PhDs in Focus: Developing a nasal swab test for early detection of lung cancer
Welcome to our PhDs in Focus blog series, where our PhD students are showcasing their pioneering research projects at the National Institute for Health and Care Research (NIHR) Manchester Biomedical Research Centre (BRC).
In this blog, Manchester BRC PhD student Rebecca Ford outlines how their project is part of the development of a nasal swab test for early detection of lung cancer, through the Cancer Prevention and Early Detection theme.
Lung cancer is the most common cause of cancer-related death and the second most common cancer. Annually, there are 2.2 million new cases diagnosed worldwide, with the majority being diagnosed in later stages. This dramatically reduces the number of treatment options available and the chance of curative treatment being successful. Manchester has the highest lung cancer rates in the UK, meaning the impact of our work will be seen in this region.
Lung cancer risks
The highest risk factor for lung cancer development is smoking, with an estimated 80% of cases being attributed to it. Whilst public intervention programmes to reduce the number of people who smoke will have positive implications for the number of lung cancer cases, it will take a while to see their impact.
Alternative risk factors such as environmental exposure to asbestos and inflammatory lung diseases mean that the number of lung cancer cases is likely to remain high for the foreseeable future.
The issue
To improve treatment outcomes and reduce the death rate from lung cancer, it needs to be diagnosed early. This is difficult with lung cancer because it is asymptomatic in the early stages, meaning there are no symptoms – a small tumour in the lungs might not have an impact on breathing until it has grown; by the time it is impacting breathing it can have spread to other organs in the body and be difficult to treat.
What’s already happening to address the issue?
Currently, there are screening programmes in place that use CT scans (a machine that takes detailed pictures of the inside of the body) to detect tumours in the lungs from an early stage. People who are considered high risk, such as those above 55 who smoke, or have previously smoked, are eligible for annual CT scans. Studies have shown that these detect lung cancer earlier and have resulted in improved treatment outcomes.
However, CT scans are not always easily accessible to people as they require specialist equipment and trained staff. This means that people who are most at risk may not be able to receive scans.
To combat this problem locally, from 2016 the Manchester Lung Health Check saw trucks equipped with CT scans located in supermarket carparks across the region. This allowed anyone who met the inclusion criteria of current or former smoker aged 55-74 years to access a CT scan. Following the results of this research, which involved researchers from Manchester BRC’s Cancer Prevention and Early Detection Theme, the UK National Screening Committee has now recommended the national adoption of lung cancer screening, with a national roll-out based on the Manchester Lung Health Check model.
Improving the diagnostic pathway
To help improve access to early screening, Manchester BRC Cancer Prevention and Early Detection researchers are developing a lateral flow test (similar to a COVID-19 test) which uses nasal swabs to detect biomarkers of lung cancer. Biomarkers are measurable markers of abnormality or disease. For this project we are looking into protein expression between lung cancer and non-lung cancer samples to find proteins that are increased or decreased in lung cancer.
The nasal cavity is easily and non-invasively accessed by nasal swabs and represents the biology and physiology of the lower respiratory tract, including the lungs. Those who have a positive biomarker test would then receive a CT scan to determine the stage and location of the tumour to receive treatment.
This test could mean that more people who are eligible for early screening can access it, as the tests would be easy to carry out at home or at the GP. It could also reduce the number of people requiring CT scans (as those who have a negative biomarker test would not require follow-up with CT scans) therefore reducing cost and pressure on services.
The tests could help ensure everyone has access to early screening for lung cancer, meaning the likelihood of curative treatment being available could increase, and the lung cancer survival rate could improve.