鈴木 秀海

OBJECTIVES: The objective of this study was to clarify the clinicopathological features and prognostic factors of resected lung adenosquamous carcinoma (ASC) using a nationwide multi-institutional database. METHODS: We retrospectively reviewed the records of 15,542 patients who underwent complete R0 resection for ASC (n = 326), adenocarcinoma (AC, n = 11,820), or squamous cell carcinoma (SC, n = 3396) from a Japanese lung cancer registry in 2010. To reduce the selection bias, an inverse probability of treatment weighting (IPTW) method using a propensity score was implemented. RESULTS: The ASC group showed worse recurrence-free and overall survival (RFS and OS) than both the AC and SC groups (5-year OS: 57.5% in ASC, 83.9% in AC [< 0.001], and 62.3% in SC [P = .086]). In multivariate analyses, prognostic factors that affected OS for ASC included male, p-stage II-III, and postoperative complications within 30 days (grade ≥ 3 in the Clavien-Dindo classification). The sensitizing EGFR mutation was detected in 28 (21.5%) of 130 screened patients with ASC, but it did not affect either RFS, OS, or postrecurrence survival. Although more patients in the ASC group received adjuvant chemotherapy compared to the AC and SC groups, both multivariate and IPTW-adjusted analyses did not show positive impact of adjuvant chemotherapy on RFS and OS in ASC. CONCLUSIONS: In this nationwide registry study, lung ASC was more aggressive than both AC and SC. No apparent survival impact of conventional adjuvant chemotherapy prompted us to investigate novel adjuvant strategies to optimize survival outcomes.

PURPOSE: Given that left upper lobe and right upper and middle lobes share a similar anatomy, segmentectomy, such as upper division and lingulectomy, should yield identical oncological clearance to left upper lobectomy. We compared the prognosis of segmentectomy with that of lobectomy for early stage non-small-cell lung cancer (NSCLC) in the left upper lobe. METHODS: We retrospectively examined 2115 patients who underwent segmentectomy or lobectomy for c-stage I (TNM 8th edition) NSCLC in the left upper lobe in 2010. We compared the oncological outcomes of segmentectomy (n = 483) and lobectomy (n = 483) using a propensity score matching analysis. RESULTS: The 5-year recurrence-free and overall survival rates in the segmentectomy and lobectomy groups were comparable, irrespective of c-stage IA or IB. Subset analyses according to radiological tumor findings showed that segmentectomy yielded oncological outcomes comparable to those of lobectomy for non-pure solid tumors. In cases where the solid tumor exceeded 20 mm, segmentectomy showed a recurrence-free survival inferior to that of lobectomy (p = 0.028), despite an equivalent overall survival (p = 0.38). CONCLUSION: Segmentectomy may be an acceptable alternative to lobectomy with regard to the overall survival of patients with c-stage I NSCLC in the left upper lobe.

PURPOSE: To investigate how revision of the organ transplant law in Japan affected lung transplantation in this country. METHODS: Lung transplant candidates registered between January, 2000 and December, 2009 were designated as the pre-revision group (n = 396) and those registered between January, 2011 and December, 2020, as the post-revision group (n = 1326). Both groups were analyzed retrospectively using data collected by the Japanese Society of Lung and Heart-Lung Transplantation. RESULTS: The number of patients who underwent brain-dead donor lung transplantation (BDLT) increased significantly after the law amendment (32.2 vs. 13.8%, p < 0.01). The median waiting time for BDLT was significantly reduced (708 days vs. 1163 days, p < 0.01) and the mortality rate while waiting for BDLT improved significantly after the law amendment (33.1 vs. 42.6%, p < 0.01). In the post-revision group, 18 pediatric patients underwent BDLT. The 5-year survival rates after BDLT were comparable between the groups (73.5% in the pre-revision group vs. 73.2% in the post-revision group, p = 0.32). CONCLUSIONS: The organ transplant law revision shortened the waiting time for BDLT significantly and decreased the mortality rate while waiting for BDLT. The posttransplant outcomes in Japan remained favorable throughout the study period.

BACKGROUND: Tracheobronchial injuries resulting from blunt trauma are relatively rare among chest injuries. However, if these injuries are not managed properly, they can be fatal. The prognosis is intricately linked to the precise diagnosis and treatment. We herein report three cases of tracheobronchial trauma that required surgical intervention. Case 1:A 17-year-old male sustained injuries when his torso became entangled in heavy machinery. The diagnosis revealed a tear in the right main bronchus, which required transportation with left single- lung ventilation. The patient was treated by tracheobronchial reconstruction. Case 2:A 71-year-old male experienced trauma when his car collided with a utility pole. He was transported to the hospital after tracheal intubation due to a laceration of the tracheal membranous area. The site of the injury was closed with sutures. Case 3:A 17-year-old female who had been struck by a train suffered acute respiratory failure and was transported to the hospital after intubation. Veno-venous extracorporeal membrane oxgenation (VV-ECMO) was initiated in response to poor oxygenation. Complete rupture of the right middle bronchial trunk and laceration of the right main bronchial membrane were observed, and bronchoplasty was performed. CONCLUSION: A swift and accurate diagnosis, coupled with timely and judicious therapeutic interventions, play a pivotal role in managing tracheal and bronchial injuries.

BACKGROUND: Despite the low number of lung transplantations (LTs) in Japan, 10 LT facilities are accredited and good outcomes have been reported. A database review was conducted to clarify the impact of case volume at LT facilities in Japan on short- and long-term outcomes. METHODS: All cadaveric LT cases treated between 2000 and 2021 in Japan were analyzed using the database of the Japanese Society of Lung and Heart-Lung Transplantation (JSLHT). The nine institutions represented were categorized into the low-volume (LV; <80 cumulative LT cases, <8 LTs/year, n=5) and high-volume (HV; ≥80 cumulative LT cases, ≥8 LTs/year, n=4) centers. Ninety-day and 1-year mortality, as well as 5- and 10-year survival data were evaluated. RESULTS: A total of 658 cadaveric LTs were performed at the nine institutions. The 90-day rates of mortality at the HV and LV centers were 3.5% and 3.9%, respectively (P=0.801), while the 1-year mortality rates were 9.2% and 11.5%, respectively (P=0.199). Additionally, log-rank analysis of Kaplan-Meier curves showing case volume did not reveal a significant difference in long-term survival between the HV and LV centers (P=0.272), though the LV centers had wide differences for long-term outcomes (P=0.030). CONCLUSIONS: Case volume did not have effects on short- or long-term outcomes following LT in Japan, while there were large variations in long-term outcomes among the LV centers compared to those of the HV centers.

BACKGROUND: Home oxygen therapy (HOT) is used to treat chronic respiratory diseases and is sometimes required in patients with lung cancer after radical surgery. We aimed to identify the risk factors for postoperative home-based oxygen therapy in patients with lung cancer. METHODS: Patients who underwent surgery for primary lung cancer at Chiba University Hospital between January 2019 and March 2021 were included. Patients who did not undergo complete resection, died in hospital after surgery, or used oxygen therapy preoperatively were excluded. Eligible patients were divided into HOT and non-HOT groups. They were retrospectively analyzed for risk factors for postoperative HOT using medical records in a multivariate analysis. RESULTS: A total of 410 patients were included in this study, 24 (5.9%) of whom required HOT after surgery. The HOT group comprised significantly more men, heavy smokers, and patients with pulmonary comorbidities, low percent forced expiratory volume, percent forced vital capacity, predicted postoperative forced expiratory volume in 1 s, and postoperative pulmonary complications on univariate analysis. In a multivariate analysis, independent risk factors for postoperative HOT were pulmonary comorbidities [odds ratio (OR): 5.94; 95% confidence interval (CI): 1.64-21.5; P=0.002) and postoperative pulmonary complications (OR: 5.39; 95% CI: 2.14-13.5; P<0.001). The postoperative HOT application rate was calculated according to a formula developed for this purpose. CONCLUSIONS: Comorbid pulmonary diseases and postoperative pulmonary complications were significantly associated with postoperative HOT in patients with lung cancer.

BACKGROUND: The efficacy of adjuvant chemotherapy (ACT) in elderly patients with completely resected p-stage II-IIIA non-small-cell lung cancer (NSCLC) remains unclear because all previous randomized controlled trials on ACT have been conducted among patients aged <75 years. Thus, this study aimed to evaluate the effectiveness of ACT in elderly patients with completely resected NSCLC. PATIENTS: We extracted the nationwide data of 812 patients aged ≥75 years who underwent lobectomy with mediastinal nodal dissection in 2010 and were diagnosed with p-stage II-IIIA NSCLC, from nationwide registry data accumulated in 2016. METHODS: We classified the 812 patients into 2 groups based on the ACT administration status and analyzed the differences in their postoperative overall survival (OS). RESULTS: Overall, 295 patients received ACT (36.3%; group A), whereas 517 patients did not (63.70%; group N). Group A showed significantly better OS as a whole (hazard ratio [HR]: 0.650 [95% confidence interval {CI}: 0.526-0.804]), in the p-stage II subset (HR: 0.688 [95% CI: 0.513-0.925]), and p-stage IIIA subset (HR: 0.547 [95% CI: 0.402-0.743]) than group N. Even after propensity score matching, group A showed significantly better OS as a whole (HR: 0.626 [95% CI: 0.495-0.792]), in the p-stage II subset (HR: 0.690 [95% CI: 0.493-0.964]), and p-stage IIIA subset (HR: 0.554 [95% CI: 0.398-0.772]) than group N. CONCLUSION: ACT is recommended even in elderly patients with completely resected p-stage II-IIIA NSCLC. Hence, physicians should not avoid ACT in patients with completely resected NSCLC based solely on age.

Solid organ transplant (SOT) recipients with coronavirus disease-2019 (COVID-19) experience prolonged viral shedding, and they are forced to stay in the hospital because of the requirement for COVID-19 isolation. Here, we present two cases (lung and renal transplant recipients), wherein the isolation period was shortened by reducing the dosage of mycophenolate mofetil (MMF). Both patients recovered well from COVID-19 pneumonia. This case study suggests that a reduction in MMF dosage may lead to a shorter hospitalization period in SOT recipients with COVID-19.

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disease that often causes progressive pulmonary fibrosis (HPS-PPF) in some genetic types with high mortality rates. No effective treatment for HPS-PPF other than lung transplantation has been established. Herein, we report a case of HPS type 1 with progressive pulmonary fibrosis treated with long-term nintedanib administration followed by lung transplantation. The resected lungs revealed diffuse interstitial lung lesions, including fibroblastic foci, suggesting the potential beneficial effects of anti-fibrotic drugs in HPS-PPF. Together with previous reports, the present case suggests that nintedanib might be a safe and effective drug for HPS-PPF.

PURPOSE: This study aimed to compare the outcomes of patients with ground-grass opacity (GGO)-dominant non-small cell lung cancer (NSCLC) who were treated with carbon ion radiotherapy (CIRT) versus segmentectomy. METHODS: A retrospective review of medical records was conducted. The study included 123 cases of clinical stage 0/IA peripheral NSCLC treated with single-fraction CIRT from 2003 to 2012, 14 of which were determined to be GGO-dominant and were assigned to CIRT group. As a control, 48 consecutive patients who underwent segmentectomy for peripheral GGO-dominant clinical stage IA NSCLC were assigned to segmentectomy group. RESULTS: The patients in CIRT group, compared with segmentectomy group, were significantly older (75 ± 7.2 vs. 65 ± 8.2 years, P = 0.000660), more likely to be male (13/14 vs. 22/48, P = 0.00179), and had a lower forced vital capacity (91 ± 19% vs. 110 ± 13%, P = 0.0173). There was a significant difference in the 5-years overall survival rate (86% vs. 96%, P = 0.000860), but not in the 5-years disease-specific survival rate (93% vs. 98%, P = 0.368). DISCUSSION: Compared with segmentectomy, CIRT may be an alternative option for patients with early GGO-dominant NSCLC who are poor candidates for, or who refuse, surgery.

OBJECTIVE: The efficacy of tegafur-uracil as adjuvant chemotherapy for patients with completely resected stage I non-small-cell lung cancer is proven; however, its efficacy for elderly patients remains unclear. Herein, we evaluated the effectiveness of adjuvant chemotherapy for elderly patients with completely resected stage I non-small-cell lung cancer based on real-world Japanese data using propensity score matching. METHODS: This retrospective study extracted data from a nationwide registry study, performed in 2016, on patients ≥75 years who underwent lobectomy with mediastinal nodal dissection for non-small-cell lung cancer in 2010 and were diagnosed with p-stage IA (>2 cm) or stage IB non-small-cell lung cancer. We classified the 1294 patients into two groups-Group A, postoperative adjuvant chemotherapy (n = 295, 22.8%) and Group N, no adjuvant chemotherapy (n = 999, 77.2%)-and analyzed differences in postoperative overall survival between groups. RESULTS: Group A showed no advantage in overall survival over Group N as a whole (hazard ratio: 0.824 [95% confidence interval: 0.631-1.076]), in p-stage IA (hazard ratio: 0.617 [95% confidence interval: 0.330-1.156]) and in p-stage IB (hazard ratio: 0.806 [95% confidence interval: 0.597-1.088]) subsets. Even after propensity score matching, Group A showed no significant advantage in overall survival over Group N as a whole (hazard ratio: 0.975 [95% confidence interval: 0.688-1.381]), in p-stage IA (hazard ratio: 1.390 [95% confidence interval: 0.539-3.586]) and in p-stage IB (hazard ratio: 0.922 [95% confidence interval: 0.633-1.343]). CONCLUSIONS: adjuvant chemotherapy for completely resected p-stage IA (>2 cm) and stage IB non-small-cell lung cancer showed no benefit for recommendation for elderly patients; considering the risk of adverse events, we do not recommend adjuvant chemotherapy for elderly patients.

Due to the scarcity of large-sized prospective databases, the Japanese Joint Committee for Lung Cancer Registry conducted a nationwide prospective registry for newly diagnosed and untreated pleural mesothelioma. All new cases diagnosed pathologically as any subtype of pleural mesothelioma in Japan during the period between April 1, 2017, to March 31, 2019, were included before treatment. Data on survival were collected in April 2021. The eligible 346 patients (285 men [82.3%]; 61 women [17.7%]; median age, 71.0 years [range, 44-88]) were included for analysis. Among these patients, 138 (39.9%) underwent surgery, 164 (47.4%) underwent non-surgical therapy, and the remaining 44 (12.7%) underwent best supportive care. The median overall survival for all 346 patients was 19.0 months. Survival rates at 1, 2, and 3 years for all patients were, 62.8%, 42.3%, and 26.5%, respectively. Median overall survival was significantly different among patients undergoing surgery, non-surgical treatment, and best supportive care (32.2 months vs. 14.0 months vs. 3.8 months, p < 0.001). The median overall survival of patients undergoing pleurectomy/decortication and extrapleural pneumonectomy was 41.8 months and 25.0 months, respectively. Macroscopic complete resection resulted in longer overall survival than R2 resection and partial pleurectomy/exploratory thoracotomy (41.8 months vs. 32.2 months vs. 16.8 months, p < 0.001). Tumor shape, maximum tumor thickness, and sum of three level thickness were significant prognostic factors. The data in the prospective database would serve as a valuable reference for clinical practice and further studies for pleural mesothelioma.

BACKGROUND AND OBJECTIVE: The number of lung transplantations performed in Japan is increasing, and post-transplant outcomes are relatively favorable. A major concern is the extremely long waiting time and the high mortality rate on the waitlist. The management of patients before transplantation is very important and essential for further improvement of outcomes. In this review, we summarize the management of patients awaiting lung transplantation in Japan. METHODS: A literature search was conducted via PubMed in November 2022 using the following keywords: lung transplantation, waiting, management, recipient, and Japan. Peer-reviewed academic journal articles published in English were also included. KEY CONTENT AND FINDINGS: A growing number of studies have evaluated the management of pre-transplant patients. This includes infection control, vaccination, respiratory disease-specific treatment, malignancy, nutrition, rehabilitation, psychosocial assessment, and health-related quality of life (HRQOL) for patients on the waitlist. Each is important, and various evaluation methods and strategies to improve outcomes have been reported. CONCLUSIONS: Proper and multifaceted management of pretransplant patients is extremely important to reduce the mortality of candidates for lung transplantation. Integrated management is crucial to the success and survival of lung transplant recipients.

Antibody-mediated rejection (AMR) is a risk factor for chronic lung allograft dysfunction, which impedes long-term survival after lung transplantation. There are no reports evaluating the efficacy of the single use of anti-CD20 antibodies (aCD20s) in addition to calcineurin inhibitors in preventing AMR. Thus, this study aimed to evaluate the efficacy of aCD20 treatment in a murine orthotopic lung transplantation model. Murine left lung transplantation was performed using a major alloantigen strain mismatch model (BALBc (H-2d) → C57BL/6 (BL/6) (H-2b)). There were four groups: isograft (BL/6→BL/6) (Iso control), no-medication (Allo control), cyclosporine A (CyA) treated, and CyA plus murine aCD20 (CyA+aCD20) treated groups. Severe neutrophil capillaritis, arteritis, and positive lung C4d staining were observed in the allograft model and CyA-only-treated groups. These findings were significantly improved in the CyA+aCD20 group compared with those in the Allo control and CyA groups. The B cell population in the spleen, lymph node, and graft lung as well as the levels of serum donor-specific IgM and interferon γ were significantly lower in the CyA+aCD20 group than in the CyA group. Calcineurin inhibitor-mediated immunosuppression combined with aCD20 therapy effectively suppressed AMR in lung transplantation by reducing donor-specific antibodies and complement activation.

PURPOSE: To clarify the impact of donor and recipient characteristics on the survival of recipients before and after lung transplantation in the Japanese population. METHODS: Patients' data were collected for retrospective analysis from all authorized lung transplant centers in Japan. We included 1963 patients listed for lung transplantation by the end of December 2021, comprised of 658 deceased-donor and 270 living-donor lung transplants. RESULTS: Primary disease had a significant impact on the mortality of patients waiting for transplantation. The indications for transplant significantly affected the post-transplant survival rate of deceased-donor lung transplant recipients. The recipient's age also significantly affected the post-transplant survival rate of the deceased-donor and living-donor lung transplant recipients. The recipients of grafts transplanted from donors aged 61 years or older showed a worse post-transplant survival rate (≧60 years old). The survival rate for the combination of a female donor to a male recipient among the deceased-donor lung transplant recipients was the worst among the four combinations. CONCLUSION: The donor and recipient characteristics significantly impacted the survival of recipients after lung transplantation. The underlying mechanism of the negative impact of the gender mismatch of female donor to male recipient on post-transplant survival needs to be investigated further.

BACKGROUND AND OBJECTIVES: Anaplastic lymphoma kinase (ALK) rearrangement is a representative driver mutation in lung cancer. However, the biology of early-stage ALK-rearranged lung cancer remains unclear. We aimed to assess the clinicopathological features, prognostic implications, and influence of ALK rearrangement on the postoperative course in surgically resected lung cancer. METHODS: We retrospectively analyzed data from the Japanese Joint Committee of Lung Cancer Registry database. Of the 12 730 patients with lung adenocarcinoma, 794 (6.2%) were tested for ALK rearrangement and were included. RESULTS: ALK rearrangements were detected in 76 patients (10%). The 5-year overall survival (OS) rate was significantly higher in the ALK rearrangement-positive group than in the ALK rearrangement-negative group (p = 0.030). Multivariable analysis revealed that ALK rearrangement was an independent prognostic factor for improved OS (hazard ratio, 0.521; 95% confidence interval, 0.298-0.911; p = 0.022). Regarding the postrecurrence state, there was no difference in the initial recurrence sites between both groups. Administration of ALK-tyrosine kinase inhibitors (TKIs) improved postrecurrence survival in any treatment lines. CONCLUSION: In one of the largest national surveys, ALK rearrangement was associated with improved long-term outcomes in surgically resected patients. ALK-TKIs may be an important treatment strategy for ALK rearrangement-positive lung adenocarcinoma in the postrecurrence state.

PURPOSE: Coccidioidomycosis, caused by the Coccidioides species, is a well-known disease in the Southwestern United States and North Mexico, with scattered reports in Latin America countries. While this disease is still rare in Japan and other Asian countries, its incidence has been increasing over the last two decades. Coccidioides species are highly infectious and require caution when encountered. This study presents a case series of chronic pulmonary coccidioidomycosis surgically treated at a single institution. METHODS: We conducted a retrospective chart review of six patients who underwent lung resection for pulmonary coccidioidomycosis at Chiba University Hospital between January 2007 and December 2021. RESULTS: All six patients had travelled to the Southwestern United States. Preoperative serology was negative for the anti-Coccidioides antibody in four patients and positive in two. Chest computed tomography revealed a single, well-defined round nodule in all patients. Preoperative biopsy taken from three patients failed to obtain a definitive diagnosis. Histopathological examination of the resected pulmonary nodules revealed granulomas that contained numerous spherules with many endospores, thereby confirming the diagnosis of pulmonary coccidioidomycosis. CONCLUSIONS: Pulmonary coccidioidomycosis should be suspected based on travel history and radiological findings. Meticulous care should be taken during specimen processing to prevent cross infection.

Bronchopleural fistulas are rare complications of bevacizumab treatment. Herein, we report a case of bronchopleural fistula after bevacizumab therapy. The patient was a 65-year-old man with lung cancer who underwent a right lower lobectomy with systemic lymph node dissection after induction chemotherapy with bevacizumab. Pathological examination revealed no residual tumor cells in the resected specimen. The patient presented with severe dyspnea on postoperative day 26. Bronchoscopy revealed a bronchopleural fistula in the membranous portion of the right intermediate bronchus; the bronchial stump remained intact. The bronchopleural fistula was repaired with muscle flaps, and bronchoscopy 9 months after surgery showed satisfactory healing of the fistula. The patient has been alive for 5 years without evidence of recurrence. Careful attention must be paid to postoperative management when bevacizumab is used for induction therapy.

BACKGROUND: Robot-assisted thoracic surgery (RATS) has become widely used for mediastinal procedures since 2018 when it was included in insurance coverage in Japan. Few studies have compared the surgical outcomes of RATS with the more established video-assisted thoracic surgery (VATS) approach to mediastinal surgery. We aimed to compare the perioperative outcomes of VATS and RATS to examine the advantages of the RATS approach in a single institutional cohort. METHODS: A total of 144 patients who underwent VATS and 46 who underwent RATS mediastinal surgery between 2014 and 2022 were enrolled. We compared clinicopathological features such as age, sex, smoking history, respiratory function, surgical field, laterality, surgical procedure, board certification of the surgeon, and histology between the two groups. Perioperative outcomes including operation time, volume of blood lost, number of conversion cases to open surgery, duration of chest drainage, postoperative hospital stay, and postoperative complications were also reviewed. RESULTS: The comparison of patient characteristics between the groups showed significant differences in median age (VATS, 52.5 years; RATS, 67.0 years; P=0.001), combined resection of surrounding tissues of the tumor (VATS, 2.1%; RATS, 10.9%; P=0.02), board certification of the surgeon (VATS, 53.5%; RATS, 100.0%; P<0.001), and histology (RATS group had a higher percentage of thymic epithelial tumors, P=0.01). Regarding perioperative outcomes, the median operation time was 120 min in the VATS group and 88 min in the RATS group, showing a significant difference (P=0.03). There were no significant differences in the volume of blood lost, incidence of conversion to open chest surgery, duration of chest drainage, postoperative length of stay in hospital, and incidence of perioperative complications. In the perioperative outcomes of cases operated on by board-certified surgeons, the median operation time (VATS, 117 min; RATS, 88 min; P=0.02) and median postoperative length of stay in hospital (VATS, 7 days; RATS, 6 days; P=0.001) showed significant differences, while other postoperative outcomes were not significantly different. CONCLUSIONS: RATS for mediastinal surgery is as safe as the VATS approach and may result in a shorter operative time and postoperative hospital stay. Further analysis of RATS for mediastinal surgery in a larger cohort is warranted.

PURPOSES: Secondary spontaneous pneumothorax (SSP) is occasionally observed in elderly patients suffering from diffuse lung diseases. The purpose of this study was to analyze the outcomes of surgical treatment of SSP patients with chronic lung diseases. METHODS: In total, 242 patients who underwent surgery for spontaneous pneumothorax at Chiba University Hospital from January 2006 to October 2016 were included in this study. The patients' records were reviewed retrospectively for data on their background, surgical treatment, morbidity, mortality, and recurrence. RESULTS: Of the spontaneous pneumothorax cohort, primary spontaneous pneumothorax (PSP) accounted for 144 patients. Among the 98 patients with SSP, 57 cases were caused by chronic obstructive pulmonary disease (COPD) and 21 were caused by interstitial pneumonia (IP). The postoperative complication rate was 19.3% in the COPD group, 42.9% in the IP group, and 11.1% in the PSP group. The recurrence rate was 5.3% in the COPD group, 28.6% in the IP group, and 21.5% in the PSP group. CONCLUSIONS: The morbidity and recurrence were comparable between PSP and SSP cases with COPD, whereas these values were unfavorable in SSP cases with IP compared with PSP ones. Surgical intervention should be carefully considered in SSP patients with IP.

PURPOSE: The impact of the modified frailty index (mFI) on postoperative complications after lung cancer surgery was investigated. METHODS: Patients who underwent lung cancer surgery in 2017 were included. 30-day postoperative mortality and morbidity were evaluated according to their Clavien-Dindo classification. mFI values are presented as the sum of values of 11 included items. Logistic regression was used to assess the effect of mFI on postoperative severe complication incidence. RESULTS: Among 190 patients considered, severe postoperative complications (Grade 3 or more) were observed in 30 (16%). No patients died within 30 days of surgery. The incidence of severe complications was 3.6% in patients with mFI of 0, 16.2% in patients with mFI of 1, 23.4% in patients with mFI of 2, and 31.6% in patients with mFI of 3 or more, and was correlated with the grade of mFI. Univariate and multivariate analyses showed that the high mFI was significantly predictive of postoperative complications. Frail patients of mFI ≥ 2 were at 3.0-fold greater risk of severe complications than non-frail patients of mFI 0 or 1. CONCLUSION: mFI was associated with morbidity after lung cancer surgery. Preoperative frailty assessment and appropriate intervention to frail patients would be required to improve postoperative outcomes.

In Japan, robot-assisted thoracic surgery (RATS) was introduced in thoracic surgery in 2001, but it did not become widespread. However, surgery for mediastinal tumors and lobectomy for lung cancer with RATS were covered by insurance in 2018 and are currently becoming popular as a general practice, following video-assisted thoracic surgery(VATS). Forty-six patients with mediastinal tumors were treated by RATS from February 2014 to November 2022 in our institution. Theoretically, the RATS approach is performed from one side in a semi-supine position under CO2 insufflation as with the VATS approach of our institution. In the case of extended thymectomy, a bilateral approach is performed by changing the patient's position. The median surgery time was 88 min, and the median surgery time in unilateral and bilateral approaches were 79 and 208 min, respectively. Blood loss during surgery was quite minimum, and no patients required conversion to VATS or thoracotomy. Regarding adverse events, postoperative bleeding was observed in one patient (2.2%). RATS has been successfully introduced and expanded safely for mediastinal tumors. Considering further expansion of RATS indications while conducting verification by comparison with VATS in the future is necessary.

PURPOSE: Preoperative investigations to detect invasion to neighboring organs are important for deciding on the most appropriate surgical approach for thymoma. We evaluated preoperative computed tomography (CT) findings in thymoma patients to identify the CT features associated with tumor invasion. METHODS: Clinicopathologic information on 193 patients who underwent surgical resection for thymoma at Chiba University Hospital between 2002 and 2016 was collected retrospectively. The surgical pathology identified invasion of thymoma in 35 patients: in the lung (n = 18), pericardium (n = 11), or both (n = 6). Contact lengths between the tumor contour and lung (CLTL) or pericardium (CLTP) were measured at the maximum section of the tumor on axial CT. Univariate and multivariate analyses were performed to analyze the relationship between pathological invasion of the lung or pericardium and the clinicopathologic features. RESULTS: The mean CLTL and CLTP were significantly longer in patients with invasion of the neighboring organs than in those without invasion. A lobulated tumor contour was identified in 95.6% of the patients with invasion of the neighboring organs. A multivariate analysis revealed that a lobulated tumor contour was significantly associated with both lung and pericardial invasion. CONCLUSIONS: A lobulated tumor contour was significantly associated with lung and/or pericardial invasion in thymoma patients.

Pleural empyema often requires surgical intervention; however, surgical invasiveness should be minimized. We utilized the modified Claget procedure as an alternative to thoracoplasty for acute pleural empyema with a dead space. The procedure was performed as follows: first, 500 mg of kanamycin and 500,000 units of polymyxin sulfate dissolved in 10-100 ml saline was instilled intrapleurally via tube thoracostomy. The chest tube was clamped overnight and then removed. The modified Clagett procedure might be effective for acute pleural empyema with a dead space without pulmonary or bronchopleural fistula. We report our successful experience of performing modified Clagett procedure for pleural empyema with a dead space, through a detailed case presentation.

PURPOSE: Latent lymph node metastasis is a clinical concern in the surgical treatment of non-small cell lung cancer (NSCLC). The present study identified a simple tool, including the volume-doubling time (VDT), for evaluating the risk of nodal metastasis. METHODS: We reviewed, retrospectively, 560 patients who underwent radical resection for cN0M0 NSCLC. The whole tumor VDT and solid component VDT (SVDT) for differentiating the histological type and adenocarcinoma subtype were analyzed and a nomogram was constructed using variables selected through a stepwise selection method. The model was assessed through a calibration curve and decision curve analysis (DCA). RESULTS: Lymph node metastases were detected in 89 patients (15.9%). The SVDT tended to be longer in patients with adenocarcinoma (294.5 days, p < 0.0001) than in those with other histological types of NSCLC, but was shorter when the solid/micropapillary component was predominant (127.0 days, p < 0.0001). The selected variables (tumor location, solid component diameter, consolidation tumor ratio, SVDT, and carcinoembryonic antigen) demonstrated significant differences and were used for the nomogram. The calibration curve indicated consistency, and the DCA showed validity across most threshold ranges from 0 to 68%. CONCLUSIONS: The established nomogram is a useful tool for the preoperative prediction of lymph node metastasis, and the SVDT was the most influential factor in the nomogram.

PURPOSE: Recent reports suggest that postoperative cerebral infarction following lung cancer surgery is caused by thrombus formation at the stump of the pulmonary vein and that the risk is highest after left upper lobectomy (LUL). Thrombosis at the stump of the pulmonary vein and the incidence of cerebral infarction was investigated prospectively in patients who underwent lobectomy for lung cancer. METHODS: Lung cancer patients undergoing planned pulmonary lobectomy were enrolled. The endpoint was to confirm if there is a higher incidence of thrombus formation (primary) and a higher incidence of cerebral infarction (secondary) in patients undergoing LUL. We planned to accrue 600 patients. An interim analysis was scheduled for just after the data center received the final clinical review form of the 300th patient. RESULTS: The interim analysis revealed a significant difference in the primary endpoint. In the final analysis, thrombus was identified in 16 of 88 LUL patients (20.5%), and in 4 of 247 patients who underwent other types of lobectomy (1.6%) (p < 0.05). Cerebral infarction was identified in 1 of the LUL patients (1.3%) and in 9 of the other patients (3.6%) (p = 0.318). CONCLUSIONS: Thrombus frequently forms at the stump of the left superior pulmonary vein after LUL. However, our study did not identify a relationship between thrombosis and cerebral infarction.

BACKGROUND: In the surgical treatment of chest wall tumors requiring large chest wall resection, reconstruction of the chest wall defect is required using various autologous tissues or artificial materials. However, no appropriate method has been reported to evaluate whether each reconstruction is successful or not. Therefore, we performed lung volumetry before and after surgery to evaluate the negative effects of chest wall surgery on lung expansion. METHODS: Twenty-three patients with chest wall tumors who underwent surgery were included in this study. Lung volume (LV) before and after surgery was measured using SYNAPSE VINSENT (FUJIFILM, Tokyo, Japan). The rate of change in LV was calculated as the postoperative and preoperative LV of the operative side × preoperative/postoperative LV of the opposite side. The excised chest wall area was calculated as vertical diameter × horizontal diameter of the tissue specimen. RESULTS: Reconstruction methods included rigid reconstruction (a combination of titanium mesh and extended polytetrafluoroethylene sheet) in four patients, non-rigid reconstruction (extended polytetrafluoroethylene sheet only) in 11, no reconstruction in five, and no chest wall resection in three. Changes in LV were generally well preserved, regardless of the resected area. In addition, LVs were well maintained in most patients who underwent chest wall reconstruction. However, in some cases, decreased lung expansion was observed with migration and deflection of the reconstructive material into the thorax due to postoperative lung inflammation and shrinking. CONCLUSIONS: Lung volumetry can be used to evaluate the effectiveness of chest wall surgery.

Lung adenocarcinoma is classified morphologically into five histological subtypes according to the WHO classification. While each histological subtype correlates with a distinct prognosis, the molecular basis has not been fully elucidated. Here we conducted DNA methylation analysis of 30 lung adenocarcinoma cases annotated with the predominant histological subtypes and three normal lung cases using the Infinium BeadChip. Unsupervised hierarchical clustering analysis revealed three subgroups with different methylation levels: high-, intermediate-, and low-methylation epigenotypes (HME, IME, and LME). Micropapillary pattern (MPP)-predominant cases and those with MPP components were significantly enriched in HME (p = 0.02 and p = 0.03, respectively). HME cases showed a significantly poor prognosis for recurrence-free survival (p < 0.001) and overall survival (p = 0.006). We identified 365 HME marker genes specifically hypermethylated in HME cases with enrichment of "cell morphogenesis" related genes; 305 IME marker genes hypermethylated in HME and IME, but not in LME, with enrichment "embryonic organ morphogenesis"-related genes; 257 Common marker genes hypermethylated commonly in all cancer cases, with enrichment of "regionalization"-related genes. We extracted surrogate markers for each epigenotype and designed pyrosequencing primers for five HME markers (TCERG1L, CXCL12, FAM181B, HOXA11, GAD2), three IME markers (TBX18, ZNF154, NWD2) and three Common markers (SCT, GJD2, BARHL2). DNA methylation profiling using Infinium data was validated by pyrosequencing, and HME cases defined by pyrosequencing results also showed the worse recurrence-free survival. In conclusion, lung adenocarcinomas are stratified into subtypes with distinct DNA methylation levels, and the high-methylation subtype correlated with MPP-predominant cases and those with MPP components and showed a poor prognosis.