The national investigation was triggered by a reference case focusing on Tracey, a 50 year old woman, who visited her GP multiple times over the course of a year with respiratory symptoms. The three chest X-rays she had during this time did not identify her lung cancer and Tracey was finally diagnosed a CT scan. She is still undergoing cancer treatment.
The report highlights that the delayed diagnosis of lung cancer has a wide geographic spread and is well recognised as a national safety risk. Research cited in the report highlights that estimated five-year survival rates in the UK are among the lowest in Europe. This reflects the fact that that two thirds of patients are diagnosed at an advanced stage.
Following analysis of the reference case, we examined the national context and considered the factors that contribute to this delay when patients repeatedly attend primary care with non-specific symptoms.
The national investigation identified that lung cancer in people who don’t have the usual risk factors, in particular, smoking, is increasing. However, the close link between smoking and lung cancer together with the often non-specific symptoms of the disease create a significant diagnostic challenge for GPs. In our reference case, for example, Tracey was considered low risk because she had never smoked.
Key findings also focused on the use of chest X-rays as they are the recommended first test to assess for lung cancer. However, our report emphasises that X-rays can be difficult to interpret, and notes evidence that shows one in five cancers are missed. Even if the patient has ongoing symptoms, a chest X-ray that does not identify a lung cancer has the potential to falsely reassure GPs.
The report concludes with three recommendations. These focus on commissioning research to evaluate how clinical and cost-effective low-dose CT scans are compared to chest X-rays to assess for lung cancer in symptomatic patients seen in primary care.
It also recommends reviewing and improving safety netting advice for health professionals and creating guidance to support independent benchmarking of artificial intelligence (AI) designed for the identification of lung diseases such as cancer.
Kathryn Whitehill, Principal National Investigator at HSIB says:
“Delayed diagnosis of lung cancer is a well-known safety issue across England and it was prioritised by HSIB as a theme for national investigation. Even though there has been advances in diagnostic technology, we wanted to understand why the risk remained of missing lung cancer on chest X-rays and explore the complexities associated with making improvements to the diagnostic process.
“While smoking is still the key risk factor for lung cancer, our report emphasised that it is increasing in those that have never smoked. The continued focus on the smoking link, across the media and public messaging, can exacerbate the existing diagnostic challenge for GPs and heighten the risk that a lung cancer is missed. The investigation’s findings, safety recommendations and safety observation aim to facilitate the timely diagnosis of lung cancer and so improve care for patients across the NHS.”
Key findings in full
- Lung cancer in people who have never smoked is increasing.
- Media messaging highlighting the close link between lung cancer and smoking, and the often non-specific symptoms of lung cancer, have created a significant diagnostic challenge for GPs.
- A chest X-ray is the recommended first test to assess whether a patient may have lung cancer. Chest X-rays are difficult to interpret and about one in five cancers are missed. A chest X-ray report that does not identify cancer has the potential to falsely reassure GPs.
- Evidence indicates that it may be beneficial to amend the safety netting advice for healthcare professionals in the National Institute for Health and Care Excellence guidance.
- CT scanning is a more accurate test to diagnose lung cancer and is used more widely in other developed countries which have better cancer survival rates. There is national recognition that major investment is needed in CT scanning equipment and workforce to perform and report scans.
- Using low-dose CT (a scan that exposes a patient to a smaller amount of radiation compared to conventional CT) to screen people at high risk of lung cancer, such as current or past smokers, has been shown to be beneficial. There is no significant evidence, and differing opinion, as to whether low-dose CT should replace chest X-ray as the first-line diagnostic test to assess for lung cancer in patients seeing their GP with non-specific symptoms. Research is needed to determine the clinical and cost-effectiveness of this.
- An increasing number of artificial intelligence products are being marketed to aid the detection of lung disease including cancer. There is variable testing and evaluation of these products.
- Expertise is an important factor in mitigating the risk of missed cancer on chest X-rays. There are educational platforms that can help the healthcare staff who review and interpret X-rays to develop their skills and assess their own performance. These may be helpful to assure quality and contribute to ongoing professional development.