Blood test can rule out lung cancer ‘with 98 per cent accuracy’

Researchers at the Medical University of South Carolina have participated in a multicentre clinical trial to evaluate the accuracy of a blood test, or ‘biomarker,’ that can detect lung cancer.

The research, which has been published in the journal Chest, finds that by combining measured levels of two proteins in a patient’s plasma (LG3BP and C163A) and clinical predictors of cancer (such as age, size of the nodule and other nodule characteristics) the test can distinguish between benign from malignant nodules with 98 per cent accuracy.

Gerard A. Silvestri, the study’s lead author, said: ‘It serves as a ‘rule out’ test for those with low-to-moderate risk. The biomarker is a tool to help calculate the general risk of cancer and present a patient with recommendations and options. It can push people out of indeterminate risk and into low-risk – without having to undergo invasive and potential risky procedures.’

‘Think of your lung as a two-liter bottle of soda, and the nodule as a pea in the centre of it. During a biopsy, for example, the lung could collapse and need a tube to expand it. Our goals for this biomarker are to help calculate the risk of cancer, present the patient with options and recommendations and avoid subjecting patients with benign disease to expensive, unnecessary and intrusive procedures.’

Even if biomarker results are negative, patients will need ongoing CT scans to monitor a lung nodule. ‘A low-risk tumor will be followed with serial imaging. After two years of CT scans being performed periodically and without evidence of growth, we can say it’s benign,’ Silvestri said.

If the biomarker’s results were used in direct care, the researchers say 40 per cent fewer unnecessary procedures would be performed on patients with benign nodules.