Scientists have developed a new method that will allow patients suspected of lung cancer to be subjected to fewer and less-invasive tests to determine if they have the disease.

Researchers found that a genomic biomarker can accurately determine the likelihood of a lung lesion being malignant.

"We are seeing an increase in the number of lesions suspicious for lung cancer found on chest imaging of current and former smokers," said senior author Avi Spira, professor of medicine, pathology and bioinformatics at Boston University School of Medicine (BUSM).

In the past, these patients have been subjected to invasive tests when traditional bronchoscopy tests prove inconclusive, Spira said.

The findings are from two large, prospective, multicenter studies called Airway Epithelium Gene Expression in the Diagnosis of Lung Cancer (AEGIS) I and II.

These findings will allow physicians to confidently identify patients who are at low probability for having lung cancer thus sparing them from costly and risky procedures.

"While the test itself is simple, the science behind it is remarkable," said Spira.

The study involved 639 patients (298 in AEGIS I and 341 in AEGIS II) at 28 sites in the US, Canada and Ireland who were undergoing bronchoscopy, a common nonsurgical procedure to assess lung lesions for cancer.

Using airways cells collected by the bronchoscopy, the researchers found this genomic test, when evaluated with the bronchoscopy, had a combined sensitivity of 97 per cent for detecting lung cancer, compared to 75 per cent for bronchoscopy alone.

"This study validates the effectiveness of the bronchial genomic biomarker among those undergoing bronchoscopy in two independent groups. We found that it has high sensitivity across different sizes, locations, stages and cell types of lung cancer," said Spira.

"The combination of the biomarker and bronchoscopy has a sensitivity of 96 per cent and 98 per cent in the AEGIS-1 and AEGIS-2 groups, respectively," said Spira.

An estimated 250,000 patients undergo a bronchoscopy for suspected lung cancer each year with approximately 40 per cent
producing non-diagnostic results.

This can lead to invasive procedures such as transthoracic needle biopsy or surgical lung biopsy that are risky and expensive, researchers said.

The findings appear in the New England Journal of Medicine.