In this study, we will examine how many people in England qualify for testing for possible undiagnosed cancer. The testing is guided by recommendations from the National Institute for Health and Care Excellence (NICE), and sometimes means going to a hospital. These tests are good at finding cancers in the brain, lungs, in the gut, and in the urinary or reproductive systems.
In the past, these tests were only carried out when a doctor thought there was quite a high chance that a person had cancer. But nowadays more people are sent for testing, because of worries that cancers were being caught too late. The greater number of tests has put pressure on the hospital departments where the tests are done. The Department of Health needs to have a good idea of the number of people who qualify for testing, so that they can plan their services well enough to make sure that everyone can be seen quickly.
In our study, we will look at the medical records of around two hundred thousand ordinary people in England. We will work out how many of them should be sent for these cancer tests. We will use our results to work out how many people in England overall qualify for testing for cancer. We will compare this with the number of urgent two-week-wait appointments currently being done, to get an idea of the size of unmet need. This will help future planning of services. We will also find out how many of these people are later diagnosed with cancer, to check how well the NICE recommendations for cancer investigation are working.
In this study, we will provide a robust estimate of the likely numbers of people in England presenting in primary care who are eligible for investigation because they have symptoms of possible cancer. Eligibility is guided by the NICE 2015 Suspected Cancer Recognition and Referral Guidelines (NG12). The number of two-week-wait referrals for suspected cancer is increasing year on year, with no sign of levelling out. Direct investigation for possible cancers is also increasing relentlessly. An estimate of the likely maximum number of annual appointments and direct investigations would help to improve capacity and workforce projection planning by the Department of Health, both for existing and future planned services.
We will study a representative sample of 200,000 adults aged 40 or over who are registered with general practices in England in the Clinical Practice Research Datalink (CPRD). We will use existing lists of medical codes to estimate how many patients have symptoms, signs or abnormal blood test results (from hereon called "cancer features") that warrant referral or direct investigation according to the NICE NG12 guidelines. We will then use publicly available population data from the Office for National Statistics to estimate the total number of adults aged 40 and over in England who are eligible for referral or investigations. We will also use publicly available data from Public Health England to estimate the current numbers of urgent two-week-wait appointments, to quantify unmet need.
As a secondary analysis, we will examine the one-year incidence of cancer in people eligible for cancer investigation (equivalent to the positive predictive value for each NICE recommendation). This is important to help with any future revision of NICE guidance, particularly with the recent Government suggestion that the 3% risk threshold warranting urgent investigation for cancer should be lowered.
Health Outcomes to be Measured:
Primary outcomes: The proportions of patients in England eligible for any of the following investigations for suspected cancer:
- An urgent two-week-wait referral;
- A direct GP request for any of the following investigations:
a. chest X-ray;
c. computed tomography (CT) scan;
d. magnetic resonance imaging (MRI) of the head; or
Note: We are not identifying codes for the testing itself - instead examining eligibility based on a person's recorded cancer features.
Secondary outcomes: the incidence of cancer in the year after meeting criteria for each of the above investigations.