Positive CT scan for lung cancer may resolve

Many positive CT scans for lung cancer screening resolve after short-term follow-up, doctors have observed.

The value of CT screening for lung cancer is unclear. In people at high risk for the disease, CT scanning may detect early lung cancer, but it's usefulness as a screening tool is limited because it misses tumors in certain areas of the lung and often falsely identifies harmless spots as being cancerous.

Positive CT screening for lung cancer usually results in the diagnosis of early stage I lung cancer, the authors explain, but benign lesions are also found.

Dr. Daniel M. Libby from the Weill Cornell Medical Center in New York and colleagues reviewed their experience with first-time and repeat CT screenings to determine if short-term CT follow-up might shorten the workup of lesions.

Among the 41 individuals who had follow-up CT scans within 2 months of the initial scan, five patients had complete resolution and seven patients had partial resolution of the original findings, the authors report.

Eight of 10 patients with patchy consolidated spots showed complete or partial resolution after antibiotic therapy, the results indicate, compared with 4 of 31 patients with lesions.

Based on these findings, 12 patients would not require further tests and would simply be asked to return for a repeat screening in 1 year, the researchers note.

The results were similar among 39 patients who returned for follow-up CT scan within 2 months of their annual repeat screening, the report indicates. Sixteen of these patients had complete resolution, and 13 patients had partial resolution of their abnormal findings.

In both groups of patients, none of those who showed partial resolution had subsequent lesion growth or cancer, the investigators report. However, for 37 patients whose nodules remained unchanged or grew, 17 cancers were subsequently identified.

"On the basis of this study," the authors conclude, "we recommend a course of antibiotics followed by another CT within 2 months to people with patchy consolidation or nonsolid opacities detected on the baseline screening and all those with new nodules on repeat screening."

"It must be emphasized that the use of antibiotics and short-term CT follow-up is only one of the options in the regimen of CT screening for lung cancer," the researchers add, "and further research in this area promises to continue to improve the efficiency of CT screening for lung cancer."

SOURCE: Chest April 2006.