Cone-Beam Computed Tomography-Guided Marking of Small Pulmonary Nodules with Surgical Clips.

BACKGROUND: Preoperative computed tomography-guided marking can help identify small non-palpable pulmonary nodules during surgery. However, this technique is associated with the risk of air embolism. We retrospectively evaluated whether small pulmonary nodules could be intraoperatively localized using cone-beam computed tomography (CBCT). METHODS: A hybrid operating room permitting stable lateral positioning and scanning from the pulmonary apex to the base was used in all patients. CBCT images were obtained using a 10-s protocol with 180º rotation of the C-arm flat panel detector around the patient. Clips were placed on the visceral pleura to help guide pulmonary nodule localization. Partial pulmonary resection was performed using video-assisted thoracoscopic surgery at the predicted nodule site. RESULTS: Between July 2013 and June 2019, 132 patients with 145 lesions underwent this procedure at our center. The detection rate of lesions on CBCT was 100%. The pathological diagnoses were primary lung cancer, metastatic pulmonary tumors, and benign lesions. The average consolidation-to-tumor ratio was 0.65 for all nodules, with ratios of 0.33, 0.96, and 0.70 for primary lung cancer, metastatic pulmonary tumors, and benign lesions, respectively. No complications related to this localization method were observed. CONCLUSIONS: CBCT-guided intraoperative localization is safe and feasible for non-palpable small pulmonary nodules. This technique may eliminate the risk of serious complications such as air embolism.

T1 invasive lung adenocarcinoma: Thin-section CT solid score and histological periostin expression predict tumor recurrence.

Adenocarcinoma is the most common histological type of non-small cell lung cancer (NSCLC), and various biomarkers for predicting its prognosis after surgical resection have been suggested, particularly in early-stage lung adenocarcinoma. Periostin (also referred to as POSTN, PN or osteoblast-specific factor) is an extracellular matrix protein, the expression of which is associated with tumor invasiveness in patients with NSCLC. In the present study, the novel approach, in which the thin-section CT findings prior to surgical resection and periostin expression of resected specimens were analyzed in combination, was undertaken to assess whether the findings could be a biomarker for predicting the outcomes following resection of T1 invasive lung adenocarcinoma. A total of 73 patients who underwent surgical resection between January 2000 and December 2009 were enrolled. A total of seven parameters were assessed in the thin-section CT scans: i) Contour; ii) part-solid ground-glass nodule or solid nodule; iii) percentage of solid component (the CT solid score); iv) presence of air-bronchogram and/or bubble-like lucencies; v) number of involved vessels; vi) shape linear strands between the nodule and the visceral pleura; and vii) number of linear strands between the nodule and the visceral pleura. Two chest radiologists independently assessed the parameters. Periostin expression was evaluated on the basis of the strength and extent of staining. Univariate and multivariate analyses were subsequently performed using the Cox proportional hazards model. There was a substantial to almost perfect agreement between the two observers with regard to classification of the seven thin-section CT parameters (κ=0.64-0.85). In the univariate analysis, a CT solid score >80%, pathological lymphatic invasion, tumor and lymph node status and high periostin expression were significantly associated with recurrence (all P<0.05). Multivariate analysis demonstrated that a CT solid score >80% and high periostin expression were risk factors for recurrence (P=0.002 and P=0.011, respectively). The cumulative recurrence rates among the three groups (both negative, CT solid score >80% or high periostin expression, or both positive) were significantly different (log-rank test, P<0.001). Although the solid component is already known to be a major predictor of outcome in lung adenocarcinomas according to previous studies, the combined analysis of CT solid score and periostin expression might predict the likelihood of tumor recurrence more precisely.

Integrity of circulating cell-free DNA as a prognostic biomarker for vaccine therapy in patients with nonsmall cell lung cancer.

BACKGROUND: Many clinical trials of immune checkpoint blockade-based combination therapies are under way. Vaccine therapy is a promising partner of combination therapies. We have developed a personalized peptide vaccination and conducted clinical trials of it in patients with various cancers. At the present time, we have only a limited number of biomarkers related to the prognosis of vaccine-treated patients. Thus, new biomarkers are urgently needed. METHODS: In this study, we investigated the plasma cell-free DNA (cfDNA) integrity-a ratio of the necrotic tumor cell-derived long cfDNA fragments to the total dead cell-derived short cfDNA fragments from genomic Alu elements-in patients with advanced nonsmall cell lung cancer during treatment with the personalized peptide vaccination. RESULTS: We found that (1) the cfDNA integrity was decreased after the first cycle of vaccination, and (2) the patients with high prevaccination cfDNA integrity survived longer than those with low prevaccination integrity (median survival time (MST): 17.9 versus 9.0 months, respectively; hazard ratio (HR): 0.58, p = .0049). A similar tendency was observed in postvaccination cfDNA integrity (MST: 16.4 vs 9.4 months; HR: 0.65, p = .024). CONCLUSIONS: These results suggest that cfDNA integrity is a possible prognostic biomarker in patients treated with the personalized peptide vaccine.

Identification of biomarkers for personalized peptide vaccination in 2,588 cancer patients.

Peptide­based cancer vaccines have failed to provide sufficient clinical benefits in order to be approved in clinical trials since the 1990s. To understand the mechanisms underlying this failure, the present study investigated biomarkers associated with the lower overall survival (OS) among 2,588 patients receiving personalized peptide vaccination (PPV). Survival data were obtained from a database of 2,588 cancer patients including 399 patients with lung, 354 with prostate and 344 with colon cancer. They entered into phase II clinical trials of PPV in which 2 to 4 of 31 warehouse peptides were selected for vaccination on an individual patient basis based on human leukocyte antigen (HLA) class IA­types and pre­existing peptide­specific IgG levels. Higher pre­vaccination neutrophil, monocyte and platelet counts, and lower pre­vaccination lymphocyte and red blood cell counts were inversely associated with OS, with higher sensitivities in the proportions of neutrophils and lymphocytes, respectively. The most potent unfavorable and favorable factors for OS were the median percentage of neutrophils (≥64.8%) or percentage of lymphocytes (≥25.1%) with correlation coefficients (R2) of 0.98 and 0.92, respectively. Higher pre­vaccination levels of c­reactive protein and other inflammatory soluble factors were inversely associated with OS. Pre­vaccination peptide­specific immunity levels had no effect on OS, although lower immune boosting levels were inversely associated with OS. None of the 31 peptides was inversely associated with OS, although a few peptides were positively associated with it. On the whole, the findings of the present study suggested that pre­vaccination inflammatory signatures, but not those of post­vaccination immune induction, were associated with lower clinical benefits of PPV.

Prognostic value of dual-point fluorine-18 fluorodeoxyglucose PET imaging, partial volume correction and glucose transporter-1 expression in resected nonsmall cell lung cancer patients.

OBJECTIVE: To investigate the relationship between the prognosis and glucose transporter-1 (Glut-1) expression or fluorine-18 fluorodeoxyglucose uptake using partial volume correction and dual-point imaging in surgically resected nonsmall cell lung cancer (NSCLC) patients. METHODS: Our patient population consisted of 108 NSCLC cases. The early maximum standardized uptake value (ESUVmax), delayed SUVmax (DSUVmax), partial volume correction SUVmax (cSUVmax) and retention index of primary lesions were calculated. Cox proportional hazard model was applied to evaluate the effects of PET parameters and Glut-1 expression. Overall survival (OS) and disease-free survival (DFS) were evaluated by Kaplan-Meier methods, and the difference in survival between subgroups was analyzed by log-rank test. RESULTS: On the Cox regression analysis, ESUVmax, DSUVmax, cSUVmax and Glut-1 were significantly related to DFS [ESUVmax, hazard ratio = 2.301, 95% confidential interval (CI) = 1.146-4.618, P = 0.019; DSUVmax, hazard ratio = 2.483, 95% CI = 1.257-4.905, P = 0.009; cSUVmax, hazard ratio = 2.205, 95% CI = 1.038-4.686, P = 0.04; Glut-1, hazard ratio = 2.095, 95% CI = 1.086-4.041, P = 0.001] and OS (ESUVmax, hazard ratio = 3.197, 95% CI = 1.339-7.633, P = 0.009; DSUVmax, hazard ratio = 3.599, 95% CI = 1.521-8.516, P = 0.004; cSUVmax, hazard ratio = 8.655, 95% CI = 2.048-36.658, P = 0.003; Glut-1, hazard ratio = 2.427, 95% CI = 5.140, P = 0.021). Retention index had no significant association with DFS or OS. On the Kaplan-Meier survival curves, the patients with high ESUVmax, DSUVmax, cSUVmax and Glut-1 showed significantly worse prognosis than those with low values (ESUVmax: DFS, P = 0.001, OS, P = 0.003; DSUVmax: DFS, P = 0.002, OS, P = 0.004; cSUVmax: DFS, P < 0.001, OS, P = 0.013; Glut-1: DFS, P = 0.012, OS, P = 0.002). CONCLUSIONS: cSUVmax, ESUVmax, DSUVmax and Glut-1 may be more useful biomarkers than retention index for predicting outcomes in NSCLC patients.

Temporary airway stenting for giant anterior mediastinal tumor biopsy: Two case reports.

INTRODUCTION: When the management of an anterior mediastinal tumor requires general anesthesia, airway narrowing and obstruction may occur secondary to muscle relaxation. PRESENTATION OF CASES: Two men (ages, 15 and 36 years) presented with a giant anterior mediastinal tumor and central airway obstruction. We used Dumon stents to effectively secure the airway in both patients. After chemotherapy, stent removal was safely performed in each case because the tumor was substantially smaller. DISCUSSION: Dumon stents effectively secured the airway. These stents were easily removed after chemotherapy without severe complications. CONCLUSION: Temporary stenting is useful in patients with a giant anterior mediastinal tumor who require general anesthesia.

Surgical resection of extramedullary haematopoiesis in the posterior mediastinum.

Extramedullary haematopoiesis is a rare disease that is usually associated with haematologic disorders such as thalassemia, myelodysplastic syndrome, and hereditary spherocytosis. It frequently occurs in the liver, spleen, and lymph nodes. Rarely, it occurs in the posterior mediastinum. We report the case of a 59-year-old man with lateral posterior mediastinal masses that were incidentally detected during treatment for hereditary spherocytosis. We performed video-assisted thoracic surgery to confirm the diagnosis and differentiate the masses from neurogenic tumours and other posterior mediastinal diseases. The pathological findings were consistent with intrathoracic extramedullary haematopoiesis. Although extramedullary haematopoiesis can be managed without interventions, surgery may be required in some cases. In such cases, video-assisted thoracoscopic surgery is advised because it is a useful and less invasive procedure.

The assessment of correlation and prognosis among 18F-FDG uptake parameters, Glut1, pStat1 and pStat3 in surgically resected non-small cell lung cancer patients.

INTRODUCTION: To assess the correlation among 18F-FDG uptake, Glut1, pStat1 and pStat3, and to investigate the relationship between the prognosis and 18F-FDG uptake and these molecular markers in surgically resected non-small cell lung cancer (NSCLC) patients. RESULTS: Knockdown of Glut1 led to a significant increase in pStat1 expression. Glut1 expression positively correlated with the SUVmax, SUVmean, and TLG significantly (P<0.001). pStat3 expression negatively correlated with all PET parameters significantly (P<0.001). pStat1 had positive weak correlations with the SUVmax and SUVmean. All PET parameters and Glut1 were significantly associated with DFS (P<0.05). TLG, MTV, Glut1 and pStat1 were significantly associated with OS (P<0.05). CONCLUSION: pStat3 and Glut1 may be associated with 18F-FDG uptake mechanism. TLG, MTV, and Glut1 may be independent prognostic factors. METHODS: The SUVmax, SUVmean, MTV and TLG of primary lesions were calculated in 140 patients. The expressions of Glut1 and Stat pathway proteins in NSCLC cell lines were examined by immune blots. Excised tumor tissue was analyzed by immunohistochemistry. OS and DFS were evaluated by the Kaplan-Meier method. The difference in survival between subgroups was analyzed by log-rank test. The prognostic significance of clinicopathological, molecular and PET parameters was assessed by Cox proportional hazard regression analysis.

Lung function in the late postoperative phase and influencing factors in patients undergoing pulmonary lobectomy.

BACKGROUND: Lung function in the late postoperative phase after pulmonary lobectomy is insufficiently characterized. This study aimed to appraise lung function in the late postoperative phase according to vital capacity (VC) and forced expiratory volume in 1 second (FEV1) in patients who underwent pulmonary lobectomy. METHODS: Pre- and postoperative VC and FEV1 were reviewed in 112 patients who underwent pulmonary lobectomy. Postoperative lung volume was assessed >1 year after surgery. Postoperative decreases in VC and FEV1 were compared with preoperative predicted values among patients who underwent resection of specific lobe. Determinants effecting a decrease in lung function were also investigated. RESULTS: A mean postoperative decreased VC of 10.5%±1.8% was recorded in patients who underwent right upper lobectomy (RU), 7.2%±1.5% for right middle lobectomy (RM), 14.3%±2.3% for right lower lobectomy (RL), 16.6%±3.0% for left upper lobectomy (LU), and 14.7%±2.5% for left lower lobectomy (LL). Corresponding FEV1 values were 14.8%±1.8% for RU, 11.9%±4.0% for RM, 14.9%±2.3% for RL, 17.9%±2.9% for LU, and 15.1%±2.4% for LL. The actual decreasing rate of VC was overestimated in patients who underwent RU, RL, LU, and LL. In contrast, FEV1 was overestimated only in patients who underwent RL and LL. Patients with chronic obstructive pulmonary disease (COPD) exhibited significantly better preservation of FEV1. CONCLUSIONS: Patients scheduled for RL and LL, or those with COPD, appeared to exhibit preserved lung function in the late postoperative phase after pulmonary lobectomy.

Periostin Expression in Non-Small Cell Lung Cancer: Clinical Significance.

Periostin is an extracellular matrix N-glycoprotein that is a major constituent of the desmoplastic stroma around solid tumors. Periostin promotes tumor invasion and metastasis via epithelial-mesenchymal transition. The aims of this study were to evaluate periostin expression immunohistochemically and quantitatively in patients with non-small cell lung cancer (NSCLC) and to assess any associations with clinical features and prognosis. A total of 184 specimens of NSCLC tissue were investigated, including 134 adenocarcinomas, 39 squamous cell carcinomas, and 11 other histologic subtypes. The intra-tumoral periostin expression area in each captured field was calculated using the image processing integration software WinROOF. The mean periostin expression score was classified as high or low by the median value of its expression area. Univariate analysis demonstrated that gender, tumor size, T status, N status, stage, histologic type, smoking habits, percent vital capacity, 1% forced expiratory volume, and pleural invasion were each significantly associated with periostin scores. Multivariate analysis revealed that high periostin expression score was an independent prognostic factor significantly associated with decreased cancer-specific survival (HR, 3.65; 95% CI, 1.04-12.84; P=0.0439). We concluded that intratumoral periostin expression was an independent prognostic factor for NSCLC.

Survival after initial lung metastasectomy for metastatic colorectal cancer in the modern chemotherapeutic era.

BACKGROUND: A clear survival benefit has been reported for lung metastasectomy for colorectal cancer, and several clinicopathological prognostic factors have been proposed in the past. However, clinical advances, such as chemotherapy and radiographic imaging, should have improved patient outcome and may have altered prognosticators. This study aimed to assess patient survival and determine prognostic factors for survival and recurrence in patients who underwent initial lung metastasectomy for colorectal cancer in the modern clinical era. METHODS: Clinicopathological data and outcomes of 59 patients who underwent curative initial lung metastasectomy for colorectal cancer from 2004 to 2012 at a single institution in Japan were retrospectively investigated. Survival was estimated using the Kaplan - Meier method, and Cox proportional hazards regression models were used to estimate the prognostic impacts of each variable in univariate and multivariate analysis. RESULTS: The 5-years overall and disease-free survival rates were 54.3 and 40.6%, respectively. A disease-free interval < 24 months after colorectal cancer resection (P = 0.004) and a serum carcinoembryonic antigen ≥ 5.0 ng/mL before initial lung metastasectomy (P = 0.015) were independent predictors for poor overall survival. Moreover, the disease-free interval after colorectal cancer resection < 24 months (P = 0.010) and a colorectal cancer with N2 stage disease (P = 0.018) were independently associated with poor disease-free survival. On the other hand, the number of lung metastasis was not identified as a poor prognostic factor for both overall and disease-free survival. CONCLUSIONS: Our findings demonstrated similar or slightly better overall survival, and substantially favorable disease-free survival as compared with past reports. Poor prognostic factors for overall survival appeared not to differ from those of past studies, although this modern series did not determine the number of lung metastasis as a poor prognostic factor, which should be investigated in future studies. Moreover, initial lung metastasectomy is not expected to be a curable treatment for patients with both a short disease-free survival after colorectal cancer resection and colorectal cancers with N2 stage disease.

Feasibility Study of Personalized Peptide Vaccination for Advanced Small Cell Lung Cancer.

INTRODUCTION: The prognosis of patients with small cell lung cancer (SCLC) remains very poor. Therefore, the development of new therapeutic approaches, including immunotherapies, is desirable. PATIENTS AND METHODS: We conducted a phase II study of personalized peptide vaccination (PPV), in which a maximum of 4 human leukocyte antigen-matched peptides were selected from 31 pooled peptides according to the pre-existing peptide-specific IgG responses before vaccination. The PPV was subcutaneously administered. RESULTS: Forty-six patients were enrolled (median age, 63 years; 40 patients were men). Grade 1 (n = 13), 2 (n = 10), or 3 (n = 1) skin reactions at the injection sites were observed; however, no other severe adverse events related to the PPV were observed. The median survival time was 466, 397, 401, and 107 days in the subgroups with 0 (n = 5), 1 (n = 15), 2 (n = 12), and ≥ 3 (n = 14) previous chemotherapy regimens, respectively. Peptide-specific IgG responses to the vaccinated peptides were augmented in 70% and 95% of patients after 1 and 2 vaccination cycles, respectively. The overall survival (OS) of patients with augmented IgG responses to a greater number of nonvaccinated peptides after the second cycle of vaccination was significantly longer (median survival time, 1237 days vs. 382 days; P = .010). In addition, augmentation of IgG responses specific to 6 peptides, including Lck-derived peptides, was significantly related to better OS (P < .05, in each peptide). CONCLUSION: These results suggest the feasibility of PPV for SCLC patients from the viewpoints of safety, immune boosting, and possible prolongation of OS. Therefore, further evaluation of PPV for advanced SCLC in prospective randomized trials is warranted.

Prognostic impact of GATA binding protein-3 expression in primary lung adenocarcinoma.

GATA binding protein-3 (GATA3) is a transcription factor that regulates cell differentiation and maintenance in some types of normal cells. This study aimed to investigate the association between GATA3 expression and primary lung adenocarcinoma and to clarify the clinical significance of GATA3 expression in lung adenocarcinoma. Immunohistochemical GATA3 expression was evaluated using completely resected lung adenocarcinoma samples from 95 cases. GATA3 immunohistochemical staining was performed and scored. Associations between clinicopathological factors and GATA3 expression were analyzed by using the χ2 test and Fisher exact test. The Kaplan-Meier method was used to analyze overall survival (OS) and disease-free survival (DFS). Forty-nine cases expressed high levels of GATA3, which were associated with lymphatic invasion (P=.003). In univariate and multivariate analyses, vascular invasion (P<.001) and high GATA3 expression (P=.023) were identified as independent risk factors for OS. Higher pathological stages (P=.012), vascular invasion (P=.010), and high GATA3 expression (P=.009) were identified as independent risk factors for DFS. The high GATA3 expression group exhibited statistically worse OS (P=.031) and DFS (P=.011) than the low-expression group based on the Kaplan-Meier curves. In resected lung adenocarcinoma, high GATA3 expression is associated with poorer prognosis for both OS and DFS. Therefore, the immunohistochemical evaluation of GATA3 represents a potentially useful prognostic tool for postoperative patients.

Single nucleotide polymorphisms of the haptoglobin gene in non-small cell lung cancer treated with personalized peptide vaccination.

The present study analyzed polymorphisms of the 5' flanking region (from nt -840 to +151) of the haptoglobin gene in 120 patients with advanced non-small cell lung cancer (NSCLC) receiving personalized peptide vaccinations. In the region, six single nucleotide polymorphisms (SNPs) were confirmed, of which two, rs5472 and rs9927981, were completely linked to each other. The minor allele frequencies of rs5472/rs9927981 and rs4788458 were higher than those of the other three SNPs. The genotype frequencies of rs5472 or rs9927981 were A/A or C/C (42.5%, n=51), A/G or C/T (40.8%, n=49), and G/G or T/T (16.7%, n=20), respectively; and those of rs4788458 were T/T (34.2%, n=41), T/C (40.0%, n=48), and C/C (25.8%, n=31). The association between polymorphism rs5472/rs9927981 and prognosis, or between rs4788458 and prognosis, was analyzed further. However, no correlation was found between these SNPs and overall survival, regardless of subgroup analysis of gender, histology or concurrent therapy. These results suggest that the polymorphisms rs5472/rs9927981 and rs4788458 are not useful prognostic tools for patients with NSCLC treated with personalized peptide vaccination.

Immunological evaluation of peptide vaccination for cancer patients with the HLA -A11+ or -A33+ allele.

The HLA-A11 or -A33 allele is found in approximately 18% or 10% of the Asian population, respectively, but each of which is a minor allele worldwide, and therefore no clinical trials were previously conducted. To develop a therapeutic peptide vaccine for each of them, we investigated immunological responses of advanced cancer patients with the HLA-A11+ /A11+ (n = 18) or -A33+ /A33+ (n = 13) allele to personalized peptide vaccine (PPV) regimens. The primary sites of HLA-A11+/A11+ or -A33+/A33+ patients were the colon (n = 4 or 2), stomach (2 or 3), breast (3 or 2), lung and pancreas (2 or 2), and so on. For PPV, a maximum of four peptides were selected from nine different peptides capable of binding to HLA-A11 and -A33 molecules based on the pre-existing peptide-specific IgG responses. There were no severe adverse events related to PPV. At the end of the first cycle, peptide-specific CTL responses were augmented in 4/12 or 2/9 of HLA-A11+ /A11+ or -A33+ /A33+ patients, while peptide-specific IgG responses were augmented in 6/14 or 4/10 patients, respectively. Clinical responses consisted of four stable diseases and 14 progressive diseases in HLA-A11+ /A11+ patients, versus seven and six in -A33+ /A33+ patients, respectively. Further clinical study of PPV could be recommended because of the safety and positive immunological responses.

Randomized Phase II Study of Docetaxel plus Personalized Peptide Vaccination versus Docetaxel plus Placebo for Patients with Previously Treated Advanced Wild Type EGFR Non-Small-Cell Lung Cancer.

Objectives. To evaluate the efficacy and safety of personalized peptide vaccination (PPV) combined with chemotherapy for patients with previously treated advanced non-small-cell lung cancer (NSCLC). Patients and Methods. Previously treated PS0-1 patients with IIIB/IV EGFR (epidermal growth factor receptor) wild genotype NSCLC were randomly assigned to docetaxel (60 mg/m(2) on Day 1) plus PPV based on preexisting host immunity or docetaxel plus placebo. Docetaxel administration was repeated every 3 weeks until disease progression. Personalized peptides or placebo was injected subcutaneously weekly in the first 8 weeks and biweekly in subsequent 16 weeks. The primary efficacy endpoint was progression-free survival (PFS). Results. PPV related toxicity was grade 2 or less skin reaction. The median PFS for placebo arm and PPV arm was 52 days and 59 days, respectively. There was no significant difference between two arms by log-rank test (p = 0.42). Interestingly, PFS and overall survival (OS) in humoral immunological responder were significantly longer than those in nonresponder. Conclusion. PPV did not improve the survival in combination with docetaxel for previously treated advanced NSCLC. However, PPV may be efficacious for the humoral immunological responders and a further clinical investigation is needed.

Experimental validation of talc pleurodesis for carcinomatous pleuritis in an animal model.

OBJECTIVE: This study was performed to evaluate the change of pleural cavity by talc pleurodesis for carcinomatous pleuritis in an animal model. METHODS: Models of malignant pleuritis were produced by an intra-venous injection of lung adenocarcinoma cells to male BALB/c nude mice at 6 weeks of age. Two weeks after the injection, either talc or saline was injected into the left thoracic cavity and the mice were further observed for 4 weeks. Six weeks after the injection, they were killed and the occurrence of lung cancer, amount of pleural effusion, and histological change of the pleural cavity were examined and compared between the two groups with or without talc administration. RESULTS: Talc administration caused a significant reduction in pleural effusion with no increase of pleural adhesion. Talc administration resulted in marked pleural thickening compared to saline treatment. The vascular architecture and its area did not differ between the two groups. CONCLUSION: Talc pleurodesis to reduce pleural effusion is valid for carcinomatous pleuritis, potentially through an acceleration of pleural thickening.

Prognostic Value of Programmed Death Ligand 1 and Programmed Death 1 Expression in Thymic Carcinoma.

PURPOSE: The immune checkpoint of the programmed death 1/programmed death ligand 1 (PD-1/PD-L1) pathway is believed to play an important role in evasion of host antitumor immune surveillance in various malignancies; however, little is known about its role in thymic carcinoma. This study investigated PD-1/PD-L1 expression and its association with clinicopathologic features, the expression of immune-related proteins in tumor-infiltrating lymphocytes (TIL), and patient prognosis. EXPERIMENTAL DESIGN: PD-L1 and PD-1 expression was evaluated by IHC in 25 thymic carcinoma tissue specimens. Copy number alterations of the PD-L1 gene in 11 cases were assessed in formalin-fixed, paraffin-embedded material using qRT-PCR. RESULTS: Compared with normal subjects, 3 thymic carcinoma patients showed an increase in PD-L1 copy number, whereas 8 did not. PD-L1 was significantly overexpressed in cases with copy number gain as compared with normal cases. High PD-L1 expression was associated with higher disease-free and overall survival rates as compared to cases with low expression. Prognostic analysis revealed low PD-L1 expression and high number of PD-1(+) TILs as significant predictors of poor survival, together with Masaoka-Koga stage IVa/IVb disease and incomplete resection. In the quantitative analysis of TILs, PD-L1 expression correlated proportionally with the number of infiltrating CTLs. CONCLUSIONS: Here, for the first time, we report that PD-L1 and PD-1 expression might be useful prognostic predictors in thymic carcinoma. Further studies are expected to substantiate the prognostic value of PD-L1 and PD-1 expression, and the potential efficacy of targeting the PD-1/PD-L1 pathway in thymic carcinoma via immunotherapy. Clin Cancer Res; 22(18); 4727-34. ©2016 AACR.

Clinicopathologic and Prognostic Implications of Programmed Death Ligand 1 Expression in Thymoma.

BACKGROUND: Programmed death ligand 1 (PD-L1) has been reported to be expressed in various malignancies and is considered to be a prognostic factor and an immunotherapeutic target. The aim of this study was to characterize PD-L1 expression in thymoma and determine statistical associations between this expression and clinical features. METHODS: We reviewed formalin-fixed, paraffin-embedded tissue specimens from 82 thymoma cases accumulated at Kurume University, the majority of which achieved surgical complete resection. Expression of PD-L1 was evaluated by immunohistochemistry. Statistical associations between PD-L1 expression and clinicopathologic features were evaluated by using χ(2) test and Fisher's exact test. Disease-free survival and overall survival curves were established by the Kaplan-Meier method and compared using a log-rank test. Predictive factors for disease-free survival after complete resection were analyzed by using a Cox proportional hazards model in univariate and multivariate analysis. RESULTS: Overall, 44 thymoma cases (54%) revealed high PD-L1 expression. High PD-L1 expression was statistically associated with Masaoka stage III/IV disease (p = 0.043) and World Health Organization type B2 or B3 thymoma (p = 0.044). Disease-free survival after complete resection in high PD-L1 expression was significantly worse than that in low PD-L1 expression (p = 0.021), although there was no significant difference in overall survival (p = 0.957). Multivariate analysis also revealed high PD-L1 expression as an independent risk factor for recurrence (p = 0.008). CONCLUSIONS: Characterization of PD-L1 expression in thymoma should enable more effective clinical approaches, including prognostic stratification of patients and potential use of anti-PD-L1 antibody immunotherapy.