[Thymoma Showing Elevating Anti-acetylcholine Receptor Antibody without Clinical Symptoms of Myasthenia Gravis;Report of a Case].

A 46-year-old man was referred to our hospital with a suspicion of pericardial cyst. Chest computed tomography (CT) revealed an anterior mediastinal tumor. He had no symptoms, but laboratory data showed positive titer to acetylcholine receptor antibody (Anti-AchR Ab). Under a clinical diagnosis of thymoma, extended thymectomy was performed. This case may represent subclinical myasthenia gravis, so we suggest extended thymectomy is crucial for thymoma with elevated level of Anti-AchR Ab without any symptoms.

Molecular determinants of photodynamic therapy for lung cancers.

BACKGROUND AND OBJECTIVES: PDT induces apoptosis, inflammatory reactions, immune reactions, and damage to the microvasculature around the tumors. The mechanisms responsible for the anticancer effects of Photofrin-PDT and NPe6-PDT differ somewhat. To select a photosensitizer for lung cancer treatment and to improve the efficacy of PDT, the mechanisms of action for PDT using Photofrin or NPe6 must be elucidated and the phenomena validated by analyzing molecular determinants from clinical samples. STUDY DESIGN/MATERIALS AND METHODS: We examined the role of immunological reactions in the anti-tumor effects of PDT using cytokine-overexpressing cells and investigated whether the anti-apoptotic protein Bcl-2 may be a molecular target. Moreover, we investigated the association between ATP-binding cassette transporter proteins such as breast cancer-resistant protein (BCRP), which can pump out some types of photosensitizer, and the efficacy of PDT using clinical samples from 81 early lung cancer lesions treated with PDT between 1998 and 2006 at the Tokyo Medical University Hospital. RESULTS: Photofrin-PDT damaged Bcl-2 and rapidly induced apoptosis, but NPe6-PDT did not damage Bc-2 nor did it induce morphologically typical apoptosis. However, NPe6-PDT exerted a strong anti-tumor effect, regardless of the overexpression of Bcl-2. By analyzing the BCRP-overexpressing cells, Photofrin, but not NPe6, was found to be a substrate of BCRP. All 81 lung cancer lesions were BCRP-positive; as Photofrin was found to be a substrate of BCRP, the expression of BCRP significantly affected the efficacy of Photofrin-PDT. However, NPe6-PDT exerted a strong antitumor effect regardless of BCRP expression, and the complete response rate after NPe6-PDT was much higher than that after Photofrin-PDT. CONCLUSIONS: Our translational research suggests that NPe6-PDT may be superior to Photofrin-PDT for the treatment of lung caner, and individualized approaches to PDT based on the expression status of Bcl-2 and/or BCRP may improve the efficacy of PDT in patients with lung cancers.

Tailor-made approach to photodynamic therapy in the treatment of cancer based on Bcl-2 photodamage.

It is very important to elucidate the mechanism of action and identify the molecular determinant of photodynamic medicine, in order to increase the number of clinical applications of photodynamic therapy (PDT) and perform personalized medicine. We have previously reported that PDT using some photosensitizers, such as phthalocyanine 4 (Pc 4) damages the anti-apoptotic protein Bcl-2, and that Bcl-2 is a molecular PDT target using a mitochondrion-targeting photosensitizer. In this study, we examined the molecular targets of Photofrin-PDT and NPe6-PDT, which are approved for early stage lung cancers by the Japanese Ministry of Health Labor and Welfare, by evaluating the photodamage to Bcl-2 using Western blot analysis. Our results showed that Photofrin-PDT damaged Bcl-2, induced morphologically typical apoptosis, and demonstrated equal sensitivity between MCF-7c3 cells (human breast cancer cells expressing stably transfected procaspase-3) and Bcl-2 overexpressing cells, MCF-7c3-GFP-Bcl-2 cells, with a clonogenic assay. However, NPe6-PDT did not damage Bcl-2 and took longer to induce typical apoptosis compared with Photofrin-PDT. MCF-7c3-GFP-Bcl-2 cells were considerably more resistant to the lethal effects of NPe6-PDT than parental MCF-7c3 cells. In conclusion, Photofrin-PDT damages different molecular targets, and our data indicate that the extent of Bcl-2 photodamage can determine the sensitivity of cancer cells to apoptosis and to overall cell killing caused by PDT using Photofrin, but not the lysosomal targeting NPe6. The application of these findings to clinical PDT may depend on the levels of the Bcl-2 proteins in the tumor being treated, and the tailor-made medicine based on the Bcl-2 photodamage may overcome any resistance afforded by elevated amounts of Bcl-2.

Photodynamic therapy for lung cancers based on novel photodynamic diagnosis using talaporfin sodium (NPe6) and autofluorescence bronchoscopy.

BACKGROUND: We had previously developed the possibility of use of a photodynamic diagnosis (PDD) system using a tumor-selective photosensitizer and laser irradiation for the early detection and photodynamic therapy (PDT) for centrally located early lung cancers. Recently, we established the autofluorescence diagnosis system integrated into a videoendoscope (SAFE-3000) as a very useful technique for the early diagnosis of lung cancer. PATIENTS AND METHODS: Twenty-nine patients (38 lesions) with centrally located early lung cancer received PDD and PDT using the second-generation photosensitizer, talaporfin sodium (NPe6). Just before the PDT, we defined the tumor margin accurately using the novel PDD system SAFE-3000 with NPe6 and a diode laser (408nm). RESULTS: Red fluorescence emitted from the tumor by excitation of the photosensitizer by the diode laser (408nm) from SAFE-3000 allowed accurate determination of the tumor margin just before the PDT. The complete remission (CR) rate following NPe6-PDT in the cases with early lung cancer was 92.1% (35/38 lesions). We also confirmed the loss of red fluorescence from the tumors immediately after the PDT using SAFE-3000. We confirmed that all the NPe6 in the tumor had been excited and photobleached by the laser irradiation (664nm) and that no additional laser irradiation was needed for curative treatment. CONCLUSIONS: This novel PDD system using SAFE-3000 and NPe6 improved the quality and efficacy of PDT and avoided misjudgement of the dose of the photosensitizer or laser irradiation in PDT. PDT using NPe6 will become a standard option of treatments for centrally located early lung cancer.

Photodynamic therapy for peripheral lung cancer.

Photodynamic therapy (PDT) has now achieved the status of a standard treatment modality for centrally located early-stage lung cancer. In the last decade, CT screening for lung cancer has attracted much attention for its ability to detect early peripheral lung cancer. Extremely recently, treatment using PDT has been introduced for the first time in patients with peripheral lung cancer, who did not meet the previous criteria for surgery. The procedure was carried out with local anesthesia with xylocain infiltrated into the chest wall, 48 h after Photofrin administration. Needles (19 gauge) containing an internal catheter were inserted percutaneously under CT guidance. The needles were then extracted and a diffuser fiber with a 2 cm long tip for light delivery was positioned in the tumor through the catheter. Of the nine patients enrolled in this trial, seven achieved partial remission (PR). No serious complications, except for two cases of pneumothorax, were noted. As an increasing number of patients consider quality of life after therapy, the indications for PDT are expected to expand. We conclude that PDT is a promising new technique for curative treatment of localized, peripheral lung cancer less than 1cm in size in patients who are unfit for surgery or radiotherapy.

Klotho predicts good clinical outcome in patients with limited-disease small cell lung cancer who received surgery.

BACKGROUND: The important role of surgery in early-stage small cell lung cancer (SCLC) has been recognized, and curative surgical resection is recommended. However, the role of adjuvant chemotherapy for stage I SCLC has not yet been evaluated, and novel approaches focusing on the specific genomic characteristics of SCLC may be invaluable for customized therapy. In this study, we focused on the Klotho gene, which is an anti-aging gene known to be a potential tumor suppressor. We investigated whether the expression of Klotho, assessed by immunohistochemistry, can predict survival in patients with resected SCLC. METHODS: The medical records of patients diagnosed as having limited-disease (LD) SCLC and treated by surgical resection (n=30) at Tokyo Medical University Hospital were retrospectively reviewed. The expression status of Klotho, and of the ATP-binding cassette (ABC) transporters MRP1, MDR and breast cancer resistant protein (BCRP), which can cause resistance to anticancer drugs, including irinotecan, was assessed by immunohistochemical analysis in resected surgical specimens of patients with early-stage SCLC. RESULTS: Of the 30 patients, Klotho expression was seen in the specimens from 18 patients (60.0%), but not in those of the remaining 12 patients (40.0%). The immunostaining for Klotho was mostly localized in the cytoplasm. The expression of Klotho was significantly associated with the overall survival (OS) (ratio 0.088; 95% confidence interval 0.019-0.409; P=0.002). The administration of perioperative chemotherapy had no significant effect in improving the survival, as assessed by the Kaplan-Meier method. However, the patients showing Klotho expression in the resected specimens in p-stage I and II, may have benefited from perioperative chemotherapy. A multivariate analysis revealed no significant association between the expression status of MRP1, MDR or BCRP and the OS. CONCLUSION: Expression of Klotho was predictive of a favorable outcome following resection in limited-disease SCLC patients, and the Klotho expression status may serve as a new biomarker for the need of additional therapies to be developed in the future.

Klotho is a novel biomarker for good survival in resected large cell neuroendocrine carcinoma of the lung.

BACKGROUND: In terms of prognosis, large cell neuroendocrine carcinoma (LCNEC) differs distinctively from other non-small cell lung cancers, with the prognosis of LCNEC being poor, even for early-stage disease. Improvements in survival require a biomarker capable of defining a subset of patients destined to do poorly so that these patients can be targeted for additional therapies, including chemotherapy. In this study, we focused on the Klotho gene, which is an anti-aging gene known to be a potential tumor suppressor. We investigated whether the immunohistochemical expression of Klotho can predict survival patients with resected LCNEC. METHODS: The histological characteristics of patients receiving an initial diagnosis of LCNEC (n=30) at Tokyo Medical University Hospital were retrospectively reviewed, and multiple variables including stage, lymphangioinvasion, lymph node status and the expression of Klotho as identified using an immunohistochemical analysis, were assessed. RESULTS: Immunostaining for Klotho was mostly cytoplasmic, and Klotho expression was seen in 10 patients (33.3%) but not in 20 patients (66.7%). The expression of Klotho was significantly associated with a good outcome of resected patients with LCNEC and Klotho(-) was associated with increased LCNEC risk by multivariate analysis (hazard ratio 4.92, 95% confidence interval 1.04-23.24, p=0.044). Neither lymph node status nor lymphangioinvasion were significantly associated with a poor survival. However, among patients without lymph node metastasis or angioinvasion, the survival benefit of Klotho expression in the primary tumor was significantly higher, compared with that of patients without Klotho expression. CONCLUSION: Klotho staining provides a new biomarker for a good outcome in patients with LCNEC, especially among patients without lymph node metastasis or lymphangioinvasion.

Management of multiple primary lung cancer in patients with centrally located early cancer lesions.

BACKGROUND: Patients with centrally located early lung cancer (CLELC) are often heavy smokers with a considerably high risk of multiple primary lung cancer (MPLC) lesions; treatment strategies for such patients must preserve the cardiopulmonary function. METHODS: Between July 2004 and July 2008, patients with CLELC underwent photodynamic therapy (PDT) using NPe6, second-generation photosensitizer at Tokyo Medical University Hospital. Among these patients, we retrospectively analyzed MPLC, which was treated by surgery plus PDT or PDT alone and examined the effectiveness of PDT, and we propose a treatment strategy for patients with MPLC. RESULTS: A total of 64 patients with CLECL received NPe6-PDT, and MPLCs were found in 22 patients (34.4%) using sputum cytology and a bronchoscopical examination using autofluorescence bronchoscopy. Among these 22 patients, 10 patients underwent surgery for primary lung cancer and underwent NPe6-PDT for the treatment of secondary primary CLELC, one patient underwent PDT for CLELC as a primary lesion followed by an operation for peripheral-type lung cancer as a secondary primary lesion, and 11 patients underwent PDT alone for MPLC lesions (28 lesions) that were roentgenographically occult lung cancers. Among these 22 patients with MPLC including peripheral-type lung cancers, which were resected by surgery, all 39 CLELC lesions exhibited a complete response after PDT, and all patients were alive. CONCLUSIONS: For patients with lung cancer with a long-term history of smoking, careful follow-up examinations after surgical resection are needed considering the incidence of metachronous primary lung cancers. PDT can play an important role for the treatment strategy for MPLC.

Breast cancer resistant protein (BCRP) is a molecular determinant of the outcome of photodynamic therapy (PDT) for centrally located early lung cancer.

The ATP-binding cassette (ABC) transporter protein, BCRP (breast cancer resistance protein)/ABCG2 pumps out some types of photosensitizers used in photodynamic therapy (PDT) and causes resistance to the antitumor effect of PDT. The purpose of this study was to investigate the association between the expression of BCRP and the efficacy of PDT using Photofrin, or the second-generation photosensitizer, NPe6, for centrally located early lung cancers. Using human epidermoid carcinoma cells, A431 cells and the BCRP-overexpressing A431/BCRP cells, we examined the effects of BCRP expression on the effect of PDT by cell viability assay in vitro, and investigated the expression of BCRP by immunohistochemical analysis in 81 tumor samples obtained from patients with centrally located early lung cancers. The A431/BCRP cells were more resistant to Photofrin-PDT than A431 cells in vitro, and Fumitremorgin C, a specific inhibitor of BCRP, reversed the resistance. However, there was no significant difference in the antitumor effect of NPe6-PDT between these cells. All of the 81 centrally located early lung cancer lesions were BCRP-positive (2+, 45 lesions; 1+, 30 lesions) and all the patients were male and heavy smokers (>30 pack-years). The expression of BCRP significantly affected the efficacy of Photofrin-PDT in cancer lesions > or =10mm in diameter (P=0.04). On the other hand, NPe6-PDT exhibited a strong antitumor effect, regardless of the expression status of BCRP. Photofrin may be a substrate of BCRP and be pumped out from the cells, therefore, BCRP may be a molecular determinant of the outcome of Photofrin-PDT.

Outcome of photodynamic therapy using NPe6 for bronchogenic carcinomas in central airways >1.0 cm in diameter.

PURPOSE: Most centrally located early lung cancers (CLELC) <1.0 cm in diameter do not invade beyond the bronchial cartilage, and photodynamic therapy (PDT) with Photofrin is currently recommended as a treatment option for such lesions. NPe6 is a second-generation photosensitizer, and because it has a longer absorption band (664 nm) than Photofrin (630 nm), we hypothesized that NPe6-PDT would exert a strong antitumor effect against cancer lesions >1.0 cm in diameter, which are assumed to involve extracartilaginous invasion and to be unsuitable for treatment with Photofrin-PDT. EXPERIMENTAL DESIGN: Between June 2004 and December 2008, 75 patients (91 lesions) with CLELC underwent NPe6-PDT after the extent of their tumors had been assessed by fluorescence bronchoscopy for photodynamic diagnosis and tumor depth had been assessed by optical coherence tomography. RESULTS: Seventy cancer lesions < or =1.0 cm in diameter and 21 lesions >1.0 cm in diameter were identified, and the complete response rate was 94.0% (66 of 70) and 90.4% (19 of 21), respectively. After the mass of large tumors and deeply invasive tumors had been reduced by electrocautery, NPe6-PDT was capable of destroying the residual cancer lesions. CONCLUSION: NPe6-PDT has a strong antitumor effect against CLELCs >1.0 cm in diameter that have invaded beyond the bronchial cartilage, thereby enabling the destruction of residual cancer lesions after mass reduction of large nodular- or polypoid-type lung cancers by electrocautery. The PDT guidelines for lung cancers should therefore be revised because use of NPe6-PDT will enable expansion of the clinical indications for PDT.