What is the oesophageal cancer score?
This is a risk score given by an evidence-based model which uses a range of factors such as age, sex, ethnicity and existing medical conditions to predict the risk of developing oesophageal cancer. The model was developed to estimate risk over a 10 year period. It is also known as CanPredict™ (oesophageal cancer), and internally as X05.
Why has it been developed?
Oesophageal cancer is the sixth most common cause of cancer related deaths worldwide. Compared to the rest of the European countries, the UK has some of the worst outcomes, mainly due to late diagnosis. There are two types of oesophageal cancer, adenocarcinoma and squamous cell carcinoma. The most common type in the UK is adenocarcinoma and the main risk factor for this is chronic reflux. Due to the high prevalence and non-specific nature of reflux symptoms, most patients are treated with acid-suppressant medications without referral for endoscopy.
Three to six percent of individuals on medication for reflux may have Barrett's oesophagus, which is a health condition that may cause oesophageal cancer. Barrett's oesophagus can be treated but only 20% of patients with Barrett's oesophagus are diagnosed. It is estimated that the burden of oesophageal cancer could be reduced by up to 50% if all patients with chronic reflux are investigated. This is a formidable task since the NHS only has limited testing capacity and heartburn is common in the UK population. Currently, GPs are advised to treat their patients with antacid medications unless the patient presents with "alarm" symptoms. Patients without alarm symptoms often continue to take the antacid medications life-long and there are increasing concerns about long-term side effects of antacids.
The output of this study will allow GPs to better identify patients who may benefit from further tests to help early cancer detection or detection of Barrett's oesophagus, based on patterns of prescription acid-suppressant use as well as other characteristics of the patients. The tests can include traditional hospital-based endoscopy or newer pre-endoscopy tests such as the Cytosponge device which can be used in a GP surgery.
Who developed it?
The research team is led by Professor Julia Hippisley-Cox at the University of Oxford and includes researchers from both Oxford and Cambridge Universities. For further details see the QResearch project page.
How has it been developed?
The model has been developed using the University of Oxford hosted QResearch database, which has anonymised data from primary care linked to hospital, death and cancer registry records. This was used to determine which factors were associated with an increased risk of developing oesophageal cancer over a 10-year period. The research then produces an equation which is a weighted, cumulative calculation of the absolute risk of developing oesophageal cancer over time.
What are the important risk factors in the model?
The factors incorporated in the model include age, sex, ethnicity, body mass index, deprivation, smoking status, alcohol, medical conditions (Barrett's oesophagus, hiatus hernia, Helicobacter pylori infection, anaemia, and a previous blood, breast or lung cancer) and the regular use of antacid medication known as proton pump inhibitors.
How was the model tested?
The model was tested in an independent dataset (a different dataset to the one used to develop the model) to check how well it identifies those at high risk of developing oesophageal cancer. The research, published in The Lancet Regional Health - Europe, showed that the model performed well in predicting the risk of oesophageal cancer, particularly in its ability to rank patients according to their level of risk. It was also compared to two other similar models and found to have improved performance. See the publications page.
Who funded this research?
The research was funded by a grant awarded by Innovate UK and Cancer Research UK (grant 105857).
Which people can have a score calculated?
The calculator can be used for people aged between 25 and 84 years.
What is the Townsend score, what does it measure and why was it used?
Oesophageal cancer risk is associated with socio-economic status, such that people from deprived areas have higher risks. The use of equations that do not include a measure of socio-economic status may exacerbate health inequalities, i.e. the difference between rich and poor.
The Townsend score is a measure of material deprivation based on the area where a person lives and obtained using their postcode. It includes four variables obtained from census data: unemployment (lack of material resources and insecurity), overcrowding (material living conditions), lack of owner-occupied accommodation (a proxy indicator of wealth) and lack of car ownership (a proxy indicator of income).
This score is considered the best indicator of material deprivation currently available and has been widely used in medical research, including a range of studies conducted on the QResearch database.
What is body mass index and how is it measured?
Body mass index is a number calculated from a person's height and weight. It is their weight in kilograms divided by their height in metres squared. Conventionally a person is considered to be obese if they have a body mass index over 30 kg/m2.
Where can I find out more about oesophageal cancer?
Cancer Research UK describes the current research into oesophageal cancer, including newer ways of diagnosing it earlier.
All medical decisions need to be taken by a patient in consultation with their doctor.