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To evaluate the utility of endobronchial ultrasonography (EBUS) in selecting appropriate candidates with centrally located early-stage lung cancer for photodynamic therapy (PDT) with curative intent, we performed EBUS before PDT in 18 biopsy-proven squamous cell carcinomas (including three carcinoma in situ) that had been considered to be appropriate candidates for PDT by conventional bronchoscopy and high-resolution computed tomography (HR-CT). Nine lesions were diagnosed as intracartilaginous by EBUS and subsequently PDT was performed. Long-term complete remission has been achieved in these patients with a median follow-up term after PDT of 32 months. The remaining nine lesions were diagnosed as extracartilaginous by EBUS and were considered candidates for other therapies such as surgical resection, chemotherapy, and radiotherapy, although two were invisible by HR-CT, three were superficial, and five were < or = 1 cm in diameter on observation by bronchoscopy. The depth of tumor invasion estimated by EBUS was proven to be accurate by histopathologic findings in six specimens after surgical resection. We conclude that EBUS is a useful technique that might be considered in addition to conventional bronchoscopy and HR-CT to improve the efficacy of PDT in patients with centrally located early-stage lung cancer.

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Centrally located lung cancers in smokers frequently associated with subsequent primary tumors. We evaluated the telomerase expression chronologically in noncancerous epithelia as a risk factor of susceptibility to lung cancer development. Telomerase protein expression was examined in situ by immunohistochemistry in 26 noncancerous bronchial epithelia adjacent to centrally located early-stage lung cancers in sequential 23 patients treated by photodynamic therapy or surgery among 206 patients who underwent autofluorescence bronchoscopy from 1997 to 2003. Among the 15 lesions in 12 patients treated by photodynamic therapy alone, 11 lesions achieved complete remission after photodynamic therapy, and none of their noncancerous bronchial epithelia was telomerase positive. On the contrary, in the remaining four lesions, either recurrence or secondary lung cancer developed adjacent to the successfully treated primary cancer within 26 months, and the telomerase protein expression in noncancerous epithelia was detected before the secondary cancer development (P < 0.001). The overall relationship of human telomerase reverse transcriptase positivity in noncancerous epithelia and subsequent lung cancer development, including patients treated by radiation or surgery, showed higher significance (P < 0.0001). Histologically "normal" bronchial epithelia in smokers may unphysiologically express telomerase as a field, and such epithelia are likely susceptible to develop lung cancer. We propose that ectopic expression of telomerase in bronchial epithelia may precede transformation in human lung cancer development and that detection of telomerase protein in noncancerous bronchial epithelia will become a useful marker detecting high-risk patients for lung cancer development.

Background: Narrow band imaging (NBI), which enhances blood vessels, is a new endoscopic technology for diagnosing malignancies, but it has not been investigated for pleuroscopy. Objectives: To evaluate the efficacy of NBI applied to pleuroscopy for detecting malignant lesions by assessing vascular patterns of the pleura. Methods: From May 2006 to September 2008, 45 patients with undiagnosed pleural ef-fusion underwent pleuroscopy using a pleura-videoscope with white light (WL) and NBI under local anesthesia. For this prospective study, 73 biopsy specimens were obtained from sites where images under both WL and NBI were recorded and classified regarding vascular patterns. Results: Of the 73 lesions, WL showed blood vessels in 32 lesions, and NBI in 52 lesions (WL vs. NBI; p = 0.0014). The accuracy, sensitivity and specificity in the detection of irregular vascular patterns, e.g. blood vessels with irregular caliber or punctate vessels indicating malignant lesions, were 60.3, 76.5 and 55.4% in WL, and 80.8, 85.3 and 76.9% in NBI, respectively, resulting in a significant increase in NBI (p = 0.0106 for accuracy and p = 0.0494 for specificity). For flat lesions, NBI revealed a higher accuracy rate (90.6%) in the detection of irregular vascular patterns indicating malignant lesions. Conclusion: Our study demonstrated that NBI applied to pleuroscopy displayed blood vessels significantly better than WL. NBI was useful to detect irregular vascular patterns suggesting malignant lesions, especially for flat lesions. Therefore, NBI was considered useful in the selection of optimal biopsy sites by assessing vascular patterns.