(December 3, 2009 - Insidermedicine)

A special system for screening for lung cancer among those at high risk for the condition using computed tomography (CT) has been developed by researchers whose work is published in the December 2 issue of the New England Journal of Medicine.

Here is some information about lung cancer:

•     Symptoms may include a persistant cough that  gets worse over time or coughing associated with bloody sputum

•    It is usually caused by smoking or exposure to second-hand smoke

•    It can also be caused by exposure to chemicals such as radon and asbestos

Researchers from Erasmus Medical Center in Rotterdam used CT scanning to screen the lungs of over 7,500 individuals who were known to be at high risk for lung cancer. If the results of the scan were indeterminate –meaning it was not clear whether there were signs of cancer -- the scan was repeated three months later. The investigators outlined specific criteria by which they considered the screen to be positive or negative, based on the size of a specific type of lesion known as a noncalcified nodule found in the lungs as well as how quickly these nodules grew.

Using their criteria, the ability of the screen to detect cancer when it was present was 94.6%, and the likelihood that there was no cancer when the screen was negative was 99.9%. Among over 7,000 patients who had negative findings with the screening, only 20 were eventually diagnosed with lung cancer in the following 2 years.

Today's research demonstrates how selecting specific criteria to look for in a CT scan can improve the usefulness of this noninvasive test for screening for lung cancer in high-risk individuals.