Lung cancer detection with low-dose spiral computed tomography in chronic obstructive pulmonary disease patients

Purpose: To determine whether low-dose spiral computed tomography (LDCT) can improve the lung cancer detection rate in chronic obstructive pulmonary disease (COPD) subjects.

Material and Methods: From October 1999 to December 2003, 374 COPD patients underwent LDCT for lung carcinoma screening. All subjects with an abnormal baseline CT scan were followed with serial CT scans as part of our protocol. Follow-up was continued until the demonstration of no change over a minimum of 24 months, or resolution. Sputum samples were also obtained for cytological analysis.

Results: On the baseline spiral CT scan, 132 of 374 patients (35.2%) had at least one non-calcified nodule that required periodic follow-up with CT scans. The median follow-up time was 21 months (range 2-48 months). Of the 374 COPD subjects, nine patients with primary lung cancer (2.4%) were detected: six were squamous cell carcinomas, two were small-cell lung carcinomas (SCLC), and one was adenosquamous carcinoma. Three of the nine tumors were in stage IA, two in stage IIB, two in stage IIIA, and two were limited SCLC. Potentially curative pulmonary resection was performed in four patients, pulmonary lobectomy in three, and wedge excision in one. One subject with stage IA squamous cell carcinoma received radiotherapy, as pulmonary function was severely impaired. In addition, four patients underwent removal of benign lesions. Sputum was collected in 205 (54.8%) of 374 patients. There were 154 (75 %) metaplasia, 14 (6%) moderate dysplasia, and one (0.4%) malignant case.

Conclusion: LDCT increases early lung carcinoma detection rate in COPD patients, but pulmonary function impairment may reduce its benefit.