Levels of a key protein — called TLR2 — in tumours was found to predict a patient’s survival after being diagnosed with lung cancer, a study shows.

A drug compound that activates TLR2 was tested in mice and was found to reduce tumour growth in the early stages of the disease.

With the five-year survival rate from late stage lung cancer only six per cent — compared with 50 per cent when diagnosed earlier — experts say the breakthrough could help spot the disease sooner and improve patient outcomes.

A group, led by researchers from the University of Edinburgh, discovered that TLR2 helps control some of the body’s defense mechanisms when cancerous mutations occur in cells.

The protein is linked with senescence, a process whereby cells stop growing and secrete a variety of chemicals and other proteins which collectively act as warning signals and defences against cancer.

Senescent cells are present in early lung cancers, but are no longer present in late-stage cancers, suggesting that senescence can prevent cancer progression.

Having identified TLR2’s importance, the team used data from human tumour samples to confirm that patients with high levels of the protein in the early stages of lung cancer had increased survival compared to those who had lower levels.

The team then used a drug known to activate TLR2 in a mouse model of lung cancer. Researchers found that the drug reduced lung tumour growth.

Experts hope these findings could lead to research into using senescence and the associated secreted chemicals as part of a screening programme to provide earlier lung cancer diagnosis.

Further research is needed, the team adds, such as clinical trials to confirm whether the drug is effective in humans.

The research is a collaboration between researchers from University of Edinburgh, University College London, University of Cantabria in Spain, the Spanish National Research Council and the Mayo Clinic in the USA.

The study is published in Cell Reports. It was funded by Cancer Research UK, Wellcome, the Ministry of Science and Innovation of the Government of Spain and the US National Institute of Aging.

Dr Fraser Millar, Clinical Lecturer in Respiratory Medicine at the University of Edinburgh, said: “I think these results are really exciting. Very little is known about the biology of early lung cancer and by understanding this process more we have identified a possible new treatment for this devastating disease. This project highlights the value of basic science research and how this can be translated into new treatments for patients.”