A research team from the MRC Toxicology Unit at the University of Cambridge has partnered with University of Leicester scientists to devise a blood test that could enable the earlier diagnosis of lung cancer by analysing the circulating DNA levels.
The circulating DNA is released by cancer cells into the blood during their growth and multiplication. Measuring these DNA levels is also expected to enable the prediction of tumours in the lungs even before they turn cancerous.
During the study, the team used mice with KRAS mutation as models for the pre-cancerous lung cancer stages. Standard computed tomography (CT) scans were used to track the development of small pre-cancerous lung tumours.
The researchers also collected blood samples at various intervals in order to analyse if circulating DNA can be used to detect the tumours before becoming malignant.
Higher circulating DNA levels were observed in mice that developed cancerous lung tumours, compared to those in healthy mice.
Findings also showed that the levels of DNA shed by the cancerous tumours correlated with the tumour size seen on the CT scans.
The team also assessed the DNA for the KRAS mutation that is responsible for the development of tumours. They found that the mutation could be detected in circulating DNA when the tumours were still pre-cancerous.
MRC Toxicology Unit cancer programme manager Mariana Delfino-Machin said: “This is a really promising piece of early-stage research. Lung cancer is incredibly difficult to diagnose at the stage where it can be successfully treated, leading to a poor rate of survival.
“Developing early detection strategies to improve survival rates is key, and if this can be achieved using only a blood sample it would greatly benefit patients and the NHS.”
The research has been published in the Disease Models and Mechanisms journal.
The team intends to carry out further studies to determine whether the measurement of circulating levels of DNA will facilitate early detection of tumours in other tissues.
Last month, researchers at University College London (UCL) devised an approach to use molecular profiling for predicting lung cancer via analysis of precancerous lesions.
Lung cancer is the biggest killing cancer in both men and women. Around 45,500 people are diagnosed with lung every year in the UK and symptoms of the condition are usually not apparent until the cancer has spread through the lungs or to other parts of the body.
Additional reporting by Charlotte Edwards.