Kazunori Okabe

Prognostic potential of FOXP3 expression in non-small cell lung cancer cells combined with tumor-infiltrating regulatory T cells

Expression of the transcription factor FOXP3 characterizes regulatory T cells (Tregs) that engage in the maintenance of immunological self-tolerance and immune homeostasis. Intra-tumoral accumulation of Tregs is associated with unfavorable prognosis in several kinds of cancers. Recently, expression of FOXP3 and its association with prognosis have also been shown in some cancer cells in clinical studies. For non-small cell lung cancer (NSCLC), however, prognostic significance of tumor FOXP3 expression and its relationship with Tregs remain unknown. FOXP3 expression in cancer cells and tumor-infiltrating lymphocytes was examined by immunohistochemical staining of surgical specimens from 87 patients with NSCLC. Prognostic values of the tumor-infiltrating Treg count and tumor FOXP3 expression status were evaluated retrospectively. FOXP3-positive cancer cells were observed in 27 of 87 (31.0%) patients. There was no significant relationship between Treg count and tumor FOXP3 status. Increased Treg counts were associated with worse overall and relapse-free survival whereas the influence of tumor FOXP3 status on survival was not significant. However, when FOXP3-positive cancer cells were present, the relationship between Treg accumulation and worse prognosis was attenuated. In contrast, patients without tumor FOXP3 expression and high Treg count had significantly worse overall and relapse-free survival (hazard ratio: 3.118 and 3.325, p=0.028 and 0.024, respectively) than other groups. These results suggest that tumor FOXP3 expression has a better prognostic potential in NSCLC and that in combination with tumor-infiltrating Treg count the absence of tumor FOXP3 allows the selection of high-risk patients.

Mechanisms of Inhaled Fine Particulate Air Pollution–induced Arterial Blood Pressure Changes

Background Epidemiologic studies suggest a positive association between fine particulate matter and arterial blood pressure, but the results have been inconsistent. Objectives We investigated the effect of ambient particles on systemic hemodynamics during a 5-hr exposure to concentrated ambient air particles (CAPs) or filtered air (FA) in conscious canines. Methods Thirteen dogs were repeatedly exposed via permanent tracheostomy to CAPs (358.1 ± 306.7 μg/m3, mean ± SD) or FA in a crossover protocol (55 CAPs days, 63 FA days). Femoral artery blood pressure was monitored continuously via implanted telemetry devices. We measured baroreceptor reflex sensitivity before and after exposure in a subset of these experiments (n = 10 dogs, 19 CAPs days, 20 FA days). In additional experiments, we administered α-adrenergic blockade before exposure (n = 8 dogs, 16 CAPs days, 15 FA days). Blood pressure, heart rate, rate–pressure product, and baroreceptor reflex sensitivity responses were compared using linear mixed-effects models. Results CAPs exposure increased systolic blood pressure (2.7 ± 1.0 mmHg, p = 0.006), diastolic blood pressure (4.1 ± 0.8 mmHg; p < 0.001), mean arterial pressure (3.7 ± 0.8 mmHg; p < 0.001), heart rate (1.6 ± 0.5 bpm; p < 0.001), and rate–pressure product (539 ± 110 bpm × mmHg; p < 0.001), and decreased pulse pressure (−1.7 ± 0.7 mmHg, p = 0.02). These changes were accompanied by a 20 ± 6 msec/mmHg (p = 0.005) increase in baroreceptor reflex sensitivity after CAPs versus FA. After α-adrenergic blockade, responses to CAPs and FA no longer differed significantly. Conclusions Controlled exposure to ambient particles elevates arterial blood pressure. Increased peripheral vascular resistance may mediate these changes, whereas increased baroreceptor reflex sensitivity may compensate for particle-induced alterations in blood pressure.

Experimental study of tracheal allotransplantation with cryopreserved grafts

OBJECTIVE Tracheal reconstruction is necessary in patients with extensive tracheal stenosis caused by neoplasm, trauma, and congenital disease. We investigated the possibility of tracheal allotransplantation with cryopreserved grafts in a canine model. METHODS A seven-ring section of thoracic trachea was removed in 19 adult mongrel dogs. In group A (n = 4), a five-ring tracheal autograft was implanted. In group B (n = 6), a five-ring allograft was implanted without immunosuppression. In group C (n = 9), a five-ring cryopreserved tracheal allograft was implanted without immunosuppression. Omentopexy wrapping around the grafts and both anastomotic sites was used in all animals. RESULTS All grafts survived without any evidence of atrophy or stenosis in group A. All animals in group B died of severe airway obstruction within 1 month, and postmortem examination of these grafts showed epithelial defect and necrotic tracheal cartilage in the scar tissue. In group C, no animals died of asphyxia caused by severe stenosis of the grafts. The graft epithelium was no longer present 20 days after transplantation, and the graft was covered with regenerated epithelium within about 60 days after the operation. CONCLUSION These findings show that cryopreserved tracheal allografts can be transplanted by means of omentopexy without immunosuppression and that cryopreservation may reduce tracheal allogenicity.

Long-term prognosis of video-assisted limited surgery for early lung cancer §

OBJECTIVE The present intervention study was conducted to prospectively evaluate the long-term prognosis for video-assisted limited surgery, such as wedge resection and segmentectomy, for clinically early lung cancers depending on findings in high-resolution computed tomography (HRCT). SUBJECTS AND METHODS Patients were enrolled in the study between 2001 and 2004, and followed up for five subsequent years. Of these patients, those with a clinical stage IA lung cancer mainly comprising a ground glass-opacity (GGO) less than 1.5 cm across underwent thoracoscopic wedge resection of the lung (Group A). Patients with a tumour less than 2.0 cm in diameter, not classified in Group A, underwent video-assisted segmentectomy and hilar lymph node dissection with lobe-specific mediastinal nodes sampling (Group B). For patients with a tumour less than 3.0 cm in diameter, not classified in to any of the foregoing two groups, underwent video-assisted lobectomy and hilar and mediastinal lymph node dissection (Group C). RESULTS During the case registration period, 159 patients were registered for enrollment in the study (21 for Group A, 43 for Group B and 95 for Group C). Of the patients in Groups A and B, 28% were shifted to a surgical procedure involving a larger volume resected; 6% of the entire study population were shifted to thoracotomy. All patients completed the 5-year follow-up. The recurrence-free survival rate was 100% for Group A, 90.5% for Group B and 94.5% for Group C, with no significant difference among the groups. The total recurrence rate was 11.9% with localised recurrences observed in 6.3% of the patients and remote recurrences in 5.7%. The localised recurrences observed included stump recurrence in one case of Group B, and malignant pleural effusions/pleural dissemination in two cases of Group B and one case of Group C. Intrathoracic lymph node recurrences were observed in one case of Group B and five cases of Group C. CONCLUSIONS The present intervention study showed that thoracoscopic-limited surgery for clinically early lung cancers depending on findings in preoperative HRCT is feasible and appropriate from the viewpoint of oncology.

Concentrated Ambient Particles Alter Myocardial Blood Flow During Acute Ischemia in Conscious Canines

Background Experimental and observational studies have demonstrated that short-term exposure to ambient particulate matter (PM) exacerbates myocardial ischemia. Objectives We conducted this study to investigate the effects of concentrated ambient particles (CAPs) on myocardial blood flow during myocardial ischemia in chronically instrumented conscious canines. Methods Eleven canines were instrumented with a balloon occluder around the left anterior descending coronary artery and catheters for determination of myocardial blood flow using fluorescent microspheres. Telemetric electrocardiographic and blood pressure monitoring was available for four of these animals. After recovery, we exposed animals by inhalation to 5 hr of either filtered air or CAPs (mean concentration ± SD, 349.0 ± 282.6 μg/m3) in a crossover protocol. We determined myocardial blood flow during a 5-min coronary artery occlusion immediately after each exposure. Data were analyzed using mixed models for repeated measures. The primary analysis was based on four canines that completed the protocol. Results CAPs exposure decreased total myocardial blood flow during coronary artery occlusion by 0.12 mL/min/g (p < 0.001) and was accompanied by a 13% (p < 0.001) increase in coronary vascular resistance. Rate–pressure product, an index of myocardial oxygen demand, did not differ by exposure (p = 0.90). CAPs effects on myocardial blood flow were significantly more pronounced in myocardium within or near the ischemic zone versus more remote myocardium (p interaction < 0.001). Conclusions These results suggest that PM exacerbates myocardial ischemia by increased coronary vascular resistance and decreased myocardial perfusion. Further studies are needed to elucidate the mechanism of these effects.

Prognostic impact of lymphovascular invasion compared with that of visceral pleural invasion in patients with pN0 non–small-cell lung cancer and a tumor diameter of 2 cm or smaller

BACKGROUND Both visceral pleural invasion (VPI) and lymphovascular invasion (LVI) have been shown to be adverse prognostic factors for early-stage non-small-cell lung cancer (NSCLC). Positive VPI upstages the T category of tumors ≤ 2 cm (T1a) to T2a, whereas LVI is not adapted as a descriptor for the Tumor, Node, Metastasis classification system. This study was conducted to evaluate the prognostic impacts of VPI and LVI in patients with pN0 NSCLC and a tumor diameter of ≤ 2 cm. METHODS We reviewed records of a total of 142 patients with pN0 NSCLC and a tumor diameter of ≤ 2 cm, who underwent lobectomy with hilar and mediastinal lymph node dissection between January 2001 and December 2009. We conducted univariate and multivariate analyses to evaluate the impact of VPI, LVI, and other clinicopathologic factors on survival. RESULTS Visceral pleural invasion and LVI were diagnosed as positive in 18 (12.7%) and 22 (15.5%) patients, respectively. Male sex, squamous cell carcinoma, positive VPI, and positive LVI were risk factors for overall survival. Squamous cell carcinoma, positive VPI, and positive LVI were risk factors for relapse-free survival. In multivariate analysis, squamous cell carcinoma and positive LVI were independent risk factors for overall survival, and positive LVI was an independent risk factor for relapse-free survival. CONCLUSIONS Positive LVI was more important than VPI as a prognostic factor in patients with pN0 NSCLC and a tumor diameter of ≤ 2 cm. Adjuvant chemotherapy should be considered for such patients, to improve the treatment outcomes.

Technique for Implantation of Chronic Indwelling Aortic Access Catheters

Introduction For chronic, repeated cardiovascular studies in trained, conscious dogs, we describe a technique for implantation of an arterial vascular access catheter in the aorta. In comparison to previous techniques, our technique enables arterial catheter implantation without interrupting the systemic circulation or compromising peripheral arterial flow, requires only a single penetration of the aortic wall, and results in a catheter facing downstream in the aorta. The catheter is usable for both arterial blood sampling and intra-arterial injection of pharmacologic agents. Methods After thoracotomy, two purse-string sutures were set in the aortic wall at the catheter entry-site. A Debakey–Satinsky vena cava clamp was used to partially clamp and isolate a 3-cm portion of aorta surrounding the pursestring sutures. The catheter was prepared by inserting a 0.35 mm guide wire, curve tip end first, into a 7 French silicone Access Technologies catheter. This caused a slight bend at the tip of the catheter, which later facilitated entry into the aorta and prevented damage to the intima of the aortic wall. Catheters were tunneled from the thorax to the nape of the neck, attached to a subcutaneous vascular access port (VAP), and buried in the fascia. Catheters were locked with 2 mL heparinized saline (20 IU/mL). With this technique, we implanted 16 aortic vascular access catheters in 16 dogs. Results Of the 16 animals, 8 are being maintained for long-term study, 7 were sacrificed for histopathological examination, and 1 died due to improper catheter implantation without the aid of the curved-tip guide-wire technique. VAPs have remained bidirectionally patent in all long-term animals (n = 8) ongoing for 7.5 ± 1.4 months (mean ± SEM), with an ongoing maximum of 14 months. In these long-term animals, VAPs were used 5.88 ± 1.34 times. Postmortem examinations were performed on short-term animals (n = 8) sacrificed at 2.85 ± 1.29 months. The catheters have remained bidirectionally patent in all but the one animal that died. In the short-term animals, the 7 patent VAPs were used 12.71 ± 1.64 times. Histopathological examination of hematoxylin and eosin (H&E) slides from the catheter entry site revealed only minimal chronic inflammation. No evidence of tissue overgrowth around any of the intravascular segments of these silicone catheters was noted in any animal. Conclusions Thus, this dependable subcutaneous arterial access system provides a means for examining acute and long-term effects of environmental and pathophysiological influences in conscious dogs. These catheters have remained bidirectionally patent ongoing for more than 1 year and allowed infusion of agents and withdrawal of central arterial blood samples.

Thoracic Duct Cyst of the Mediastinum

A mediastinal thoracic duct cyst was incidentally found in an asymptomatic 45-year-old man. The cyst, 6 cm in diameter, was soft and unilocular, with an extremely thin wall, and contained chyle. It was successfully excised.

Current status of postoperative follow-up for lung cancer in Japan: questionnaire survey by the Setouchi Lung Cancer Study Group-A0901.

PurposeThere is no recommended standard follow-up program after resection for lung cancer. Under these circumstances, each doctor establishes his or her own follow-up protocol. This questionnaire survey was conducted to grasp the current status of postoperative follow-up in Japan.MethodsThe questionnaire survey was aimed at determining what examinations were performed and at what frequencies in the setting of postoperative follow-up. Based on these results, examinations performed at a frequency of >50% and the time points after resection at which they were performed were selected and presented as components of an average follow-up program.ResultsQuestionnaires were sent to 44 institutions, and 26 doctors responded to the questionnaire. All 26 of the doctors performed physical examinations, blood examinations, chest radiography, and computed tomography (CT) routinely, but their frequencies varied widely among the doctors. The average frequencies of the follow-up examinations as judged from this survey are as follows: Physical and blood examinations are performed three to four times a year for the first 3 years and twice a year during the next 2 years. CT is scheduled at 6 and 12 months after resection and is repeated annually thereafter. Chest radiography is performed three to four times a year for the first 3 years and once a year thereafter, between the CT examinations.ConclusionThe follow-up programs used in clinical practice vary widely among institutions and doctors in terms of the types of examination performed and the frequencies at which they are performed.

Density of Tumor-Infiltrating FOXP3 + T Cells as a Response Marker for Induction Chemoradiotherapy and a Potential Prognostic Factor in Patients Treated with Trimodality Therapy for Locally Advanced Non-Small Cell Lung Cancer

PURPOSE To examine the relationship between the density of tumor-infiltrating T cell subpopulations and the pathological response to induction chemoradiotherapy (CRT) in patients with locally advanced NSCLC, and to assess the impact of T cell density on patient prognosis. METHODS A total of 64 patients with c-stages IIA-IIIB NSCLC who underwent induction CRT followed by R0 surgery were enrolled. Tumor-infiltrating T cells expressing either FOXP3 or CD8 were detected by immunohistochemical staining. RESULTS Mean numbers of tumor-infiltrating FOXP3+ T cells were 39.9 for patients with minor pathological responses (n = 9), 18.4 for those with major pathological responses (n = 25), and 12.9 for those with complete pathological responses (n = 30; P <0.001). The number of CD8+ T cells was not associated with pathological responses. Patients with lower FOXP3+ T cell densities showed better survival, although the difference was not statistically significant. CONCLUSION Our study demonstrated that the density of tumor-infiltrating FOXP3+ T cells indicated the degree of response for induction CRT and prognosis in patients treated with trimodality therapy for locally advanced NSCLC, suggesting that FOXP3+ T cells may be target for adjunct immunotherapy.