CT Lung Cancer Screening Could Save 12,000 Lives - Or More

CT lung cancer screening could save up to 12,000 lives per year in the United States, says one study published in the most recent issue of Cancer. However, a second recent study in the New England Journal of Medicine found that even more lives could be saved if screening selection criteria were expanded to cover a broader group of people.

Results from the National Lung Screening Trial (NLST) published in 2011 showed that low-dose CT screening among people at high risk for lung cancer reduced cancer mortality by 20 percent compared with chest X-ray alone. High-risk candidates for screening include current or former smokers with no signs and symptoms or history of lung cancer, with a smoking history of at least 30 pack-years.

For the first study, researchers from the American Cancer Society used the NLST findings to estimate the number of lives that could be saved annually if the screening guidelines were implemented among all eligible Americans. Analyses were performed by age, sex, and smoking status.

Using census data, the researchers identified about 8.6 million Americans (5.2 million men, 3.4 million women) who were eligible for lung cancer screening in 2010. If 100 percent of the group had been screened and based on the 20 percent drop in deaths found in the NLST trial, the researchers estimated that 12,250 lung cancer deaths could have been prevented (8,990 men, 3,260 women).

Because 100 percent participation is not realistic, the researchers recalculated the numbers based on a 70 percent participation rate, which resulted in 8,575 lives saved.

In a second study, from Brock University in Ontario, Canada, researchers concluded that if lung cancer screening guidelines were expanded to include those from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial (PCLO), even more lives would be saved.

The PCLO criteria include body mass index, level of education, family history of lung cancer, and presence of chronic obstructive pulmonary disease (COPD), in addition to smoking history and age.

Using this approach, which the researchers called PLCO_M2012, allowed for using a broader history, rather than the NLST criteria yes/no questions and answers. Applying the PLCO model, the researchers found that among 37,332 smokers, 81 more patients were screened and were diagnosed with lung cancer than would have been with the NLST model.

Sensitivity rose from 71 percent to 83 percent when the PCLO criteria were used. “The use of the PLCO_M2012 model was more sensitive than the NLST criteria for lung-cancer detection,” concluded the study’s authors.