- Lung Cancer Basics
Washington, DC [April 28, 2010] -- Lung Cancer Alliance acknowledges the on-going work by the Office of Disease Prevention (ODP) at the National Institutes of Health (NIH) on lung cancer screening research and the need for people who may be at risk for lung cancer to be well informed.
However, the paper by Jennifer M. Croswell, MD and co-authors published last week in the Annals of Internal Medicine, claiming that CT scans yield twice as many false positives as chest x-rays and lead to a high percentage of invasive follow-up procedures, is based on a study (the Lung Screening Trial -LSS) done in 2000-2001 that used outdated equipment and failed to follow a uniform diagnostic protocol.
This repackaged data from a flawed ten year old study ignores the exponential advances in CT imaging that have been made since then, and fails to acknowledge the great progress that dedicated screening researchers in the United States and abroad have made and are continuing to make in perfecting the CT screening protocol.
It is not surprising that CT scans picked up more suspicious nodules than the chest x-rays in the LSS study. CT scanners are designed to be more sensitive and can pick up smaller nodules which chest x-rays will frequently miss.
But screening is not a one step procedure. The protocol for how those nodules are evaluated, followed-up and diagnosed is critical to the screening process.
The LSS did not have a defined, uniform, well-considered procedure in place and, from a patient advocate perspective, showed the pitfalls of screening without a good diagnostic protocol. Indeed, every screening research trial since then has included one.
Recently, the first published papers on the Nederlands-Leuvens Longkanker Screenings Onderzoek (NELSON) trial, a randomized controlled trial of 16,000 people in the Netherlands and Belgium that uses a defined diagnostic work-up protocol, reported that over 70% of cases were being diagnosed at Stage 1, with unprecedented levels of 95% sensitivity and 99% specificity in diagnosing lung cancer accurately.
The International Early Lung Cancer Action Program (I-ELCAP), the longest and largest ongoing CT research program involving over 50,000 people at 50 sites in nine countries, has developed a diagnostic and management protocol that incorporates technology advances as they come on line and which is continuously update to improve detection and reduce risk. Under this optimized protocol, 80% of lung cancers are being diagnosed at Stage 1 and those treated promptly have 10 year survival rates of nearly 90%.
Both these trials show a marked distinction from 16% rate of Stage 1 diagnoses for lung cancer outside of screening.
The first actuarial analysis ever done of over 300,000 lung cancer patients in the NCI's SEER registry was published two months ago. Carried out by Milliman Inc, an internationally renowned insurance actuarial firm, the analysis found that diagnosing a greater frequency of newly detected lung cancer cases at Stage I rather than Stage III or VI could be associated with a reduction of lung cancer deaths by 70,000 lives a year.
If there were a more balanced presentation of the current state-of-the-art in the promising areas of CT-based lung cancer screening, the headline should be: “How far we have come in 10 years to better detect, diagnose and treat lung cancer – the most lethal of all cancers.”