Can lung cancer screening by computed tomography be effective in areas with endemic histoplasmosis?

Low-dose chest computed tomography (CT) is being evaluated in several national trials as a screening modality for the early detection of lung cancer. The goal of the present study was to determine whether lung cancer screening could be done while minimizing the number of benign biopsy specimens taken in an area endemic for histoplasmosis.

The subjects were recruited by letters mailed to area physicians and local advertisement. The inclusion criteria were age older than 50 years and at least a 20 pack-year smoking history. The exclusion criteria were symptoms suggestive of lung cancer or a history of malignancy in the previous 5 years. The participants completed a questionnaire and underwent a chest CT scan at baseline and annually for 5 years. The management of positive screening results was determined using a defined algorithm: annual follow-up CT scan for nodules less than 5 mm; 6-month follow-up CT scan for nodules 5 to 7 mm; review by our multidisciplinary tumor board for nodules 8 to 12 mm; and biopsy for nodules greater than 12 mm.

A total of 132 patients were recruited. Of the 132 patients, 61% had positive baseline CT findings and 22% had positive findings on the annual CT scans. Six cancers were detected. Of these 6 patients, 5 had stage I disease and underwent lobectomy, and 1 had stage IIIA disease and underwent induction chemotherapy and radiotherapy followed by lobectomy. All patients were alive and disease free at a mean follow-up of 41.7 ± 18.6 months. No biopsies were performed for benign lesions. Also, no cancers were missed when the protocol was followed.

Screening with CT can be done effectively in an area endemic for histoplasmosis while minimizing benign biopsies.