lies in establishing causation as it does not always follow that a delay in treatment causes harm. 

Early expert input can therefore be particularly valuable in these claims. A focused review should seek to distinguish between the alleged breach, the period of avoidable delay and the consequences attributable to that delay. For solicitors considering prospects, the key issue is ultimately not simply whether the diagnosis should have been made sooner, but whether earlier diagnosis would probably have resulted in a materially different clinical outcome.