Researchers at the Boston University Medical Centre say they have developed a "minimally-invasive" technique to detect lung cancer early by using cells from a patient's nose.

Epithelial cells sampled from the inside of a person's nose share the same genetic markers that show up in people with lung cancer, the researchers said.

The "simple technique using cells from the interior of the nose could help clinicians detect lung cancer in its earliest and most treatable stages".

For their study, the researchers collected nasal epithelial cells from 33 smokers who were undergoing tests for suspicion of lung cancer.

Of these patients, 11 were found to have benign disease and 22 had lung cancer.

Brushings were taken from the right or left nostril and profiled on microarrays, a process that allows researchers to study gene expression changes.

"Our data suggests that evaluating gene expression changes in nasal cells found in the interior surface of the nose may serve as a non-invasive approach for the early detection of lung cancer in smokers," said study author Christina Anderlind, Instructor of medicine at Boston University Medical Centre.

After analyzing the cells, the researchers found there were 170 different genes whose level of activity was different, depending on whether or not a patient had lung cancer.

Lung cancer is the most common cause of cancer mortality, with an average five-year survival rate of only 15 percent.

However, survival rates are highly dependent upon how advanced the cancer is when detected.

"At an early stage, the five-year survival rate is 60 percent compared to only two per cent at a late stage," Anderlind said.

"Despite this fact, early diagnosis is hard to achieve since the diagnostic tests currently available are highly invasive, such as open lung biopsy.

"We wanted to determine if a minimally invasive site like the nose could be used to diagnose cancer in its early stages, when there is a much greater chance of long-term survival".

Anderlind said the results of the current study are an initial indication that simple nasal brushings could offer an alternative to lung biopsy and other invasive techniques aimed at identifying lung cancer in its early stages.

"The development of a nasal biomarker for diagnosis of lung cancer would make early diagnosis of lung cancer more feasible," Anderlind said.