Clinical Significance of SIRPα Expression on Tumor-Associated Macrophages in Patients with Lung Squamous Cell Carcinoma.

BACKGROUND: Signal-regulatory protein alpha (SIRPα) is an immune checkpoint molecule expressed on macrophages that functions to inhibit phagocytosis by binding to CD47 expressed on tumor cells. SIRPα has attracted increasing attention as a novel target for cancer immunotherapy; however, the expression and immune function of SIRPα in lung squamous cell carcinoma (LUSC) remain unclear. Therefore, this study aimed to identify the clinical importance of SIRPα expression in LUSC and to explore the factors that elevate SIRPα expression. PATIENTS AND METHODS: Primary LUSC specimens surgically resected from 172 patients underwent immunohistochemical evaluation of the association of SIRPα expression on tumor-associated macrophages with clinicopathological features and clinical outcomes. Furthermore, we analyzed the association of SIRPα expression with tumor-infiltrating lymphocytes and the expression of programmed cell death ligand 1 (PD-L1). In vitro, monocytes were treated with cytokines, and SIRPα protein expression was assessed by flow cytometry. RESULTS: There were no differences in SIRPα expression and clinicopathological factors. High SIRPα expression was significantly associated with PD-L1-positive expression, and high CD8, PD-1, and CD163 expression. The high SIRPα expression group showed significantly shorter recurrence-free survival (RFS) and overall survival (OS). On multivariate analysis, high SIRPα expression was an independent poor prognostic factor for RFS and OS. The expression of SIRPα protein in monocytes was upregulated by treatment with IFNγ. CONCLUSION: Our analysis revealed that high SIRPα expression significantly predicts poor prognosis in patients with surgically resected LUSC.

CD155 Expression in Early-stage Lung Adenocarcinoma.

BACKGROUND: CD155 is a transmembrane protein that belongs to the nectin-like molecule family that is widely overexpressed in several types of cancer. However, the clinical significance of CD155 in pathological stage I lung adenocarcinoma remains poorly understood. METHODS: We analyzed 320 patients diagnosed with pathological stage I lung adenocarcinoma who underwent surgical treatment at Kyushu University Hospital between 2006 and 2015. The number of tumor cells expressing CD155 was assessed by immunohistochemistry, and patients were categorized into high and low CD155 expression groups. We compared the clinicopathological characteristics and clinical outcomes between these groups. RESULTS: EGFR mutation status was determined in 237 patients. A total of 106 patients (33.1%) had EGFR wild-type, while 131 patients (40.9%) were EGFR mutant-type. Regarding CD155 expression, 77 patients (24.1%) were classified as high and 243 (75.9%) as low. The multivariate analysis identified pleural invasion and EGFR wild-type as independent predictors of high CD155 expression. The Kaplan-Meier plot demonstrated significantly poorer recurrence-free survival and overall survival in the high CD155 group compared with the low CD155 group. In multivariate analysis, high CD155 expression was an independent poor prognostic factor for both recurrence-free and overall survival. Subgroup analyses revealed that a prognostic difference related to CD155 expression was observed only in patients with EGFR wild-type but not in those with EGFR mutant-type. CONCLUSIONS: Our findings suggest that high expression of CD155 is associated with EGFR wild-type and could serve as a valuable prognostic marker in pathological stage I lung adenocarcinoma, particularly in cases without EGFR mutation.

Maximum resistance pressure at the time of lung tissue rupture after porcine lung transection using automatic linear staplers with different reinforcement methods.

PURPOSES: Polyglycolic acid (PGA) sheets, fibrin glue, and staple line reinforcement are frequently used to prevent air leakage during lung resection. However, the optimal staple-line reinforcement method remains unclear. METHODS: Cranial lung lobes of pigs were used to evaluate different staple line reinforcement methods (n = 6). Ventilator-assisted manometry was used to measure the maximum resistance pressure at the time of rupture of the lung tissue after stapling. RESULTS: The mean maximum resistance pressures at the time of lung tissue rupture after using the stapler alone, stapler with PGA sheet and fibrin glue, and stapler with reinforcement were 38.0 cmH2O, 51.3 cmH2O, and 62.7 cmH2O, respectively. A significant increase in the maximum resistance pressure was observed with stapler reinforcement (P < 0.001), while the differences between the other groups were not statistically significant (P = 0.055, P = 0.111). A histological assessment revealed disruption of alveolar structures near the needle-stitching site in the stapler alone, and in the stapler with PGA sheet and fibrin glue groups. Pleural rupture near the staple line was observed in the stapler with reinforcement group. CONCLUSIONS: The maximum resistance pressure before air leakage was significantly higher when using a stapler with reinforcement than when using a stapler alone.

Clinical and Prognostic Significance of Glutathione Peroxidase 2 in Lung Adenocarcinoma.

BACKGROUND: Glutathione peroxidase 2 (GPX2) is an antioxidant enzyme with an important role in tumor progression in various cancers. However, the clinical significance of GPX2 in lung adenocarcinoma has not been clarified. METHODS: Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to analyze GPX2 mRNA expression. Then, we conducted immunohistochemistry (IHC) to assess GPX2 expression in specimens acquired from 351 patients with lung adenocarcinoma who underwent surgery at Kyushu University from 2003 to 2012. We investigated the association between GPX2 expression and clinicopathological characteristics and further analyzed the prognostic relevance. RESULTS: qRT-PCR revealed that GPX2 mRNA expression was notably higher in tumor cells than in normal tissues. IHC revealed that high GPX2 expression (n = 175, 49.9%) was significantly correlated with male sex, smoking, advanced pathological stage, and the presence of pleural, lymphatic, and vascular invasion. Patients with high GPX2 expression exhibited significantly shorter recurrence-free survival (RFS) and overall survival. Multivariate analysis identified high GPX2 expression as an independent prognostic factor of RFS. CONCLUSIONS: GPX2 expression was significantly associated with pathological malignancy. It is conceivable that high GPX2 expression reflects tumor malignancy. Therefore, high GPX2 expression is a significant prognostic factor of poor prognosis for completely resected lung adenocarcinoma.

Usefulness of free subcutaneous fat pads for refractory secondary pneumothorax due to lung cancer.

Surgical treatment for a pneumothorax involves resection of the pulmonary pleural fistula, and closure of the fistula or coverage of the fistula using pericardial fat pads or an intercostal muscle flap. In some cases, however, these treatments are difficult because of thickened pleura or dense pleural adhesions in the thoracic cavity. We report two cases of refractory secondary pneumothorax due to lung cancer that were successfully treated using free subcutaneous fat pads to cover the pulmonary pleural fistulas. Both patients had advanced lung cancer, and each developed a pneumothorax after chemotherapy or the administration of osimertinib. Each had a prolonged air leak despite chest tube drainage. We harvested a free subcutaneous fat pad around the thoracotomy site and sutured it to cover the fistula. After the operation, the air leak disappeared immediately, and the chest tube was removed from each patient on postoperative day 2. Computed tomography at 2 or 4 months postoperatively demonstrated that the free subcutaneous fat pads were still present with no sign of pneumothorax. Application of free subcutaneous fat pads to cover a persistent pulmonary pleural fistula is useful for the treatment of secondary pneumothorax due to lung cancer.

MUC1-C Is a Common Driver of Acquired Osimertinib Resistance in NSCLC.

INTRODUCTION: Osimertinib is an irreversible EGFR tyrosine kinase inhibitor approved for the first-line treatment of patients with metastatic NSCLC harboring EGFR exon 19 deletions or L858R mutations. Patients treated with osimertinib invariably develop acquired resistance by mechanisms involving additional EGFR mutations, MET amplification, and other pathways. There is no known involvement of the oncogenic MUC1-C protein in acquired osimertinib resistance. METHODS: H1975/EGFR (L858R/T790M) and patient-derived NSCLC cells with acquired osimertinib resistance were investigated for MUC1-C dependence in studies of EGFR pathway activation, clonogenicity, and self-renewal capacity. RESULTS: We reveal that MUC1-C is up-regulated in H1975 osimertinib drug-tolerant persister cells and is necessary for activation of the EGFR pathway. H1975 cells selected for stable osimertinib resistance (H1975-OR) and MGH700-2D cells isolated from a patient with acquired osimertinib resistance are found to be dependent on MUC1-C for induction of (1) phospho (p)-EGFR, p-ERK, and p-AKT, (2) EMT, and (3) the resistant phenotype. We report that MUC1-C is also required for p-EGFR, p-ERK, and p-AKT activation and self-renewal capacity in acquired osimertinib-resistant (1) MET-amplified MGH170-1D #2 cells and (2) MGH121 Res#2/EGFR (T790M/C797S) cells. Importantly, targeting MUC1-C in these diverse models reverses osimertinib resistance. In support of these results, high MUC1 mRNA and MUC1-C protein expression is associated with a poor prognosis for patients with EGFR-mutant NSCLCs. CONCLUSIONS: Our findings reveal that MUC1-C is a common effector of osimertinib resistance and is a potential target for the treatment of osimertinib-resistant NSCLCs.

Impact of Chronic Obstructive Pulmonary Disease on the Long-term Prognosis of Patients Undergoing Lobectomy for Non-small-cell Lung Cancer: A Propensity Score-matched Analysis.

BACKGROUND/AIM: Recent advances in surgery, such as thoracoscopic surgery, have made it possible to treat patients with chronic obstructive pulmonary disease (COPD) more safely than before. This study evaluated the short- and long-term prognosis of lobectomy in non-small cell lung cancer (NSCLC) patients with COPD. PATIENTS AND METHODS: This retrospective, propensity-matched, cohort analysis was conducted from January 2014 to December 2018. Among 441 patients who underwent lobectomy for NSCLC, 158 (35.8%) had a preoperative diagnosis of COPD. Propensity-matched analysis, incorporating preoperative variables, was used to compare postoperative hospital stay and complications, and long-term prognosis between the groups. RESULTS: Propensity matching estimated 145 patients in each group. There was no difference between the two groups for length of postoperative hospital stay (12 vs. 11 days, p=0.306). Postoperative complications were more frequent in the COPD group (24.1%) than in the non-COPD group (16.6%), but the difference was not significant (p=0.108). The 5-year overall survival rate was 86.2% in the COPD group and 82.1% in the non-COPD group after matching (p=0.580). The corresponding 5-year recurrence-free survival rate was 72.8% in the COPD group and 67.2% in the non-COPD group after matching (p=0.601). CONCLUSION: In case of Global Initiative for Chronic Obstructive Lung Disease (GOLD) I/II classification, COPD did not significantly worsen the prognosis of patients with NSCLC after lobectomy.

Lobectomy for Pulmonary Arteriovenous Fistula in a Patient With Rendu-Osler-Weber Disease: A Case Report.

BACKGROUND: Rendu-Osler-Weber disease (Osler's disease) is the most common cause of pulmonary arteriovenous fistula. We report a case of pulmonary arteriovenous fistula associated with Osler's disease that was treated by lobectomy. CASE REPORT: A 44-year-old man with Osler's disease presented with respiratory distress. Computed tomography showed a pulmonary arteriovenous fistula, which had a 26-mm-long diameter in S6 of the left lung. Transcatheter treatment had a high risk of recurrence, and surgery was indicated. The pulmonary arteriovenous fistula was found at the beginning of A6. A6 and the basilar artery were cut together with a stapler. The postoperative course was uneventful, and respiratory distress symptoms improved with no recurrence. CONCLUSION: We report a case of pulmonary arteriovenous fistula caused by Osler's disease treated by lobectomy. Although transcatheter treatment is the mainstream treatment for pulmonary arteriovenous fistulas, surgical resection may be effective depending on the size of the lesion.

Development of artificial intelligence prognostic model for surgically resected non-small cell lung cancer.

There are great expectations for artificial intelligence (AI) in medicine. We aimed to develop an AI prognostic model for surgically resected non-small cell lung cancer (NSCLC). This study enrolled 1049 patients with pathological stage I-IIIA surgically resected NSCLC at Kyushu University. We set 17 clinicopathological factors and 30 preoperative and 22 postoperative blood test results as explanatory variables. Disease-free survival (DFS), overall survival (OS), and cancer-specific survival (CSS) were set as objective variables. The eXtreme Gradient Boosting (XGBoost) was used as the machine learning algorithm. The median age was 69 (23-89) years, and 605 patients (57.7%) were male. The numbers of patients with pathological stage IA, IB, IIA, IIB, and IIIA were 553 (52.7%), 223 (21.4%), 100 (9.5%), 55 (5.3%), and 118 (11.2%), respectively. The 5-year DFS, OS, and CSS rates were 71.0%, 82.8%, and 88.7%, respectively. Our AI prognostic model showed that the areas under the curve of the receiver operating characteristic curves of DFS, OS, and CSS at 5 years were 0.890, 0.926, and 0.960, respectively. The AI prognostic model using XGBoost showed good prediction accuracy and provided accurate predictive probability of postoperative prognosis of NSCLC.

Modulation of host glutamine anabolism enhances the sensitivity of small cell lung cancer to chemotherapy.

Small cell lung cancer (SCLC) is one of the deadliest human cancers, with a 5-year survival rate of ∼7%. Here, we performed a targeted proteomics analysis of human SCLC samples and thereby identified hypoxanthine phosphoribosyltransferase 1 (HPRT1) in the salvage purine synthesis pathway as a factor that contributes to SCLC malignancy by promoting cell survival in a glutamine-starved environment. Inhibition of HPRT1 by 6-mercaptopurine (6-MP) in combination with methotrexate (MTX), which blocks the de novo purine synthesis pathway, attenuated the growth of SCLC in mouse xenograft models. Moreover, modulation of host glutamine anabolism with the glutamine synthetase inhibitor methionine sulfoximine (MSO) in combination with 6-MP and MTX treatment resulted in marked tumor suppression and prolongation of host survival. Our results thus suggest that modulation of host glutamine anabolism combined with simultaneous inhibition of the de novo and salvage purine synthesis pathways may be of therapeutic benefit for SCLC.

Granzyme B (GZMB)-Positive Tumor-Infiltrating Lymphocytes in Lung Adenocarcinoma: Significance as a Prognostic Factor and Association with Immunosuppressive Proteins.

BACKGROUND: Granzyme B (GZMB) is a serine protease produced by cytotoxic lymphocytes that reflects the activity of anti-tumor immune responses in tumor-infiltrating lymphocytes (TILs); however, the prognostic significance of GZMB+ TILs in lung adenocarcinoma is poorly understood. METHODS: We analyzed 273 patients with pathological stage (pStage) I-IIIA lung adenocarcinoma who underwent surgery at Kyushu University from 2003 to 2012. We evaluated GZMB+ TIL counts by immunohistochemistry. We set the cut-off values at 12 cells/0.04 mm2 for GZMB+ TILs and divided the patients into GZMB-High (n = 171) and GZMB-Low (n = 102) groups. Then, we compared the clinicopathological characteristics of the two groups and clinical outcomes. Programmed cell death ligand-1 (PD-L1) and indoleamine 2,3-dioxygenase 1 (IDO1) expression in tumor cells was also evaluated, and combined prognostic analyses of GZMB+ TILs with PD-L1 or IDO1 were performed. RESULTS: GZMB-Low was significantly associated with pStage II-III, PD-L1 positivity, and IDO1 positivity. Disease-free survival (DFS) and overall survival (OS) in the GZMB-Low group were significantly worse than in the GZMB-High group. In multivariable analysis, GZMB-Low was an independent prognostic factor for both DFS and OS. Furthermore, combined prognostic analyses of GZMB+ TILs with PD-L1 or IDO1 showed that GZMB-Low with high expression of these immunosuppressive proteins had the worst prognosis. CONCLUSIONS: We analyzed GZMB+ TIL counts in lung adenocarcinoma and elucidated its prognostic significance and association with PD-L1 and IDO1. GZMB+ TIL counts might reflect the patient's immunity against cancer cells and could be a useful prognostic marker of lung adenocarcinoma.

MicroRNA-326 negatively regulates CD155 expression in lung adenocarcinoma.

Treatment with immune checkpoint inhibitors induces a durable response in some patients with non-small-cell lung cancer, but eventually gives rise to drug resistance. Upregulation of CD155 expression is implicated as one mechanism of resistance to programmed death receptor-1 (PD-1)/PD-1 ligand (PD-L1) inhibitors, and it is therefore important to characterize the mechanisms underlying regulation of CD155 expression in tumor cells. The aim of this study was to identify microRNAs (miRNAs) that might regulate CD155 expression at the posttranscriptional level in lung cancer. Comprehensive miRNA screening with target prediction programs and a dual-luciferase reporter assay identified miR-346, miR-328-3p, miR-326, and miR-330-5p as miRNAs that bind to the 3'-UTR of CD155 mRNA. Forced expression of these miRNAs suppressed CD155 expression in lung cancer cell lines. Immunohistochemical staining of CD155 in tissue specimens from 57 patients with lung adenocarcinoma revealed the median tumor proportion score for CD155 to be 68%. The abundance of miR-326 in these specimens with a low level of CD155 expression was significantly greater than in specimens with a high level (p < 0.005). Our results thus suggest that miR-326 negatively regulates CD155 expression in lung adenocarcinoma and might therefore play a role in the development of resistance to PD-1/PD-L1 inhibitors.

Transducin Beta-Like 2 is a Potential Driver Gene that Adapts to Endoplasmic Reticulum Stress to Promote Tumor Growth of Lung Adenocarcinoma.

BACKGROUND: Endoplasmic reticulum (ER) stress has a close relation with cancer progression. Blocking the adaptive pathway of ER stress could be an anticancer strategy. Here, we identified an ER stress-related gene, Transducin beta-like 2 (TBL2), an ER-localized type I transmembrane protein, on increased chromosome 7q as a candidate driver gene of lung adenocarcinoma (LUAD). METHODS: The association between TBL2 mRNA expression and prognostic outcomes and clinicopathological factors was analyzed using The Cancer Genome Atlas (TCGA) datasets of LUAD and lung squamous cell carcinoma (LUSC). Localization of TBL2 in tumor tissues was observed by immunohistochemical staining. Gene set enrichment analysis (GSEA) was conducted using TCGA dataset. In vitro cell proliferation assays were performed using TBL2 knockdown LUAD cells, LUSC cells, and LUAD cells overexpressing TBL2. Apoptosis and ATF4 expression (ER stress marker) were evaluated by western blotting. RESULTS: TBL2 was overexpressed in LUAD and LUSC cells. Multivariate analysis indicated high TBL2 mRNA expression was an independent poor prognostic factor of LUAD. GSEA revealed high TBL2 expression was positively correlated to the ER stress response in LUAD. TBL2 knockdown attenuated LUAD cell proliferation under ER stress. TBL2 inhibited apoptosis in LUAD cells under ER stress. TBL2 knockdown reduced ATF4 expression under ER stress. CONCLUSIONS: TBL2 may be a novel driver gene that facilitates cell proliferation, possibly by upregulating ATF4 expression followed by adaptation to ER stress, and it is a poor prognostic biomarker of LUAD.

Prognostic Impact of Central Nervous System Recurrence After Surgery in Patients With Epidermal Growth Factor Receptor Mutation-positive Non-small-cell Lung Cancer.

BACKGROUND/AIM: Adjuvant therapy using third-generation tyrosine kinase inhibitors (TKI) demonstrated improved central nervous system (CNS) disease-free survival after surgery in patients with epidermal growth factor receptor (EGFR) mutation-positive lung cancer. However, the prognostic impact of CNS recurrence in surgical patients remains unknown. We evaluated the effect of CNS recurrence on post-recurrence survival (PRS) in patients with postoperatively recurrent NSCLC. PATIENTS AND METHODS: We assessed the prognostic impact of CNS recurrence using a cohort from a prospective observational study (Kyushu University Lung Surgery Group Study 2: KLSS-2). Based on data from 340 patients in whom EGFR mutations were assessed among 498 total patients in the KLSS-2 cohort, factors related to CNS recurrence and prognosis after postoperative recurrence were analyzed. RESULTS: We noted no marked differences in the presence of EGFR mutations (p=0.14) between patients with CNS recurrence and those without CNS recurrence. Among the patients tested for EGFR mutations with stage IV recurrences (n=219), survival analysis of patients with EGFR mutations showed that the CNS group had a significantly poorer PRS than the no-CNS group (MST: 36.8 vs. 43.9 months, p=0.035). In multivariate survival analysis of stage IV EGFR mutation-positive cases, recurrence in multiple organs and recurrence of brain metastases were independent poor prognostic factors (hazard ratio=2.2, p=0.029; hazard ratio=3.2, p=0.0006, respectively). CONCLUSION: Postoperative CNS recurrence was associated with a poor prognosis among patients with EGFR mutation-positive lung cancer in the period when third-generation EGFR-TKIs were not available. In EGFR mutation-positive lung cancer, prevention of CNS recurrence after surgery may improve post-recurrence prognosis.

Impact of the pretreatment prognostic nutritional index on the survival after first-line immunotherapy in non-small-cell lung cancer patients.

BACKGROUND: Immunotherapy has become a standard-of-care for patients with non-small-cell lung cancer (NSCLC). Although several biomarkers, such as programmed cell death-1, have been shown to be useful in selecting patients likely to benefit from immune checkpoint inhibitors (ICIs), more useful and reliable ones should be investigated. The prognostic nutritional index (PNI) is a marker of the immune and nutritional status of the host, and is derived from serum albumin level and peripheral lymphocyte count. Although several groups reported its prognostic role in patients with NSCLC receiving a single ICI, there exist no reports which have demonstrated its role in the first-line ICI combined with or without chemotherapy. MATERIALS AND METHODS: Two-hundred and eighteen patients with NSCLC were included in the current study and received pembrolizumab alone or chemoimmunotherapy as the first-line therapy. Cutoff value of the pretreatment PNI was set as 42.17. RESULTS: Among 218 patients, 123 (56.4%) had a high PNI (≥42.17), while 95 (43.6%) had a low PNI (<42.17). A significant association was observed between the PNI and both the progression-free survival (PFS; hazard ratio [HR] = 0.67, 95% confidence interval [CI]: 0.51-0.88, p = 0.0021) and overall survival (OS; HR = 0.46, 95% CI: 0.32-0.67, p < 0.0001) in the entire population, respectively. The multivariate analysis identified the pretreatment PNI as an independent prognosticator for the PFS (p = 0.0011) and OS (p < 0.0001), and in patients receiving either pembrolizumab alone or chemoimmunotherapy, the pretreatment PNI remained an independent prognostic factor for the OS (p = 0.0270 and 0.0006, respectively). CONCLUSION: The PNI might help clinicians appropriately identifying patients with better treatment outcomes when receiving first-line ICI therapy.