Mitsuteru Yoshida

Fluoroscopy-assisted thoracoscopic resection after computed tomography-guided bronchoscopic metallic coil marking for small peripheral pulmonary lesions

OBJECTIVES To re-evaluate the efficacy of fluoroscopy-assisted thoracoscopic resection after computed tomography (CT)-guided bronchoscopic metallic coil marking (FATS-CM), which was our original method for small peripheral pulmonary lesions. METHODS Fifty-eight patients with 63 lesions underwent FATS-CM. A metallic coil was installed in the bronchus nearest to the lesion under CT fluoroscopic guidance with ultrathin bronchoscopy. The virtual bronchoscopic navigation (VBN) system was used in 14 cases. Afterwards, we basically performed wide wedge resection (WWR) using a C-arm-shaped roentgenographic fluoroscope during thoracoscopic surgery initially, and then the final procedure was determined by intraoperative histological diagnosis. Moreover, we prospectively treated ground-glass opacity (GGO) lesions of <20 mm diameter according to our treatment protocol from September 2004. RESULTS We could install coils in the objective bronchi in all cases. The average time required for the marking procedure was 38.9 (15-120) min. Pneumothorax was recognized in 1 (1.7%) case as a complication, but no fatal complications occurred. We could also install coils for each lesion in 4 cases (9 lesions) with multiple lesions. In 14 cases with the VBN system, the examination time and CT number were significantly reduced (P < 0.05 and <0.001, respectively), compared with those of 40 cases without the VBN system. The average interval between the CM and the operation was 5.6 (0-30) days. We never experienced a case of migration preoperatively. Sixty-two (98.4%) lesions were definitively identified, and WWRs were performed using three trocars in 58 (92.1%) cases during thoracoscopic surgery. Lobectomy was initially performed in only 1 case owing to coil migration. Thirty-seven of 40 cases (92.5%) were in line with the treatment protocol. There were no local-regional recurrences in all cases undergoing WWR. CONCLUSIONS We could prospectively show that our method was suitable to perform WWR with a sufficient margin for small GGO lesions of <20 mm. Moreover, we reconfirmed that the advantages of our method were safety, permitting flexibility in scheduling operations and a high ability to deal with multiple lesions. Additionally, our method became a minimally invasive and mature technique by using a new VBN system.

18F-fluorodeoxyglucose positron emission tomography/computed tomography and the relationship between fluorodeoxyglucose uptake and the expression of hypoxia-inducible factor-1α, glucose transporter-1 and vascular endothelial growth factor in thymic epithelial tumours.

OBJECTIVES The objective of this study was to evaluate the usefulness of (18)F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) and the relationships among the expressions of hypoxia-inducible factor-1α (HIF-1α), glucose transporter-1 (Glut-1) and vascular endothelial growth factor (VEGF), histological type, other clinical factors and FDG uptake in thymic epithelial tumours. METHODS Thirty-three patients who underwent FDG-PET/CT before treatment were reviewed. All types of tumours were reclassified into three subgroups: low-risk thymomas (types A, AB and B1), high-risk thymomas (types B2 and B3) and thymic carcinomas. Tumour contour, pattern of FDG uptake, tumour size and maximum standardized uptake value (SUVmax) were obtained. Expressions of HIF-1α, Glut-1 and VEGF were analysed immunohistochemically, and these expressions were evaluated using grading scales. RESULTS FDG uptake was visually recognized in all (100%) tumours. A homogeneous pattern of FDG uptake was increasingly observed in the order of low-risk thymomas to high-risk thymomas to thymic carcinomas (P = 0.016). SUVmax for thymic carcinomas was significantly higher than that for thymomas (P = 0.008). With the optimal cut-off value of SUVmax of 5.6, the sensitivity, specificity and accuracy for diagnosing thymic carcinoma were 0.75, 0.80 and 0.79, respectively. Regarding the mean scoring of HIF-1α, Glut-1 and VEGF, increasing trends were observed in the order of low-risk thymomas to high-risk thymomas to thymic carcinomas. Tumour size revealed a significant correlation with SUVmax (r = 0.60, P < 0.001), and the expression of HIF-1α showed a moderate association, but the expression of Glut-1 showed no correlation with SUVmax. Regarding correlations between the expression of the three markers, there were moderate associations between HIF-1α and Glut-1, and HIF-1α and VEGF, and a significant correlation between Glut-1 and VEGF (r = 0.60, P < 0.001). In type B1 thymoma, HIF-1α and Glut-1 were partly expressed in non-neoplastic immature lymphocytes. CONCLUSIONS FDG-PET/CT should be performed in patients with tumours in the anterior mediastinum because the pattern of FDG uptake and SUVmax are useful in the differential diagnosis of thymic epithelial tumours. Furthermore, the expressions of HIF-1α, Glut-1 and VEGF might be associated with malignancy of thymic epithelial tumours. In contrast, FDG uptake might be dependent on tumour size rather than Glut-1 overexpression.

Fibrocyte-like cells mediate acquired resistance to anti-angiogenic therapy with bevacizumab

Bevacizumab exerts anti-angiogenic effects in cancer patients by inhibiting vascular endothelial growth factor (VEGF). However, its use is still limited due to the development of resistance to the treatment. Such resistance can be regulated by various factors, although the underlying mechanisms remain incompletely understood. Here we show that bone marrow-derived fibrocyte-like cells, defined as alpha-1 type I collagen-positive and CXCR4-positive cells, contribute to the acquired resistance to bevacizumab. In mouse models of malignant pleural mesothelioma and lung cancer, fibrocyte-like cells mediate the resistance to bevacizumab as the main producer of fibroblast growth factor 2. In clinical specimens of lung cancer, the number of fibrocyte-like cells is significantly increased in bevacizumab-treated tumours, and correlates with the number of treatment cycles, as well as CD31-positive vessels. Our results identify fibrocyte-like cells as a promising cell biomarker and a potential therapeutic target to overcome resistance to anti-VEGF therapy.

Methylation and expression profiles of MGMT gene in thymic epithelial tumors

OBJECTIVES A key challenge in diagnosis and treatment of thymic epithelial tumors (TET) is in improving our understanding of the genetic and epigenetic changes of these relatively rare tumors. METHODS Methylation specific PCR (MSP) and immunohistochemistry were applied to 66 TET to profile the methylation status of DNA repair gene O6-methylguanine DNA methyltransferase (MGMT) and its protein expression in TET to clarify the association between MGMT status and clinicopathological features, response to chemotherapy and overall survival. RESULTS MGMT methylation was significantly more frequent in thymic carcinoma than in thymoma (17/23, 74% versus 13/44, 29%; P<0.001). Loss of expression of MGMT protein was significantly more frequent in thymic carcinoma than in thymoma (20/23, 87% versus 10/44, 23%; P<0.0001). There is a significant correlation between of MGMT methylation and loss of its protein expression (P<0.0003). MGMT methylation and loss of expression were significantly more frequent in advanced thymic epithelial tumors (III/IV) than in early tumors (I/II). CONCLUSION MGMT methylation plays a soul role in development of TET, especially in thymic carcinoma. Therefore, translation of our results from basic molecular research to clinical practice may have important implication for considering MGMT methylation as a marker and a target of future therapies in TET.

Functional evaluation of pallid mice with genetic emphysema.

Studies on pallid mice models of genetic emphysema have conventionally focused on morphological or biochemical evaluations. However, it is important to consider the functional aspects. We evaluated the exercise capacity and respiratory function in male pallid mice and male C57BL/6J mice at 3, 6, 12, and 15 months of age. The functional evaluations were conducted using a treadmill and a pulmonary function analysis device. The morphology of the lungs was analyzed on the basis of mean linear intercept (Lm) values. The body weights of the pallid mice at 12 and 15 months were significantly lower than those of the age-matched C57BL/6J mice. The pallid mice showed deterioration in exercise capacity from 6 months, as indicated by the trends in running distance. At 6, 12, and 15 months, the pallid mice showed significantly higher pulmonary compliance and significantly lower forced expiratory volume in 20 ms (FEV20 ms)/vital capacity (VC) values in comparison with the corresponding values for the C57BL/6J mice. In the morphological analysis of the pallid mice, emphysema was detected from 12 months, and the mice showed a significantly larger Lm at 12 months. The exercise capacity and lung function in the pallid mice significantly deteriorated from 6 months, at which time no pathological changes in the lung were detected. The deterioration in the exercise capacity and pulmonary function preceded the microscopic morphological changes.

Video-assisted thoracic surgery lobectomy for lung cancer in a patient with complete situs inversus

Complete situs inversus is a rare abnormality of autosomal recessive inheritance; it requires particular care during surgery, because the viscus anatomy is a mirror image of the normal anatomy. Reports of surgery for lung cancer in cases of complete situs inversus are very rare. Here, we report a case of lobectomy for lung cancer of the right lower lobe performed using video-assisted thoracic surgery (VATS) in a patient with complete situs inversus. We emphasize the importance of careful examination of the relationship between the bronchus, pulmonary artery, and pulmonary vein in the hilum of the lung in cases of complete situs inversus requiring lung resection for cancer; this is even more necessary when VATS is performed.

Non-invasive monitoring of anticancer effects of cisplatin on lung cancer in an orthotopic SCID mouse model using [18F] FDG PET-CT

Positron emission tomography-computed tomography (PET-CT) with [18F] fluorodeoxyglucose (FDG) has recently been applied for evaluating tumor response to anticancer therapy. The aim of the present study was to evaluate the utility of FDG PET-CT in monitoring non-invasively and repeatedly the inhibitory effect of cisplatin (CDDP) on an orthotopic lung cancer model. Validation of in vivo FDG uptake in human lung cancer Ma44-3 cell line in an orthotopic SCID mouse model was carried out. Next, we assessed the use of FDG PET-CT to monitor the response of orthotopic lung cancer to the anticancer effect of CDDP. SCID mice were divided into the CDDP group (7 mg/kg single dose intraperitoneally) and the control group. Tumor volume and maximal standardized uptake value (SUV max) were calculated for all mice. All mice were sacrificed for histopathologic analysis. Validation of FDG PET-CT showed that tumor volume and SUV max were significantly correlated with postmortem tumor length measured in specimens (P=0.023) and (P=0.012), respectively, and there was a significant correlation between SUV max and tumor volume (P=0.048). Response monitoring showed that significant growth inhibition by CDDP in the form of SUV max of the CDDP group was significantly lower than that of the control group on day 8 (P=0.02) and on day 13 (P=0.003). Tumor volume of the CDDP group was significantly lower than that of the control group on day 13 (P=0.03). The present study supports using FDG PET-CT in monitoring tumor progression and therapeutic response of lung cancer in an orthotopic model non‑invasively and repeatedly.

Cancer of the Left Lung With Persistent Left Superior Vena Cava

As operations for lung cancer become more common, more anomalies of various pulmonary arteries and veins are being encountered. Persistent left superior vena cava (PLSVC) is caused by abnormal development of the sinus venosus in early fetal life. In cases of PLSVC with left lung cancer, particular care must be exercised during the excision of the pulmonary vein, focusing on the region into which the PLSVC flows. In such anomalous cases, proper excision of the pulmonary artery and vein and lymph node dissection require a firm grasp of anatomic detail using preoperative computed tomographic scanning.

A feasibility study of postoperative adjuvant chemotherapy with fluoropyrimidine S‐1 in patients with stage II‐IIIA non‐small cell lung cancer

BACKGROUND Adjuvant chemotherapy with uracil tegafur (UFT) improved survival among patients with completely resected stage I lung adenocarcinoma. S-1, an oral dihydropyrimidine dehydrogenase (DPD)-inhibitory 5-fluorouracil, is a more potent DPD inhibitor than UFT;therefore, we hypothesized that postoperative adjuvant chemotherapy with S-1 would be effective for advanced non-small cell lung cancer (NSCLC). We conducted a feasibility study of S-1 as postoperative adjuvant chemotherapy in patients with curatively resected pathological stage bold I back 10 bold I and bold I back 10 bold I back 20 bold I A NSCLC. METHODS Adjuvant chemotherapy consisted of 9 courses (4-week administration, 2-week withdrawal) of S-1 at 80-120 mg/body per day. Twenty-four patients with completely resected NSCLC were enrolled in this study from November 2007 through December 2010. The primary endpoint was the rate of completion of the scheduled adjuvant chemotherapy. The secondary endpoints were safety, overall survival, and relapse-free survival. RESULTS Five patients were censored because of disease recurrence. The planned 9 courses of S-1 were administered to completion in 8 patients. Twelve patients completed more than 70% of the planned courses. Grade 3 adverse reactions, such as elevated total bilirubin (4.2%) and pneumonitis (4.2%), were observed, but there were no Grade 4 adverse reactions. Patients who completed more than 70% of the 9 courses demonstrated better overall survival than those who completed less than 70%. CONCLUSION Postoperative administration of S-1 may be possible with few severe adverse events as adjuvant chemotherapy for patients with curatively resected pathological stage bold I back 10 bold I -bold I back 10 bold I back 20 bold I A NSCLC. J. Med. Invest. 65:90-95, February, 2018.

Thirty percent of ductal carcinoma in situ of the breast in Japan is extremely low-grade ER(+)/HER2(-) type without comedo necrosis

Background Overdiagnosis in mammography (MMG) is a problem. Combination of MMG and ultrasonography for breast cancer screening may increase overdiagnosis. Most cases of overdiagnosis are low-grade ductal carcinoma in situ (LGD), but no reports have focused on them. Materials and methods We immunostained 169 ductal carcinoma in situ (DCIS) cases for ER, PgR, HER2 and Ki67 and classified them into 4 subtypes: ER(+)/HER2(-), ER(+)/HER2(+), ER(-)/HER2(-) and ER(-)/HER2(+). The Ki67 index was used to evaluate the grade of malignancy and examined for correlations with each ER/HER2 subtype and the nuclear grade (NG), with/without comedo necrosis. Results The Ki67 index correlated significantly with NG, both with/without comedo necrosis, and reliably evaluated the grade of malignancy. The index for ER(+)/HER2(-) (n=117, 69.2%) was 7.45±7.10, which was significantly lower than for each of the other types. The index was 5.71±6.94 for ER(+)/HER2(-) without comedo necrosis (n=52, 30.8%), which was significantly lower than with comedo necrosis. This was considered LGD, characterized by absence of microcalcification in MMG and either presence of a solid mass or cystic lesion or absence of hypoechoic areas in ultrasound. Conclusion In Japan, ER(+)/HER2(-) without comedo necrosis accounts for about 30% of DCIS and is LGD. This may be being overdiagnosed. J. Med. Invest. 63: 192-198, August, 2016.