Why this question is important
A brain tumour is a group of cells in the brain that develop in an abnormal and uncontrollable way. There are two main types of brain tumour:
- Non-cancerous (benign) brain tumours: these grow slowly and do not spread throughout the body.
- Cancerous (malignant) brain tumours: these grow faster and can spread to other parts of the body.
Brain tumours that start in the brain are known as primary tumours. If they have spread to the brain from elsewhere, they are called secondary tumours.
All types of brain tumour are a serious health threat, since the brain controls all the functions of the body. Both benign and cancerous brain tumours can be fatal. Even when they are not, they can be very disabling. Symptoms can include:
- Epileptic seizures (fits)
- Persistent nausea (feeling sick), vomiting, and drowsiness
- Changes in behaviour or personality, trouble thinking, memory problems
- Weakness, or paralysis that develops on one side of the body
- Problems with speech or vision
It is difficult to diagnose brain tumours, because symptoms can all be mistaken for those of less serious conditions. It may take some time before their true cause – a brain tumour – is identified. Yet diagnosing a brain tumour as early as possible is important, because the bigger a tumour grows, the more difficult it is to treat, and the greater the potential for the treatment to cause collateral damage.
A range of initiatives has been designed to speed up the diagnosis of brain tumours. This includes campaigns to increase doctors’ and the public’s awareness of the symptoms they cause, and professional guidelines to speed up referral for diagnostic scans or specialist assessment. To find out how effective these initiatives are, we set out to review the research evidence. We also wanted to investigate the cost of initiatives.
How we searched for evidence
Our team of researchers searched the medical literature for studies that compared the effectiveness of an initiative designed to speed up the diagnosis of brain tumours against normal practice or another initiative, and included people of all ages with signs or symptoms that might suggest a brain tumour.
What we found
We found 115 studies that investigated the diagnosis of brain tumours, but none of them met all of our inclusion criteria, and we excluded them. We found no studies with information about the cost of initiatives.
What this means
Currently, there is no evidence from good quality studies to inform patients, health professionals, or service planners about how to reduce the time to diagnosis of brain tumours. Nor is there any information on the cost of these initiatives. This review highlights the need for research in this area.
How up-to-date is this review?
We last searched for evidence in January 2020. This review covered research that was available up to that date, but did not consider any evidence that may have been produced since then.
In this version of the review, we did not identify any studies that met the review inclusion criteria for either effectiveness or cost-effectiveness. Therefore, there is no evidence from good quality studies on the best strategies to reduce the time to diagnosis of brain tumours, despite the prioritisation of research on early diagnosis by the James Lind Alliance in 2015.
This review highlights the need for research in this area.
Brain tumours are recognised as one of the most difficult cancers to diagnose because presenting symptoms, such as headache, cognitive symptoms, and seizures, may be more commonly attributable to other, more benign conditions. Interventions to reduce the time to diagnosis of brain tumours include national awareness initiatives, expedited pathways, and protocols to diagnose brain tumours, based on a person's presenting symptoms and signs; and interventions to reduce waiting times for brain imaging pathways. If such interventions reduce the time to diagnosis, it may make it less likely that people experience clinical deterioration, and different treatment options may be available.
To systematically evaluate evidence on the effectiveness of interventions that may influence: symptomatic participants to present early (shortening the patient interval), thresholds for primary care referral (shortening the primary care interval), and time to imaging diagnosis (shortening the secondary care interval and diagnostic interval).
To produce a brief economic commentary, summarising the economic evaluations relevant to these interventions.
For evidence on effectiveness, we searched CENTRAL, MEDLINE, and Embase from January 2000 to January 2020; Clinicaltrials.gov to May 2020, and conference proceedings from 2014 to 2018. For economic evidence, we searched the UK National Health Services Economic Evaluation Database from 2000 to December 2014.
We planned to include studies evaluating any active intervention that may influence the diagnostic pathway, e.g. clinical guidelines, direct access imaging, public health campaigns, educational initiatives, and other interventions that might lead to early identification of primary brain tumours. We planned to include randomised and non-randomised comparative studies. Included studies would include people of any age, with a presentation that might suggest a brain tumour.
Two review authors independently assessed titles identified by the search strategy, and the full texts of potentially eligible studies. We resolved discrepancies through discussion or, if required, by consulting another review author.
We did not identify any studies for inclusion in this review. We excluded 115 studies. The main reason for exclusion of potentially eligible intervention studies was their study design, due to a lack of control groups. We found no economic evidence to inform a brief economic commentary on this topic.