- Project Lead: Dr Stephen Bradley
- Senior CanTest Lead: Prof Richard Neal
- Others involved: Prof Willie Hamilton, Thomas Round (Kings College London & Public Health England), Bethany Shinkins (University of Leeds), Matthew Callister (University of Leeds), Pete Wheatstone (PPI c/o University of Leeds). Carolynn Gildea (Public Health England)
Most patients who have lung cancer present first to their GPs. Chest x-ray is the first line investigation in primary care for suspected lung cancer.
There is a wide range in how advanced (‘stage’) lung cancer is when it is diagnosed across different parts of England. There is also likely to be a range in how often chest x-ray is requested in different General Practices.
In Leeds, a campaign which aimed to increase the use of chest x-ray in patients at risk of lung cancer increased the number of chest x-rays performed. This has been linked to a higher proportion of those diagnosed with lung cancer having earlier stage cancer2 and better mortality.
Despite this, it is not certain that increasing the number of chest x-rays performed will achieve earlier diagnosis for more people (‘stage shift’) since this has not been shown in a small number of other studies 3 4. Also, it is possible that at the same time as the Leeds campaign was underway there could have been other changes to lung cancer diagnosis which might have also contributed to more patients being diagnosed with earlier stage lung cancers.
To work out if lung cancer stage and mortality are lower in general practices which perform higher numbers of chest x-rays this study will look at numbers of chest x-rays performed by different practices in England and link this to the stage and mortality. We will do this in a similar way to another study which looked at the numbers of investigations for gastrointestinal cancer by different general practices and outcomes5. The chest x-ray information will be taken from the Diagnostic Imaging Dataset (DID) and the lung cancer outcomes information will come from the National Cancer Registry and Analysis Service (NCRAS).
Because many other factors can affect the number of chest x-rays requested and also the stage of lung cancer and mortality e will take account of (‘adjust for’) these factors when we analyse the data.