鈴木 秀海

Lung transplantation has become popular in Japan, showing better survival rate than other countries. However, the results are still not satisfactory compared with other solid organ transplantation. One of the reasons for this might be that knowledge on donor-specific antibodies or antibody-related rejection, which has been attracting attention these days, is less than that of kidney or liver transplantation. Our laboratory has continued basic research in this field using rodent lung transplantation model. We have previously shown that type V collagen is associated in chronic rejection as an autoimmune, and that oral administration of type V collagen induces tolerance. The murine chronic rejection model of the minor antigen mismatch was developed, and involvement of the humoral immunity and role of the complement activation were shown. We are now studying the effects of immune checkpoint molecules, which play a central role in the field of cancer therapy, on rejection after lung transplantation. We are also working to verify the effects of anti-complement drugs and molecular targeted drugs in the future treatment on rejection.

Primary racemose hemangioma of the bronchial artery (RHBA) is one of the causes of massive hemoptysis. A 72-year-old woman was admitted to our hospital with recurrent hemoptysis. Bronchoscopy showed an endobronchial lesion, and the angiography of the right bronchial arteries indicated RHBA. Bronchial arterial embolization (BAE) was performed to prevent hemoptysis. Although the endobronchial lesion shrank after the first BAE, the lesion re-increased and caused massive hemoptysis. A thoracoscopic right upper lobectomy was performed, and hemoptysis did not recur. Therefore, in cases of RHBA where there is recurrent hemoptysis and the endobronchial lesions that remain after BAE, additional treatments should be considered.

BACKGROUND: High-power diode (GaAlAs) laser systems have been used for transbronchoscopic laser ablation for central airway stenosis. Such diode laser systems show a similar clinical effect to a conventional Nd-YAG laser, but the instrument is more compact with easier handling. We use a high-power diode laser system with a non-contact probe for endobronchial ablative therapy. The present study reviewed our experience with transbronchoscopic laser ablation to explore a better clinical approach for managing central airway lesions. METHODS: We retrospectively reviewed the patients who were treated for central airway lesions by transbronchial laser ablation using the non-contact-type probe from January 2005 to December 2015 at Chiba University Hospital. We investigated the cause of stenosis, number of treatments, laser setting, total amount of energy, complications, and simultaneously performed modality. RESULTS: Thirty-three patients underwent treatment a total of 72 times. There were 23 males, with an average age of 60.3 years old (range, 18-80 years old). The primary causes of the central airway stenosis were neoplastic disease in 22 (16 malignant tumors, 6 benign tumors) and non-neoplastic disease in 11. Among malignant tumors, there were eight tracheal cancer and five lung cancer patients as well as three patients with esophageal cancer. Among benign tumors, there were three hamartomas and one patient each with papilloma, smooth muscle tumor, and glomus tumor. The non-neoplastic causes of airway stenosis were intubation or tracheotomy in four patients, tuberculosis and granulation in two each, and trauma, burn, and surgery in one each. The numbers of treatments were 30 times (1.36 times/patient) for neoplastic diseases and 42 times (3.82 times/patient) for non-neoplastic disease. The total amount of energy was 1,936 J on average (1,674 J for neoplastic diseases and 2,098 J for non-neoplastic disease). There were no major complications related to transbronchial laser ablation therapy. CONCLUSIONS: Transbronchoscopic laser ablation using a diode laser system with a non-contact probe can be safely performed and is useful for endobronchial treatment of both neoplastic and non-neoplastic central airway lesions.

OBJECTIVES: This study investigates whether the surgical correction of chest deformity is associated with the growth of the lung parenchyma after surgery for pectus excavatum. METHODS: Ten patients with pectus excavatum who were treated by the Nuss procedure were examined. The preoperative and postoperative computed tomography (2.5 ± 1.2 years after surgery) scans were performed, and the Haller index, lung volume and lung density were analyzed using a three-dimensional image analysis system (SYNAPSE VINCENT, Fujifilm, Japan). The radiological lung weight was calculated as follows: lung volume (ml) × lung density (g/ml). RESULTS: The average age of the 10 patients (men 8; women 2) was 13.8 years (range: 6-26 years). The Haller index was significantly improved from the preoperative value of 5.18 ± 2.20 to the postoperative value of 3.68 ± 1.38 (P = 0.0025). Both the lung volume and weight had significantly increased by 107.1 ± 19.6% and 121.6 ± 11.3%, respectively, after surgery. CONCLUSIONS: A significant increase in the weight of the lung after surgical correction suggests that the growth of the lung parenchyma is associated with the correction of chest deformity in younger patients with pectus excavatum.

OBJECTIVE: The innovation of novel systemic chemo/immunotherapy for metastatic head and neck cancer might contribute to prognostic improvement. We aimed to clarify the recent characteristics and outcomes of pulmonary metastasectomy for head and neck cancer. METHODS: Twenty-five patients who underwent pulmonary metastasectomy from January 2011 to December 2016 were included. The clinicopathological factors and survival were assessed by retrospective chart reviews. RESULTS: The median follow-up period was 39 months (range, 7-94 months). The median age was 66 years (range, 20-89 years), and 23 males were included. The primary tumor locations were as follows: pharynx (n = 12), nasal/paranasal cavity (n = 5), larynx (n = 4), and others (n = 4). The 5-year overall survival rate was 49%. In the univariate analysis, a history of local recurrence before pulmonary metastasis was an independent predictor of a poor prognosis. In 90% of patients with recurrence after pulmonary metastasectomy, the site of recurrence was the lung. Eight patients achieved long-term survival without any evidence of recurrence (median: 45 months). Molecular targeting chemotherapy and immune-checkpoint inhibitors were used in five patients with systemic recurrence after pulmonary metastasectomy, leading to preferable survival. CONCLUSIONS: In the current era of advances in systemic chemotherapy and immunotherapy, surgical indication has not changed for resectable pulmonary metastases and selected patients can still benefit from pulmonary metastasectomy. Further investigation is needed to clarify the significance of systemic therapy in patients with pulmonary metastasis of head and neck cancer.

Bronchiolitis obliterans syndrome (BOS) occurring after hematopoietic stem cell transplantation (HSCT) for hematologic malignancies is a progressive and refractory disease, and lung transplantation (LTx) seems to be the only promising treatment. We report two cases of BOS after HSCT, which showed distinct clinical courses and were successfully treated with LTx. The respiratory symptoms and function of the two patients progressively deteriorated to a critical level during the waiting period. In one patient, recurrent and intractable pneumothoraxes consistent with thoracic air-leak syndrome (TALS) occurred, which were associated with pleuroparenchymal fibroelastosis. TALS could accelerate clinical deterioration, thus permitting a shorter waiting period for LTx.

Tumor spread through air spaces (STAS) in non-small-cell lung cancer (NSCLC) is known to influence a poor patient outcome, even in patients presenting with early-stage disease. However, the pre-operative diagnosis of STAS remains challenging. With the progress of radiomics-based analyses several attempts have been made to predict STAS based on radiological findings. In the present study, patients with NSCLC which is located peripherally and tumors ≤ 2 cm in size on computed tomography (CT) that were potential candidates for sublobar resection were enrolled in this study. The radiologic features of the targeted tumors on thin-section CT were extracted using the PyRadiomics v3.0 software package, and a predictive model for STAS was built using the t-test and XGBoost. Thirty-five out of 226 patients had a STAS histology. The predictive model of STAS indicated an area under the receiver-operator characteristic curve (AUC) of 0.77. There was no significant difference in the overall survival (OS) for lobectomy between the predicted-STAS (+) and (-) groups (p = 0.19), but an unfavorable OS for sublobar resection was indicated in the predicted-STAS (+) group (p < 0.01). These results suggest that radiomics with machine-learning helped to develop a favorable model of STAS (+) NSCLC, which might be useful for the proper selection of candidates who should undergo sublobar resection.

Patients with idiopathic pulmonary fibrosis (IPF) are at higher risk of developing lung cancers including squamous cell lung carcinoma (SCC), which typically carries a poor prognosis. Although the molecular basis of cancer development subsequent to IPF has not been fully investigated, we recently reported two epigenetic phenotypes characterized by frequent and infrequent DNA hypermethylation in SCC, and an association of the infrequent hypermethylation phenotype with IPF-associated SCCs. Here, we conducted targeted exon sequencing in SCCs with and without IPF using the Human Lung Cancer Panel to investigate the genetic basis of IPF-associated SCC. SCCs with and without IPF displayed comparable numbers of total mutations (137 ± 22 vs 131 ± 27, P = .5), nonsynonymous mutations (72 ± 14 vs 69 ± 16, P = .5), indels (3.0 ± 3.5 vs 3.0 ± 3.9, P = 1) and synonymous mutations (62 ± 9.1 vs 60 ± 12, P = .5). Signature 1 was the predominant signature in SCCs with and without IPF. SETD2 and NFE2L2 mutations were significantly associated with IPF (44% vs 13%, P = .03 for SETD2; 38% vs 10%, P = .04 for NFE2L2). MYC amplification, assessed by copy number variant analysis, was also significantly associated with IPF (18.8% vs 0%, P = .04). Mutations in TP53 and CDKN2A were observed relatively frequently in SCCs with frequent hypermethylation (P = .02 for TP53 and P = .06 for CDKN2A). Survival analysis revealed that the SETD2 mutation was significantly associated with worse prognosis (P = .04). Collectively, we found frequent involvement of SETD2 and NFE2L2 mutations and MYC amplification in SCCs with IPF, and an association of a SETD2 mutation with poorer prognosis.