Naohiro Kajiwara

Transplantation of Endothelial Progenitor Cells into the Lung to Alleviate Pulmonary Hypertension in Dogs

Primary pulmonary hypertension (PPH) is still a refractory disease, and patients deteriorate despite any treatment. We hypothesized that neovascularization in the lung could increase the volume of the vascular bed in the pulmonary circulation and thus reduce the development of pulmonary hypertension (PH). Endothelial progenitor cells (EPCs) might be a potential cell source for neovascularization. We examined the effects of EPC transplantation into the lungs of dogs with dehydromonocrotaline-induced PH. The lung parenchyma of PH model dogs was injected with ex vivo-expanded, autologous EPCs originated from peripheral blood (experiments, n=4) or culture medium (control, n=3), using a bronchoscope. EPC transplantation gave significant improvements in mean pulmonary artery pressure, cardiac output, and pulmonary vascular resistance. Histological evaluation revealed both improvement in the medial thickness of the small pulmonary artery and neovascularization of the lung tissue. These results indicate that EPC transplantation into the lung is effective at preventing the progression of dehydromonocrotaline-induced PH in dogs, and suggest a new therapeutic option for PPH.

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 ≤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. Clin Cancer Res; 16(7); 2198–204. ©2010 AACR.

Evaluation of chest wall invasion by lung cancer using respiratory dynamic MRI

Conventional CT or MRI has low accuracy in assessing chest wall invasion in patients with peripheral lung cancer. For preoperative evaluation of chest wall invasion by peripheral lung cancer, respiratory dynamic (RD) MRI was carried out in 98 patients in whom conventional CT scan showed that the tumour was abutting the pleural surface, but there was no evidence of definite tumour invasion. We used 1.5‐T MR equipment. RD MR images were acquired by snapshot fast field echo sequence (repetition time = 8, echo time = 3, flip angle = 100) and 25 consecutive images were taken while the patient took deep breaths. These images were evaluated in cine mode to assess tumour movement along the chest wall. Sixty‐one patients underwent surgical resection of the tumour and RD MR findings were compared with those in pathological specimens. RD MR showed free tumour movement along the chest wall in 34 patients. At pathological examination, the RD MR findings were proved correct in all patients. Pathologically, 20 patients had chest wall invasion and their RD MR was positive (sensitivity 100%). There were seven false‐positive results among the 41 patients without chest wall invasion (specificity 82.9%). RD MR may improve the accuracy of conventional CT scan or MRI in the prediction of chest wall invasion of lung cancer, especially in patients in whom the results of conventional CT scan or MRI appear equivocal in the presence of a peripheral mass abutting the chest wall surface without obvious chest wall invasion.

Pathological Vascular Invasion and Tumor Differentiation Predict Cancer Recurrence in Stage ia Non–Small-Cell Lung Cancer After Complete Surgical Resection

Introduction: The appropriate therapeutic strategy and postoperative management for patients with stage IA non–small-cell lung cancer (NSCLC) still remain a matter of debate because of the prognostic heterogeneity of this population, including the risk of cancer recurrence. The objective of the current study was to identify the clinicopathological factors that affect overall prognosis and cancer recurrence of stage IA NSCLC. Methods: We reviewed the data of 532 patients in whom complete resection of stage IA NSCLC had been performed. Overall survival and recurrence-free proportion (RFP) were estimated using the Kaplan–Meier method. RFP was estimated from the date of the primary tumor resection to the date of the first recurrence or last follow-up. We performed univariate and multivariate analyses to determine the independent prognostic factors. Results: On multivariate analyses, three variables were shown to be independently significant recurrence risk factors: histological differentiation (hazard ratio [HR] = 1.925), blood-vessel invasion (HR = 1.712), and lymph-vessel invasion (HR = 1.751). On subgroup analyses combining these risk factors, the 5-year RFP was 91.3% for patients with no risk factors, 79.5% for those with either poorly differentiated carcinoma or vascular invasion, (p < 0.001 for both), and 62.9% for those with both poorly differentiated carcinoma and vascular invasion (p = 0.068). Conclusion: These results indicated that vascular invasion and tumor differentiation have a significant impact on the prediction of cancer recurrence in patients with stage IA NSCLC. Patients with these predictive factors of recurrence may be good candidates for adjuvant chemotherapy.

Prognostic impact of number of resected and involved lymph nodes at complete resection on survival in non-small cell lung cancer.

Background: Lymph node (LN) status is a major determinant of stage and survival in patients with lung cancer. In the 7th edition of the TNM Classification of Malignant Tumors, the number of involved LNs is included in the definition of pN factors in breast, stomach, esophageal, and colorectal cancer, and the pN status significantly correlates with prognosis. Methods: We retrospectively investigated the prognostic impact of the number of resected LNs (RLNs) and involved LNs in the context of other established clinical prognostic factors, in a series of 928 consecutive patients with non-small cell lung cancer (NSCLC) who underwent complete resection at our institution between 2000 and 2007. Results: The mean number of RLNs was 15. There was a significant difference in the total number of RLNs categorized between less than 10 and ≥10 (p = 0.0129). Although the incidence of LN involvement was statistically associated with poor prognosis, the largest statistically significant increase in overall survival was observed between 0 to 3 and ≥4 involved LNs (hazard ratio = 7.680; 95% confidence interval = 5.051–11.655, p < 0.0001). On multivariate analysis, we used the ratio between the number of involved LNs and RLNs. The number of RLNs was found to be a strong independent prognostic factor for NSCLC (hazard ratio = 6.803; 95% confidence interval = 4.137–11.186, p < 0.0001). Conclusion: Complete resection including 10 or more LNs influenced survival at complete NSCLC resection. Four involved LNs seemed to be a benchmark for NSCLC prognosis. The number of involved LNs is a strong independent prognostic factor in NSCLC, and the results of this study may provide new information for determining the N category in the next tumor, node, metastasis classification.

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.

Clinical response of large cell neuroendocrine carcinoma of the lung to perioperative adjuvant chemotherapy

Patients with large cell neuroendocrine carcinoma (LCNEC) of the lung are considered to have poor prognosis. However, the benefit of adjuvant chemotherapy for these patients has not been established. In this study, we retrospectively evaluated the efficacy of perioperative chemotherapy for patients with completely resected LCNEC in a single-center setting. From 1999 through 2007, 45 patients with surgically resected LCNEC or mixed LCNEC containing at least one portion of the neuroendocrine differentiation or morphology in non-small cell lung carcinoma were enrolled as participants of this study. Survival rates were calculated by the Kaplan–Meier method. Differences between survival curves were computed with the log-rank test. For multivariate analysis, the Coxs proportional hazards regression model was used to evaluate variables that were significant predictors of survival. Of 1397 patients undergoing surgical resection for primary lung cancer from 1999 to 2007, 45 (3.2%) were classified as LCNEC. Thirty-six (80%) patients were men, and nine (20%) were women. Twenty-four (92%) of 26 patients were present or past smokers. Twenty-three (41%) of 45 patients received perioperative chemotherapy, including seven induction chemotherapies and 16 adjuvant chemotherapies. Survival of patients who underwent perioperative adjuvant chemotherapy was significantly higher than that of those who received surgery alone (P = 0.04). The 5-year survival rate of patients who underwent perioperative adjuvant chemotherapy was 87.5%, whereas that of patients who underwent surgery alone was 58.5%. Even in stage I cases, perioperative adjuvant chemotherapy still favors survival compared with surgery alone. In the Cox proportional hazard multivariate analysis, surgery with or without chemotherapy showed an independent prognostic influence on overall survival (P = 0.0457). Patients who received surgery alone were 9.5 times more likely to die than patients who underwent surgery plus chemotherapy. In conclusion, perioperative chemotherapy will be needed to improve survival in patients with LCNEC. As the population of LCNEC is small, it has been difficult to conduct randomized controlled trials to show the survival benefit of adjuvant chemotherapy. This should be, therefore, evaluated further in prospective multi-institutional phase II trials.

Impact of visceral pleural invasion on the survival of patients with non-small cell lung cancer.

BACKGROUND In this study, we investigated visceral pleural invasion (VPI) as a poor prognostic factor in patients with non-small cell lung cancer (NSCLC) according to the 7th edition of the TNM classification. METHODS Between January 2000 and December 2007, 886 consecutive patients with pathological T1a-T2b NSCLC underwent complete resection with systematic lymph node dissection in Tokyo Medical University. We statistically analyzed the association between VPI and clinicopathologic factors, or clinical outcomes. RESULTS The 5-year overall survival (OS) rates of the pl0, pl1, and pl2 patients were 80.8%, 63.7%, and 49.6%, respectively, with significant differences between pl0 and pl1 (p=0.002), pl1 and pl2 (p=0.03). Thus, the pl1 and pl2 patient groups were defined as patients with VPI. VPI was found to be a significant independent prognostic factor by multivariate survival analysis (p=0.0002). In patients with tumors ≤3 cm, especially with tumors ≤2 cm, VPI was significantly associated with an increased rate of lymph node metastasis, compared with non-VPI (p=0.0003 and p=0.015, respectively). Analysis of the OS of patients stratified by tumor size (≤3 cm, 3.1-5 cm, 5.1-7 cm) and VPI status showed that in any nodal status, patients with 3.1-5 cm/VPI tumors had significantly worse survival than patients with ≤3 cm/VPI tumors (p=0.019) and patients with 3.1-5 cm/non-VPI tumors (p=0.001). On the other hand, there was no significant difference in the OS between patients with 3.1-5 cm/VPI tumors and patients with 5.1-7 cm tumors regardless of lymph node metastasis (T2b tumors). Similar relationships were observed among these groups with N0 disease. CONCLUSION We identified the presence of VPI as an independent poor prognostic factor in patients with NSCLC of ≤7 cm. Tumors 3.1-5cm with VPI should be upstaged to T2b tumors in the future in the TNM classification of the Union of International Cancer Control staging system. In addition, the surgical strategy involving more extensive lymph node dissection for patients with ≤3 cm/VPI tumors, especially ≤2 cm/VPI, is warranted owing to more frequent lymph node metastasis.

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.

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.