Yearly CT screening help doctors identify a large number of patients with early-stage lung cancer, according to research project results published in the April issue of the journal Radiology. The findings are from the New York Early Lung Cancer Action Project (NY-ELCAP).
These findings differ from the results of a recent JAMA study that suggested that CT screenings do not bring down mortality rates for the disease. The principle investigator in this study disagrees. "The JAMA article was the first application of a newly developed computer model which predicted expected deaths from lung cancer, and there are numerous concerns about its validity," said Claudia I. Henschke, PhD, MD, professor of radiology at Weill Cornell Medical College and chief of the divisions of chest imaging and healthcare policy and technology assessment at New York-Presbyterian Hospital/Weill Cornell Medical Center in New York City. "The main problem with that study is that it focused on too short a time period to assess the decrease in lung cancer deaths, which starts to be evident after the first five years of screening."
Regarding this study, "the regimen of screening determines how early the cancer is diagnosed. This is critical, as it provides the opportunity for earlier treatment which can be curative," said Henschke. "Following the appropriate regimen also markedly decreases unnecessary work-up and biopsies," she added.
According to the study, the estimated cure rate for lung cancer in the absence of screening is approximately 5 percent, but goes up when the cancer is diagnosed and treated at its earliest stage.
NY-ELCAP investigators worked at 12 medical institutions in New York State providing baseline (first-time) CT screenings to 6,295 people with no symptoms of cancer. The participants were age 60 or older with a history of smoking, but no prior cancer and no chest CT in the past three years. In all, 6,014 annual repeat screenings were provided.
CT results prompted recommendations for further work-up on 14 percent of the 6,295 baseline screening participants and 6 percent of the 6,014 repeat screening participants.
A total of 124 people were diagnosed with lung cancer, all but three directly based on screening results. Eighty-nine percent in the baseline and 85 percent in the repeat rounds of screening had no evidence of metastases when recommended for biopsy, indicating that a regimen of annual repeat screenings allows for detection of lung cancer at its earliest stage.
Long-term follow-up demonstrated a 10-year survival rate of 92 percent among patients with Stage 1 lung cancer when diagnosed early and promptly treated.
"It is critical that physicians and the people being screened understand the importance of following an optimal screening regimen," Henschke said. "Delay in the recommended diagnostic work-up detracted from the full benefit of CT screening, as it resulted in progression of the cancer in size, and sometimes resulted in a higher stage of the disease."