National Lung Screening Trial Aims to Detect Lung Cancer Earlier

Christine Wilson, cancer survivor, shares her experiences from the Abramson Cancer Center’s 2011 CANPrevent Lung Cancer Conference. You can view all the presentations from the conference here. In this blog, she discusses a presentation from Drew Torigian, MD, MA, about the National Lung Screening Trial, which compared cancer screens to detect lung cancer early.

Experts agree that if cancer is detected early, a patient has a better chance of recovery. The goal of detecting lung cancer early, however, has been elusive. 

Study after study has shown that standard chest X-rays do not detect early lung cancers. This is true even when X-rays are given on a regular basis to those at high risk for developing lung cancer. 

So how can lung cancer be caught earlier? And how can lung cancer deaths be prevented?

Lung cancer remains the second most common cancer in this country and the most common cause of cancer deaths. Additionally, lung cancer rates continue to rise in many countries around the world.


CT Scans for Lung Cancer
Computed tomography (CT) scans for cancer are more sensitive in finding lung abnormalities, and better able to detect more and smaller lesions. CT scans are, however, a more expensive technology than chest X-rays. They can also be non-specific in determining if abnormalities are lung cancers are benign nodules. 

The National Lung Screening Trial (NLST) compared two ways of detecting lung cancer in high-risk smokers: low-dose helical computed tomography (CT) and standard chest X-ray.

The study aimed to find it is possible to detect lung cancers at an earlier, more treatable stage, and whether such screening would decrease cancer deaths.  

Drew Torigian, MD, MA, associate professor of radiology at the Perelman School of Medicine at the University of Pennsylvania, served as principle investigator at Penn for this national study, which involved more than 53,000 patients in 33 different sites. He described the results of this trial, the largest, most expensive randomized screening trial ever conducted, at the Abramson Cancer Center’s 2011 CANPrevent Lung Cancer Conference.

All clinical trials have a specific primary endpoint or goal by which success is measured. For the NLST, that goal was to determine if low dose CT screening could reduce the death rate from lung cancer among heavy smokers. Patients enrolled in the trial were current or past heavy smokers between the ages of 55 and 74. Half received regular chest X-rays while the other half received helical CT scans over a period of three years.

The results were encouraging.

CT scanning detected significantly more cancerous and pre-cancerous lesions than chest X-rays. However, finding lesions isn't enough. The study had to demonstrate early detection actually saved lives.Preliminary results of the study showed 87 more lives were spared by helical CT as compared to chest X-rays, which translates into a 20 percent reduction in the death rate.

While the NLST results are positive, Dr. Torigian points out there are many questions that still need to be addressed and answered before low-dose, helical CT scanning can be considered a standard screening procedure. Many of these questions relate to the overall costs and cost-effectiveness of implementing CT scanning programs, such as:

• Who should be get a cancer screen?
• How often should they be scanned?
• At what age should screening begin?
• Will insurance cover helical CT scanning?
• How many screenings are needed?
• What is the impact, both in cost and on the health of the participants of the high rate of false positives (non-cancerous, and generally non-clinically important lesions) found in CT screening?
• Are there biomarkers that will allow better targeting of populations that will benefit from this type of screening?

There are social policy questions as well, including the impact of undergoing CT screening on smoking behavior. Does the screening encourage people to quit, or give them a false sense of security?

Dr. Torigian stressed the unanswered questions do not detract from the importance of finding better ways to detect early lung cancers. Lung cancer is a global epidemic, and finding more early stage cancers will lead to better outcomes in treating lung cancer.

Watch all the presentations from the 2011 CANPrevent Lung Cancer Conference here.

Learn more about lung cancer treatment at the Abramson Cancer Center.