Early experience using the da Vinci Surgical System for the treatment of mediastinal tumors

PURPOSE

The da Vinci Surgical System has been used in only a few cases for treating mediastinal tumors in Japan. Recently, we used the da Vinci Surgical System for various types of anterior and middle mediastinal tumors in clinical practice. We report our early experience using the da Vinci Surgical System.

METHODS

Seven patients gave written informed consent to undergo robotic surgery for mediastinal tumor dissection using the da Vinci Surgical System. We evaluated the safety and feasibility of this system for the surgical treatment of mediastinal tumors.

RESULTS

Two specialists in thoracic surgery who are certified to use the da Vinci S Surgical System and another specialist acted as an assistant performed the tumor dissection. We were able to access difficult-to-reach areas, such as the mediastinum, safely. All the resected tumors were classified as benign tumors histologically. The average da Vinci setting time was 14.0 min, the average working time was 55.7 min, and the average overall operating time was 125.9 min. The learning curve for the da Vinci setup and manipulation time was short.

CONCLUSION

Robotic surgery enables mediastinal tumor dissection in certain cases more safely and easily than conventional video-assisted thoracoscopic surgery and less invasively than open thoracotomy.

Abstract 4997: The isolation of miRNA targeting EGFR gene in lung cancer

MicroRNAs (miRNAs) belong to a class of the endogenously expressed non-coding small RNAs which primarily function as gene regulators. Growing evidence suggests that microRNAs have a significant role in tumor development.

Lung cancer, predominantly non-small cell lung cancer (NSCLC), remains the leading cause of cancer related deaths worldwide. Although EGFR signaling is important and well studied with respect to NSCLC progression, little is known about how miRNAs mediate EGFR signaling to modulate tumorigenesis.

In this study, we identified miRNAs that directly regulate the EGFR gene expression. We employed computational tools such as Pictar and Target Scan, and putative targets of 88 miRNAs were identified within the EGFR mRNA. Then, we analyzed the expression of EGFR in miRNAs-transfected human lung cancer cells (H3255, A549, Hcc827) by real time-PCR methods. In addition, we performed argonaute (AGO) IP experiments to ascertain whether these algorithmically predicted miRNA targets are biologically true targets in EGFR. Convincingly, we found that two miRNAs directly regulated the EGFR and both of these miRNAs also inhibited cell growth in cell viability assays. Identifying microRNA regulators of EGFR may contribute in development of novel therapeutics, and non-invasive early detection biomarkers for NSCLC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4997. doi:10.1158/1538-7445.AM2011-4997

Appropriate set-up of the da Vinci Surgical System in relation to the location of anterior and middle mediastinal tumors

The da Vinci® Surgical System (dV) and its later version [da Vinci S® Surgical System (dVS)] have been used only in very few cases in selected thoracic surgical areas in Japan. Recently, we used the dV and dVS for various types of anterior and middle mediastinal tumors in clinical practice. We report our experience, and review the settings which depended on tumor location. Six patients gave written informed consent to undergo robotic surgery using the dV or dVS. We evaluated the feasibility, safety and appropriate settings of this system for the surgical treatment of mediastinal tumors. Tumor dissection was performed by two specialists in thoracic surgery certified to use the dV and dVS, and another specialist who acted as an assistant. We were able to access difficult-to-reach areas like the mediastinum. All the resected tumors were classified as benign tumors histologically. Crucial to the success of these operations was the set-up of the dV, which varied according to the location of mediastinal tumors. Robotic surgery enables various types of mediastinal tumor dissection more safely and easily than conventional video-assisted thoracoscopic surgery (VATS). The dV requires the appropriate set-up configuration, which varies according to the location of the mediastinal tumor.

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.

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.

Cine MRI enables better therapeutic planning than CT in cases of possible lung cancer chest wall invasion

THE OBJECTIVE

To evaluate the hypothesis that lung cancer treatment planning (whether or not to use induction therapy) can be improved if respiratory dynamic cine magnetic resonance imaging (RD MR) is used.

METHOD

We studied 100 lung cancer patients, 76 men and 21 women, scheduled for thoracotomies between May 1997 and December 2006 wherein it was unclear preoperatively whether chest wall invasion would be found. We evaluated the accuracy of RD MR as compared with the findings at operation and postoperative pathology. The accuracy of RD MRI for evaluating chest wall invasion was compared with the efficacy of CT and MRI within our own group of patients and with data from the studies of other investigators.

RESULTS

Concerning the evaluation of chest wall invasion, conventional computed tomography (CT) had 43.9% specificity, 60.0% sensitivity and 47.1% accuracy, while RD MR had 68.5% specificity, 100.0% sensitivity and 77.0% accuracy. RD MRI was particularly useful in the evaluation of cancers around 5 cm in diameter that were located adjacent to the diaphragm. Postoperative evaluation of superior sulcus tumor cases that had received induction therapy also showed that the RD MR procedure enabled an accurate decision in 87.5% of cases, and there were no false negative cases.

CONCLUSIONS

RD MR is more useful than CT or standard MRI for evaluating thoracic wall invasion. This noninvasive method enhances the reliability of deciding whether induction therapy should be employed.

Quantitative p16 and ESR1 methylation in the peripheral blood of patients with non-small cell lung cancer

Inactivation of the p16 and ESR1 tumor suppressor genes by promoter lesion methylation has been reported in many tumor types, including lung cancer. We examined the blood of 95 non-small cell lung cancer patients (66 cases of adenocarcinoma, 23 of squamous cell carcinoma and 6 of large cell carcinoma) and 30 controls consisting of normal subjects and benign disease patients to determine the methylation ratios of p16 and ESR1 using real-time PCR. For both genes, there was a statistically significant difference in the methylation ratio between non-small cell lung cancer patients and controls (p16; p<0.01, ESR1; p<0.001). In addition, there was a strong correlation between the methylation ratio of each gene and old age (p16; p<0.01, ESR1; p<0.001 and p16 or ESR1; p<0.001), and between p16 or ESR1 methylation rate and smoking history (p<0.01). Moreover in Stage I cases, the methylation positive rate of each gene (p16, ESR1 and p16 or ESR1) was higher than the CEA positive rate (p<0.05, p<0.001, p<0.001). Evaluation of p16 and ESR1 promoter methylation in blood using real-time PCR appears to be very useful for lung cancer diagnosis and there is some possibility that these methylated genes might come to represent useful biomarkers for the early detection of lung cancer. Our study results also suggested that comparative evaluation of the methylation ratio before and after surgery might be a powerful tool to predict the prognosis of lung cancer patients.

Glomus tumor of the left main bronchus

We report a case of left main bronchial glomus tumor in a 39-year-old man who presented with a cough he had had for 1 month. A computed tomography (CT) scan revealed a polypoid tumor in the membranous portion of the left main bronchus. The tumor showed marked enhancement on the early phase of dynamic contrast-enhanced CT, and it was thought to be a hypervascular tumor. The tumor was carefully resected by a rigid bronchoscope, and the pathological and immunohistochemical findings yielded a diagnosis of glomus tumor. Marked enhancement of early phase dynamic contrast-enhanced CT may be useful for a diagnosis of bronchial glomus tumor.

Surgical strategy for non-small cell lung cancer in octogenarians

BACKGROUND AND OBJECTIVES

This study was conducted to determine the optimal surgical strategy for octogenarians with non-small cell lung cancer.

METHODS

An observational study of 73 patients aged 80 years and over who underwent surgery for non-small cell lung cancer. Postoperative survival, mortality and morbidity were analysed.

RESULTS

The age of the patients ranged from 80 to 89 with a mean of 83. Cancer types included adenocarcinoma (n = 46), squamous cell carcinoma (n = 22) and large cell carcinoma (n = 5). Lobectomy was performed in 47 patients and limited surgery in 26. The 5-year survival rate was 57.4% in pathological stage I, 88.9% in stage II and 18.2% in stage III, respectively. The 5-year survival rate of patients with stage I disease treated by limited resection (58.8%) was similar to that of patients treated by lobectomy (54.9%). Limited resection for stage IA showed slightly better survival than lobectomy (69.4% vs 48.2%, P = 0.10), however, lobectomy was superior to limited resection for stage IB (63.2% vs 16.7%, P = 0.07). Postoperative complications occurred in 27 patients (37%) and nine patients (12%) had multiple complications. There were three postoperative deaths (4.1%).

CONCLUSION

The early detection of the disease, hopefully in stage IA enables surgical treatment by limited resection of patients aged 80 years and over. A favourable prognosis as well as low morbidity can be anticipated in such cases.

Met-RANTES ameliorates fibrous airway obliteration and decreases ERK expression in a murine model of bronchiolitis obliterans

OBJECTIVES

Bronchiolitis obliterans (BO) is the main cause of late mortality among long-term survivors of lung transplantation. Chemokine-chemokine receptor (CCR) interaction and subsequent recruitment of infiltrating cells to the graft are early events in the development of chronic rejection of transplanted lungs. The present study investigated whether blockade of chemokine receptors CCR1 and CCR5 with Met-regulated-on-activation, normal T cells expressed and secreted (RANTES), an amino-terminal modified derivative of RANTES/CCL5, affects the development of BO in murine model and we sought to determine the expression of RANTES/CCL5 and their relationship with extracellular signal-regulated kinase (ERK).

MATERIALS AND METHODS

BALB/c mouse tracheas were heterotopically transplanted into C57Black6 recipients and treated for 21 days with either Met-RANTES at 20 microg/day or vehicle. Animals were killed at 21 days after transplantation for histologic examination of ERK expression.

RESULTS

RANTES/CCL5 was highly expressed in allografts compare to isografts. Met-RANTES treatment ameliorated fibrous airway obliteration in a mouse model of BO and decreased ERK expression.

CONCLUSION

Blockade of chemokine receptors by Met-RANTES ameliorated airway obliteration and decreased ERK expression. These findings suggest that chemokine receptors CCR1 and CCR5 play significant roles in the development of chronic rejection and ERK may be a new molecular target for chronic rejection.

The present status of postoperative adjuvant chemotherapy for completely resected non-small cell lung cancer

Non-small cell lung cancer (NSCLC) constitutes approximately 85% of all lung cancers, with patients having a poor prognosis. Approximately one third of NSCLC patients present with early-stage disease in which potentially curative resection and multi-modality therapy. Although adjuvant chemotherapy is the standard practice for patients with stages I-III breast and colorectal cancer, the therapeutic efficacy of adjuvant chemotherapy, following complete surgical resection of early stage NSCLC, has not been fully established. Several prospective randomized trials for patients with early stage NSCLC (stages I-IIIA) have confirmed a survival benefit with cisplatin-based adjuvant chemotherapy, as demonstrated in the 1995 meta-analysis performed by the NSCLC Collaborative Group. Studies from Japan have reported that adjuvant therapy with uracil-tegaful (UFT) afforded an improvement of 4% in the 5-year survival rate and a relative risk reduction of 26% in mortality at 5 years among patients with T1-2N0 (stage I) disease. In particular, the Japan Lung Cancer Research Group has demonstrated an improvement in the 5-year survival rate of 11%, favoring chemotherapy with UFT in the subset of patients with T2N0 (stage IB) disease. Two published meta-analyses based on abstracts have estimated a relative risk reduction in mortality of 11-13% at 5 years. The Lung Adjuvant Cisplatin Evaluation (LACE), which was based on a pooled analysis of five randomized trials, has demonstrated that cisplatin-based adjuvant chemotherapy improved survival in patients with completely resected NSCLC. This benefit depended on stage, being greatest in patients with stage II or IIIA disease. This analysis has suggested that platinum-based adjuvant chemotherapy may have no benefit for patients with stage IA and only a marginal benefit for patients with stage IB. Thus, the information available at the current time supports the administration of adjuvant chemotherapy for patients who have undergone complete resection of stages IB-IIIA NSCLC. Further research is needed to define the role of adjuvant platinum-based chemotherapy and its use, in conjunction with chest radiotherapy as the treatment for patients with resected stages IB and IIIA NSCLC.

Human blood monitoring program in Japan: contamination and bioaccumulation of persistent organochlorines in Japanese residents

Concentrations of persistent organochlorines (OCs)-such as polychlorinated biphenyls (PCBs), 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene, and tris(4-chlorophenyl)methane [TCPMe]-were determined in plasma samples from residents of three sub-metropolitan locations in Japan (Miyako, Saku, and Tottori) for the purpose of studying the geographic variation and specific accumulation of OCs. Residue concentrations of PCBs and DDTs were the highest in samples collected in Saku (400 and 370 ng/g lipid wt, respectively) whereas samples from Miyako contained greater CHL residues (70 ng/g lipid wt) than those from the other two locations. This contamination pattern reflects the historic use of OCs in each area. For the first time, tris (4-chlorophenyl) methane (TCPMe) concentrations were detected in most of the plasma sample analyzed. Concentrations of TCPMe which ranged from <0.1 to 8.1 ng/g lipid wt eight, were lower than those previouly reported in other human tissue. Larger geographic differences in OC accumulation were observed for PCBs and CHLs, whereas DDTs and HCHs exhibited little variability. PCB concentrations in samples from Saku residents were higher than those from residents of countries in the circumpolar Arctic region but lower than those reported for some populations in the United States and Western European countries. Interestingly, CHL residue concentrations in human blood from Japan are among the highest values reported for the countries examined, suggesting continued increased exposure to CHLs of the Japanese population. Time-trend analysis of CHLs in human blood samples from Miyako (Okinawa prefecture) showed that CHL residues have decreased substantially during the last decade, indicating the effect of the official ban of CHLs in 1986 in Japan. Isomer-specific analysis of PCBs revealed lower proportions of higher chlorinated congeners such as hepta- and octachlorobiphenyls in women than in men, suggesting the possibility of preferential elimination of higher chlorinated biphenyls in women. The difference in sex-dependent accumulation of OC compounds in healthy and ill persons was suggested. To our knowledge, this is the first report on the specific accumulation of persistent QCs, including TCPMe, in human blood samples from Japan.

Contamination by persistent organic pollutants in dumping sites of Asian developing countries: implication of emerging pollution sources

In Asian developing countries, large amounts of municipal wastes are dumped daily in open dumping sites without proper management. This practice may cause several adverse environmental consequences and increased health risk to local communities. To elucidate contamination by persistent organic pollutants (POPs)--including dichloro-diphenyl-trichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), chlordanes, hexachlorobenzene (HCB), and polychlorinated biphenyls (PCBs)--in such dumping sites, soil samples were collected from open dumping sites and respective control sites in Cambodia, India, and Vietnam from 1999 through 2001. Our results demonstrated that DDTs, PCBs, and HCHs were dominant contaminants in the dumping sites. However, the contamination pattern was not consistent, showing higher HCHs in India than in Cambodia and Vietnam. Interestingly, in all of the countries, extremely higher levels of POPs were observed in the dumping sites compared with those in the respective control sites, suggesting significant amplification of POP contamination in the dumping sites of Asian developing countries. Mean concentrations of DDTs and PCBs were 350 and 140 ng/g dry weight, respectively, in the dumping sites of Cambodia and 26 and 210 ng/g, respectively, in India. These residue levels were hundreds to thousands times higher than those in general soils, implying possible risk to human health of the local communities, especially to the rag pickers, including children who work in these sites to collect recyclable materials. Composition of DDT compounds suggested their recent use in populated areas, which in turn might have caused increased levels of DDTs in the open dumping sites. In addition, composition of HCH isomers revealed their different use pattern in different countries.

Cytokine responsiveness in cultured human small airway epithelial cells in relation to lung transplantation

BACKGROUND

We report a new method for collecting and establishing small airway epithelial cells (SAEC). This method enables the evaluation of the cytokine responsiveness of SAEC, which is still unknown. In this study we evaluated intercellular adhesion molecule-1 (ICAM-1) expression on SAEC stimulated with several inflammatory cytokines and compared it with that on large airway epithelial cells (LAEC).

MATERIALS AND METHODS

LAEC and SAEC were treated with IFN-gamma, TNF-alpha, IL-1beta, or their combination. ICAM-1 expression under various conditions was quantified by flow cytometry. Furthermore, immunocytochemical staining was performed to determine intranuclear displacement of signal transducer and activator transcription 1 (Stat1) during ICAM-1 expression by various cytokine stimulations.

RESULTS

1) ICAM-1 expression on both LAEC and SAEC was significantly increased by IFN-gamma stimulation alone and synergistically enhanced by IFN-gamma plus TNF-alpha or IL-1beta stimulation, 2) intranuclear displacement of Stat1 in SAEC by the stimulation with IFN-gamma plus TNF-alpha or IL-1beta was recognized earlier in comparison with that by IFN-gamma stimulation alone.

CONCLUSION

The previously unknown peripheral cytokine responsiveness and its mechanisms of SAEC were revealed by this study, which contributes to the understanding of chronic lung allograft rejection recognized around small airways.

CCL5-CCR5 interaction provides antiapoptotic signals for macrophage survival during viral infection

Host defense against viruses probably depends on targeted death of infected host cells and then clearance of cellular corpses by macrophages. For this process to be effective, the macrophage must presumably avoid its own virus-induced death. Here we identify one such mechanism. We show that mice lacking the chemokine Ccl5 are immune compromised to the point of delayed viral clearance, excessive airway inflammation and respiratory death after mouse parainfluenza or human influenza virus infection. Virus-inducible levels of Ccl5 are required to prevent apoptosis of virus-infected mouse macrophages in vivo and mouse and human macrophages ex vivo. The protective effect of Ccl5 requires activation of the Ccr5 chemokine receptor and consequent bilateral activation of G(alphai)-PI3K-AKT and G(alphai)-MEK-ERK signaling pathways. The antiapoptotic action of chemokine signaling may therefore allow scavengers to finally stop the host cell-to-cell infectious process.

Organochlorine pesticides, polychlorinated biphenyls, and polybrominated diphenyl ethers in Irrawaddy dolphins from India

The Irrawaddy dolphin (Orcaella brevirostris) is at risk of extinction throughout its range as a result of incidental catches, habitat degradation, and pollution. Populations of Irrawaddy dolphins are constrained by the species' narrow habitat requirement-lagoons, estuaries, rivers, and lakes-and are therefore particularly vulnerable to the effects of human activities. In this study, for the first time, concentrations of organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in tissues of Irrawaddy dolphins collected from Chilika Lake, India, to understand the status of contamination. Dichlorodiphenyltrichloroethane and its metabolites (DDTs) were the predominant contaminants found in Irrawaddy dolphins; the highest concentration found was 10,000 ng/g lipid weight in blubber. Hexachlorocyclohexanes (HCHs) were the second most prevalent contaminants in dolphin tissues. Concentrations of PCBs, chlordanes, hexachlorobenzene, tris(4-chlorophenyl)methane, and tris(4-chlorophenyl)methanol were in the ranges of few ng/g to few hundreds of ng/g on a lipid-weight basis. In general, concentrations of OC pesticides and PCBs in Irrawaddy dolphins were lower than the concentrations reported for coastal and riverine dolphins collected in Asia. PBDEs were detected in the blubber of Irrawaddy dolphins at concentrations ranging from 0.98 to 18 ng/g lipid weight. BDE congener 47 accounted for 60% to 75% of the total PBDE concentrations. Although these results establish the baseline levels of persistent organic pollutants in Irrawaddy dolphins, efforts should be made to decrease the sources of contamination by DDTs and HCHs in Chilika Lake.

Microwave coagulation therapy in canine peripheral lung tissue

BACKGROUND

New modalities for local treatments that destroy tumor effectively but which are less invasive and less damaging to normal lung tissue must be developed for patients who are unable to undergo even video-assisted thoracic surgery (VATS) due to poor cardiopulmonary function, severe adhesion, or advanced age, etc. We evaluated the use of microwave coagulation therapy (MCT), which has been used successfully for coagulation of hepatic tumors, in normal canine lung tissue to evaluate its efficacy and safety.

MATERIALS AND METHODS

Measurements of thermal response and coagulation area and histological examinations after microwave coagulation were performed in normal canine lung tissue.

RESULTS

The temperature in normal canine lung tissue increased to 90-100 degrees C at 5 mm from the electrode after 60 s and 70-80 degrees C at 10 mm after 90 s at 40 or 60 W. The coagulation area was approximately 20 mm in diameter at 40 W and 60 W. Histological analysis demonstrated thickening of collagen fiber shortly after coagulation, stromal edema and granulation tissue after 3 months, and, finally, scar tissue was seen after 6 months.

CONCLUSIONS

Microwave coagulation therapy (MCT) is a useful modality for minimally invasive therapy in peripheral lung tumors.