Purpose: To evaluate the role of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in radiologically occult preinvasive lesions and lung cancer in the central airways. Experimental Design: Twenty-two patients with 24 preinvasive lesions and early squamous cell cancer (SCC) being occult on high-resolution computed tomography were studied. All lesions were diagnosed based on histology sampled using autofluorescence bronchoscopy. FDG-PET findings were correlated with WHO histologic classification. FDG-PET was considered true-positive when the final diagnosis was SCC and true-negative when the lesions were classified as severe dysplasia or less. Results: FDG-PET was true-positive in 8 of 11 and true-negative in 11 of 13 cases corresponding with a sensitivity of 73% [95% confidence interval (CI), 0.43-0.91] and specificity of 85% (95% CI, 0.57-0.97). Positive and negative predictive values were 80% (95% CI, 0.48-0.96) and 79% (95% CI, 0.52-0.93), respectively. Conclusions: Our very preliminary data suggest that FDG-PET might be useful for the evaluation of early central airway lesions, being positive in most SCC and negative in cases of severe dysplasia. Validation in a larger multicenter study is needed.

Expression levels of hTERT mRNA were investigated by RT‐PCR in tissue specimens of patients with (Group A) and without (Group B) clinically overt bronchial carcinoma, respectively. Bronchial carcinoma ( n = 9) and distant normal ( n = 9) specimens were analyzed in Group A. The chance of carcinoma seemed to increase with increasing hTERT mRNA levels (OR = 6.04, 95% CI = 1.02–37). Group B was comprised of 21 patients who underwent autofluorescence bronchoscopy. After analysis of 66 bronchial biopsies the chance of prevalent carcinoma in situ or carcinoma increased with increasing hTERT mRNA levels (OR = 6.19, 95% CI = 1.55–25). Variables like age, gender, smoking history, history of cancer within the airways or the degree of lymphocyte infiltrate in the specimens did not modify this relation. In 7 Group B patients in whom bronchial cancer was diagnosed during follow‐up, biopsies taken before cancer diagnosis from both the area of the newly developed tumor and distantly from this area had been analyzed for hTERT expression. The median hTERT mRNA level in the biopsies from the area of future cancer was significantly higher than in biopsies taken from distant sites ( p < 0.03). These data indicate that elevated hTERT mRNA is associated with an increased relative risk of prevalent and incident bronchial squamous cell carcinoma ( in situ ). © 2004 Wiley‐Liss, Inc.

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.