SlicerPIT: software development and implementation for planning and image-guided therapy in photoimmunotherapy

BACKGROUND

Photoimmunotherapy is a treatment modality that induces targeted cell death by binding a molecular-targeted drug activated by infrared light to the tumor cells and subsequently illuminating the lesion with infrared light. For deep lesions, a needle catheter is used to puncture the tumor, and an illumination fiber (cylindrical diffuser) is inserted into the catheter lumen for internal illumination. However, it can be challenging to place the cylindrical diffusers in an appropriate position as the deep lesions cannot be often confirmed accurately during surgery.

MATERIALS AND METHODS

We have developed "SlicerPIT", a planning simulation software for photoimmunotherapy. SlicerPIT allows users to place the cylindrical diffuser with its illumination range on preoperative images in 2D and 3D and export the planning data to external image-guided surgical navigation systems. We performed seven cycles of photoimmunotherapy with SlicerPIT in three patients with recurrent head and neck cancer.

RESULTS

Preoperative planning for photoimmunotherapy was conducted using SlicerPIT, which could be imported into the navigation system. During the operation, we punctured the needle catheters along with the treatment plan on the navigation screen. Subsequently, intraoperative CT imaging was performed and overlaid with the preoperative treatment plan to confirm the alignment of the cylindrical diffusers as planned, followed by infrared light illumination. Postoperative imaging showed necrosis and shrinkage of the entire tumor in all cycles.

CONCLUSION

SlicerPIT allows for detailed preoperative treatment planning and accurate puncture. It may be a valuable tool to improve the accuracy of photoimmunotherapy for deep lesions and improve patient outcomes.

A simple and safe surgical technique for nonpalpable lung tumors: One-stop Solution for a nonpalpable lung tumor, Marking, Resection, and Confirmation of the surgical margin in a Hybrid operating room (OS-MRCH)

When performing thoracoscopic partial resections of nonpalpable lung tumors such as ground-glass opacities (GGOs) and small tumors, detecting the location of the lesion and assessing the resection margins can be challenging. We have developed a novel method to ease this difficulty, the One-stop Solution for a nonpalpable lung tumor, Marking, Resection, and Confirmation of the surgical margin in a Hybrid operating room (OS-MRCH), which uses a hybrid operating room wherein the operating table is seamlessly integrated with cone-beam computed tomography (CBCT). We performed the OS-MRCH method on 62 nodules including primary lung cancer presenting with GGO. Identification of the lesion and confirmation of the margin were performed in 58 of the cases, while nodules were detected in all. The frequency of computed tomography (CT) scans performed prior to resection was one time in 51 cases, two times in eight cases, and ≥3 times in three cases. Additional resection was performed in two cases. The median operative time was 85.0 minutes, and the median pathological margin was 11.0 mm. The key advantages of this method are that all surgical processes can be completed in a single session, specialized skill sets are not required, and it is feasible to perform in any facility equipped with a hybrid operating room. To overcome its disadvantages, such as longer operating time and limited patient positioning, we devised various methods for positioning patients and for CT imaging of the resected specimens. OS-MRCH is a simple, useful, and practical method for performing thoracoscopic partial resection of nonpalpable lung tumors.

Viral uptake and pathophysiology of the lung endothelial cells in age-associated severe SARS-CoV-2 infection models

Thrombosis is the major cause of death in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, and the pathology of vascular endothelial cells (ECs) has received much attention. Although there is evidence of the infection of ECs in human autopsy tissues, their detailed pathophysiology remains unclear due to the lack of animal model to study it. We used a mouse-adapted SARS-CoV-2 virus strain in young and mid-aged mice. Only mid-aged mice developed fatal pneumonia with thrombosis. Pulmonary ECs were isolated from these infected mice and RNA-Seq was performed. The pulmonary EC transcriptome revealed that significantly higher levels of viral genes were detected in ECs from mid-aged mice with upregulation of viral response genes such as DDX58 and IRF7. In addition, the thrombogenesis-related genes encoding PLAT, PF4, F3 PAI-1, and P-selectin were upregulated. In addition, the inflammation-related molecules such as CXCL2 and CXCL10 were upregulated in the mid-aged ECs upon viral infection. Our mouse model demonstrated that SARS-CoV-2 virus entry into aged vascular ECs upregulated thrombogenesis and inflammation-related genes and led to fatal pneumonia with thrombosis. Current results of EC transcriptome showed that EC uptake virus and become thrombogenic by activating neutrophils and platelets in the aged mice, suggesting age-associated EC response as a novel finding in human severe COVID-19.

Low-dose metronomic cisplatin as an antiangiogenic and anti-inflammatory strategy for cancer

BACKGROUND

Conventional chemotherapy is based on the maximum tolerated dose (MTD) and requires treatment-free intervals to restore normal host cells. MTD chemotherapy may induce angiogenesis or immunosuppressive cell infiltration during treatment-free intervals. Low-dose metronomic (LDM) chemotherapy is defined as frequent administration at lower doses and causes less inflammatory change, whereas MTD chemotherapy induces an inflammatory change. Although several LDM regimens have been applied, LDM cisplatin (CDDP) has been rarely reported. This study addressed the efficacy of LDM CDDP on tumour endothelial cell phenotypic alteration compared to MTD CDDP.

METHODS

Tumour growth and metastasis were assessed in bladder cancer-bearing mice treated with LDM or MTD gemcitabine (GEM) and CDDP. To elucidate the therapeutic effects of LDM CDDP, the change of tumour vasculature, tumour-infiltrating immune cells and inflammatory changes were evaluated by histological analysis and mRNA expression in tumour tissues.

RESULTS

Tumour growth and bone metastasis were more suppressed by LDM CDDP + MTD GEM treatment than MTD CDDP + MTD GEM. Myeloid-derived suppressor cell accumulation was reduced by LDM CDDP, whereas inflammatory change was induced in the tumour microenvironment by MTD CDDP.

CONCLUSION

LDM CDDP does not cause inflammatory change unlike MTD CDDP, suggesting that it is a promising strategy in chemotherapy.

Nationwide prospective registry database of patients with newly diagnosed untreated pleural mesothelioma in Japan

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

Oral bacterium Streptococcus mutans promotes tumor metastasis through thrombosis formation

Thrombosis is a well-known cardiovascular disease (CVD) complication that has caused death in many patients with cancer. Oral bacteria have been reported to contribute to systemic diseases, including CVDs, and tumor metastasis. However, whether oral bacteria-induced thrombosis induces tumor metastasis remains poorly understood. In this study, the cariogenic oral bacterium Streptococcus mutans was used to examine thrombosis in vitro and in vivo. Investigation of tumor metastasis to the lungs was undertaken by intravenous S. mutans implantation using a murine breast cancer metastasis model. The results indicated that platelet activation, aggregation, and coagulation were significantly altered in S. mutans-stimulated endothelial cells (ECs), with elevated neutrophil migration, thereby inducing thrombosis formation. Streptococcus mutans stimulation significantly enhances platelet and tumor cell adhesion to the inflamed ECs. Furthermore, S. mutans-induced pulmonary thrombosis promotes breast cancer cell metastasis to the lungs in vivo, which can be reduced by using aspirin, an antiplatelet drug. Our findings indicate that oral bacteria promote tumor metastasis through thrombosis formation. Oral health management is important to prevent CVDs, tumor metastasis, and their associated death.

High density and proximity of CD8+ T cells to tumor cells are correlated with better response to nivolumab treatment in metastatic pleural mesothelioma

BACKGROUND

The efficacy of immune checkpoint inhibitors (ICIs) in pleural mesothelioma has recently been established. The response to ICIs can be predicted by quantitative analysis of cells and their spatial distribution in the tumor microenvironment (TME). However, the detailed composition of the TME in pleural mesothelioma has not been reported. We evaluated the association between the TME and response to ICIs in this cancer.

METHODS

A retrospective analysis of 22 pleural mesothelioma patients treated with nivolumab in different centers was performed using surgical specimens. Four patients had a partial response to nivolumab (response group) and 18 patients had stable or progressive disease (nonresponse group). The number of CD4, CD8, FoxP3, CK, and PD-L1 positive cells, cell density, and cell-to-cell distance were analyzed by multiplex immunofluorescence.

RESULTS

PD-L1 expression did not differ significantly between the response and nonresponse groups. The density of total T cells and of CD8⁺ T cells was significantly higher in the response than in the nonresponse group. CD8⁺ T cells were more clustered and located closer to tumor cells, whereas regulatory T cells were located further from tumor cells in the response than in the nonresponse group.

CONCLUSIONS

High density and spatial proximity of CD8⁺ T cells to tumor cells were associated with better response to nivolumab, whereas the proximity of regulatory T cells to tumor cells was associated with worse response, suggesting that the distinct landscape of the TME could be a potential predictor of ICI efficacy in pleural mesothelioma.

A novel edge-marking method in pleural covering with video-assisted thoracic surgery

Total pleural covering is implemented to reinforce the visceral pleura with surgical sheets. It has been adopted for diffuse cystic lung diseases such as lymphangioleiomyomatosis to prevent pneumothorax and has achieved good results. The procedure is technically demanding, because it is difficult to cover the entire visceral pleura without disarrangement and jamming of surgical sheets, especially during thoracoscopic surgery, where grasping of a wrong site might happen when unfolding the sheets. Herein, we report a technique to cover the entire pleura with dotted line folded sheets to ease the thoracoscopic procedure. We found that the use of this marking method made the procedure easier, with just a little ingenuity, because marking the edges of sheets with dashed lines clarifies the site that should be grasped, thus preventing the incidence of grasping the wrong part of the sheet. Pleural covering with dotted line folded surgical sheets is a useful method for reduced port thoracoscopic surgery.

Angiogenic inhibitor pre-administration improves the therapeutic effects of immunotherapy

In lung cancer, immune checkpoint inhibitors (ICIs) are often inadequate for tumor growth inhibition. Angiogenic inhibitors (AIs) are required to normalize tumor vasculature for improved immune cell infiltration. However, in clinical practice, ICIs and cytotoxic antineoplastic agents are simultaneously administered with an AI when tumor vessels are abnormal. Therefore, we examined the effects of pre-administering an AI for lung cancer immunotherapy in a mouse lung cancer model. Using DC101, an anti-vascular endothelial growth factor receptor 2 (VEGFR2) monoclonal antibody, a murine subcutaneous Lewis lung cancer (LLC) model was used to determine the timing of vascular normalization. Microvessel density (MVD), pericyte coverage, tissue hypoxia, and CD8-positive cell infiltration were analyzed. The effects of an ICI and paclitaxel after DC101 pre-administration were investigated. On Day 3, increased pericyte coverage and alleviated tumor hypoxia represented the highest vascular normalization. CD8+ T-cell infiltration was also highest on Day 3. When combined with an ICI, DC101 pre-administration significantly reduced PD-L1 expression. When combined with an ICI and paclitaxel, only DC101 pre-administration significantly inhibited tumor growth, but simultaneous administration did not. AI pre-administration, and not simultaneous administration, may increase the therapeutic effects of ICIs due to improved immune cell infiltration.

Stroma biglycan expression can be a prognostic factor in prostate cancers

OBJECTIVES

This study analyzes the relationship between biglycan expression in prostate cancer and clinicopathological parameters to clarify the potential link between biglycan and prognosis and progression to castration-resistant prostate cancer (CRPC).

METHODS

We retrospectively analyzed 60 cases of prostate cancer patients who underwent robot-assisted laparoscopic radical prostatectomy in Hokkaido University Hospital.

RESULTS

Biglycan was expressed in the tumor stroma but not in tumor cells. There was no significant relationship with biochemical recurrence (p = 0.5237), but the expression of biglycan was 36.1% in the group with progression to CRPC. This indicates a significant relationship with progression to CRPC (p = 0.0182). Furthermore, the expression of biglycan-positive blood vessels was significantly higher (15.9%) in the group with biochemical recurrence than in the group without biochemical recurrence (8.5%) (p = 0.0169). The biglycan-positive vessels were 28.6% in the group with progression to CRPC, which was significantly higher than that in the group without progression to CRPC (p < 0.0001).

CONCLUSION

This is the first study to show that stroma biglycan is a useful prognostic factor for prostate cancer.

miR-1246 in tumor extracellular vesicles promotes metastasis via increased tumor cell adhesion and endothelial cell barrier destruction

Background

Tumor blood vessels play a key role in tumor metastasis. We have previously reported that tumor endothelial cells (TECs) exhibit abnormalities compared to normal endothelial cells. However, it is unclear how TECs acquire these abnormalities. Tumor cells secrete extracellular vesicles (EVs) to create a suitable environment for themselves. We have previously identified miR-1246 to be more abundant in high metastatic melanoma EVs than in low metastatic melanoma EVs. In the current study, we focused on miR-1246 as primarily responsible for acquiring abnormalities in TECs and examined whether the alteration of endothelial cell (EC) character by miR-1246 promotes cancer metastasis.

Methods

We analyzed the effect of miR-1246 in metastatic melanoma, A375SM-EVs, in vivo metastasis. The role of tumor EV-miR-1246 in the adhesion between ECs and tumor cells and the EC barrier was addressed. Changes in the expression of adhesion molecule and endothelial permeability were examined.

Results

Intravenous administration of A375SM-EVs induced tumor cell colonization in the lung resulting in lung metastasis. In contrast, miR-1246 knockdown in A375SM decreased lung metastasis in vivo. miR-1246 transfection in ECs increased the expression of adhesion molecule ICAM-1 via activation of STAT3, followed by increased tumor cell adhesion to ECs. Furthermore, the expression of VE-Cadherin was downregulated in miR-1246 overexpressed EC. A375SM-EV treatment enhanced endothelial permeability. VE-Cadherin was validated as the potential target gene of miR-1246 via the target gene prediction database and 3' UTR assay.

Conclusion

miR-1246 in high metastatic tumor EVs promotes lung metastasis by inducing the adhesion of tumor cells to ECs and destroying the EC barrier.

The oral bacterium Streptococcus mutans promotes tumor metastasis by inducing vascular inflammation

Recent studies have demonstrated a relationship between oral bacteria and systemic inflammation. Endothelial cells (ECs), which line blood vessels, control the opening and closing of the vascular barrier and contribute to hematogenous metastasis; however, the role of oral bacteria-induced vascular inflammation in tumor metastasis remains unclear. In this study, we examined the phenotypic changes in vascular ECs following Streptococcus mutans (S. mutans) stimulation in vitro and in vivo. The expression of molecules associated with vascular inflammation and barrier-associated adhesion was analyzed. Tumor metastasis was evaluated after intravenous injection of S. mutans in murine breast cancer hematogenous metastasis model. The results indicated that S. mutans invaded the ECs accompanied by inflammation and NF-κB activation. S. mutans exposure potentially disrupts endothelial integrity by decreasing VE-cadherin expression. The migration and adhesion of tumor cells were enhanced in S. mutans-stimulated ECs. Furthermore, S. mutans-induced lung vascular inflammation promoted breast cancer cell metastasis to the lungs in vivo. The results indicate that oral bacteria promote tumor metastasis through vascular inflammation and disruption of vascular barrier function. Improving oral hygiene in patients with cancer is of great significance in preventing postoperative pneumonia and tumor metastasis.

Antiviral effect of cetylpyridinium chloride in mouthwash on SARS-CoV-2

Cetylpyridinium chloride (CPC), a quaternary ammonium compound, which is present in mouthwash, is effective against bacteria, fungi, and enveloped viruses. This study was conducted to explore the antiviral effect of CPC on SARS-CoV-2. There are few reports on the effect of CPC against wild-type SARS-CoV-2 at low concentrations such as 0.001%–0.005% (10–50 µg/mL). Interestingly, we found that low concentrations of CPC suppressed the infectivity of human isolated SARS-CoV-2 strains (Wuhan, Alpha, Beta, and Gamma) even in saliva. Furthermore, we demonstrated that CPC shows anti-SARS-CoV-2 effects without disrupting the virus envelope, using sucrose density analysis and electron microscopic examination. In conclusion, this study provided experimental evidence that CPC may inhibit SARS-CoV-2 infection even at lower concentrations.

Metastatic neuroendocrine carcinoma of right adrenal gland successfully treated with laparoscopic adrenalectomy after multimodal therapy

Introduction

We report a case of laparoscopic adrenalectomy in a salvage setting after multiple chemotherapies for neuroendocrine carcinoma.

Case presentation

A 49‐year‐old man was diagnosed with unknown primary carcinoma with single brain metastasis, and right supraclavicular and mediastinal lymph node metastases. After stereotactic radiotherapy of the brain metastasis and systemic chemotherapy, lymphadanectomy was performed. The pathologic diagnosis was neuroendocrine carcinoma. At 11 months after surgery, computed tomography revealed right adrenal metastasis. Local radiotherapy initially resulted in complete remission. However, adrenal recurrence was noted 10 months later. Laparoscopic adrenalectomy was performed with curative intent. The patient is currently alive without recurrence at 20 months after the operation.

Conclusion

Adrenalectomy can become a treatment option if other metastases are well‐controlled with systemic therapy. Surgical elimination of oligometastases can offer long‐term disease control in selected patients as part of a multimodal approach.

The oxidized-LDL/LOX-1 axis in tumor endothelial cells enhances metastasis by recruiting neutrophils and cancer cells

Epidemiological relationships between cancer and cardiovascular diseases have been reported, but a molecular basis remains unclear. Some proteoglycans that strongly bind low-density-lipoprotein (LDL) are abundant both in atherosclerotic regions and in high metastatic-tumor tissue. LDL retention is crucial for the initiation of atherosclerosis, although its contribution to malignancy of cancer is not known. In this study, we show the importance of the accumulation of LDL in tumor metastasis. We demonstrated that high metastatic-tumor tissue contains high amounts of LDL and forms more oxidized LDL (ox-LDL). Interestingly, lectin-like ox-LDL receptor 1 (LOX-1), a receptor for ox-LDL and a recognized key molecule for cardiovascular diseases, was highly expressed in tumor endothelial cells (TECs). Neutrophils are important for ox-LDL formation. Since we observed the accumulation and activation of neutrophils in HM-tumors, we evaluated the involvement of LOX-1 in neutrophil migration and activation. LOX-1 induced neutrophil migration via CCL2 secretion from TECs, which was enhanced by ox-LDL. Finally, we show genetic manipulation of LOX-1 expression in TECs or tumor stroma tended to reduce lung metastasis. Thus, the LOX-1/ox-LDL axis in TECs may lead to the formation of a high metastatic-tumor microenvironment via attracting neutrophils. This article is protected by copyright. All rights reserved.

Novel antiangiogenic therapy targeting biglycan using tumor endothelial cell-specific liposomal siRNA delivery system

Tumor blood vessels play important roles in tumor progression and metastasis. Targeting tumor endothelial cells (TECs) is one of the strategies for cancer therapy. We previously reported that biglycan, a small leucine‐rich proteoglycan, is highly expressed in TECs. TECs utilize biglycan in an autocrine manner for migration and angiogenesis. Furthermore, TEC‐derived biglycan stimulates tumor cell migration in a paracrine manner leading to tumor cell intravasation and metastasis. In this study, we explored the therapeutic effect of biglycan inhibition in the TECs of renal cell carcinoma using an in vivo siRNA delivery system known as a multifunctional envelope‐type nanodevice (MEND), which contains a unique pH‐sensitive cationic lipid. To specifically deliver MEND into TECs, we incorporated cyclo(Arg–Gly–Asp–d–Phe–Lys) (cRGD) into MEND because α_Vβ₃ integrin, a receptor for cRGD, is selective and highly expressed in TECs. We developed RGD‐MEND‐encapsulating siRNA against biglycan. First, we confirmed that MEND was delivered into OS‐RC‐2 tumor‐derived TECs and induced in vitro RNAi‐mediated gene silencing. MEND was then injected intravenously into OS‐RC‐2 tumor‐bearing mice. Flow cytometry analysis demonstrated that MEND was specifically delivered into TECs. Quantitative RT‐PCR indicated that biglycan was knocked down by biglycan siRNA‐containing MEND. Finally, we analyzed the therapeutic effect of biglycan silencing by MEND in TECs. Tumor growth was inhibited by biglycan siRNA‐containing MEND. Tumor microenvironmental factors such as fibrosis were also normalized using biglycan inhibition in TECs. Biglycan in TECs can be a novel target for cancer treatment.

Elevated serum CYFRA 21-1 level as a diagnostic marker for thymic carcinoma

Background

No useful tumor markers have been identified for the diagnosis of thymic carcinomas. Serum cytokeratin 19 fragment, measured using the CYFRA 21‐1 immunoassay, is used as a tumor marker for squamous cell carcinomas in various malignant tumors. Here, we evaluated the value of CYFRA 21‐1 in diagnosing thymic carcinoma.

Methods

We retrospectively reviewed 94 patients with pathological diagnoses of thymic carcinoma or thymoma (32 and 62 patients, respectively) who were referred to our departments between January 2000 and March 2019. Primary outcomes included tumor marker levels and their diagnostic accuracy.

Results

Patients with thymic carcinoma were significantly more likely to be male (thymic carcinoma, 68.8%; thymoma, 40.3%; p = 0.02), have an advanced TNM stage (p < 0.01), and a significantly higher CYFRA 21‐1 level than those with thymoma (thymic carcinoma: median = 4.2 ng/ml; interquartile range [IQR] = 2.1–6.1 ng/ml vs. thymoma: median = 1.2 ng/ml; IQR = 0.9–1.7 ng/ml; p < 0.01). Receiver operating characteristic curves demonstrated that the area under the curve for CYFRA 21‐1 to distinguish thymic carcinoma from thymoma was 0.86 (95% confidence interval [CI]: 0.74–0.93; cutoff = 2.7 ng/ml; sensitivity = 68.8%; specificity = 95.2%). Multivariable analysis demonstrated that CYFRA 21‐1 (odds ratio = 25.6; 95% CI: 4.6–141.6; p < 0.01) was an independent predictor for thymic carcinoma after adjusting for TNM stage.

Conclusions

Serum CYFRA 21‐1 level may help in diagnosing thymic carcinoma.

Intralobar pulmonary sequestration associated with left main coronary artery obstruction and mitral regurgitation

A 4-year-old boy with left intralobar pulmonary sequestration associated with left main coronary artery obstruction (LMCAO) and severe mitral regurgitation (MR) was admitted to our hospital. Since the patient presented with dyskinesia of the cardiac apex and increased left ventricular end-diastolic volume (LVEDV), left main coronary artery reconstruction and mitral annuloplasty were performed. The enlargement of the left ventricle was improved after sequential surgeries. There was a risk of deterioration of MR and regrowth of LVEDV due to shunt blood flow; therefore, left lower lobectomy and aberrant artery division were performed. This is a very rare case of a patient with pulmonary sequestration associated with LMCAO and severe MR.

miRNA-1246 in extracellular vesicles secreted from metastatic tumor induces drug resistance in tumor endothelial cells

Tumor endothelial cells (TECs) reportedly exhibit altered phenotypes. We have demonstrated that TECs acquire drug resistance with the upregulation of P-glycoprotein (P-gp, ABCB1), contrary to traditional assumptions. Furthermore, P-gp expression was higher in TECs of highly metastatic tumors than in those of low metastatic tumors. However, the detailed mechanism of differential P-gp expression in TECs remains unclear. miRNA was identified in highly metastatic tumor extracellular vesicles (EVs) and the roles of miRNA in endothelial cell resistance were analyzed in vitro and in vivo. In the present study, we found that treatment of highly metastatic tumor-conditioned medium induced resistance to 5-fluorouracil (5-FU) with interleukin-6 (IL-6) upregulation in endothelial cells (ECs). Among the soluble factors secreted from highly metastatic tumors, we focused on EVs and determined that miR-1246 was contained at a higher level in highly metastatic tumor EVs than in low metastatic tumor EVs. Furthermore, miR-1246 was transported via the EVs into ECs and induced IL-6 expression. Upregulated IL-6 induced resistance to 5-FU with STAT3 and Akt activation in ECs in an autocrine manner. These results suggested that highly metastatic tumors induce drug resistance in ECs by transporting miR-1246 through EVs.

Rare Diagnosis of a Multilobular Pulmonary Mass

CASE PRESENTATION

A 57-year-old woman was admitted to our hospital for an abnormal chest shadow found during routine chest radiography. She had no respiratory symptoms. Her medical history included dyslipidemia, and her surgical history included conization for cervical cancer at age 38 years. She was a social drinker and ex-smoker of approximately 10 cigarettes per day (from ages 20 to 30 years); she denied recreational drug use.

Prediction of Pulmonary Embolism Following Resection of Pulmonary Infarction: A Case Series

Purpose: Pulmonary nodules suspected to be cancerous are rarely diagnosed as pulmonary infarction (PI). This study examined the clinical, radiological, and laboratory data in cases diagnosed with PI to determine their potential utility as preoperative diagnostic markers. We also assessed factors affecting the postoperative course.

Methods: A total of 603 cases of peripheral pulmonary nodules undiagnosed preoperatively were resected at Hokkaido University Hospital from 2012 to 2019. Of these, we reviewed cases with a postoperative diagnosis of PI. We investigated clinical symptoms, preoperative laboratory data, radiological characteristics, and postoperative complications.

Results: Four patients (0.7%) were diagnosed with PI. All patients had a smoking history. One patient received systemic steroid administration, and none had predisposing factors for thrombosis. One case showed chronologically increased nodule size. Three cases showed weak uptake of ¹⁸F-fluorodeoxyglucose. One patient with preoperative high D-dimer levels developed a massive pulmonary embolism (PE) in the postoperative chronic phase and was treated with anticoagulants.

Conclusions: Preoperative diagnosis of PI is difficult, and we could not exclude lung cancer. However, if a patient diagnosed with PI has a high D-dimer level, we recommend postoperative physical examination for deep venous thrombosis. Prophylactic anticoagulation therapy should be considered to avoid fatal PE.

Inhibition of stromal biglycan promotes normalization of the tumor microenvironment and enhances chemotherapeutic efficacy

Background

Biglycan is a proteoglycan found in the extracellular matrix. We have previously shown that biglycan is secreted from tumor endothelial cells and induces tumor angiogenesis and metastasis. However, the function of stroma biglycan in breast cancer is still unclear.

Methods

Biglycan gene analysis and its prognostic values in human breast cancers were based on TCGA data. E0771 breast cancer cells were injected into WT and Bgn KO mice, respectively.

Results

Breast cancer patients with high biglycan expression had worse distant metastasis-free survival. Furthermore, biglycan expression was higher in the tumor stromal compartment compared to the epithelial compartment. Knockout of biglycan in the stroma (Bgn KO) in E0771 tumor-bearing mice inhibited metastasis to the lung. Bgn KO also impaired tumor angiogenesis and normalized tumor vasculature by repressing tumor necrosis factor-ɑ/angiopoietin 2 signaling. Moreover, fibrosis was suppressed and CD8+ T cell infiltration was increased in tumor-bearing Bgn KO mice. Furthermore, chemotherapy drug delivery and efficacy were improved in vivo in Bgn KO mice.

Conclusion

Our results suggest that targeting stromal biglycan may yield a potent and superior anticancer effect in breast cancer.

Derivation and validation of a nomogram model for pulmonary thromboembolism in patients undergoing lung cancer surgery

Background

A specific risk-stratification tool is needed to facilitate safe and cost-effective approaches to the prophylaxis of acute pulmonary thromboembolism (PTE) in lung cancer surgery patients. This study aimed to develop and validate a simple nomogram model for the prediction of PTE after lung cancer surgery using readily obtainable clinical characteristics.

Methods

A total of 14,427 consecutive adult patients who underwent lung cancer surgery between January 2015 and July 2018 in our institution were retrospectively reviewed. Included in the cohort were 136 patients who developed PTE and 544 non-PTE patients. The patients were randomly divided into the derivation group (70%, 95 PTE patients and 380 non-PTE patients) and the validation group (30%, 41 PTE patients and 164 non-PTE patients). A nomogram model was developed based on the results of multivariate logistic analysis in the derivation group. The cut-off values were defined using Youden's index. The prognostic accuracy was measured by area under the curve (AUC) values.

Results

In the derivation group, multivariate logistic analysis was carried out to evaluate the risk score. The risk assessment model contained five variables: age [95% confidence interval (CI): 1.008-1.083, P=0.016], body mass index (95% CI: 1.077-1.319, P=0.001), operation time (95% CI: 1.002-1.014, P=0.008), the serum level of cancer antigen 15-3 (CA15-3) before surgery (95% CI: 1.019-1.111, P=0.005), and the abnormal results of compression venous ultrasonography before surgery (95% CI: 2.819-18.838, P<0.001). All of them were independent risk factors of PTE. To simplify the risk assessment model, a nomogram model was established, which showed a good predictive performance in the derivation group (AUC 0.792, 95% CI: 0.734-0.853) and in the validation group (AUC 0.813, 95% CI: 0.737-0.890).

Conclusions

A high-performance nomogram was established on the risk factors for PTE in patients undergoing lung cancer surgery. The nomogram could be used to provide an individual risk assessment and guide prophylaxis decisions for patients. Further external validation of the model is needed in lung cancer surgery patients in other clinical centers.

Correlation between endothelial CXCR7 expression and clinicopathological factors in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) impairs functionality and sensuousness resulting in poor quality of life. Biomarkers can predict disease trajectory and lead to effective treatments. Transcriptomics have identified genes that are upregulated in tumor endothelial cells (TECs) compared with normal endothelial cells (NECs). Among them, chemokine receptor 7 (CXCR7) is highly expressed in TECs of several cancers and involved in angiogenesis of TECs. However, levels of CXCR7 in OSCC blood vessels have not been fully investigated. In this study, we analyzed the correlation between CXCR7 expression in TECs and clinicopathological factors in OSCC. Immunohistochemistry for CXCR7 and CD34 was performed on 59 OSCC tissue specimens resected between 1996 and 2008 at Hokkaido University Hospital. CXCR7 expression in blood vessels was evaluated by the ratio of CXCR7+/CD34+ blood vessels. CXCR7 expression was 42% and 19% in tumor and non-tumor parts, respectively, suggesting that CXCR7 expression is higher in TECs than in NECs. CXCR7 expression in TECs correlated with advanced T-stage and cancer stage. Overall survival and disease-free survival rates were higher in low-expressing CXCR7 patients than in high-expressing. These results suggest that CXCR7 expression in blood vessels may be a useful diagnostic and prognostic marker for OSCC patients.

Biglycan, tumor endothelial cell secreting proteoglycan, as possible biomarker for lung cancer

OBJECTIVES

In lung cancer, surgery remains the most curative treatment and limited resection is beneficial for patients with low cardiopulmonary function and low malignancy tumors. However, there are no biomarkers of low malignancy to select candidates for limited resection without compromising the outcome of treatments. Recently we identified biglycan (BGN) as a tumor endothelial cell (TEC) marker that is associated with tumor progression in various cancers. In this study, we analyzed the association between BGN expression in TECs in lung cancer and cancer progression in patients.

MATERIALS AND METHODS

First, we performed immunohistochemistry of BGN with resected lung tumor tissues of 155 patients who had undergone thoracic surgery and analyzed the correlation between BGN-positive vessel density in primary lung tumors and clinicopathological factors. Second, we measured the BGN levels in preoperative serum of other 46 patients with lung cancer by ELISA, and analyzed the correlation between BGN expression in tumor tissues and blood BGN levels.

RESULTS

High BGN expression in the TECs was significantly associated with T factor, and was a significant negative predictor. BGN levels in preoperative serum of 46 patients with lung cancer was significantly correlated with BGN expression in the TECs. Preoperative serum BGN level was significantly lower in healthy volunteers and less invasive adenocarcinoma than in invasive adenocarcinoma and other lung carcinomas. These results suggest that low BGN level in preoperative serum in patients with lung cancer might indicate low malignancy.

CONCLUSIONS

BGN can be a potential biomarker for lung cancer.

Pneumatosis Intestinalis After Living Donor Lung Transplantation Associated With Alpha-Glucosidase Inhibitor Treatment: A Case Report

INTRODUCTION

Pneumatosis intestinalis (PI) is a rare but critical condition in which gas is found in the bowel wall. Although organ transplant recipients have an increased PI risk because of long-term immunosuppression, alpha-glucosidase inhibitors (α-GI), a standard diabetes therapy, often contribute to PI. However, little is known about the postorgan transplantation relationship between PI and α-GI. To the best of our knowledge, this is the first reported case of PI in a lung transplant recipient treated with α-GI.

CASE REPORT

A 59-year-old man underwent hybrid (living-donor and cadaveric) lung transplantation (LTx). The patient was treated with prednisolone and tacrolimus as immunosuppressive therapy and α-GI for diabetes for 4 years. He developed asymptomatic PI 1031 days after transplantation without any acute abdominal finding. After excluding other possible causes of PI, his PI was attributed to α-GI. The suspected α-GI was immediately withdrawn. The patient was managed conservatively with bowel rest and oxygen therapy. After 11 days of α-GI discontinuation, PI improved, and the patient completely recovered.

CONCLUSION

Physicians should keep this rare adverse drug reaction in mind when prescribing α-GI, particularly in patients with diabetes after organ transplantation and including LTx. The management strategy for asymptomatic PI caused by α-GI is the immediate discontinuation of α-GI therapy, followed by conservative management initiation.

Developing a virtual reality simulation system for preoperative planning of thoracoscopic thoracic surgery

Background

Video-assisted thoracoscopic surgery (VATS) has become a standard approach for the treatment of lung cancer. However, its minimally invasive nature limits the field of view and reduces tactile feedback. These limitations make it vital that surgeons thoroughly familiarize themselves with the patient’s anatomy preoperatively. We have developed a virtual reality (VR) surgical navigation system using head-mounted displays (HMD). The aim of this study was to investigate the potential utility of this VR simulation system in both preoperative planning and intraoperative assistance, including support during thoracoscopic sublobar resection.

Methods

Three-dimensional (3D) polygon data derived from preoperative computed tomography data was loaded into BananaVision software developed at Colorado State University and displayed on an HMD. An interactive 3D reconstruction image was created, in which all the pulmonary structures could be individually imaged. Preoperative resection simulations were performed with patient-individualized reconstructed 3D images.

Results

The 3D anatomic structure of pulmonary vessels and a clear vision into the space between the lesion and adjacent tissues were successfully appreciated during preoperative simulation. Surgeons could easily evaluate the real patient’s anatomy in preoperative simulations to improve the accuracy and safety of actual surgery. The VR software and HMD allowed surgeons to visualize and interact with real patient data in true 3D providing a unique perspective.

Conclusions

This initial experience suggests that a VR simulation with HMD facilitated preoperative simulation. Routine imaging modalities combined with VR systems could substantially improve preoperative planning and contribute to the safety and accuracy of anatomic resection.

A novel approach for the complete extraction of large tumours in video-assisted thoracoscopic surgery

Background:

Video-assisted thoracoscopic (VATS) lobectomy has recently become the standard for treating lung cancer. However, the complete removal of large tumours from the chest cavity is often difficult. Therefore, we developed a novel approach to extract large tumours from the wound without rib resection or fracture (the eXtraction of resected specimens through the Lower INterCostal route [XLINC] method).

Subjects and Methods:

In XLINC, a skin incision is made on the tenth intercostal space, and the resected lung tissue is extracted. This retrospective study included patients who underwent VATS lobectomy using XLINC in our institution from 2016 to 2018. As a control group, six patients who had undergone thoracotomy during VATS surgery due to a large tumour diameter were included in the conversion group.

Results:

Four men and six women (median age = 66 years, maximum median tumour diameter = 59 mm) were included in the study. The median length of the wound incision for XLINC was 4.5 (range: 4–8) cm. The median operative time was 183 min, and the estimated blood loss was 50 ml. Rib resection was not required, and no fractures were noted. The median length of hospital stay was 8 days. No patients developed major complications caused by XLINC. There were no significant differences, except in operation time and amount of blood loss, between the two groups. However, the XLINC group used fewer post-operative analgesics.

Conclusion:

Our report suggests that XLINC might be a simpler, less invasive procedure that could be used in patients with large tumours.

Correction to: Left upper lobectomy is a risk factor for cerebral infarction after pulmonary resection: a multicentre, retrospective, case-control study in Japan

The original article can be found online.

Preoperative identification of clinicopathological prognostic factors for relapse-free survival in clinical N1 non-small cell lung cancer: a retrospective single center-based study

Background

Given the difficulty in preoperatively diagnosing lymph node metastasis, patients with Stage I–III non-small cell lung cancer (NSCLC) are likely to be included in the clinical N1 (cN1) group. However, better treatment options might be selected through further stratification. This study aimed to identify preoperative clinicopathological prognostic and stratification factors for patients with cN1 NSCLC.

Methods

This retrospective study evaluated 60 patients who were diagnosed with NSCLC during 2004–2014. Clinical nodal status had been evaluated using routine chest computed tomography (CT) and/or positron emission tomography (PET). To avoid biasing the fluorodeoxyglucose uptake values based on inter-institution or inter-model differences, we used only two PET systems (one PET system and one PET/CT system). Relapse-free survival (RFS) and overall survival (OS) were the primary study outcomes. The maximum standardized uptake value (SUVmax) was calculated for each tumor and categorized as low or high based on the median value. Patient sex, age, histology, tumor size, and tumor markers were also assessed.

Results

Poor OS was associated with older age (P = 0.0159) and high SUVmax values (P = 0.0142). Poor RFS was associated with positive carcinoembryonic antigen (CEA) expression (P = 0.0035) and high SUVmax values (P = 0.015). Multivariate analyses confirmed that poor OS was independently predicted by older age (hazard ratio [HR] = 2.751, confidence interval [CI]: 1.300–5.822; P = 0.0081) and high SUVmax values (HR = 5.121, 95% CI: 1.759–14.910; P = 0.0027). Furthermore, poor RFS was independently predicted by positive CEA expression (HR = 2.376, 95% CI: 1.056–5.348; P = 0.0366) and high SUVmax values (HR = 2.789, 95% CI: 1.042–7.458; P = 0.0410). The primary tumor’s SUVmax value was also an independent prognostic factor for both OS and RFS.

Conclusions

For patients with cN1 NSCLC, preoperative prognosis and stratification might be performed based on CEA expression, age, and the primary tumor’s SUVmax value. To enhance the prognostic value of the primary tumor’s SUVmax value, minimizing bias between facilities and models could lead to a more accurate prognostication.

Intraoperative real-time hemodynamics in intralobar pulmonary sequestration using indocyanine green and near-infrared thoracoscopy

A 33-year-old man with left pulmonary sequestration was admitted to our hospital. We planned left basilar segmentectomy to preserve the lung function, using indocyanine green (ICG) and near-infrared thoracoscopy. The intravenous (IV) administration of ICG (0.1 mg/kg) showed the distribution of fluorescence from the aberrant arteries, blood flow blockage from the aberrant arteries after they were divided, and the superior-basal boundary after the pulmonary artery and vein were divided. In adult patients with intralobar pulmonary sequestration, ICG and near-infrared thoracoscopic techniques are useful to confirm abnormal hemodynamics and demonstrate a safe and successful basilar segmentectomy.

A Novel Insertion Technique for the Extra-Long Montgomery T-Tube in Patients with a Large Mediastinal Tumor

The Montgomery T-tube is widely used to stent airway stenotic diseases. Conventional insertion methods can sometimes fail in the case of long-distance subglottic stenosis due to the flexibility of a T-tube made of silicon, which kinks when forced against resistance. Therefore, an alternative approach can assist in the insertion of an extra-long T-tube, especially when using a long proximal limb. We report herein the case of a patient with a large mediastinal tumor caused by neurofibromatosis type 1 in which airway obstruction was avoided through the use of a novel extra-long T-tube placement technique.

Chemotherapy-Induced IL8 Upregulates MDR1/ABCB1 in Tumor Blood Vessels and Results in Unfavorable Outcome

Tumor endothelial cells (TEC) lining tumor blood vessels actively contribute to tumor progression and metastasis. In addition to tumor cells, TEC may develop drug resistance during cancer treatment, allowing the tumor cells to survive chemotherapy and metastasize. We previously reported that TECs resist paclitaxel treatment via upregulation of ABCB1. However, whether TEC phenotypes are altered by anticancer drugs remains to be clarified. Here, we show that ABCB1 expression increases after chemotherapy in urothelial carcinoma cases. The ratio of ABCB1-positive TEC before and after first-line chemotherapy in urothelial carcinoma tissues (n = 66) was analyzed by ABCB1 and CD31 immunostaining. In 42 cases (64%), this ratio increased after first-line chemotherapy. Chemotherapy elevated ABCB1 expression in endothelial cells by increasing tumor IL8 secretion. In clinical cases, ABCB1 expression in TEC correlated with IL8 expression in tumor cells after first-line chemotherapy, leading to poor prognosis. In vivo, the ABCB1 inhibitor combined with paclitaxel reduced tumor growth and metastasis compared with paclitaxel alone. Chemotherapy is suggested to cause inflammatory changes in tumors, inducing ABCB1 expression in TEC and conferring drug resistance. Overall, these findings indicate that TEC can survive during chemotherapy and provide a gateway for cancer metastasis. Targeting ABCB1 in TEC represents a novel strategy to overcome cancer drug resistance. SIGNIFICANCE: These findings show that inhibition of ABCB1 in tumor endothelial cells may improve clinical outcome, where ABCB1 expression contributes to drug resistance and metastasis following first-line chemotherapy.

[Bronchial Stump Coverage Technique by da Vinci Xi]

da Vinci's greatest attractions are the fine images acquired with a high-resolution 3-dimensional( 3D) endoscope and the precise operation by forceps equipped with an articulated arm. We believed that complicated procedures can benefit from robot-assisted surgery. We have been actively performing collection and sewing of viable tissue using da Vinci Xi for the purpose of preventing bronchial stump fistulas. Of the 44 cases of lobectomy performed by the end of November 2019 using da Vinci Xi, 13 cases underwent bronchial stump covering. The covering procedure was intended for patients with conditions such as diabetes and a history of internal use of steroids. As the dressing, pedicled intercostal muscle was used in 4 cases, and free pericardial fat tissue was used in 9 cases. A good visual field was obtained by appropriately turning the oblique mirror upside down. The smoke emission effect of AirSeal was useful for securing the visual field. The dressing was sutured and fixed using 3-0 or 4-0 Prolene( SH) cut to a length of 10 to 12 cm. The postoperative course was good and bronchial stump fistula did not occur in all cases.

Landiolol, an ultra-short acting beta-1 blocker, for preventing postoperative lung cancer recurrence: study protocol for a phase III, multicenter randomized trial with two parallel groups of patients

Background

Recurrence of cancer after curative surgery is a major problem after most cancer treatments. Increased sympathetic activity during the perioperative period could promote cancer cell invasion to blood vessels and angiogenesis, resulting in cancer metastasis. Recent studies showed that use of beta blockers can be associated with the prolonged survival of patients with cancer. The objective of this study is to evaluate the preventive effects of landiolol hydrochloride, which is an ultra-short-acting beta-1-selective blocker that has been developed in Japan, on reducing recurrence of cancer after curative surgery for patients with lung cancer.

Methods

The present study is a phase III, multicenter, randomized trial with two parallel groups of patients with lung cancer, comparing surgery alone and surgery with landiolol administration for three days during the perioperative period. A total of 400 patients will be enrolled from 12 Japanese institutions. The primary endpoint is two-year relapse-free survival and overall survival after curative surgery for lung cancer. The secondary endpoints are additional treatment after recurrence of cancer, safety events, and the incidence of postoperative complications.

Discussion

The principal question addressed in this trial is whether landiolol can reduce recurrence of cancer after curative surgery for lung cancer.

Trial registration

Japan Registry of Clinical Trials, jRCT2011180004. Registered 17 January 2019.

Development of Immortalized Human Tumor Endothelial Cells from Renal Cancer

Tumor angiogenesis research and antiangiogenic drug development make use of cultured endothelial cells (ECs) including the human microvascular ECs among others. However, it has been reported that tumor ECs (TECs) are different from normal ECs (NECs). To functionally validate antiangiogenic drugs, cultured TECs are indispensable tools, but are not commercially available. Primary human TECs are available only in small quantities from surgical specimens and have a short life span in vitro due to their cellular senescence. We established immortalized human TECs (h-imTECs) and their normal counterparts (h-imNECs) by infection with lentivirus producing simian virus 40 large T antigen and human telomerase reverse transcriptase to overcome the replication barriers. These ECs exhibited an extended life span and retained their characteristic endothelial morphology, expression of endothelial marker, and ability of tube formation. Furthermore, h-imTECs showed their specific characteristics as TECs, such as increased proliferation and upregulation of TEC markers. Treatment with bevacizumab, an antiangiogenic drug, dramatically decreased h-imTEC survival, whereas the same treatment failed to alter immortalized NEC survival. Hence, these h-imTECs could be a valuable tool for drug screening to develop novel therapeutic agents specific to TECs or functional biological assays in tumor angiogenesis research.

Synergistic Enhancement of Cellular Uptake With CD44-Expressing Malignant Pleural Mesothelioma by Combining Cationic Liposome and Hyaluronic Acid-Lipid Conjugate

Malignant pleural mesothelioma (MPM) is a highly aggressive form of cancer, with a median survival of less than 1 year. It is well known that the hyaluronan (HA) receptor CD44 is highly expressed by MPM cells and is reported to be correlated with a poor prognosis. We herein report on the development of a new type if drug delivery system against CD44 that involves the use of lipid nanoparticles (LNPs) equipped with a new type of HA derivative. In this study, we evaluated HA-lipid conjugation (HAL) via the end of the HA molecule through reductive amination, a process that allowed the carboxylate group to remain intact. As a result, the HAL-modified LNP appears to be a potent nanoparticle for dealing with MPM. Surprisingly, the use of a combination of a cationic lipid and HAL had a synergistic effect on cellular uptake in MPM and consequently permitted an anti-cancer drug such as cis-diamminedichloro-platinum(II) (CDDP). Intrapleural injection of CDDP-loaded HAL-LNP (1.5 mg/kg as CDDP) per week significantly suppressed the progression of this type of cancer in an MPM orthotopic model. These results suggest that HAL-modified LNP represents a potent delivery system for MPM cells that express high levels of CD44.

Downregulated expression of human leukocyte antigen class I heavy chain is associated with poor prognosis in non-small-cell lung cancer

The aim of this study was to clarify the association between expression of human leukocyte antigen (HLA) class I in non-small-cell lung cancer (NSCLC) cells and patient survival. To address this, immunohistochemical staining for HLA class I was performed on specimens from 111 patients with NSCLC, and overall survival curves were compared using the log-rank test. In addition, multivariate analyses were performed using Cox's proportional hazard model. The cases were divided into 5 classes based on the expression of HLA class I heavy chain and β2-microglobulin. The overall survival rate for patients with tumors lacking HLA class I heavy chain (30 cases; 27.0%) was significantly decreased. The multivariate analysis demonstrated that the absence of HLA class I heavy chain was an independent predictor of poor prognosis. There was a trend towards an unfavorable prognosis for patients whose tumors did not express β2-microglobulin (57 cases; 51.4%). Downregulation of HLA class I heavy chain expression was significantly associated with the downregulation of β2-microglobulin. Cases lacking HLA class I heavy chain as well as β2-microglobulin expression (23 cases; 20.7%) had a statistically significant unfavorable prognosis compared with other cases. The present findings demonstrate that the lack of HLA class I heavy chain expression in tumor cells is an independent prognostic factor for poor NSCLC survival, and is likely to exert an important influence on immune surveillance in patients.

Familial multifocal micronodular pneumocyte hyperplasia with a novel splicing mutation in TSC1: Three cases in one family

Multifocal micronodular pneumocyte hyperplasia (MMPH) is a rare pulmonary disease, generally manifesting as a tuberous sclerosis complex (TSC), characterised by multiple, small ground-glass nodular shadows on chest computed tomography (CT). Histological examination typically reveals multicentric, well-demarcated, nodular type II pneumocystic growth. Herein, we describe three cases of this rare pulmonary disease occurring within one family. Using reverse transcription polymerase chain reaction (RT-PCR) and direct DNA sequencing, we identified a novel germline mutation, a point mutation in TSC1 intron 5, which yielded a splice variant and loss of function of TSC1. Furthermore, immunohistochemical staining indicated the expression of phospho-p70S6K and phospho-4E-BP1, suggesting that TSC1 function was impaired by the novel gene mutation in MMPH cells.

Resected thymic large cell neuroendocrine carcinoma: report of a case

BACKGROUND

Thymic large cell neuroendocrine carcinoma (LCNEC) is extremely rare. The detailed clinical features of thymic LNCECs remain unknown.

CASE PRESENTATION

A 90-year-old man with a history of diabetes mellitus, chronic renal failure, and an abdominal aortic aneurysm underwent computed tomography for follow-up, which showed an anterior mediastinal tumor, measuring 31 mm × 28 mm in diameter. Magnetic resonance imaging showed an iso-intensity mass on T1-weighted images and high intensity on T2-weighted images. 18F-Fluorodeoxyglucose-positron emission tomography showed marked uptake in the mass, which was diagnosed as invasive thymoma or thymic carcinoma. Video-assisted thoracic surgery through the left thoracic cavity was converted to median sternotomy due to severe adhesions between the left lung and the chest wall. Partial thymectomy and combined partial resection of left upper lobectomy and the first and the second costal cartilages were performed. The pathologic diagnosis was thymic LCNEC, Masaoka stage III. The patient developed pleural dissemination and left lung metastases in 5 months and died 12 months after surgery.

CONCLUSIONS

Thymic LCNEC has high malignant potential. More cases need to be studied.

Abstract 2574: Biglycan, tumor endothelial secreting proteoglycan, as possible biomarker for lung cancer

[Backgroud and Purpose]: Tumor endothelial cells (TECs) have been reported to have various abnormalities. For example, TECs demonstrate higher expression levels of several molecules (TEC markers) compared with normal endothelial cells (NECs). Recently we identified biglycan (Bgn) as one of TEC markers. Bgn has been reported to be associated with tumor progression in various cancers. In addition, we have found that Bgn secreted by TEC promoted intravasation of tumor cells and lung metastasis in vivo mouse tumors. Lung cancer, of which non-small-cell lung cancer (NSCLC) is the most common form, remains the leading cause of cancer-related mortality worldwide, with many patients presenting with advanced disease at initial diagnosis. Moreover, in spite of recent advances in chemotherapy and targeted therapy, 5-year survival for patients with NSCLC is still disappointingly low at less than 20%. Therefore, it is urgent need to develop effective biomarkers for early diagnosis or new therapeutic target. In this study, we analyzed the association between Bgn expression in TEC in lung cancer and the cancer progression of these patients to evaluate the possibility of Bgn as a biomarker. [Method]: A total 46 patients with lung cancer, who had undergone thoracic surgery at Hokkaido university hospital from February 2015 to March 2017 , were enrolled in this study. First, we performed immunohistochemistry of CD31 and Bgn with serial sections of resected lung tumor tissues, and analyzed the correlation between Bgn positive vessel density in primary lung tumors and clinicopathological factors. Second, we measured the Bgn levels in preoperative serum by ELISA,and the correlation between Bgn positive vessel density in lung tumor tissue and blood Bgn levels. [Result]: The Bgn positive vessel density in primary lung tumor tissue was significantly correlated with primary tumor invasion (p=0.036) and pleural invasion (p=0.036). The preoperative serum Bgn level was also significantly correlated with primary tumor invasion (p=0.0017), pleural invasion (p=0.046) and preoperative blood c-reactive protein level (p=0.012). The Bgn positive vessel density in primary lung tumors was significantly correlated with preoperative serum Bgn level (p&lt;0.0001). In case of lung adenocarcinoma, average of serum Bgn level in Ground Glass Opacity (GGO) positive cases (178ng/ml) was significantly lower than that in GGO negative cases (473ng/ml) (p=0.043). The serum Bgn level was significantly higher in the patients classified into high-grade group (1082ng/ml) by IASLC/ATS/ERS classification than that in intermediate-grade or low-grade groups (264ng/ml, p=0.037). [Conclusion]: In conclusion, these results suggested that Bgn expression in TEC could be a biomarker of lung cancer

Citation Format: Hirofumi Morimoto, Nako Maishi, Yasuhiro Hida, Hiroshi Nishihara, Yutaka Hatanaka, Yoshihiro Matsuno, Toru Nakamura, Satoshi Hirano, Kyoko Hida. Biglycan, tumor endothelial secreting proteoglycan, as possible biomarker for lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2574.

Abstract 3927: Clinicopathologic features and immune microenvironment of non-small cell lung cancer with primary resistance to epidermal growth factor receptor-tyrosine kinase inhibitors

Background: Approximately 20-30% of non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) activating mutations are not responsive to EGFR-tyrosine kinase inhibitors (TKIs). Although, primary resistance to EGFR-TKI is attributed to various genetic alterations, little is known about the clinical and immunopathological features of patients with primary resistance. The tumor immune microenvironment including tumor infiltrating lymphocytes (TILs) and programmed death ligand 1 (PD-L1) has been reported to play an important role in tumor progression in NSCLC. However, few studies have directly focused on the relationship between the tumor immune microenvironment and primary resistance to EGFR-TKI.

Materials and Methods: Characteristics of 124 NSCLC patients with EGFR mutations who received EGFR-TKI were analyzed. Primary resistance was defined as disease progression within 3 months after EGFR-TKI treatment. Tumor specimens obtained before EGFR-TKI treatment were assessed for the density of TILs expressing CD4 or CD8, and for the expression rate of PD-L1 on tumor cells and tumor-infiltrating immune cells, immunohistochemically.

Results: Primary resistance was observed in 13.7% (17/124) of patients. Smoking Tobacco correlated significantly with primary resistance compared to non-primary resistance. Lower density of total TILs and negative PD-L1 expression as per immunohistochemical analysis correlated significantly with primary resistance. Moreover, immune ignorant phenotype of tumor microenvironment, negative PD-L1 expression with low TIL density, was significantly observed in primary resistance.

Conclusions: Smoking and immune ignorance in the tumor microenvironment might result in primary resistance to EGFR-TKIs.

Citation Format: Yuta Takashima, Jun Sakakibara-Konishi, Yutaka Hatanaka, Kanako C. Hatanaka, Yoshihito Ohhara, Satoshi Oizumi, Yasuhiro Hida, Kichizo Kaga, Ichiro Kinoshita, Hirotoshi Dosaka-Akita, Yoshihiro Matsuno, Masaharu Nishimura. Clinicopathologic features and immune microenvironment of non-small cell lung cancer with primary resistance to epidermal growth factor receptor-tyrosine kinase inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3927.

Numb has distinct function in lung adenocarcinoma and squamous cell carcinoma

Some reports suggest that Numb is a potential tumor suppressor. However, its role in non-small cell lung cancer remains unclear. Non-small cell lung cancer comprises two major histological subtypes, adenocarcinoma and squamous cell carcinoma. To investigate the role of Numb in tumorigenesis of lung adenocarcinoma and squamous cell carcinoma, we firstly performed loss-of-function and gain-of-function assays. Moreover, Numb expression was investigated in surgically resected lung adenocarcinoma and squamous cell carcinoma tissues by immunohistochemistry and correlations with prognosis were analyzed. Numb suppressed the proliferation, migration, and invasion of adenocarcinoma cells and inhibited Notch signaling and epithelial-mesenchymal transition in vitro. Numb overexpression also inhibited subcutaneous adenocarcinoma tumor growth. In contrast, Numb promoted the proliferation, migration, and invasion of squamous cell carcinoma cells, but did not induce any consistent changes in Notch signaling. High Numb expression was associated with favorable prognosis in patients with lung adenocarcinoma, but not in those with squamous cell carcinoma. Collectively, our data demonstrate that Numb plays distinct roles in lung adenocarcinoma and squamous cell carcinoma. In lung adenocarcinoma, Numb impairs tumor growth and inhibits the Notch pathway and epithelial-mesenchymal transition, whereas in lung squamous cell carcinoma it may promote proliferation.

Prognostic value of MAGEA4 in primary lung cancer depends on subcellular localization and p53 status

Melanoma antigen family A4 (MAGEA4), a cancer/testis antigen, is overexpressed and is thus an immunotherapy target in various malignant tumors, including non-small cell lung cancer. However, whether MAGEA4 induces or inhibits the apoptosis of lung cancer cells remains controversial, as is its prognostic significance, particularly since there is no reliable method with which to detect MAGEA4 specifically. In this study, we optimized assay conditions to detect MAGEA4 based on cells transiently transfected with MAGEA genes, and found that MAGEA4 was expressed in four of eight non-small cell lung cancer cell lines, and in 25.4% of clinical lung cancer specimens. We also found that MAGEA4 overexpression decreased apoptosis, as measured by the levels of cleaved caspase-3 in stably transfected 293F cells. Notably, patients with nuclear MAGEA4, but not p53 expression exhibited a significantly poorer survival than those expressing both nuclear MAGEA4 and p53. Indeed, multivariate analysis identified nuclear MAGEA4 as an independent prognostic factor (P=0.0042), albeit only in the absence of p53. In this study, to the best of our knowledge, we are the first to demonstrate that the function and prognostic value of MAGEA4 depends on its subcellular localization and on the p53 status.

Extrapleural pneumonectomy of recurrent thymoma with pleural dissemination

Complete surgical resection has been considered the only curable treatment for thymoma. The efficacy of extrapleural pneumonectomy (EPP) for stage IV thymomas remains controversial. In this case report, we utilize EPP for recurrent thymoma with pleural dissemination and describe the resulting outcome. A 39-year-old female with a history of thoracoscopic thymectomy for type B2 thymoma was referred to our hospital for a recurrence of thymoma with pleural dissemination. She underwent EPP as a radical surgery. Histopathological investigation revealed complete resection. The postoperative course was uneventful. She returned to her full-time job and showed no sign of recurrence at 31 months after surgery. EPP for recurrent thymoma with pleural dissemination may be considered to achieve macroscopically complete resection when the patient is young and has a sufficient pulmonary function reservoir without preoperative complications.