NEW YORK—Spiral CT screening of high-risk individuals could prevent about 80% of deaths from lung cancer, according to the latest results from the large collaborative I-ELCAP trial. “In our study, the estimated 10-year lung-cancer- specific survival rate among the 484 participants with disease diagnosed on CT, regardless of the stage at diagnosis or type of treatment, was 80%,” said Claudia I. Henschke, MD, of Weill Medical College of Cornell University, leader of the International Early Lung Cancer Action Program (I-ELCAP). Dr. Henschke and her colleagues reported the results in a recent issue of the New England Journal of Medicine (355:1763-1771, 2006).
In the study, screening was defined according to the I-ELCAP protocol allowing data from the participating institutions to be pooled. Further, I-ELCAP provided a management algorithm for baseline CT and repeated CT screening.
Participants were at least 40 years of age and were at risk for lung cancer due to a history of cigarette smoking, occupational exposure, or exposure to secondhand smoke (with the exception of patients from Azumi, Japan, who participated as part of their annual health screening program).
Between 1993 and 2005, a total of 31,567 asymptomatic men and women underwent baseline CT screening. From 1994 to 2005, a total of 27,456 annual CT screenings were conducted. Biopsies as recommended by the protocol were performed in 535 participants, and 492 were diagnosed with malignant disease (479 lung cancers). Of these 479 lung cancers, 405 were found at baseline and 74 at an annual screening. Another 5 were defined as interim diagnoses, prompted by the development of symptoms within 12 months of the baseline screening.
Of the 484 participants diagnosed with lung cancer, 411 had surgery; 57 received radiation, chemotherapy, or both; and 16 received no treatment. Two patients died within 4 weeks after surgery, for an operative mortality rate of 0.5%.
Among the 412 participants (85%) with clinical stage I lung cancer found by CT screening, the estimated 10-year survival rate was 88%. This rose to 92% among the 302 patients with clinical stage I disease who had surgical resection within 1 month of their diagnosis. All 8 untreated patients with stage I disease died within 5 years of diagnosis.
Comparison to Mammography Dr. Henschke compared the results with those of breast cancer screening. “For lung cancer, the rates of detection among the participants in the study who were 40 years of age and older were 1.3% on baseline CT screening and 0.3% on annual screening, values that were slightly higher than those for the detection of breast cancer on baseline screening (0.6% to 1%) and similar to those for annual screening (0.2% to 0.4%), among women 40 years of age and older,” she said.