Do Current Lung Cancer Screening Guidelines Apply for Populations With High Prevalence of Granulomatous Disease?...

Low-dose computed tomography (LDCT) screening for lung cancer has been demonstrated to be effective in reducing cancer mortality. However, these studies have not been undertaken in countries where the incidence of granulomatous disease is high. The First Brazilian Lung Cancer Screening Trial (BRELT1) has completed initial accrual and is now in the follow-up phase. We present results from the initial prevalence round of screening.

The inclusion criteria were the same as those for the National Lung Cancer Screening Trial (NLST). Pulmonary nodules larger than 4 mm were considered positive and required evaluation by a multidisciplinary team. Indeterminate nodules were evaluated with fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) or biopsy when indicated. Statistical analysis was performed with Fisher's exact test to compare our positive findings with those of the NLST.

From January 2013 to July 2014, 790 participants were enrolled. Positive LDCT scans were reported in 312 (39.4%) participants, with a total of 552 nodules larger than 4 mm. The comparison between positive findings in the NLST (7,191 of 26,722 cases) and those in the BRELT1 (312 of 790 cases) showed a significant difference (p < 0.001). The positive predictive value was lower in BRELT1 than in the NLST (3.2% versus 3.8%, respectively). Follow-up imaging was indicated in 278 of 312 (89.1%) participants; 35 procedures were performed in 25 participants. In 15 cases, benign lesions were diagnosed. Non-small-cell lung cancer (NSCLC) was diagnosed in 10 patients (prevalence of 1.3%). In 8 patients (stage IA/IB disease), treatment was by resection only, in 1 patient neoadjuvant chemotherapy was used (stage IIIA), and in 1 patient advanced disease was diagnosed (stage IV).

Using NSLT criteria, a larger number of patients had positive scans (nodules), compared with previous lung cancer screening studies. However, the number of participants requiring surgical biopsy procedures and who were ultimately identified as having cancer was similar to other reports. This supports the role of screening in patient populations with a high incidence of granulomatous inflammation.