CT screening regimen finds early-stage lung cancer

Mar 29 2007

Annual computed tomography (CT) screening identifies a high proportion of patients with early-stage lung cancer, according to the latest findings of the NewYork-Presbyterian Hospital/Weill Cornell Medical Center -- led New York Early Lung Cancer Action Project (NY-ELCAP) published in the April issue of the journal Radiology.

"This article focuses on the regimen of screening as this determines how early the cancer is diagnosed. This is critical, as it provides the opportunity for earlier treatment, which can be curative. Following the appropriate regimen also markedly decreases unnecessary workup and biopsies," says NY-ELCAP principal investigator Dr. Claudia I. Henschke, chief of the Divisions of Chest Imaging and Health-Care Policy and Technology Assessment at NewYork-Presbyterian/Weill Cornell and professor of radiology at Weill Cornell Medical College.

Lung cancer remains the leading cause of cancer death in both men and women, killing more people than breast, prostate and colon cancers combined, according to the American Cancer Society (ACS). The estimated cure rate for lung cancer in the absence of screening is about 5 percent, but increases significantly when the cancer is diagnosed and treated at its earliest stage.

NY-ELCAP investigators provided baseline (first-time) CT screenings to 6,295 patients with no symptoms of cancer at 12 medical institutions in New York State and a single round of annual screening. Participants were age 60 or older with a history of smoking but no prior cancer and no chest CT in the past three years. The initial CT led to recommendations for further workup of 14 percent of the 6,295 baseline screening and 6 percent of the 6,014 annual screenings.

A total of 124 people were diagnosed with lung cancer, all but three directly based on screening results, rather than interim symptom-prompted diagnoses. A high proportion of patients had no evidence of metastases when recommended for biopsy, 89 percent in the baseline and 85 percent in the repeat rounds of screening, indicating that a regimen of annual repeat screenings allows for detection of lung cancer at its earliest, most treatable stage.

The new results on the importance of the regimen of screening are significant because the earlier findings by the I-ELCAP sister studies (published in the Feb. 13, 2006, Archives of Internal Medicine and in the Oct. 26, 2006, New England Journal of Medicine) had shown that the smaller the cancer when diagnosed, the more likely it was stage I, and that the curability of these stage I cancers, when promptly treated, was very high: 92 percent, as compared with some 5 percent in the absence of screening.

"Delay in the recommended diagnostic workup detracted from the full benefit of CT screening, as it resulted in progression of the cancer in size, and if delayed long enough, a higher stage of the disease as well," Dr. Henschke says. "Thus, it is critical that people adhere to an optimal screening regimen and that the physician and patients being screened understand the importance of following the regimen."

While a recent JAMA study suggested that CT screening does not reduce mortality rates for lung cancer, Dr. Henschke states: "The main problem with that study is that it focused on the wrong time to assess the decrease in deaths from lung cancer, which only begins to be seen after the first five years of screening. The JAMA article was the first application of a newly developed computer model to predict expected deaths from lung cancer, and there are numerous concerns about its validity."

Dr. Henschke recommends that smokers and former smokers considering CT screening talk to their physicians and, if they decide to be screened, go to a place with quality assurance and a multidisciplinary team of physicians knowledgeable and experienced in CT screening.

NY-ELCAP co-investigators include Drs. David F. Yankelevitz and Dorothy I. McCauley of NewYork-Presbyterian/Weill Cornell and Weill Cornell Medical College; and Drs. John H. M. Austin, Gregory D. N. Pearson and Maria C. Shiau of NewYork-Presbyterian Hospital/Columbia University Medical Center. Other New York study centers include the State University of New York at Stony Brook; Roswell Park Cancer Institute, Buffalo; State University of New York, Upstate Medical University, Syracuse; North Shore-Long Island Jewish Health System, New Hyde Park; Mount Sinai School of Medicine, New York City; Memorial Sloan-Kettering Cancer Center, New York City; New York Medical College, Valhalla; and Our Lady of Mercy Medical Center, Bronx.