Dual-specificity tyrosine-regulated kinase 2 exerts anti-tumor effects by induction of G1 arrest in lung adenocarcinoma

OBJECTIVES

Lung cancer is a leading cause of cancer-related mortality and remains one of the most poorly prognosed disease worldwide. Therefore, it is necessary to identify novel molecular markers with potential therapeutic effects. Recent findings have suggested that dual-specificity tyrosine-regulated kinase 2 (DYRK2) plays a tumor suppressive role in colorectal, breast, and hepatic cancers; however, its effect and mechanism in lung cancer remain poorly understood. Therefore, this study aimed to investigate the tumor-suppressive role and molecular mechanism of DYRK2 in lung adenocarcinoma (LUAD) by in vitro experiments and xenograft models.

MATERIALS AND METHODS

The evaluation of DYRK2 expression was carried out using lung cancer cell lines and normal bronchial epithelial cells. Overexpression of DYRK2 was induced by an adenovirus vector, and cell proliferation was assessed through MTS assay and Colony Formation Assay. Cell cycle analysis was performed using flow cytometry. Additionally, proliferative capacity was evaluated in a xenograft model by subcutaneously implanting A549 cells into SCID mice (C·B17/Icr-scidjcl-scid/scid).

RESULTS

Immunoblotting assays showed that DYRK2 was downregulated in most LUAD cell lines. DYRK2 overexpression using adenovirus vectors significantly suppressed cell proliferation compared with that in the control group. Additionally, DYRK2 overexpression suppressed tumor growth in a murine subcutaneous xenograft model. Mechanistically, DYRK2 overexpression inhibited the proliferation of LUAD cells via p21-mediated G1 arrest, which was contingent on p53.

CONCLUSION

Taken together, these findings suggest that DYRK2 may serve as potential prognostic biomarker and therapeutic target for LUAD.

Mitigation of acute lung injury by human bronchial epithelial cell-derived extracellular vesicles via ANXA1-mediated FPR signaling

Acute lung injury (ALI) is characterized by respiratory failure resulting from the disruption of the epithelial and endothelial barriers as well as immune system. In this study, we evaluated the therapeutic potential of airway epithelial cell-derived extracellular vesicles (EVs) in maintaining lung homeostasis. We isolated human bronchial epithelial cell-derived EVs (HBEC-EVs), which endogenously express various immune-related surface markers and investigated their immunomodulatory potential in ALI. In ALI cellular models, HBEC-EVs demonstrated immunosuppressive effects by reducing the secretion of proinflammatory cytokines in both THP-1 macrophages and HBECs. Mechanistically, these effects were partially ascribed to nine of the top 10 miRNAs enriched in HBEC-EVs, governing toll-like receptor-NF-κB signaling pathways. Proteomic analysis revealed the presence of proteins in HBEC-EVs involved in WNT and NF-κB signaling pathways, pivotal in inflammation regulation. ANXA1, a constituent of HBEC-EVs, interacts with formyl peptide receptor (FPR)2, eliciting anti-inflammatory responses by suppressing NF-κB signaling in inflamed epithelium, including type II alveolar epithelial cells. In a mouse model of ALI, intratracheal administration of HBEC-EVs reduced lung injury, inflammatory cell infiltration, and cytokine levels. Collectively, these findings suggest the therapeutic potential of HBEC-EVs, through their miRNAs and ANXA1 cargo, in mitigating lung injury and inflammation in ALI patients.

Clinical outcomes of left upper segmentectomy vs. lobectomy for early non-small-cell lung cancer: a nationwide database study in Japan

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.

Compensatory expansion of the right middle lobe: volumetric and functional analysis of the changes after right upper or lower lobectomy

The right middle lobe often poorly expands after right upper lobectomy. Postoperative pulmonary function may be inferior after right upper lobectomy than after right lower lobectomy due to poor expansion of the middle lobe. This study examined the difference in the postoperative right middle lobe expansion and pulmonary function between right upper and right lower lobectomy. Patients who underwent right upper or right lower lobectomy through video-assisted thoracic surgery (n = 82) were enrolled in this retrospective study. Pulmonary function tests and computed tomography were performed preoperatively and at 1 year postoperatively. Using three-dimensional computed tomography volumetry, the preoperative and postoperative lung volumes were measured, and the predicted postoperative forced expiratory volume in 1 s was calculated. Middle lobe volume ratio (i.e., ratio of the postoperative to the preoperative middle lobe volume) and the postoperative forced expiratory volume in 1 s ratio (i.e., ratio of the measured to the predicted postoperative forced expiratory volume in 1 s) were compared between right upper and right lower lobectomy. Compared with the patients who underwent right upper lobectomy (n = 50), those who underwent right lower lobectomy (n = 32) had significantly higher middle lobe volume ratio (1.15 ± 0.32 vs. 1.63 ± 0.52, p < 0.001) and postoperative forced expiratory volume in 1 s ratio (1.12 ± 0.12 vs. 1.19 ± 0.13, p = 0.010). The right middle lobe showed more expansion and better recovery of postoperative pulmonary function after right lower lobectomy than after right upper lobectomy.

Reduction in drain-related adverse events using the barbed suture method for chest tube wound closure

OBJECTIVE

A chest tube is usually placed in patients undergoing general thoracic surgery. Although the barbed suture method has been introduced for chest tube wound closure, its superiority to the conventional suture methods for drain management remains unclear. The study aimed to determine whether the barbed suture method could reduce drain-related adverse events compared to the conventional method.

METHODS

We retrospectively reviewed the medical records of patients who underwent general thoracic surgery between January 2021 and December 2022, 1 year before and after the introduction of the barbed suture method at our institution. Patients who underwent the barbed suture or conventional method were included. Univariate and multivariate analyses of drain-related adverse events were performed.

RESULTS

Of the 250 participants, 110 and 140 underwent the barbed suture method and conventional suture method, respectively. The univariate analysis showed that a higher body mass index, preoperative malignant diagnosis, lobectomy, longer operative time, larger tube size, longer chest drainage duration, surgical complications, and conventional method were risk factors for drain-related adverse events. The multivariate analysis showed that the barbed suture method was a protective factor against drain-related adverse events (odds ratio 0.267; 95% confidence interval 0.103-0.691; P = 0.007).

CONCLUSIONS

The barbed suture method could reduce drain-related adverse events compared to the conventional method. Therefore, it might be a potential standard method for chest tube wound closure in patients undergoing general thoracic surgery.

Weight loss of 5% or more after lobectomy for lung cancer via minimally invasive approaches is associated with poor prognosis

INTRODUCTION

We analyzed the association between postoperative weight loss (WL), preoperative body mass index (BMI), and prognosis in patients with lung cancer who underwent lobectomy using minimally invasive approaches.

METHODS

Weight change in 325 patients who underwent radical lobectomy for non-small cell lung cancer was assessed at 3, 6, and 12 months postoperatively and compared to preoperative weight. Patients were divided into three groups according to their preoperative BMI interquartile range: low BMI ≤20.3 kg/m2 , middle BMI 20.4-24.4 kg/m2 , and high BMI ≥24.5 kg/m2 . Postoperative WL ≥5% was evaluated with reference to frailty.

RESULTS

There were no significant differences in pathological findings, postoperative complications, or postoperative hospital stay among the three groups. Thirty all-cause deaths and 39 cancer recurrences occurred. Within the first year after surgery, WL of any grade was observed in 229 patients (70.5%) and WL ≥5% in 86 patients (26.5%). Postoperative WL of any grade within 1 year after surgery was not associated with OS and RFS (both p > .05). However, WL ≥5% within 1 year after surgery was associated with worse OS and RFS (p = .007 and .006, respectively). WL ≥5% within 1 year after surgery was more common in the low BMI group (p = .045). There was no difference in OS and RFS among the BMI groups in patients with WL ≥5% and those without WL ≥5% (all p > .05).

CONCLUSION

WL ≥5% was associated with poor prognosis after lobectomy via minimally invasive approaches. Weighing is a useful prognostic marker that can be easily self-checked.

Benefit of Adjuvant Chemotherapy for Patients Older Than 75 Years With Completely Resected p-Stage II-IIIA Non-Small-Cell Lung Cancer: A Retrospective Cohort Study Using Japanese Nationwide Real-World Data

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.

Prognostic Impact of Visceral Pleural Invasion in Resected Solitary Lung Metastases from Gastric Cancer

PURPOSE

Pulmonary resection of metastases from gastric cancer is extremely rare because gastric cancer metastasis to the lungs or thoracic cavity occurs as multiple pulmonary metastases, carcinomatous lymphangitis, or carcinomatous pleurisy. Therefore, the significance of surgery for pulmonary metastasis of gastric cancer remains unclear. This study aimed to investigate the surgical outcomes and prognostic factors for survival after the resection of pulmonary metastases from gastric cancer.

METHODS

From 2007 to 2019, 13 patients with pulmonary metastasis of gastric cancer underwent metastasectomy. Surgical outcomes were analyzed to determine the prognostic factors for recurrence and overall survival (OS).

RESULTS

All the patients underwent pulmonary resection for solitary metastases. At the median follow-up time of 45.6 months (range, 4.8-106.8 months), five patients experienced a recurrence of gastric cancer after metastasectomy. The 5-year recurrence-free survival rate was 44.4%, and the 5-year OS rate after pulmonary resection was 45.3%. Univariate analysis revealed that visceral pleural invasion (VPI) was an unfavorable prognostic factor for both recurrence-free and OS.

CONCLUSION

Pulmonary resection of solitary metastases from gastric cancer may be an effective therapeutic option to improve survival. VPI in gastric cancer metastasis is a negative prognostic factor.

Is adjuvant chemotherapy for completely resected p-stage IA (>2 cm) and stage IB non-small-cell lung cancer beneficial for elderly patients? A large, retrospective cohort study based on real-world data from Japan

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.

Comparative study of local versus general anesthesia in video-assisted thoracoscopic surgery for empyema

OBJECTIVE

This study evaluated the feasibility of performing non-intubated video-assisted thoracoscopic surgery (VATS) with local anesthesia for parapneumonic effusion and empyema resistant to conservative treatment.

METHODS

We retrospectively reviewed 80 patients who underwent surgery for parapneumonic effusions and empyema between 2015 and 2021. Patients were divided into those who received non-intubated local anesthesia and general anesthesia during surgery. Patient demographics, characteristics, laboratory findings, treatment progress, and treatment outcomes were compared. The primary outcomes were duration of postoperative drainage, postoperative complication rate, and postoperative mortality rate within 30 days.

RESULTS

Among patients who received local (n = 21) and general anesthesia (n = 59), there was a significant difference in age (median 79.0 years [interquartile range (IQR) 77.0-80.0] vs. 68.0 years [IQR 54.5-77.5]; p < 0.001), preoperative performance status (3.0 [IQR 2.0-4.0] vs. 2.0 [IQR 1.0-3.0]; p < 0.001), and operative time (69 min [IQR 50-128] vs. 150 min [IQR 107-198]; p < 0.001) but not in preoperative white blood cell count (12,100/μL [IQR 8,400-18000] vs. 12,220/μL [IQR 8,950-16,724]; p = 0.840), C-reactive protein (15.2 mg/dL [8.8-21.3] vs. 17.9 mg/dL [IQR 9.5-23.6]; p = 0.623), postoperative drainage period (11 days [IQR 7-14] vs. 9 days [7-13]; p = 0.216), postoperative hospital stay (22 days [IQR 16-53] vs. 18 days [IQR 12-26]; p = 0.094), reoperation rate (9.5% vs. 15.3%; p = 0.775), postoperative complication rate (19.0% vs. 18.6%; p = 0.132), or postoperative 30-day mortality rate (4.8% vs. 0%; p = 0.587).

CONCLUSIONS

VATS using local anesthesia is feasible for patients with treatment-resistant parapneumonic effusion and empyema with poor general condition.

Features of anaplastic lymphoma kinase rearrangement in early-stage lung cancer: Analysis of a nationwide Japanese database

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.

[Management of Postoperative Surgical Site Infection and Empyema After Thoracic Surgery]

Surgical site infections (SSI)[wound infection, empyema] after thoracic surgery can lead to severe complications. Targeted antibiotic treatment and drainage are the keys. For the treatment of postoperative empyema without bronchopleural fistula, chest tube thoracostomy and irrigation with normal saline is effective. For postoperative empyema with bronchopleural fistula, open window thoracotomy is a good treatment option. Since the condition of empyema is different in each patient, treatment should be individualized depending on the patient's condition.

Risk factors for the recurrence of primary spontaneous pneumothorax after video-assisted thoracoscopic surgery in patients younger than 40 years

BACKGROUND

Video-assisted thoracoscopic surgery (VATS) is a standard primary spontaneous pneumothorax (PSP) procedure. However, its high recurrence rate compared to open thoracotomy is a problem. Therefore, various methods to prevent recurrence have been developed. The present study investigated the risk factors for postoperative recurrence of PSP after VATS.

METHODS

From January 2008 to November 2022, 207 patients younger than 40 years of age without underlying pulmonary disease underwent thoracoscopic bullectomy for PSP. Among them, 96 underwent staple line reinforcement with a polyglycolic acid (PGA) sheet and autologous blood spraying. Patient characteristics and surgical outcomes were analyzed to determine the prognostic factors for postoperative recurrence.

RESULTS

Twenty-seven patients (13.0%) experienced recurrences. A multivariate analysis using Cox regression analysis revealed that age younger than 20 years [P=0.039; hazard ratio (HR) =2.337; 95% confidence interval (CI): 3.283-17.287], history of contralateral pneumothorax (P<0.001; HR =7.533; 95% CI, 1.486-12.336), and no staple line reinforcement (P=0.007; HR =4.282; 95% CI, 1.043-5.236) were risk factors for recurrence after pneumothorax surgery.

CONCLUSIONS

Age younger than 20 years and history of contralateral pneumothorax were risk factors for postoperative recurrence of pneumothorax. Staple line reinforcement with a PGA sheet and spraying of autologous blood reduced the postoperative recurrence rate of PSP.

Fibroblast-derived Extracellular Vesicles Induce Lung Cancer Progression in the Idiopathic Pulmonary Fibrosis Microenvironment

Idiopathic pulmonary fibrosis (IPF) is a progressive aging-related lung disease associated with increased lung cancer risk. Although previous studies have shown that IPF worsens the survival of patients with lung cancer, whether IPF independently affects cancer malignancy and prognosis remains inconclusive. Extracellular vesicles (EVs) have recently emerged as active carriers of molecular biomarkers and mediators of intercellular communication in lung homeostasis and pathogenesis. EV cargo-mediated fibroblast-tumor cell communication might participate in the development and progression of lung cancer by modulating various signaling pathways. In this study, we examined the impact of lung fibroblast (LF)-derived EVs on non-small cell lung cancer (NSCLC) malignancy in the IPF microenvironment. Here, we showed that LFs derived from patients with IPF have phenotypes of myofibroblast differentiation and cellular senescence. Furthermore, we found that IPF LF-derived EVs have markedly altered microRNA compositions and exert proproliferative functions on NSCLC cells. Mechanistically, the phenotype was attributed mainly to the enrichment of miR-19a in IPF LF-derived EVs. As a downstream signaling pathway, mir-19a in IPF LF-derived EVs regulates ZMYND11-mediated c-Myc activation in NSCLC, potentially contributing to the poor prognosis of patients with NSCLC with IPF. Our discoveries provide novel mechanistic insights for understanding lung cancer progression in the IPF microenvironment. Accordingly, blocking the secretion of IPF LF-derived EV miR-19a and their signaling pathways is a potential therapeutic strategy for managing IPF and lung cancer progression.

Pulmonary metastases of a borderline ovarian tumor with multiple cystic formations: a case report

BACKGROUND

Metastatic lung tumors rarely present with cystic formations. This is the first report of multiple cystic formations in pulmonary metastases from mucinous borderline ovarian tumors written in English.

CASE PRESENTATION

A 41-year-old woman underwent left adnexectomy + partial omentectomy + para-aortic lymphadenectomy for a left ovarian tumor 4 years ago. The pathological finding was mucinous borderline ovarian tumor with a microinvasion. A chest computed tomography performed 3 years after surgery revealed multiple cystic lesions in both lungs. After 1-year follow-up, the cysts increased in size and wall thickness. Subsequently, she was referred to our department with multiple cystic lesions in both lungs. No laboratory findings indicated infectious diseases or autoimmune disorders that could cause cystic lesions in both lungs. Positron emission tomography showed slight accumulation in the cyst wall. Partial resection of the left lower lobe was performed to confirm the pathological diagnosis. The diagnosis was consistent with pulmonary metastases from a previous mucinous borderline ovarian tumor.

CONCLUSIONS

This is a rare case of lung metastases from a mucinous borderline ovarian tumor presenting with multiple lesions with cystic formation. Pulmonary cystic formations in patients with a borderline ovarian tumor should be considered as possible pulmonary metastases.

Postoperative surveillance using low-dose computed tomography for non-small-cell lung cancer

OBJECTIVES

We retrospectively analysed the surgical prognosis of patients with pathological stage I non-small-cell lung cancer (NSCLC) who after complete resection underwent low-dose computed tomography (LDCT) or conventional CT as postoperative surveillance.

METHODS

We investigated 416 patients who underwent lobectomy or segmentectomy between January 2013 and December 2016. We compared the prognosis between the LDCT and conventional CT groups using the propensity score-matched analysis.

RESULTS

The median follow-up period was 57 months. Cancer recurrence occurred in 47 patients (11.3%). In the entire cohort (n = 416), recurrence-free survival (RFS) and overall survival (OS) were better in the LDCT group (P = 0.001 and 0.002, respectively). Both intrathoracic recurrence and distant metastasis were higher in the conventional group (P = 0.015 and 0.009, respectively). However, there was no statistical difference in the factors leading to recurrence detection (routine radiological examination, symptoms and elevated tumour markers: all P > 0.05). Both groups were matched using a ratio of 1:1. The area under the receiver operating characteristic curve was 0.788. A total of 226 patients were successfully matched. After matching, there was no statistical difference between the 2 groups for RFS and OS (P = 0.263 and 0.226). There were also no statistical differences in recurrence rate, the factors leading to recurrence detection or recurrence site (all P > 0.05).

CONCLUSIONS

After using propensity score matched, RFS and OS did not differ significantly between LDCT and conventional CT groups. Retrospective comparisons suggest no disadvantages of using LDCT for postoperative surveillance of pathological stage I NSCLC. Further validation will be needed in the future.

Analysis of postoperative weight loss associated with prognosis after lobectomy for lung cancer

OBJECTIVES

Weight assessment is an easy-to-understand method of health checkup. The present study investigated the association between weight loss (WL) after lung cancer surgery and short-mid-term prognosis.

METHODS

The data of patients who underwent radical lobectomy for primary lung cancer were assessed between December 2017 and June 2021. Percentage weight gain or loss was determined at 3, 6 and 12 months postoperatively based on preoperative weight. The timing of decreased weight was divided into 0-3, 3-6 and 6-12 months. We also evaluated the relationship between severe WL (SWL) and prognosis.

RESULTS

We reviewed 269 patients, of whom 187 (69.5%) showed WL within 1 year after surgery. The interquartile range for maximal WL was 2.0-8.2% (median 4.0%). Further, we defined SWL as WL ≥ 8%. Twenty-five patients (9.3%) died: 9 from primary lung cancer (LC) and 16 from non-LC causes. Cancer recurrences occurred in 45 patients (16.7%). WL occurred from 6 to 12 months postoperatively was associated with poor overall survival (OS) and recurrence-free survival (RFS) (p < 0.05, both). Body mass index <18.5 kg/m2 and idiopathic pulmonary fibrosis were predictive factors (p < 0.05, all). In the SWL group, OS, RFS and non-cancer-specific were worse (p = 0.001, 0.005 and 0.019, respectively). Age ≥70 years and severe postoperative complications were predictive factors for SWL (p < 0.05, all).

CONCLUSIONS

WL from 6 to 12 months postoperatively and SWL were associated with poor prognosis. Ongoing nutritional management is important to prevent life-threatening WL in patients with predictive factors.

Effect of resected lung lobe on the prediction of postoperative pulmonary function

OBJECTIVES

This study examined whether a resected lung lobe can affect the accuracy of postoperative forced expiratory volume in 1 second (FEV1) predicted using the subsegment counting method and three-dimensional computed tomography (3D-CT) volumetry.

METHODS

Overall, 125 patients who underwent lobectomy through video-assisted thoracic surgery (VATS) were enrolled in this retrospective study. Pulmonary function tests (PFTs) were performed preoperatively and postoperatively at 3 months. We defined the accuracy index as the ratio of predicted postoperative FEV1 to measured postoperative FEV1 and compared the accuracy index of the subsegment counting method and 3D-CT volumetry. Factors affecting the accuracy index were also examined.

RESULTS

The accuracy index of the subsegment counting method was 0.94 ± 0.12, versus 0.93 ± 0.11 for 3D-CT volumetry (p = 0.539). There was a significant difference among the resected lobes in the accuracy index of the subsegment counting method (p < 0.001) but not in that of 3D-CT volumetry (p = 0.370). The resected lobe, the number of staples used for interlobar dissection, and interstitial pneumonia (IP) were significantly associated with the accuracy index of the subsegment counting method (all p < 0.001). The number of staples and IP were significantly associated with the accuracy index of 3D-CT volumetry (p < 0.001, respectively), whereas the resected lobe was not a significant factor (p = 0.240).

CONCLUSIONS

The resected lobe affected the accuracy of the subsegment counting method but not that of 3D-CT volumetry. Further, 3D-CT volumetry predicted postoperative FEV1 independent of the resected lobe.

CLINICAL REGISTRATION NUMBER

This study was approved by the ethics committee of Jikei University School of Medicine [approval number: 33-259 (10877)].

Esophagobronchial fistula successfully managed with a self-expandable metallic stent followed by fixation using a silicon Y stent

Esophagobronchial fistula (EBF) formation is a severe complication of advanced thoracic malignancies, that affects the prognosis and quality of life of patients. This study reports the case of an 80‐year‐old man with advanced esophageal cancer, complicated by EBF formation in the left main bronchus proximal to the carina following chemoradiation therapy. A fully covered stent was placed in the left main bronchus but was dislocated on the oral side. The attempt to place a partially covered self‐expandable metallic stent (SEMS) also failed due to stent dislocation on the oral side. To avoid stent dislocation, a partially covered SEMS with a length of 40 mm and a diameter of 16 mm was placed to cover the EBF in the left main bronchus. Then, a silicone Y stent (16 × 13 × 13 mm in outer diameter) was inserted to support the SEMS from the inside. After placing the SEMS and Y stent, the position of the SEMS was stabilized. The patient remained stable with adequate oral intake.

Efficacy of a combined tool for stage I non‑small cell lung cancer against lymph node metastasis

In patients with clinical stage I non-small cell lung cancer (NSCLC), the prediction of occult lymph node metastasis (LNM) based on a combination of morphology using high-resolution computed tomography (HRCT) and metabolism using positron emission tomography (PET)-CT is unknown. The present study evaluated the use of predictive radiological tools, chest CT and PET-CT, for occult LNM in patients with clinical stage I NSCLC. The records of patients who underwent lobectomy between July 2014 and November 2021 were retrospectively reviewed. The differences in clinicopathological parameters, including CT and PET, between the LNM and non-LNM groups were assessed. Pure solid tumor was defined as a consolidation-to-tumor ratio of 1. The optimal cut-off value for predictive radiological tools for LNM was assessed according to the area under the receiver operating characteristic (ROC) curve. The present study included 288 patients, of whom 39 (13.5%) had LNM; of these 38 (97.4%) were pure solid type. Larger consolidation size (CS), higher maximal standardized uptake (SUVmax) value and histological type were statistically associated with LNM (all P<0.05). The optimal cutoff values of CS and SUVmax for predicting LNM were 19 mm and 5.5 respectively, as assessed using the area under the ROC curve. The combination of CS ≥19 mm and SUVmax ≥5.5 demonstrated a markedly higher odds ratio (9.184; 95% CI, 4.345-19.407) than each parameter individually. The minimum values of CS and SUVmax associated with LNM were 10 mm and 0.8 respectively. Pure solid formation and CS as morphology and SUVmax as metabolism were useful tools that complemented each other in predicting LNM. The combined method of evaluating SUVmax and CS may identify eligibility for LN dissection. However, considering the minimum values of CS and SUVmax in LNM, it cannot affirm the omission of LN dissection for cases that do not meet the combined criteria using HRCT and PET-CT.

Limited resection for stage IA radiologically invasive lung cancer: a real-world nationwide database study

OBJECTIVES

Radiologically invasive non-small cell lung cancer, defined as consolidation size to maximum tumour diameter ratio of over 0.5, is associated with pathological invasiveness and worse prognosis. However, there are no real-world, nationwide database studies on limited resections that consider radiological invasiveness. This study aimed to investigate the prognostic validity of limited resection, such as segmentectomy and wedge resection, in cStage IA (TNM 8th edition) radiologically invasive lung cancer.

METHODS

We conducted a retrospective analysis of patients who underwent complete resection according to the Japanese Joint Committee of Lung Cancer Registry Database. The relationship between surgical procedures and prognosis was examined using stratification by cT factor and radiological invasiveness.

RESULTS

Among the 5,692 patients enrolled, lobectomy, segmentectomy, and wedge resection were performed in 4,323 (80.0%), 657 (11.5%), and 712 (12.5%) patients, respectively. Multivariable analysis with or without propensity score matching indicated that older age, poor performance status, and wedge resection were significantly associated with worse prognosis and that patients who underwent segmentectomy showed an equivalent prognosis to those who underwent lobectomy. Subset analyses revealed that segmentectomy showed an equivalent prognosis to lobectomy in patients with cT1b or less, but not in those with cT1c, especially for non-pure radiological invasive cT1c; 5-year overall survival rates were 91.4% vs 90.4% in cT1b with non-pure radiological invasiveness, and 80.0% vs 83.8% in cT1b with pure radiological invasiveness, respectively.

CONCLUSIONS

Segmentectomy can be an alternative to lobectomy in patients with radiologically invasive lung cancer with cT1b or less, but not in those with cT1c.

New evaluation of the tumor immune microenvironment of non-small cell lung cancer and its association with prognosis

BACKGROUND

A better understanding of the tumor immune microenvironment (TIME) will facilitate the development of prognostic biomarkers and more effective therapeutic strategies in patients with lung cancer. However, little has been reported on the comprehensive evaluation of complex interactions among cancer cells, immune cells, and local immunosuppressive elements in the TIME.

METHODS

Whole-exome sequencing and RNA sequencing were carried out on 113 lung cancers. We performed single sample gene set enrichment analysis on TIME-related gene sets to develop a new scoring system (TIME score), consisting of T-score (tumor proliferation), I-score (antitumor immunity) and S-score (immunosuppression). Lung cancers were classified according to a combination of high or low T-score, I-score, and S-scores (eight groups; G1-8). Clinical and genomic features, and immune landscape were investigated among eight groups. The external data sets of 990 lung cancers from The Cancer Genome Atlas and 76 melanomas treated with immune checkpoint inhibitors (ICI) were utilized to evaluate TIME scoring and explore prognostic and predictive accuracy.

RESULTS

The representative histological type including adenocarcinoma and squamous cell carcinoma, and driver mutations such as epidermal growth factor receptor and TP53 mutations were different according to the T-score. The numbers of somatic mutations and predicted neoantigens were higher in T^hi (G5-8) than T^lo (G1-4) tumors. Immune selection pressure against neoantigen expression occurred only in T^hi and was dampened in T^hi/I^lo (G5-6), possibly due to a reduced number of T cells with a high proportion of tumor specific but exhausted cells. T^hi/I^lo/S^hi (G5) displayed the lowest immune responses by additional immune suppressive mechanisms. The T-score, I-score and S-scores were independent prognostic factors, with survival curves well separated into eight groups with G5 displaying the worst overall survival, while the opposite group T^lo/I^hi/S^lo (G4) had the best prognosis. Several oncogenic signaling pathways influenced on T-score and I-scores but not S-score, and PI3K pathway alteration correlated with poor prognosis in accordance with higher T-score and lower I-score. Moreover, the TIME score predicted the efficacy of ICI in patients with melanoma.

CONCLUSION

The TIME score capturing complex interactions among tumor proliferation, antitumor immunity and immunosuppression could be useful for prognostic predictions or selection of treatment strategies in patients with lung cancer.

Intraoperative Multimodal Approach for Pain After Thoracoscopic Pulmonary Resection

BACKGROUND

The optimal preemptive analgesia for thoracoscopic surgery remains unclear. We evaluated the utility of intraoperative intravenous analgesia on postoperative pain and the postoperative course in patients who underwent thoracoscopic lobectomy.

METHODS

We retrospectively reviewed 228 consecutive patients who underwent single-lobe thoracoscopic lobectomy for malignant pulmonary tumors between October 2017 and December 2019. Instead of epidural anesthesia, intercostal nerve blocks were performed from the thoracic cavity. We assessed the differences in the clinical and perioperative parameters including postoperative pain among the following: (1) N group (nonintraoperative intravenous analgesia), (2) A group (1000 mg acetaminophen), and (3) AF group (1000 mg acetaminophen with 50 mg flurbiprofen axetil). The numerical rating scale (NRS) was used to assess pain.

RESULTS

Receiver operating characteristic curve analysis revealed that the optimal cutoff pain score for the additional analgesic within 12 h postsurgery was 3.5 (area under the curve = 0.771; sensitivity = 63%; specificity = 19.4%; 95% confidence interval [CI] = 0.703-0.839; p < 0.01). Less pain scores on the surgical day were related to the AF group (NRS; N, 3 ± 2.6; A, 3 ± 2.4; AF, 2 ± 1.9; p = 0.008, respectively). No pain or mild pain (NRS = 0-2) on the operative day was strongly associated with the AF group (N = 36.4%; A = 46.4%; AF = 70.5%; p = 0.005). None of the patients experienced complications associated with intraoperative intravenous analgesia.

CONCLUSION

The combined use of intravenous analgesics (acetaminophen and flurbiprofen axetil) and intercostal nerve blocks is a safe and feasible preemptive analgesic approach for thoracoscopic lobectomy.

A successful case of complete surgical resection via left upper and right lower lobectomy for bilateral lung metastases of a perivascular epithelioid cell tumor in the colon: a case report

Background

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal neoplasms with malignant potential. No effective treatment other than surgical resection has been established for lung metastases of PEComas. We describe a patient who underwent complete surgical resection via bilateral lobectomy involving a two-step procedure for lung metastases 8 years after undergoing radical surgery for a colonic PEComa.

Case presentation

A 53-year-old woman underwent partial colectomy for a PEComa in the transverse colon 8 years ago. She presented with an abnormal chest shadow during a health examination. Chest computed tomography (CT) revealed a solid nodule 2 cm in diameter located centrally in the right lower lobe and a solid nodule 3 cm in diameter located centrally in the left upper lobe. Positron emission tomography revealed 18F-fluorodeoxyglucose uptake in these nodules. These nodules were suspected to be metastatic tumors of the colonic PEComa and were considered for complete surgical resection. Segmentectomy could not be performed because of the anatomical location of the tumors straddling the segments; therefore, bilateral lobectomy was required for complete surgical resection. Therefore, we performed two-step lobectomy safely with the expectation of pulmonary function recovery. Microscopically, the tumors were diagnosed as lung metastases of the PEComa. One year after the last surgery, no recurrence was detected, and the patient’s pulmonary function improved.

Conclusions

This case indicates that even if multiple lung metastases of a PEComa require bilateral lobectomy, complete resection with a two-step surgery may be considered.

Prognostic Radiological Tools for Clinical Stage IA Pure Solid Lung Cancer

In this study, we analyzed prognostic radiological tools and surgical outcomes for radiologically pure solid adenocarcinomas (AD) and squamous cell carcinoma (SQ) in clinical stage IA. We retrospectively investigated 130 patients who underwent surgical resections. We assessed the predictive risk factors for recurrence and pathological lymph node metastasis (LNM). There was no statistical difference in recurrence free survival (RFS) or cancer-specific survival (CSS) between AD and SQ groups (p = 0.642 and p = 0.403, respectively). In the whole cohort, tumor size on lung window and mediastinal settings, and tumor disappearance ratio using high-resolution computed tomography (HRCT) were not prognostic parameters (p = 0.127, 0.066, and 0.082, respectively). The maximal standardized uptake value (SUVmax) using positron emission tomography-CT was associated with recurrence (p = 0.016). According to the receiver operating characteristic curve, the cut-off value of SUVmax for recurrence was 4.6 (p = 0.016). The quantitative continuous variables using any radiological tools were not associated with LNM. However, tumor diameter on mediastinal setting ≥8 mm with SUVmax ≥2.4 could be a risk factor for LNM. Pure solid AD and SQ were equivalent for the RFS and CSS. SUVmax was useful to predict recurrence. The tumor diameter on a mediastinal setting and SUVmax were useful in predicting pathological LNM.

Human bronchial epithelial cell-derived extracellular vesicle therapy for pulmonary fibrosis via inhibition of TGF-β-WNT crosstalk

Idiopathic pulmonary fibrosis (IPF) is characterized by devastating and progressive lung parenchymal fibrosis, resulting in poor patient prognosis. An aberrant recapitulation of developmental lung gene expression, including genes for transforming growth factor (TGF)-β and WNT, has been widely implicated in the pathogenic IPF wound healing process that results from repetitive alveolar epithelial injury. Extracellular vesicles (EVs) have been shown to carry bioactive molecules and to be involved in various physiological and pathological processes. Here, we demonstrate that, by attenuating WNT signalling, human bronchial epithelial cell-derived EVs (HBEC EVs) inhibit TGF-β mediated induction of both myofibroblast differentiation and lung epithelial cellular senescence. This effect of HBEC EVs is more pronounced than that observed with mesenchymal stem cell-derived EVs. Mechanistically, the HBEC EV microRNA (miRNA) cargo is primarily responsible for attenuating both myofibroblast differentiation and cellular senescence. This attenuation occurs via inhibition of canonical and non-canonical WNT signalling pathways. Among enriched miRNA species present in HBEC EVs, miR-16, miR-26a, miR-26b, miR-141, miR-148a, and miR-200a are mechanistically involved in reducing WNT5A and WNT10B expression in LFs, and in reducing WNT3A, WNT5A, and WNT10B expression in HBECs. Mouse models utilizing intratracheal administration of EVs demonstrate efficient attenuation of bleomycin-induced lung fibrosis development accompanied by reduced expression of both β-catenin and markers of cellular senescence. These findings indicate that EVs derived from normal resident lung HBECs may possess anti-fibrotic properties. They further suggest that, via miRNA-mediated inhibition of TGF-β-WNT crosstalk, HBEC EVs administration can be a promising anti-fibrotic modality of treatment for IPF.

Impaired TRIM16-Mediated Lysophagy in Chronic Obstructive Pulmonary Disease Pathogenesis

Insufficient autophagic degradation has been implicated in accelerated cellular senescence during chronic obstructive pulmonary disease (COPD) pathogenesis. Aging-linked and cigarette smoke (CS)-induced functional deterioration of lysosomes may be associated with impaired autophagy. Lysosomal membrane permeabilization (LMP) is indicative of damaged lysosomes. Galectin-3 and tripartite motif protein (TRIM) 16 play a cooperative role in recognizing LMP and inducing lysophagy, a lysosome-selective autophagy, to maintain lysosome function. In this study, we sought to examine the role of TRIM16-mediated lysophagy in regulating CS-induced LMP and cellular senescence during COPD pathogenesis by using human bronchial epithelial cells and lung tissues. CS extract (CSE) induced lysosomal damage via LMP, as detected by galectin-3 accumulation. Autophagy was responsible for modulating LMP and lysosome function during CSE exposure. TRIM16 was involved in CSE-induced lysophagy, with impaired lysophagy associated with lysosomal dysfunction and accelerated cellular senescence. Airway epithelial cells in COPD lungs showed an increase in lipofuscin, aggresome and galectin-3 puncta, reflecting accumulation of lysosomal damage with concomitantly reduced TRIM16 expression levels. Human bronchial epithelial cells isolated from COPD patients showed reduced TRIM16 but increased galectin-3, and a negative correlation between TRIM16 and galectin-3 protein levels was demonstrated. Damaged lysosomes with LMP are accumulated in epithelial cells in COPD lungs, which can be at least partly attributed to impaired TRIM16-mediated lysophagy. Increased LMP in lung epithelial cells may be responsible for COPD pathogenesis through the enhancement of cellular senescence.

Measured versus predicted postoperative pulmonary function at repeated times up to 1 year after lobectomy

OBJECTIVES

Postoperative pulmonary function is difficult to predict accurately, because it changes from the time of the operation and is also affected by various factors. The objective of this study was to assess the accuracy of predicted postoperative forced expiratory volume in 1 s (FEV1) at different postoperative times after lobectomy.

METHODS

This retrospective study enrolled 104 patients who underwent lobectomy by video-assisted thoracic surgery. Pulmonary function tests were performed preoperatively and postoperatively at 3, 6 and 12 months. We investigated time-dependent changes in FEV1. In addition, the ratio of measured to predicted postoperative FEV1 calculated by the subsegmental method was evaluated to identify the factors associated with variations in postoperative FEV1.

RESULTS

Compared with the predicted postoperative FEV1, the measured postoperative FEV1 was 8% higher at 3 months, 11% higher at 6 months and 13% higher at 12 months. The measured postoperative FEV1 significantly increased from 3 to 6 months (P = 0.002) and from 6 to 12 months (P = 0.015) after lobectomy resected lobe, smoking history and body mass index were significant factors associated with the ratio of measured to predicted postoperative FEV1 at 12 months (P < 0.001, P = 0.036 and P = 0.025, respectively).

CONCLUSIONS

Postoperative FEV1 increased up to 12 months after lobectomy by video-assisted thoracic surgery. The predicted postoperative pulmonary function was underestimated after 3 months, particularly after lower lobectomy.

Upregulation of FGF9 in Lung Adenocarcinoma Transdifferentiation to Small Cell Lung Cancer

Transdifferentiation of lung adenocarcinoma to small cell lung cancer (SCLC) has been reported in a subset of lung cancer cases that bear EGFR mutations. Several studies have reported the prerequisite role of TP53 and RB1 alterations in transdifferentiation. However, the mechanism underlying transdifferentiation remains understudied, and definitive additional events, the third hit, for transdifferentiation have not yet been identified. In addition, no prospective experiments provide direct evidence for transdifferentiation. In this study, we show that FGF9 upregulation plays an essential role in transdifferentiation. An integrative omics analysis of paired tumor samples from a patient with transdifferentiated SCLC exhibited robust upregulation of FGF9. Furthermore, FGF9 upregulation was confirmed at the protein level in four of six (66.7%) paired samples. FGF9 induction transformed mouse lung adenocarcinoma-derived cells to SCLC-like tumors in vivo through cell autonomous activation of the FGFR pathway. In vivo treatment of transdifferentiated SCLC-like tumors with the pan-FGFR inhibitor AZD4547 inhibited growth. In addition, FGF9 induced neuroendocrine differentiation, a pathologic characteristic of SCLC, in established human lung adenocarcinoma cells. Thus, the findings provide direct evidence for FGF9-mediated SCLC transdifferentiation and propose the FGF9-FGFR axis as a therapeutic target for transdifferentiated SCLC. SIGNIFICANCE: This study demonstrates that FGF9 plays a role in the transdifferentiation of lung adenocarcinoma to small cell lung cancer.

Optimal timing of video-assisted thoracic surgery for acute pyothorax: a retrospective study

OBJECTIVE

Although the value of video-assisted thoracic surgery for acute pyothorax is becoming widely recognized, the optimal timing of surgery has not been established. Therefore, we aimed to determine the optimal timing of video-assisted thoracic surgery in acute pyothorax.

METHODS

We retrospectively reviewed 38 consecutive video-assisted thoracic surgeries performed for acute pyothorax between January 2013 and December 2017 at our institution. Data were analyzed using the independent samples t test and Mann-Whitney U test. A receiver-operating characteristic curve was used to identify the optimal time for intervention.

RESULTS

The average time from disease onset to surgery was 17.9 days, and the average preoperative drainage period was 8.3 days. The operation was completed in all patients with video-assisted thoracic surgery curettage and drainage under general anesthesia; single lung ventilation was administered, and one or two thoracic drains were placed. The average postoperative drainage period was 10.8 days. Intraoperative complications were observed in two cases; no perioperative death occurred. Additional surgery was performed in four cases because of poor treatment response. There was no recurrence of pyothorax over a mean postoperative follow-up period of 42.5 months. A receiver-operating characteristic curve showed that the cut-off time from disease onset to surgery was 21.0 days; complication rates were 14.3% and 25.0% for patients operated on before and after 21 days, respectively.

CONCLUSIONS

Thoracoscopic surgery for acute pyothorax is safe and curative, and should be performed within 21 days of disease onset to avoid postoperative complications.

Catamenial pneumothorax with partial liver herniation due to diaphragmatic laceration: a case report and literature review

BACKGROUND

Catamenial pneumothorax is generally uncommon, with an incidence of less than 3-6% in women with spontaneous pneumothorax. As few cases of catamenial pneumothorax with diaphragmatic defect and liver herniation have been reported, this case report may be useful for understanding the cause and treatment. This case highlights the importance of the approach for liver hernia in patients with catamenial pneumothorax and endometriosis.

CASE PRESENTATION

We report a case of catamenial pneumothorax in a 43-year-old woman with diaphragmatic partial liver hernia who was treated with thoracoscopic surgery. She was diagnosed with a right pneumothorax at menstruation onset. Chest computed tomography showed a nodule protruding above the right diaphragm. We performed thoracoscopic surgery to treat the persistent air leak and biopsied the nodule on the right diaphragm. There were blueberry spots on the diaphragm; the nodule was found to be the herniated liver. The diaphragmatic defect was sutured. Histological examination of the tissue near the partial prolapsed liver revealed endometrial tissue.

CONCLUSIONS

It is speculated that ectopic endometrial tissue in the diaphragm will periodically necrose to become a diaphragmatic tear, which is a pathway for air to enter the thoracic cavity and eventually a herniated liver. Thoracoscopic surgery should be considered in patients with catamenial pneumothorax when a diaphragmatic lesion is suspected.

Clinical features and outcomes of patients with stage I multiple primary lung cancers

The number of patients with multiple primary lung cancers (MPLC) is rising. We studied the clinical features and factors related to outcomes of MPLC patients using the database of surgically resected lung cancer (LC) cases compiled by the Japanese Joint Committee of Lung Cancer Registry. From the 18 978 registered cases, 9689 patients with clinical stage I non‐small‐cell lung cancer who achieved complete resection were extracted. Tumors were defined as synchronous MPLC when multiple LC was simultaneously resected or treatment was carried out within 2 years after the initial surgery; metachronous MPLC was defined as second LC treated more than 2 years after the initial surgery. Of these cases, 579 (6.0%) were synchronous MPLC and 477 (5.0%) metachronous MPLC, with 51 overlapping cases. Female sex, nonsmoker, low consolidation‐tumor ratio (CTR), and adenocarcinoma were significantly more frequent in the synchronous MPLC group, whereas patients with metachronous MPLC had higher frequencies of male sex, smoker, chronic obstructive pulmonary disease (COPD), and nonadenocarcinoma. There was no significant difference in survival rate between patients with and without synchronous or metachronous MPLC. Age, gender, CTR for second LC, and histological combination of primary and second LC were prognostic indicators for both types of MPLC. Logistic regression analysis showed that female sex, history of malignant disease other than LC, and COPD were risk factors for MPLC incidence. The present findings could have major implications regarding MPLC diagnosis and identification of independent prognostic factors, and provide valuable information for postoperative management of patients with MPLC.

The impact of same-day chest drain removal on pulmonary function after thoracoscopic lobectomy

OBJECTIVES

This study aims to assess the feasibility and impact on long-term pulmonary function of chest drain removal on the operation day following thoracoscopic right upper lobectomy for clinical stage I non-small cell lung cancer.

METHODS

We retrospectively evaluated the data of 116 patients between May 2013 and March 2019. We evaluated the correlations of clinical parameters of chest drain removal and medium- and long-term pulmonary function by comparing removal on operation day (R group) and retainment (D group).

RESULTS

The R group comprised 64 patients, and the D group had 52 patients. Fifty patients (96.2%) in the D group had chest drain removed within 3 postoperative days. Since February 2016, chest drain removal on operation day was performed in 64 of 74 patients (86.5%) according to our chest drain removal protocol. Removal of chest drains on operation day was associated with shorter postoperative hospitalization (p < 0.01) and lower postoperative complications ≧ grade II of the Clavien-Dindo classification (p = 0.026). Only one patient in the R group needed reinsertion. The R group had greater spirometry results at 3- and 12-postoperative months (POM). R group patients had statistically improved pulmonary functions from 3 to 12POM, while those in the D Group were stagnated at 6POM.

CONCLUSIONS

Removal of chest drains on operation day using our protocol is safe and feasible for thoracoscopic right upper lobectomy. This protocol was statistically associated with slightly better long-term pulmonary function, which could not bring clinically meaningful medium- and long-term benefit.

Four Hours Postoperative Mobilization is Feasible After Thoracoscopic Anatomical Pulmonary Resection

BACKGROUND

We aimed to analyze the feasibility and risk factors associated with early mobilization (EM) within 4 h after thoracoscopic lobectomy and segmentectomy.

METHODS

This study retrospectively evaluated 214 consecutive patients who underwent thoracoscopic anatomical pulmonary resection using our EM protocol between October 2017 and February 2019. We compared the correlations of the patients' characteristics including the total number of drugs and perioperative parameters such as air leak, and orthostatic hypotension (OH) between the EM (E group) and failed EM (F group) groups. Second, we evaluated risk factors for OH, which often causes critical complications.

RESULTS

A total of 198 patients (92.5%: E group) completed the EM protocol, whereas 16 patients did not (7.5%: F group). The primary causes of failure were severe pain, air leak, postoperative nausea and vomiting, and OH (n = 1, 3, 8, and 4). Upon univariate analysis, air leakage, OH, and non-hypertension were identified as risk factors for failed EM (all p <0.05). EM was associated with a shortened chest tube drainage period (p <0.01). Thirty patients (14%) experienced OH, and 20% of them failed EM. A total number of drugs ≥5 (p = 0.015) was an independent risk factor for OH. Operative and anesthetic variables were not associated with EM or OH.

CONCLUSIONS

The EM protocol was safe and useful for tubeless management. Surgeons should be advised to actively prevent air leak. Our EM protocol achieved a low frequency of OH in mobilization. Due to its versatility, our mobilization protocol may be promising, especially in patients without severe comorbidities. Clinical registration number: The study protocol was approved by the Review Board of Aichi Cancer Center (approval number: 2020-1-067).

Stromal metalloproteinases: Crucial contributors to the tumor microenvironment

Proteolytic balance is crucial for the maintenance of tissue homeostasis. In cancer, dysregulated proteolysis is involved in unregulated tissue remodeling and inflammation, leading to the promotion of tumor growth, local invasion, and metastasis. Metalloproteinases, which were first identified as collagen cleaving enzymes, have been shown to extensively degrade extracellular matrix proteins or selectively release cell surface-bound cytokines, growth factors, or their receptors, thereby impacting extracellular matrix integrity, immune cell recruitment and tissue turnover. Although tumor cells produce various metalloproteinases, the major source is thought to be stromal cells infiltrating the tumor. Different types of stromal cells express specific sets of metalloproteinases and their inhibitors, which specifically alter the milieu within the tumor. In this review, recent findings and knowledge regarding metalloproteinases derived from stromal cells during the creation of the tumor microenvironment are described and their contribution to the tumor progression and metastasis discussed.

Chaperone-Mediated Autophagy Suppresses Apoptosis via Regulation of the Unfolded Protein Response during Chronic Obstructive Pulmonary Disease Pathogenesis

Cigarette smoke (CS) induces accumulation of misfolded proteins with concomitantly enhanced unfolded protein response (UPR). Increased apoptosis linked to UPR has been demonstrated in chronic obstructive pulmonary disease (COPD) pathogenesis. Chaperone-mediated autophagy (CMA) is a type of selective autophagy for lysosomal degradation of proteins with the KFERQ peptide motif. CMA has been implicated in not only maintaining nutritional homeostasis but also adapting the cell to stressed conditions. Although recent papers have shown functional cross-talk between UPR and CMA, mechanistic implications for CMA in COPD pathogenesis, especially in association with CS-evoked UPR, remain obscure. In this study, we sought to examine the role of CMA in regulating CS-induced apoptosis linked to UPR during COPD pathogenesis using human bronchial epithelial cells (HBEC) and lung tissues. CS extract (CSE) induced LAMP2A expression and CMA activation through a Nrf2-dependent manner in HBEC. LAMP2A knockdown and the subsequent CMA inhibition enhanced UPR, including CHOP expression, and was accompanied by increased apoptosis during CSE exposure, which was reversed by LAMP2A overexpression. Immunohistochemistry showed that Nrf2 and LAMP2A levels were reduced in small airway epithelial cells in COPD compared with non-COPD lungs. Both Nrf2 and LAMP2A levels were significantly reduced in HBEC isolated from COPD, whereas LAMP2A levels in HBEC were positively correlated with pulmonary function tests. These findings suggest the existence of functional cross-talk between CMA and UPR during CSE exposure and also that impaired CMA may be causally associated with COPD pathogenesis through enhanced UPR-mediated apoptosis in epithelial cells.

Clinical Impacts of EGFR Mutation Status: Analysis of 5780 Surgically Resected Lung Cancer Cases

BACKGROUND

To elucidate the clinical, pathologic, and prognostic impacts of epidermal growth factor receptor (EGFR) mutation and mutation subtypes in early-stage lung cancer, the study investigators conducted a retrospective analysis of the Japanese Joint Committee of Lung Cancer Registry database (a nationwide database for patients with surgically resected lung cancer; n = 18,973).

METHODS

Of 13,951 patients classified as having nonsquamous non-small cell lung cancer in the database, 5780 patients (41.0%) had been tested for an EGFR mutation and were included in this study.

RESULTS

An EGFR mutation was detected in 2410 patients (41.7%), and the presence of an EGFR mutation was significantly correlated with clinicopathologic factors such as the presence of ground-glass opacity (P < .001) and better prognosis. Analysis of initial recurrence sites identified significantly higher frequencies of brain and adrenal gland metastases in patients with and without an EGFR mutation, respectively. Of 2410 patients with EGFR mutations, 983 (40.8%) had an exon 19 deletion (Exon 19 Del), 1170 (48.5%) had an L858R mutation, and 257 (10.7%) had other EGFR mutations. A higher smoking rate was found in patients with other EGFR mutations (P = .02). In the comparison of Exon 19 Del and L858R, we found that Exon 19 Del correlated with younger age (P < .001), a higher rate of pure solid tumors (P < .001), advanced pathologic stage (trend P < .001), and poorer recurrence-free survival (P = .001).

CONCLUSIONS

In addition to the clinicopathologic and prognostic impacts of EGFR mutation status, tumors with Exon 19 Del have a more aggressive phenotype and patients have a poorer prognosis than with L858R in early-stage lung cancers.

Definitive lobectomy without frozen section analysis is a treatment option for large or deep nodules selected carefully with clinical diagnosis of malignancy

Background

Tissue harvesting for patients with a lung nodule is sometimes unsuitable due to the size and location of the nodule. In such cases, it is unclear whether it is acceptable to proceed to definitive lobectomy without intraoperative frozen section analysis.

Methods

We retrospectively reviewed patients who underwent definitive lobectomy or wedge resection for frozen section analysis at our institution between 2014 and 2018. The sensitivity, specificity, and accuracies of the clinical and frozen section diagnoses were evaluated against the final pathological diagnosis.

Results

There were 141 patients in the definitive lobectomy group and 58 patients in the frozen section analysis group, with the latter having smaller and less deep nodules and a lower rate of malignancy on clinical and final pathological diagnoses. The sensitivity, specificity, and accuracy of the clinical diagnosis were 100%, 82%, and 95%, respectively, in the frozen section analysis group and 99%, 67%, and 97%, respectively, in the definitive lobectomy group; values of frozen section diagnosis were 98%, 82%, and 93%, respectively. On subgroup analysis, all ground‐glass nodules clinically diagnosed as malignant had a final pathological diagnosis of malignancy.

Conclusions

The accuracy of the clinical diagnosis was high and was not inferior to the frozen section diagnosis. These data suggest that definitive lobectomy is an acceptable treatment option for carefully selected patients with large or deep nodules and ground‐glass nodules clinically diagnosed as malignant. To avoid unnecessary lobectomy, frozen section diagnosis should be considered for nodules likely to be benign.

Key points

Effective exchange to a larger size catheter for a lung abscess with initial percutaneous drainage failure: a case report

BACKGROUND

Percutaneous catheter drainage is an effective therapy for antibiotic-refractory lung abscesses. Pulmonary resection is usually considered in cases of drainage failure, although it remains controversial.

CASE PRESENTATION

A 42-year-old man with antibiotic-refractory lung abscess underwent percutaneous abscess drainage with a 10-Fr pigtail catheter. However, adequate evacuation of the abscess content was not achieved, and his respiratory condition worsened and he required a ventilator. To achieve and maintain effective drainage, insertion of a larger size 28-Fr catheter to replace the 10-Fr catheter was performed under general anesthesia and one-lung ventilation with a double-lumen tube to isolate the left lung. Exchange with a larger size catheter was effective and achieved adequate drainage. The procedure was performed safely by expanding the route of the old catheter as a guide for accessing the abscess cavity. His condition immediately improved and he was discharged on day 40 post-catheter exchange with no complications and cured with a small residual thin wall cavity.

CONCLUSIONS

Small size catheters are generally recommended for initial percutaneous drainage; however, we argue that exchange with larger size catheters should be primarily considered instead of pulmonary resection in cases of initial drainage failure. This may avoid the need for pulmonary resection.

Simultaneous Two-Dimensional and Three-Dimensional Simulation of Thoracoscopic Sleeve Lobectomy: A Quick Understanding of Pitfalls

Thoracoscopic sleeve lobectomy is challenging, considering the technical difficulty in controlling the needle angle and thread through the port. However, effective simulation of the procedure remains to be established. Here, we describe our first experience with thoracoscopic sleeve lobectomy simulation using a three-dimensional printed thoracic model and a handmade rolled sponge. Owing to the transparent structure, we could simultaneously confirm the suturing technique through the monitor (two-dimensional) and direct vision (three-dimensional). We are certain that our realistic and easily repeatable simulation will assist in developing better technique and conduct feasible thoracoscopic sleeve lobectomy.

Infiltration of tumor-associated macrophages is involved in tumor programmed death-ligand 1 expression in early lung adenocarcinoma

Programmed death-ligand 1 (PD-L1) is an immune modulator that promotes immunosuppression by binding to programmed death-1 of T-lymphocytes. Although tumor cell PD-L1 expression has been shown to be associated with the clinical response to anti-PD-L1 antibodies, its concise regulatory mechanisms remain elusive. In this study, we evaluated the associations of tumor PD-L1 expression and immune cell infiltrating patterns in 146 cases of early lung adenocarcinoma (AC) to investigate the possible extrinsic regulation of tumor PD-L1 by immune cells. Using immunohistochemistry, cell surface PD-L1 expression in tumor cells was observed in 18.5% of stage 0-IA lung AC patients. Tumor PD-L1 positivity was significantly associated with stromal invasion, which was accompanied by increased tumor-associated macrophages (TAM), CD8⁺ cytotoxic T cells and FoxP3⁺ regulatory T cells. Among these immune cells, TAM and CD8⁺ T cells significantly accumulated in PD-L1-positive carcinoma cell areas, which showed a tumor cell nest-infiltrating pattern. Although CD8⁺ T cells are known to induce tumor PD-L1 expression via interferon-ɣ production, the increased TAM within tumors were also associated with tumor cell PD-L1 positivity, independently of CD8⁺ T cell infiltration. Our in vitro experiments revealed that PD-L1 expression in lung cancer cell lines was significantly upregulated by co-culture with M2-differentiated macrophages; expression of PD-L1 was reduced to baseline levels following treatment with a transforming growth factor-β inhibitor. These results demonstrated that tumor-infiltrating TAM are extrinsic regulators of tumor PD-L1 expression, indicating that combination therapy targeting both tumor PD-L1 and stromal TAM might be a possible strategy for effective treatment of lung cancer.

Recovery of pulmonary function after lung wedge resection

Background

Pulmonary function following lung wedge resection is not fully understood. This study aimed to assess the influence of wedge resection upon postoperative pulmonary function.

Methods

We retrospectively evaluated pulmonary function at 3, 6, and 12 months postoperatively in 29 patients who underwent lung wedge resection. The values of the pulmonary function tests (PFTs) were compared among the time points using a paired t-test.

Results

The vital capacity (VC) values before surgery and at 3, 6 and 12 months postoperatively were 2,994±793, 2,845±799, 2,941±801, and 2,964±839 mL, respectively. The VC decreased at 3 months postoperatively (P=0.002) and recovered by 6 and 12 months postoperatively (P=0.003 and 0.003, respectively). The VC values at 6 and 12 months postoperatively did not significantly differ from that before surgery (P=0.152 and 0.361, respectively). The forced expiratory volume in one second (FEV₁) values before surgery and at 3, 6, and 12 months postoperatively were 2,156±661, 2,034±660, 2,091±672 and 2,100±666 mL, respectively. The values decreased at 3 months postoperatively (P<0.001) and recovered; however, they remained lower than the preoperative value (P=0.036).

Conclusions

The postoperative VC decreased temporarily but recovered to near the preoperative level after 12 months. We concluded that the loss of VC following lung wedge resection is minimal. These findings are beneficial for planning surgery and explaining the procedure to patients who are undergoing lung wedge resection.