Key Point

The diagnosis of lung cancer after a positive spiral CT screen does not usually conform to published algorithms.

BETHESDA, MD—When faced with patients who have had a positive lung cancer screen, what tests do physicians use to make a firm diagnosis? And how well do their work-ups conform to published diagnostic algorithms for suspected lung cancer? Paul F. Pinsky, PhD, and coworkers addressed these questions in an investigation of 522 current and former smokers, the subpopulation that screened positive for lung cancer in the 1,660-person Lung Screening Study (LSS).¹

The LSS was a feasibility trial of lung cancer screening with low-radiation-dose spiral CT, a newer and more sensitive form of spiral CT capable of detecting asymptomatic lung neoplasms. It was compared to chest x-ray films in the LSS, noted Dr. Pinsky, a statistician in the Division of Cancer Prevention at the National Institutes of Health in Bethesda, Maryland.

In the present study, the diagnosis of suspected lung cancer did not follow a specific set of rules. “The patients were referred to their own health care providers, enabling us to study lung cancer diagnosis as it occurs in the community rather than as part of a research protocol,” Dr. Pinsky emphasized.

Of the patients studied, 12% underwent biopsy of their suspected lung cancers. A biopsy was significantly less likely to be performed when a patient’s lung nodule was 4 to 9 mm in size than when it was more than 10 mm or when there was no nodule but other suspicious findings were present.

Lung cancer diagnosis included chest CT in 63% of cases. The median time between screening and follow-up chest CT was 82 days. “Only a minority of subjects received diagnostic work-ups that were consistent with published algorithms,” Dr. Pinsky and colleagues related.

Because the study encompassed five metropolitan areas and one rural area, the investigators maintained that their findings are at least somewhat representative of how lung cancer is diagnosed in the United States after a positive spiral CT screen. Thus, the study could be taken as a sign that current practice in lung cancer diagnosis may need adjustment, Dr. Pinsky told Pulmonary Reviews. “Our findings could also be used to estimate the burden of follow-up for suspected lung cancer in terms of cost and medical risk,” he suggested.

—Timothy Begany

Reference
1. Pinsky PF, Marcus PM, Kramer BS, et al. Diagnostic procedures after a positive spiral computed tomography lung carcinoma screen. Cancer. 2005;103:157-163.

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