Targeting of Low-Dose CT Screening According to the Risk of Lung-Cancer Death

"Using low-dose CT screening for lung cancer prevents the greatest number of deaths (and gives the lowest proportion of false-positives) among those at highest risk, according to a New England Journal of Medicine study. CT screening was previously shown to reduce such deaths by 20% compared with radiography, and researchers stratified over 25,000 CT-screened patients into risk quintiles to examine whether the benefits of screening varied according to risk levels. The quintiles ranged from 0.15% to more than 2% in 5-year risk for lung cancer mortality. They found that percentage death reduction was constant across all quintiles, however, the number of deaths prevented was highest among those in the top three risk quintiles (77) versus those in the bottom two (11). Similarly, the number needed to screen to prevent one lung cancer death was 208 for those in the top three quintiles, compared with 302 for the entire group. The proportion of false-positive results also declined significantly with increasing risk quintile. " ref NEJM