Autofluorescence bronchoscopy improves staging of radiographically occult lung cancer and has an impact on therapeutic strategy.

BACKGROUND The ability of conventional CT scans and fiberoptic bronchoscopy to localize and properly stage radiographically occult lung cancer (ROLC) in the major airways is limited. High-resolution CT (HRCT) scanning and autofluorescence bronchoscopy (AFB) may improve the assessment of ROLC before the most appropriate therapy can be considered. PATIENTS AND METHODS We prospectively studied 23 patients with ROLC, who were referred for intraluminal bronchoscopic treatment (IBT) with curative intent. Additional staging with HRCT and AFB was performed prior to treatment. Twenty patients were men, 9 patients had first primary cancers, and 14 patients had second primary cancers or synchronous cancers. RESULTS HRCT scanning showed that 19 patients (83%) had no visible tumor or enlarged lymph nodes. With AFB, only 6 of the 19 patients (32%) proved to have tumors < or = 1 cm(2) with visible distal margins. They were treated with IBT. In the remaining 13 patients, abnormal fluorescence indicated more extensive tumor infiltration than could be seen with conventional bronchoscopy alone. Six patients underwent radical surgery for stage T1-2N0 (n = 5) and stage T2N1 (n = 1) tumors. Specimens showed that tumors were indeed more invasive than initially expected. The remaining seven patients technically did not have operable conditions, so they were treated with external irradiation (n = 4) and IBT (n = 3). The range for the time of follow-up for all patients has been 4 to 58 months (median, 40 months). The follow-up data underscore the correlation between accurate tumor staging and survival. CONCLUSIONS Our data showed that 70% of patients presenting with ROLC had a more advanced cancer than that initially diagnosed, which precludes IBT with curative intent. Additional staging with HRCT and AFB enabled better classification of true occult cancers. Our approach enabled the choice of the most appropriate therapy for each individual patient with ROLC.