Jun 21, 2001
The Early Lung Cancer Action Project (ELCAP), a nine-year-old project led by New York Weill Cornell Medical Center, has already demonstrated that an initial "baseline" screening of high-risk persons by low-dose advanced computed tomography (CT) can detect lung cancer at earlier, presumably more curable stages than ordinary x-ray. Now, a new study by the physicians of ELCAP reports the results of repeating the CT screenings on an annual basis—a more significant event than doing the screenings just once. The new study found that with repeat screenings false positives were uncommon, and 83% of the lung cancers discovered were in the earliest, most curable stage. Demonstrating that the repeat screenings are both beneficial and cost-effective, the findings should give even more hope to people at high risk for lung cancer (smokers aged 60 and over).
Published in the July 1 issue of Cancer, the article, by Dr. Claudia I. Henschke, Chief of the Chest Imaging Division at New York Weill Cornell, and 12 colleagues, gives the results of 1,184 repeat screenings, performed at intervals of about a year, on a cohort of 841 high-risk individuals.
A positive result from the screening test was defined as newly detected, noncalcified pulmonary nodules with interim growth. Because of the precision of CT, this meant nodules as small as two millimeters in size. Compared to the baseline screenings, positive results were, as one would expect, less common (2.5% compared to 23%).
In two of these 30 positive cases, the patient died of an unrelated cause. In 12 of the remaining cases, the nodules resolved on follow-up high-resolution CT (HRCT)—half of these after a course of antibiotics. Of the remaining 16 cases, eight showed further growth, and biopsies revealed malignancies in seven of these. In another two subjects, symptoms led to an interim diagnosis of lung cancer, but neither of these malignancies was nodule-associated; rather, they were endobronchial.
Six of the seven malignancies were nonsmall cell carcinomas, and all of them were deemed to be resectable—that is, operable. The article notes, "The 5-year survival rate of Stage IA nonsmall cell malignancies measuring less than 20 mm and detected by CT has been reported to be greater than 90%, suggesting a curability rate of these malignancies of greater than 80%." This compares to an overall survival rate for lung cancer detected through traditional means of just 12%.
An important question facing the study was whether the repeated screenings would give false positives. By methodically setting the standards for diagnosis, ELCAP found that "False-positive screening test results were uncommon and usually manageable without biopsy."
The article says, "Even if a given regimen of CT screening . . . does serve to increase the overall rate of curability for lung carcinoma . . . this does not . . . justify the use of that regimen of screening." Rather, "the prospect of early diagnosis and its associated curability" must "translate into a gain in life expectancy sufficient to justify the cost of . . . the screening test together with the result-contingent definitive diagnostics."
Fortunately, "it is evident that . . . the cost per life-year saved can be as low as $10,000. . . Such a cost . . . is well below that for existing screening programs for breast carcinoma or cervical carcinoma and is well below the benchmark of $50,000 used in the U.S." With this finding by ELCAP, early CT screening as standard practice for persons at high risk of lung cancer should come much closer to reality.
The other authors of the article are (from New York Weill Cornell) David F. Yankelevitz, Dorothy I. McCauley, James P. Smith, Daniel Libby, Mark Pasmantier, June Koizumi, Madeline Vazquez, Douglas Flieder, Nasser Altorki, and Olli S. Miettinen, and (from New York University Medical Center) David P. Naidich and Georgeann McGuinness. All are M.D.'s, and Drs. Henschke and Miettinen are also Ph.D.'s.
The study was supported, in part, by the Eastman-Kodak Corporation, the General Electric Corporation, and the National Cancer Institute.
Building on these promising results, AMDeC (Academic Medicine Development Company), a consortium of 39 New York medical and research institutions, in conjunction with New York Weill Cornell Medical Center, has launched a larger-scale study to reach more people across the state of New York. NY-ELCAP builds on the original ELCAP study by using an updated version of the clinical research protocol that combines both the knowledge accumulated from ELCAP and the latest and most accurate technologies. Participating institutions include Columbia University College of Physicians & Surgeons, Maimonides Medical Center, Memorial Sloan-Kettering Cancer Center, Mount Sinai School of Medicine, New York Medical College, Our Lady of Mercy Medical Center, Rosswell Park Cancer Institute, SUNY-Health Science Center at Brooklyn, SUNY-Stony Brook, and SUNY-Upstate Medical University at Syracuse.
To find out if you are eligible for NY-ELCAP, call 1-866-NY-ELCAP. To find out more about lung cancer screening, call 212-746-1325.