Search

Chimeric antigen receptor (CAR) T cells are effective against hematological cancers, but are less effective against solid tumors such as non-small cell lung cancer (NSCLC). One of the reasons is that only a few cell surface targets specific for NSCLC cells have been identified. Here, we report that CD98 heavy chain (hc) protein is overexpressed on the surface of NSCLC cells and is a potential target for CAR T cells against NSCLC. Screening of over 10,000 mAb clones raised against NSCLC cell lines showed that mAb H2A011 bound to NSCLC cells but not normal lung epithelial cells. H2A011 recognized CD98hc. Although CAR T cells derived from H2A011 could not be established presumably due to the high level of H2A011 reactivity in activated T cells, those derived from the anti-CD98hc mAb R8H283, which had been shown to lack reactivity with CD98hc glycoforms expressed on normal hematopoietic cells and some normal tissues, were successfully developed. R8H283 specifically reacted with NSCLC cells in six of 15 patients. R8H283-derived CAR T cells exerted significant anti-tumor effects in a xenograft NSCLC model in vivo. These results suggest that R8H283 CAR T cells may become a new therapeutic tool for NSCLC, although careful testing for off-tumor reactivity should be performed in the future., (© 2024. The Author(s).)

This pilot study analyzed the dietary patterns of patients with non-small cell lung cancer undergoing initial pembrolizumab, an immune checkpoint inhibitor (ICI), treatment in the month before treatment. Serum fatty acid fractions and their associations with ICI treatment efficacy were also investigated. The results showed that long-term survivors (those who survived for ≥ 3 years) consumed significantly more seafood than short-term survivors (those who survived for < 3 years). Furthermore, the serum levels of eicosapentaenoic acid (EPA) as well as the ratio of EPA to arachidonic acid (EPA/AA) were higher in the long-term survivors than those in the short-term survivors. The group with a high serum EPA/AA ratio had a significantly higher overall survival rate after ICI treatment than the group with a low serum EPA/AA ratio. In conclusion, higher dietary seafood consumption may improve OS in lung cancer patients treated with ICI and the serum EPA/AA ratio may be a useful biomarker for determining the efficacy of ICI treatment. Thus, supplements that increase the serum EPA/AA ratio could serve as new nutritional interventions for enhancing the efficacy of ICI treatment. However, further large-scale case and intervention studies are required., (© 2024. The Author(s).)

Background: Poor oral health has been linked to various systemic diseases, including multiple cancer types, but studies of its association with lung cancer have been inconclusive., Methods: We examined the relationship between dental status and lung cancer incidence and mortality in the Golestan Cohort Study, a large, prospective cohort of 50,045 adults in northeastern Iran. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between three dental health measures (i.e., number of missing teeth; the sum of decayed, missing, or filled teeth (DMFT); and toothbrushing frequency) and lung cancer incidence or mortality with adjustment for multiple potential confounders, including cigarette smoking and opium use. We created tertiles of the number of lost teeth/DMFT score in excess of the loess adjusted, age- and sex-specific predicted numbers, with subjects with the expected number of lost teeth/DMFT or fewer as the reference group., Results: During a median follow-up of 14 years, there were 119 incident lung cancer cases and 98 lung cancer deaths. Higher DMFT scores were associated with a progressively increased risk of lung cancer (linear trend, p = 0.011). Compared with individuals with the expected DMFT score or less, the HRs were 1.27 (95% CI: 0.73, 2.22), 2.15 (95% CI: 1.34, 3.43), and 1.52 (95% CI: 0.81, 2.84) for the first to the third tertiles of DMFT, respectively. The highest tertile of tooth loss also had an increased risk of lung cancer, with a HR of 1.68 (95% CI: 1.04, 2.70) compared with subjects with the expected number of lost teeth or fewer (linear trend, p = 0.043). The results were similar for lung cancer mortality and did not change substantially when the analysis was restricted to never users of cigarettes or opium. We found no associations between toothbrushing frequency and lung cancer incidence or mortality., Conclusion: Poor dental health indicated by tooth loss or DMFT, but not lack of toothbrushing, was associated with increased lung cancer incidence and mortality in this rural Middle Eastern population., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Background and Objectives: Atezolizumab has demonstrated safety and efficacy in patients with metastatic non-small cell lung cancer (NSCLC) in the IMpower110 trial. The aim of this study was to evaluate the cost-effectiveness of atezolizumab as the first-line treatment for patients with unresectable advanced NSCLC, including programmed cell death ligand-1 (PD-L1)-positive probability testing, from the perspective of healthcare costs in Japan., Methods: A cost-effectiveness analysis model for atezolizumab, including PD-L1-positive probability testing, was used to construct a partitioned survival model with three health states. To assess the robustness, a probabilistic sensitivity analysis (PSA) was conducted. The acceptable probability was defined as the probability of willingness-to-pay (WTP) over the incremental cost-effectiveness ratio (ICER). Multiple repetitions at WTP thresholds were calculated by continuously reducing the atezolizumab price., Results: The ICER per quality-adjusted life year (QALY) for atezolizumab therapy only for patients with high PD-L1 expression compared to platinum-based chemotherapy for all patients was 31,975,792 yen per QALY. This is higher than the WTP threshold of 15,000,000 yen. If the cost of atezolizumab were reduced to 54% of the original cost (563,917 yen), the strategy of using atezolizumab for patients with high PD-L1 could become more cost-effective., Conclusions: The results indicated that atezolizumab was not cost-effective compared to platinum-based chemotherapy as a first-line treatment for patients with unresectable advanced NSCLC. However, we suggest that the price of atezolizumab should be reduced to 54% of the original cost to meet the WTP threshold of 15,000,000 yen per QALY., (© 2023. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: Resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has limited treatment options for patients with EGFR-mutated non-small-cell lung cancer (NSCLC). Although osimertinib or afatinib alone induced drug-resistant clones with EGFR secondary mutation in a preclinical model, its combination prevented the appearance of these mutations. We investigated alternating-dose therapy of osimertinib and afatinib in patients with EGFR-mutant NSCLC in a single-arm Phase II trial., Methods: Treatment-naïve patients with stage IV NSCLC harboring an activating EGFR mutation were enrolled. Alternating cycles of osimertinib (80 mg/day) followed by afatinib (20 mg/day) were administered every 8 weeks. Genomic analysis was performed using circulating tumor DNA obtained before and after the treatment., Results: Among the 46 enrolled patients, the median progression-free survival was 20.2 months. The overall response rate was 69.6%. The median overall survival was not reached. Among the 26 plasma samples obtained after the acquisition of resistance, 3 showed an increased MET gene copy number, and 1 showed BRAF mutation. Meanwhile, no EGFR secondary mutation was detected., Conclusion: The efficacy of our treatment was not significantly different from osimertinib alone, as reported previously in untreated advanced NSCLC patients with EGFR mutations. Although the sample size was limited, this treatment may prevent the emergence of EGFR secondary mutations that trigger drug resistance. Further studies are warranted to establish the significance of this treatment., Clinical Trial Registration: jRCTs051180009., Competing Interests: Disclosure The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Immune checkpoint inhibitors (ICIs) have caused revolutionary changes in cancer treatment, but low response rates remain a challenge. Semaphorin 4A (Sema4A) modulates the immune system through multiple mechanisms in mice, although the role of human Sema4A in the tumor microenvironment remains unclear. This study demonstrates that histologically Sema4A-positive non-small cell lung cancer (NSCLC) responded significantly better to anti-programmed cell death 1 (PD-1) antibody than Sema4A-negative NSCLC. Intriguingly, SEMA4A expression in human NSCLC was mainly derived from tumor cells and was associated with T cell activation. Sema4A promoted cytotoxicity and proliferation of tumor-specific CD8 + T cells without terminal exhaustion by enhancing mammalian target of rapamycin complex 1 and polyamine synthesis, which led to improved efficacy of PD-1 inhibitors in murine models. Improved T cell activation by recombinant Sema4A was also confirmed using isolated tumor-infiltrating T cells from patients with cancer. Thus, Sema4A might be a promising therapeutic target and biomarker for predicting and promoting ICI efficacy.

Background: Pulmonary tumor thrombotic microangiopathy is a rapidly progressive and fatal disease in which tumor cells embolize to the pulmonary microvasculature. This condition is characterized by severe dyspnea and right heart failure. Although pulmonary tumor thrombotic microangiopathy typically occurs in patients with untreated and/or advanced cancer, its occurrence in patients who are responding well to medical therapy is poorly documented., Case Presentation: A 68-year-old Japanese woman who had received four cycles of immuno-chemotherapy (pembrolizumab, carboplatin, and pemetrexed) followed by three cycles of maintenance therapy (pembrolizumab and pemetrexed) for advanced non-small cell lung cancer and had achieved a partial response with a stable clinical course was admitted to the emergency ward because of worsening breathlessness and general fatigue for 1 week. Chest computed tomography showed no evidence of tumor progression or any new lung lesion. Two-dimensional transthoracic echocardiography demonstrated right atrial and ventricular dilatation, tricuspid regurgitation, and a high trans-tricuspid pressure gradient of 65 mmHg. Despite her percutaneous oxygen saturation being 96% on room air at the time of admission, it worsened rapidly; the patient requiring 8 L/min of oxygen within 4 h. Repeat computed tomography with contrast medium revealed no evidence of pulmonary embolism. The patient developed progressive respiratory failure that was unresponsive to optimal cardio-pulmonary supportive therapy. An autopsy revealed tumorous clusters in pre-capillary lung vessels, whereas the primary lesion had shrunk to the point of almost complete resolution., Conclusion: Pulmonary tumor thrombotic microangiopathy occurs not only in patients with advanced and/or uncontrolled cancer but also in those whose primary lesion seems to have been well controlled by medical treatment., (© 2023. The Author(s).)

Anti-programmed cell death-1 (PD-1) therapy exerts beneficial effects in a limited population of cancer patients. Therefore, more accurate diagnostics to predict the efficacy of anti-PD-1 therapy are desired. The present study investigated whether peripheral T cell cytotoxicity predicts the efficacy of anti-PD-1 therapy for advanced non-small cell lung cancer (NSCLC) patients. Advanced NSCLC patients treated with anti-PD-1 monotherapy (nivolumab or pembrolizumab) were consecutively enrolled in the present study. Peripheral blood samples were subjected to an analysis of peripheral T cell cytotoxicity and flow cytometry prior to the initiation of anti-PD-1 therapy. Peripheral T cell cytotoxicity was assessed using bispecific T-cell engager (BiTE) technology. We found that progression-free survival was significantly longer in patients with high peripheral T cell cytotoxicity (p = 0.0094). In the multivariate analysis, treatment line and peripheral T cell cytotoxicity were independent prognostic factors for progression-free survival. The analysis of T cell profiles revealed that peripheral T cell cytotoxicity correlated with the ratio of the effector memory population in CD4+ or CD8+ T cells. Furthermore, the results of flow cytometry showed that the peripheral CD45RA+CD25+/CD4+ T cell ratio was higher in patients with than in those without severe adverse events (p = 0.0076). These results indicated that the peripheral T cell cytotoxicity predicted the efficacy of anti-PD-1 therapy for advanced NSCLC patients., (© 2022. The Author(s).)

Background: Since 2015, immune checkpoint inhibitors have been a clinical treatment strategy for patients with advanced or recurrent non-small cell lung cancer (NSCLC). However, the relationship between immune-related adverse event (irAE) risk factors and patient clinical characteristics is unclear. This study aimed to evaluate the relationship between irAE risk and the clinical characteristics of patients with NSCLC., Methods: We included patients with advanced or recurrent NSCLC with known programmed death-ligand 1 expression levels treated with immune checkpoint inhibitors. We retrospectively examined the medical records of 260 patients with NSCLC (March 2016-November 2020) and analyzed the relationship between the patient clinical characteristics and irAEs., Results: Our retrospective analysis revealed that tumor proportion score (TPS) ≥ 90% and adenocarcinoma histology were independent risk factors for irAEs (odds ratio: 3.750 95% confidence interval [CI]: 1.58-8.89 and 0.424 95% CI: 0.19-0.97, respectively) in first-line treatment. However, in patients receiving second- or later-line treatments, no clinical characteristics were identified as risk factors for irAEs. Furthermore, no difference was observed in the response rates to first-line treatments between the TPS ≥ 90% and TPS < 90% groups (74% vs. 71%, p = 0.83). In later-line treatments, the TPS ≥ 90% group had a better response rate than the TPS < 90% group (55% vs. 17%, p < 0.05). However, no significant differences in overall survival were observed in either of the groups., Conclusions: TPS ≥ 90% and adenocarcinoma histology were independent risk factors for irAEs in previously untreated patients with advanced or recurrent NSCLC. Therefore, patients at high risk of irAEs require additional monitoring., (© 2022 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)

Introduction: Alternation of osimertinib and afatinib is a potential approach to overcome osimertinib resistance and to allow complementation of drug efficacy without compromising safety in patients with epidermal growth factor receptor gene (EGFR)-mutated non-small cell lung cancer (NSCLC)., Methods: Treatment-naive patients with stage IV NSCLC harboring an activating EGFR mutation (L858R or exon-19 deletion) were enrolled. Alternating cycles of osimertinib at 80 mg/day for 8 weeks followed by afatinib at 20 mg/day for 8 weeks were administered. The primary end point was 12-month progression-free survival (PFS) probability., Results: Forty-six patients were enrolled and treated with study therapy. The 12-month PFS probability was 70.2% (60% confidence interval [CI], 63.9-75.6%; 95% CI, 54.2-81.5%), which did not meet the primary end point. After a median follow-up time of 25.7 months, the median PFS was 21.3 months (95% CI, 16.3 months-not reached). The overall response rate was 69.6% (95% CI, 54.2-82.3%). The most common treatment-related adverse events (any grade or grade ≥ 3, respectively) were diarrhea (73.9%, 4.3%), rash acneiform (63.0%, 2.2%), and paronychia (52.2%, 0%). Five cases of pneumonitis, two of grade 2 and thres of grade 3, were apparent, all of which developed during osimertinib treatment. Exploratory evaluation of circulating tumor DNA suggested that coexisting TP53 mutations did not influence PFS for the alternating therapy., Conclusions: Alternating therapy with osimertinib and afatinib for treatment-naive patients with EGFR- mutated advanced NSCLC did not meet its primary end point, despite the encouraging efficacy and safety profile of this treatment strategy., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Background and Objectives: Immune checkpoint inhibitors (ICIs) are effective in various types of cancer and cause immune-related adverse events (irAEs). The occurrence of irAEs is associated with improved survival outcome. We investigated the association between the occurrence of irAEs and overall survival (OS) and progression free survival (PFS), and the risk factors for the development of irAEs, in patients with non-small-cell lung cancer (NSCLC), gastric cancer (GC) and melanoma (MM) treated with ICIs., Methods: This was a retrospective observational cohort study, and the data were taken from inpatients in a hospital. OS and PFS were compared among patients with different numbers of irAEs. Log-rank test and Cox regression and logistic regression analysis were applied, and details of irAEs characteristics were summarized., Results: We obtained data from 200 patients. The major tumor types were NSCLC, GC, and MM. Median OS and PFS in all patients were 9.3 and 3.5 months, respectively. Patients without irAEs tended to have shorter OS or PFS compared with those with a single irAE or multi-system irAEs. Covariate analysis suggested that age (≥75 years), albumin (≥3.5 g/dL) and smoking history were significant for increased occurrence of irAEs. Pneumonitis and thyroiditis tended to occur frequently in patients with NSCLC and MM. The irAE grade was ≤2 in 67.3% of all irAEs, and days of irAEs onset varied., Conclusion: We observed patients with irAEs tended to have better OS or PFS in patients with various types of cancers treated with ICIs. We suggest that ICIs should be used appropriately by continuously monitoring the irAEs.

Pulmonary pleomorphic carcinoma is a rare malignant tumor that grows rapidly and has a poor prognosis. Although no effective treatments have so far been established, immune checkpoint inhibitors (ICIs) have shown clinical improvement in some cases of pleomorphic carcinoma. However, pseudoprogression is a major concern for treatment of this carcinoma using ICIs. Here, we report the case of a 61-year-old man who was diagnosed with large cell carcinoma of the lung with brain metastases. Systemic chemotherapy comprising carboplatin and pemetrexed was administered as a first-line therapy; however, disease progression was observed. A tonsillar lesion grew rapidly after the administration of nivolumab as a second-line therapy. Tracheostomy was planned to avoid suffocation, but the patient naturally expectorated the tumor. Pathological examination revealed that it was a palatine tonsillar metastasis of pulmonary pleomorphic carcinoma with infiltration of CD8+/CD4- lymphocytes and necrosis. The primary lesion expanded after nivolumab administration and shrank with no additional nivolumab administration. We therefore concluded that pseudoprogression caused expectoration of the tonsillar metastasis. Hence, ICIs can cause serious adverse events due to pseudoprogression., (© 2021 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)

Here, we report a rare case involving a 66-year-old man with epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma and antisynthetase syndrome (ASS) treated with osimertinib. The patient presented with respiratory failure and bilateral pulmonary opacities; he was diagnosed with ASS accompanied by interstitial lung disease (ILD), consistent with paraneoplastic syndrome. After steroid pulse therapy, osimertinib was administered for lung adenocarcinoma without ILD exacerbation. Osimertinib could therefore be a treatment option for EGFR-mutant lung cancer with paraneoplastic ILD., (© 2021 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.)

Aim: Osimertinib is a key drug for EGFR mutation-positive non-small-cell lung cancer (NSCLC). As the hazards ratio of overall survival in comparison with first-generation EGFR-tyrosine kinase inhibitors was almost similar between FLAURA and ARCHER 1050, salvage use of osimertinib is still a treatment option. Patients & methods: We retrospectively analyzed the clinical courses of EGFR mutation-positive NSCLC patients who were potential candidates for salvage osimertinib. Results: Among 524 patients enrolled from five hospitals, 302 patients underwent biopsy, with 52.6% detection rate of T790M. Osimertinib was administered in 93.6% of the T790M-positive patients. The overall response rate and median progression-free survival time of osimertinib were calculated with 147 patients, to be 55.6% and 17.2 months, respectively. Conclusion: Osimertinib is active for T790M-driven acquired resistance in EGFR -mutant NSCLC, but the detection of T790M was unsatisfactory. Clinical Trial Registration: UMIN000028989 (UMIN Clinical Trials Registry).

Background and Objectives: Immune-checitors have been established as a novel standard treatment for non-small cell lung cancer (NSCLC). The aim of this study was to identify factors associated with efficacy and nivolumab-related interstitial pneumonia in NSCLC by evaluating clinical data at the initiation of and during treatment., Methods: We retrospectively reviewed the medical records of patients who underwent treatment with nivolumab between October 2015 and December 2017. Using pretreatment patient data, we investigated factors associated with overall survival (OS) and the onset of nivolumab-related pneumonitis. We investigated serum biochemistry during treatment to identify the determinants associated with progressive disease (PD) and the onset of nivolumab-related pneumonitis., Results: A total of 94 patients were included. Eleven patients continued treatment, and 54 patients were diagnosed with progressive disease. Nivolumab-related pneumonitis occurred in 15 patients. A pretreatment Eastern Cooperative Oncology Group Performance Status (ECOG PS) = 0 was linked to significantly longer OS than ECOG PS = 1 (median: 20.1 vs. 6.5 months, respectively; p < 0.001). There was a higher incidence of nivolumab-related pneumonitis in patients with a history of interstitial pneumonia than in those without it ( p = 0.008). During treatment, the level of albumin gradually decreased prior to PD and onset of nivolumab-related pneumonitis., Conclusion: These results suggest that the pretreatment ECOG PS is the determining factor that is associated with OS, whereas history of interstitial pneumonia is the factor associated with nivolumab-related pneumonitis. A decrease in albumin during treatment may be associated with both PD and nivolumab-related pneumonitis.

Background: The PD-1-blocking antibody nivolumab persists in patients several weeks after the last infusion. However, no study has systematically evaluated the maximum duration that the antibody persists on T cells or the association between this duration and residual therapeutic efficacy or potential adverse events., Methods: To define the duration of binding and residual efficacy of nivolumab after discontinuation, we developed a simplified strategy for T cell monitoring and used it to analyze T cells from peripheral blood from 11 non-small cell lung cancer patients previously treated with nivolumab. To determine the suitability of our method for other applications, we compared transcriptome profiles between nivolumab-bound and nivolumab-unbound CD8 T cells. We also applied T cell monitoring in 2 nivolumab-treated patients who developed progressive lung tumors during long-term follow-up., Results: Prolonged nivolumab binding was detected more than 20 weeks after the last infusion, regardless of the total number of nivolumab infusions (2-15 doses) or type of subsequent treatment, in 9 of the 11 cases in which long-term monitoring was possible. Ki-67 positivity, a proliferation marker, in T cells decreased in patients with progressive disease. Transcriptome profiling identified the signals regulating activation of nivolumab-bound T cells, which may contribute to nivolumab resistance. In 2 patients who restarted nivolumab, T cell proliferation markers exhibited the opposite trend and correlated with clinical response., Conclusions: Although only a few samples were analyzed, our strategy of monitoring both nivolumab binding and Ki-67 in T cells might help determine residual efficacy under various types of concurrent or subsequent treatment., Trial Registration: University Hospital Medical Information Network Clinical Trials Registry, UMIN000024623., Funding: This work was supported by Japan Society for the Promotion of Science KAKENHI (JP17K16045, JP18H05282, and JP15K09220), Japan Agency for Medical Research and Development (JP17cm0106310, JP18cm0106335 and JP18cm059042), and Core Research for Evolutional Science and Technology (JPMJCR16G2).

Background: Preclinical studies suggested that the addition of bevacizumab could overcome acquired resistance (AR) to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). The aim of this study was to evaluate the clinical efficacy and safety of a combination of afatinib and bevacizumab after AR., Methods: Patients with EGFR-mutant non-small cell lung cancer after AR were enrolled during any line of therapy. Afatinib was prescribed at 30 mg, and 15 mg/kg bevacizumab was administered every 3 weeks until progression., Results: Between October 2014 and May 2017, 32 eligible patients were evaluated. The mutation subtypes were Del-19 (20 [63%]), L858R (11 [34%]), and L861Q (1 [3%]). T790M was detected in 14 patients (44%). The median number of prior regimens was 4 (range, 1-10). Six patients obtained a partial response, and 23 had stable disease; this resulted in an objective response rate (ORR) of 18.8% (95% confidence interval [CI], 7.2%-36.4%) and a disease control rate of 90.7% (95% CI, 75.0%-98.0%). The median progression-free survival (PFS) was 6.3 months (95% CI, 3.9-8.7 months). The ORRs and median PFS times of T790M+ and T790M- patients were 14.3% and 22.2%, respectively, and 6.3 and 7.1 months, respectively; those of Del-19 and L858R patients were 20.0% and 11.1%, respectively, and 6.3 and 5.1 months, respectively. Grade 3 or higher adverse events (incidence ≥ 10%) included paronychia (25%), hypertension (41%), and proteinuria (19%). There were no treatment-related deaths, interstitial lung disease, or bevacizumab-associated severe bleeding., Conclusions: Afatinib plus bevacizumab demonstrated clinical efficacy and safety after AR to EGFR TKIs and could be a therapeutic salvage option for T790M- populations., (© 2018 American Cancer Society.)

Objectives: The effectiveness of treatment after cessation of nivolumab in patients with advanced non-small cell lung cancer (NSCLC) has not been well investigated. The aim of the present study was to clarify the clinical benefit of post-nivolumab treatment in such patients., Materials and Methods: A retrospective review was conducted on patients who received treatment after cessation of nivolumab due to disease progression or adverse events at the Toneyama National Hospital between January 2016 and April 2017., Results: Among 64 patients treated with nivolumab, 26 patients received treatment after cessation of nivolumab due to disease progression (n = 21) or adverse events (n = 5). The median age of the patients was 68 years and 19 patients were male. Nineteen patients had performance status (PS) 1 or less at initiation of post-nivolumab treatment. Four, 20, and 2 patients were treated with platinum doublets, a single agent, and molecular targeting agents, respectively. Response rate, disease control rate, and median progression-free survival of first-line post-nivolumab treatment were 34.6% (9 patients), 73.1% (19 patients), and 2.8 months (95% confidence interval [CI]: 1.7-5.2), respectively. Adverse events (≥ grade 3) and treatment cessation were observed in 57.7% (15 patients) and 19.2% (5 patients), respectively. There were no statistically significant differences for the majority of patient characteristics between the groups with (n = 26) and without post-nivolumab treatment. However, PS at cessation of nivolumab and post-progression survival (PPS) after cessation of nivolumab (median PPS: 12.6 vs. 1.4 months, 95% CI: 3.8-14.7 vs. 0.4-2.2) were significantly different between the groups. A multivariate Cox regression analysis showed significant correlation of PS at cessation of nivolumab (hazard ratio [HR]: 0.34, 95% CI: 0.13-0.87) and post-nivolumab treatment (HR: 0.19, 95% CI: 0.08-0.43) with prolonged PPS after nivolumab., Conclusion: Median post-progression survival in patients with advanced NSCLC who received post-nivolumab treatment was approximately 1 year., Competing Interests: The authors have declared that no competing interests exist.

A 59-year-old woman suffering from dry cough and dyspnea was admitted to our hospital. She had undergone concurrent chemo-radiotherapy five months earlier. Chest computed tomography revealed bilateral ground-glass opacities extending outside the irradiated lung field. Her eosinophil numbers were increased in both the peripheral blood and the bronchoalveolar lavage fluid; therefore, she was diagnosed with radiation pneumonitis accompanied by eosinophilic alveolitis. Steroid therapy promptly improved the pneumonitis. Radiation pneumonitis accompanied by eosinophilic alveolitis extending outside the irradiated field is rare. Bronchoalveolar lavage is useful for a diagnosis, and steroid therapy is effective for treatment.

Nivolumab, an anti-programmed cell death-1 protein monoclonal antibody, is effective for treating patients with late-stage non-small-cell lung cancer. Immune checkpoint inhibitors such as nivolumab induce various kinds of immune-related adverse events, including vitiligo. Vitiligo has been reported in patients with melanoma but not lung cancer. We describe a 75-year-old man with lung adenocarcinoma, stage 4 with pleural and pericardial effusion, that progressed after first-line chemotherapy. Subsequently, he was treated with nivolumab as second-line therapy. After 6days of administering nivolumab, he developed vitiligo suddenly on the trunk of his body. Except for vitiligo, his physical examination was normal, and treatment with nivolumab was well tolerated. Therefore, this treatment was continued without further development or expansion of vitiligo. A computed tomography scan showed a reduction in the size of the lung nodule and stabilization of the pleural and pericardial effusion. This is the first case of vitiligo associated with the use of nivolumab in a patient with lung adenocarcinoma., (Copyright © 2017. Published by Elsevier B.V.)

The purpose of this study was to propose a time-series modeling and simulation (M&S) strategy for probabilistic cost-effective analysis in cancer chemotherapy using a Monte-Carlo method based on data available from the literature. The simulation included the cost for chemotherapy, for pharmaceutical care for adverse events (AEs) and other medical costs. As an application example, we describe the analysis for the comparison of four regimens, cisplatin plus irinotecan, carboplatin plus paclitaxel, cisplatin plus gemcitabine (GP), and cisplatin plus vinorelbine, for advanced non-small cell lung cancer. The factors, drug efficacy explained by overall survival or time to treatment failure, frequency and severity of AEs, utility value of AEs to determine QOL, the drugs' and other medical costs in Japan, were included in the model. The simulation was performed and quality adjusted life years (QALY) and incremental cost-effectiveness ratios (ICER) were calculated. An index, percentage of superiority (%SUP) which is the rate of the increased cost vs. QALY-gained plots within the area of positive QALY-gained and also below some threshold values of the ICER, was calculated as functions of threshold values of the ICER. An M&S process was developed, and for the simulation example, the GP regimen was the most cost-effective, in case of threshold values of the ICER=&#36;70000/year, the %SUP for the GP are more than 50%. We developed an M&S process for probabilistic cost-effective analysis, this method would be useful for decision-making in choosing a cancer chemotherapy regimen in terms of pharmacoeconomic.

Objective: To evaluate the confidence ratings of diagnoses of simulated lesions other than lung cancer on low-dose screening CT with hybrid iterative reconstruction (IR)., Methods: Simulated lesions (emphysema, mediastinal masses and interstitial pneumonia) in a chest phantom were scanned by a 320-row area detector CT. The scans were performed by 64-row and 160-row helical scans at various dose levels and were reconstructed by filtered back projection (FBP) and IR. Emphysema, honeycombing and reticular opacity were visually scored on a four-point scale by six thoracic radiologists. The ground-glass opacity as a percentage of total lung volume (%GGO), CT value and contrast-to-noise ratio (CNR) of mediastinal masses were calculated. These scores and values were compared between FBP and IR. Wilcoxon's signed-rank test was used (p < 0.05). Interobserver agreements were evaluated by κ statistics., Results: There were no significant differences in visual assessment. Interobserver agreement was almost perfect. CT values were almost equivalent between FBP and IR, whereas CNR with IR was significantly higher than that with FBP. %GGO significantly increased at low-dose levels with FBP; however, IR suppressed the elevation., Conclusion: The confidence ratings of diagnoses of simulated lesions other than lung cancer on low-dose CT screening were not degraded with hybrid IR compared with FBP., Advances in Knowledge: Hybrid IR did not degrade the confidence ratings of diagnoses on visual assessment and differential diagnoses based on CT value of mediastinal masses, and it showed the advantage of higher GGO conspicuity at low-dose level. Radiologists can analyse images of hybrid IR alone on low-dose CT screening for lung cancer.

Aim: Non-small cell lung cancer (NSCLC) with minor mutations in the epidermal growth factor receptor (EGFR) gene, except for the common 15 base-pair deletions in exon 19 and the L858R mutation in exon 21, is rare, and only few data exist on this patient population. The aim of the present study was to describe the clinical characteristics and to clarify the efficacy of EGFR-tyrosine kinase inhibitors (TKIs) in patients with NSCLC harboring minor mutations of the EGFR gene., Patients and Methods: This was a multicenter, retrospective study that analyzed specimens from patients with NSCLC who had minor EGFR gene mutations and were treated with EGFR-TKIs between June 2002 and March 2012., Results: Out of 56 patients with minor mutations of the EGFR gene, 44 were treated with either gefitinib or erlotinib. Mutation sites were G719X in exon 18 (n=35), L861Q in exon 21 (n=11), and G874S in exon 21 (n=1). Three patients had both the G719S and the L861Q mutation. The response rate to TKI treatment was 29.5%, and the disease control rate was 63.6%. The median progression-free survival (PFS) was 6.7 months [95% confidence interval (CI)=2.06-8.66 months]. The median PFS was 7.2 months (95% CI=4.23-12.3 months) in 32 patients who received first- or second-line treatment with EGFR-TKIs, whereas the median PFS was 1.57 months (95% CI=0.73-3.8 months) in 12 patients treated with EGFR-TKIs as a third-line or later treatment. In multivariate Cox analysis, erlotinib therapy was associated with a longer PFS than gefitinib (p=0.025)., Conclusion: Patients with NSCLC harboring minor mutations of the EGFR gene exhibited a modest response to EGFR-TKI treatment. Treatment with first-generation EGFR-TKIs, in particular erlotinib, may be considered a first- or second-line option for patients with NSCLC with minor EGFR mutations., (Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.)

A 61-year-old man was diagnosed with lung squamous cell carcinoma in the lower lobe of the right lung. He had received first-line chemotherapy consisting of cisplatin and docetaxel (DTX); however, an allergic/hypersensitivity reaction occurred shortly after administration of the second course of DTX. Thirty-nine months later, he received nanoparticle albumin-bound paclitaxel (nab-PTX) as sixth-line chemotherapy, which did not produce a hypersensitivity reaction. Hypersensitivity after DTX administration may have been due to the DTX vehicle. Therefore, nab-PTX administered under close supervision is a valid therapeutic option in similar cases.

Background: Gefitinib treatment results in considerably better progression-free survival compared with that of platinum doublets in the first line treatment of nonsmall-cell lung cancer (NSCLC) carrying an activating epidermal growth factor receptor (EGFR) mutation. Some patients who respond to gefitinib have an overall survival (OS) of more than 5 years, whereas other initial responders do less well. Although there has been considerable effort made to elucidate the mechanisms of acquired resistance, there have only been a few studies that addressed the effect of clinical backgrounds and treatment histories on the survival of the patients who had responded to an EGFR-tyrosine kinase inhibitor (TKI). In this study, we especially focused on the clinical benefit of EGFR-TKI administration after progression., Patients and Methods: We retrospectively analyzed consecutive patients with advanced NSCLC who were diagnosed before October 2010, treated with gefitinib after July 2002, and responded to it. The primary objective of this study was to evaluate how clinical backgrounds and treatment histories influence survival of the patients who respond to gefitinib. The secondary objectives were to evaluate the safety of long-term gefitinib use and to establish the optimal treatment sequence using a dynamic treatment regimen analysis (DTRA)., Results: A total of 335 patients were recruited. Twenty-eight (8.4%) patients survived more than 5 years. Sixty-five and 93 patients received gefitinib as rechallenge and beyond progressive disease (BPD), respectively. A statistically significant difference in OS was observed between the patients who underwent gefitinib rechallenge and those who did not rechallenge (median: 1272 days vs. 774 days; p < 0.001), a result supported by a DTRA. Patients treated with gefitinib BPD also showed a tendency of longer survival., Conclusions: Gefitinib rechallenge and BPD played a central role in long term survival of the patients who initially responded to gefitinib., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Background/aims: The cytotoxic regimens and bevacizumab (Bev) or anti-EGFR antibody are used for metastatic colorectal cancer (mCRC) that can expect conversion therapy. In this paper, we would present our practical data including the response, survival and toxicity of the capecitabine plus oxaliplatin (CAPEOX) with Bev for mCRC that cannot expect conversion therapy., Methodology: Nineteen patients with mCRC who were treated with CAPEOX with Bev were enrolled. All the patients had the disseminated hepatic, lung, peritoneal metastases or distant lymph node metastasis assessed as no possibility of R0 resection., Results: The median age was 66 (45-85) years old. Target lesion was liver and lung in 9 patients, peritoneum in 5 patients and distant lymph node in 3 patients. CAPEOX with Bev therapy was administered for a median of 8.0 cycles (range, 4-21 cycles). In the 16 evaluable cases, there were no patient with complete response (CR), 9 patients with partial response (PR), 6 with stable disease (SD), and 1 with progressive disease. The objective response rate (CR plus PR) was 56.3%, and disease control rate (CR, PR plus SD) was 93.8%. The median TTP was 9.3 months and the median OS was 21.1 months. No patients treated with surgery even though the good responses were obtained. No severe hematologic adverse toxicities were observed except only one case with grade 3 platelet decrease. Nonhematologic grade 3 events were observed totally 8 patients including 3 for peripheral neuropathy, 2 for bilirubin, and 1 for nausea/vomiting, amylase and stomatitis., Conclusions: We obtained the quite good results of CAPEOX plus Bev as the first-line treatment practically. This regimen might be useful for mCRC that cannot expect conversion therapy.

We report a case of multiple lung and liver metastases from colon cancer treated with clinical benefit by hepatic arterial infusion chemotherapy plus cetuximab mono-therapy after a standard chemotherapy was failed. A 61-year-old female who had sigmoid colon cancer with unresectable multiple lung and liver metastases underwent sigmoidectomy. Bevacizumab plus mFOLFOX6 was performed as first-line therapy. Partial response was obtained temporarily. After the first-line therapy failed, bevacizumab plus FOLFIRI as second-line, and cetuximab plus CPT-11 as third-line therapy were performed. Since these regimens did not work, her performance status got worse by cholangitis due to progressive liver metastases and anemia. Hepatic arterial infusion chemotherapy for liver metastases and cetuximab for lung metastases as fourth therapy were chosen because we thought her liver metastases should be critical for the maintenance of her QOL and diagnosis. After that, serum CEA was reduced from 14,715 to 6,940 ng/mL during the 3 month period. And her performance status got better as cholongitis and anemia were improved. Additionally, lung metastases were controlled by cetuximab.

A 61-year-old woman who had never smoked was given a diagnosis of adenocarcinoma of the lung with multiple pulmonary metastases. Systemic chemotherapy consisting of carboplatin and paclitaxel was not effective, thereafter daily oral administration of gefitinib was initiated. Six days later, bilateral pneumothorax was found. The extent of the pneumothorax was slight and she recovered without drainage within about one month although treatment of gefitinib was restarted. Gefitinib was effective for lung cancer in this case. Bilateral pneumothorax is a rare complication of chemotherapy for lung cancer. Only 3 such cases under treatment with gefitinib were reported in Japan.

A 70-year-old Japanese man was re-admitted because of relapse of adenocarcinoma of the lung. He received daily administration of gefitinib as second-line chemotherapy. He was given a diagnosis of drug-induced lung disease due to gefitinib on day 6 because of hypoxemia and ground glass opacities in the bilateral lung fields. There was no response to corticosteroid pulse therapy. Continuous administration of sivelestat was intravenously added from day 9. Although mechanical ventilation was required for 10 days, lung infiltrates and hypoxia gradually improved. Sivelestat and corcicosteroid was apparently effective in this case and may be useful treatment for drug-induced lung disease due to gefitinib.

We have previously reported that a redox-silent analogue of alpha-tocotrienol (T3), 6-O-carboxypropyl-alpha-tocotrienol (T3E) shows more potential anti-carcinogenic property than T3 in a lung cancer cell (A549 cell). However, the mechanisms by which T3E exerts its potential anti-carcinogenic effect is still unclear. As tumor malignancy is associated with hypoxia adaptation, in this study, we examined whether T3E could suppress survival and invasion in A549 cells under hypoxia. Hypoxia treatment drastically-induced activation of the protein tyrosine kinase, Src, and its regulated signaling required for hypoxia adaptation of A549 tumor cells. The survival and invasion capacity of the tumor cells under hypoxia was suppressed by T3E via the inactivation of Src. More specifically, T3E-dependent inhibition of Src-induced Akt activation contributed to suppression of cell survival under hypoxia, and the reduction of fibrinolytic factors such as plasminogen activator-1(PAI-1) via the decrease of hypoxia-inducible factor-2alpha by T3E led to inhibition of hypoxic invasion. Overall these results suggest that T3E suppresses hypoxia adaptation of A549 cells by the inhibition in hypoxia-induced activation of Src signaling.

Recently, dendritic cells (DCs) and DC-tumor cell hybrids (DC-tumor hybrids) have been used for cancer vaccine therapy in a clinical trial. DC-tumor hybrids combine the potent antigen-presenting capacity of DCs with the ability to present all tumor antigens expressed on tumor cells to T cells. We used DC-tumor hybrids as stimulator cells to induce tumor-specific cytotoxic T lymphocytes (CTLs) in vitro. DC-tumor hybrids were generated from human monocyte-derived DCs and human cancer-cell lines (GT3TKB, lung cancer; GCIY, gastric cancer) by our newly developed electrofusion technique, established and refined with the use of mouse cells. To evaluate the capacity of DC-tumor hybrids generated by our method to induce tumor antigen-specific CTLs, we performed a cytotoxic assay and an interferon-gamma release assay using CD8-dominant effector lymphocytes induced by them. DC-tumor hybrids more effectively induced tumor-specific primary T-cell response than did stimulation with DCs co-cultured with irradiated tumor cells overnight, irradiated tumor cells alone, or a mixture of DCs and irradiated tumor cells. DC-tumor hybrids were generated at a high fusion rate by our electrofusion technique. When CTLs were induced by DC-tumor hybrids in vitro, the high fusion rate did not contribute to the induction of CTLs with increased tumor-specific cytotoxicity. The addition of interleukin-12 to the culture medium did not augment the cytotoxicity of CTLs. Overall, our results suggest that DC-tumor hybrids effectively induce human tumor-specific CTLs and may thus be applicable for clinical trials of adoptive immunotherapy.

Tocotrienols are one of the most potent anticancer agents of all natural compounds and the anticancer property may be related to the inactivation of Ras family molecules. The anticancer potential of tocotrienols, however, is weakened due to its short elimination half life in vivo. To overcome the disadvantage and reinforce the anticancer activity in tocotrienols, we synthesized a redox-silent analogue of alpha-tocotrienol (T3), 6-O-carboxypropyl-alpha-tocotrienol (T3E). We estimated the possibility of T3E as a new anticancer agent against lung adenocarcinoma showing poor prognosis based on the mutation of ras gene. T3E showed cytotoxicity against A549 cells, a human lung adenocarcinoma cell line with a ras gene mutation, in a dose-dependent manner (0-40 microM), whereas T3 and a redox-silent analogue of alpha-tocopherol (T), 6-O-carboxypropyl-alpha-tocopherol (TE), showed much less cytotoxicity in cells within 40 microM. T3E cytotoxicity was based on the accumulation of cells in the G1-phase of the cell-cycle and the subsequent induction of apoptosis. Similar to this event, 24-hr treatment of A549 cells with 40 microM T3E caused the inhibition of Ras farnesylation, and a marked decrease in the levels of cyclin D required for G1/S progression in the cell-cycle and Bcl-xL, a key anti-apoptotic molecule. Moreover, the T3E-dependent inhibition of RhoA geranyl-geranylation is an inducing factor for the occurrence of apoptosis in A549 cells. Our results suggest that T3E suppresses Ras and RhoA prenylation, leading to negative growth control against A549 cells. In conclusion, a redox-silent analogue of T3, T3E may be a new candidate as an anticancer agent against lung adenocarcinoma showing poor prognosis based on the mutation of ras genes., ((c) 2005 Wiley-Liss, Inc.)

It has been assumed that prostaglandin (PG)I2 signaling contributes to the negative growth control of lung cancer cells; however, the mechanism remains unresolved. PGI2 functions through a cell surface G protein-coupled receptor (prostaglandin I2-binding receptor, IP) and also exerts an effect by interacting with a nuclear hormone receptor, peroxisome proliferator-activated receptor delta (PPARdelta). We found that PPARdelta was a key molecule of PGI2 signaling to give negative growth control of lung cancer cells (A549), using carbarprostacyclin, a PGI2 agonist for IP and PPARdelta, and L-165041, a PPARdelta agonist. Furthermore, PPARdelta-induced cell growth control was reinforced by the inhibition of cyclooxygenase. These results suggest that PPARdelta activation under the suppression of PG synthesis is important to regulate lung cancer cell growth.

We conducted a clinical study of cancer vaccine therapy with dendritic cells (DCs) and HLA-A24-restricted carcinoembryonic antigen (CEA)-derived peptide to assess the feasibility and efficacy of such therapy. Eighteen patients with CEA-expressing metastatic gastrointestinal or lung adenocarcinomas who were positive for human leukocyte antigen (HLA)-A24 were enrolled. DCs were generated from the patients' autologous monocyte-enriched fractions of granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cells in the presence of granulocyte/macrophage colony-stimulating factor and interleukin-4. The generated DCs were pulsed with CEA-derived, HLA-A24-restricted 9-mer peptide (CEA652) and injected into the patients intradermally and subcutaneously every 2 weeks. Toxicity and clinical and immunological responses were closely monitored in each patient. No severe toxicity directly attributable to the treatment was observed, and the vaccine was well tolerated. Although no definite tumor shrinkage occurred in any patient, long-term stable disease or marked decreases in the serum CEA level were observed in some patients after therapy. Most of the patients in whom treatment was clinically effective showed a positive skin response to CEA652-pulsed DCs (delayed-type hypersensitivity skin test) and a positive in vitro CTL response to CEA652 peptide after therapy. We conclude that active specific immunotherapy using DCs pulsed with CEA652 is a safe and feasible treatment that is clinically effective in some patients with metastatic gastrointestinal or lung adenocarcinomas. Our results will hopefully encourage further refinement and development of DC-based immunotherapy with HLA-A24-restricted CEA-derived peptide for refractory solid cancers that express CEA.

Regulation of ornithine decarboxylase (ODC) expression at a promotion stage of lung carcinogenesis is a key clue to suppress the cancer. In this study, we investigated that the ODC induction at the promotion stage of lung carcinogenesis in mice could be inhibited through the suppression of the expression of c-myc, a transcription factor for ODC. The treatment with c-myc antisense oligonucleotide decreased the carcinogen-elevated level of pulmonary ODC protein at the promotion stage, but the sense oligonucleotide had no influence on the level. Overall, it is possible that the induction of ODC in the carcinogenic process of lung is regulated at its transcriptional level.

We have already reported that the activation of extracellular signal-regulated kinase (Erk) is critical in the stimulation of cell proliferation during the promotion stage of urethane-induced lung tumorigenesis in mice. Also, we have found that vitamin E suppresses lung tumorigenesis by inhibiting cell proliferation at the promotion stage. However, it is still unclear whether this inhibitory effect at the promotion stage is based on the antioxidative effect of vitamin E or not. In order to address this question, we examined the inhibitory effect of alpha-tocopheryloxybutyric acid (TSE), an ether derivative of vitamin E that cannot act as an antioxidant in vivo, on cell proliferation and the activation of Erk during promotion of lung tumorigenesis. On day 30 after urethane injection (750 mg/kg, i. p.) in A/J mice, TSE or vitamin E at 100 micromol/kg, p.o. was administered. Twenty-four hours after the final administration, the mice were killed to analyze cell proliferation and related parameters. The labeling index of proliferating cell nuclear antigen (a marker of cell proliferation) and ornithine decarboxylase activity (a marker of the promotion stage in lungs) were attenuated by treatment with TSE or vitamin E. TSE or vitamin E treatment also inhibited urethane-induced activation of Erk and suppressed the activation of other essential members of the Erk cascade (Ras, Raf and Mek). These results suggest that vitamin E inhibits cell proliferation and activation of the Erk cascade during promotion of urethane-induced lung tumorigenesis in mice, independent of its antioxidative effect.

The present study was undertaken to estimate the effect of 6-methylthiohexyl isothiocyanate (6MHITC) isolated from Wasabia japonica (wasabi) pretreatment on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK)-induced lung tumorigenesis in mice. Pretreatment with 6MHITC for 4 consecutive days at a daily dose of 5 micromol significantly inhibited NNK-induced O(6)-methylguanine formation in lungs at 4 h after the injection. In conjugation with this inhibitory effect, 6MHITC suppressed the increase in proliferating nuclear cell antigen level as well as ornithine decarboxylase activity at a promotion stage of NNK-induced lung tumorigenesis. Finally, this treatment of 6MHITC suppressed the NNK-induced lung tumorigenesis in mice. These results suggest that 6MHITC inhibits the development of lung tumors in mice treated with NNK, due to the suppression of initiation stage.

The activation of extracellular signal-regulated kinase (ERK) in lung tissues of mice, as determined by the appearance of phosphorylated form, was observed on day 30 after urethane injection, and the activation also occurred in urethane-induced lung tumors. Immunohistochemical analysis using anti-phosphorylated ERK antibody indicated that the active form of ERK localized in alveolar epithelial cells. Furthermore, we confirmed by immunoprecipitation and immunoblot analysis that other essential components of the ERK cascade, that is, Ras, Raf and MEK (known as ERK kinase) were activated. These results indicate that the activation of the ERK signal in alveolar epithelial cells at the early stage of urethane-induced lung carcinogenesis is an important factor to develop lung tumors.

The present study was carried out in order to estimate a usefulness of vitamin E against 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis in mice. Feeding high doses of vitamin E suppressed the NNK-induced elevation of the activity of ornithine decarboxylase, a key enzyme of polyamine biosynthesis, in the lungs of mice at 4 weeks after injection. In contrast, the vitamin elevated the NNK-induced decrease of the activity of spermidine/spermine N1-acetyltransferase, a key enzyme of polyamine biodegradation. In conjugation with these events, the NNK-increased level of proliferating nuclear cell antigen as a marker of cell proliferation was suppressed by vitamin E treatment. Also, the supply of high doses of vitamin E suppressed NNK-induced lung tumorigenesis in mice. These results suggest that vitamin E inhibits the development of lung tumors in mice treated with NNK, partly due to the regulation of polyamine metabolism.

It is known that change in the arachidonic acid metabolism plays an important role in the development of tumors. This study was undertaken to understand the relationship of changes in lipoxygenase, cyclooxygenase and ornithine decarboxylase (ODC) to the inhibitory effect of vitamin E on urethane-induced lung tumorigenesis in mice. We analyzed the inhibitory effect of vitamin E on ornithine decarboxylase, cyclooxygenase and lipoxygenase activities at a promotion phase of lung tumorigenesis in mice. An increase in the ODC of urethane treated-mice and no significant change in the ODC of VE-treated mice were observed. An increase in the production of PGE2 and all HETES tested in the lungs of the urethane-treated mice was observed at week 8 after injection (promotion phase), showing a significant difference compared to the control group. Excessive vitamin E feeding during the initiation or promotion phases inhibited the increase in PGE2 and HETES produced by urethane treatment. These results suggest that the suppression of prostagrandin metabolism and ODC may be associated with the inhibitory effect of vitamin E against urethane-induced lung tumorigenesis.

The present study was undertaken to investigate a mechanism of the inhibitory effect of vitamin E in urethane-induced lung tumorigenesis in mice. We assayed ornithine decarboxylase (ODC) activity and the prostaglandin E2 (PGE2) level in lung at 8 weeks after urethane injection (promotion phase). Excessive vitamin E feeding or indomethacin treatment suppressed the urethane-induced increase in ODC activity, while exogenous PGE2 overcame the effect of vitamin E on ODC activity. Furthermore, the amount of PGE, and the level of ODC activity were well correlated. These results indicate that the vitamin E-induced decrease in PGE2 level probably contributes to the inhibition of ODC induction and the prevention of tumor development in the lung.

We investigated the modulating effect of vitamin E on pulmonary polyamine biosynthesis, cell proliferation and carcinogenesis in mice treated with urethane. Pulmonary ornithine decarboxylase induction and subsequent polyamine accumulation were observed during the initiation and promotion phases of the urethane-induced lung carcinogenesis in mice. The increases of ODC activity and polyamine level during both phases were almost inhibited when a high vitamin E diet was provided. The urethane-increased level of pulmonary proliferating cell nuclear antigen as a marker of cell proliferation during the carcinogenesis was inhibited by vitamin E treatment. Also, vitamin E suppressed the urethane-induced elevation of pulmonary cyclooxygenase activity as a marker of tumor promotion. In conjugation with these events, vitamin E reduced the development of lung tumors in mice treated with urethane. These results indicated that vitamin E could act as a useful chemopreventive agent against lung carcinogenesis in mice due to the regulation of cell proliferation.

To clarify the exact timing of K-ras gene mutational activation in lung tumorigenesis of mice, we applied a sensitive mutant allele specific amplification (MASA) method to pulmonary DNA from urethane-treated mice. The activation of K-ras gene with 61st codon AT mutation was detected in the lungs of mice at day 14 but not day 7 after urethane treatment by MASA. The mutation of MASA products was also checked by XbaI restriction fragment length polymorphism analysis and DNA sequencing. These data suggest that the mutation of K-ras gene in the lungs of mice treated with urethane occurred at the early stage of lung tumorigenesis.

This study was undertaken to estimate if dietary iron could stimulate factors which promote spontaneous lung tumorigenesis in A/J mice, by measuring biochemical parameters of oxidative stress on pulmonary nuclei, ornithine decarboxylase (ODC) and spermidine/spermine N1-acetyltransferase (SAT) activities as markers of tumor promotion. Feeding excessive iron (500%) to A/J mice for 28 weeks significantly elevated pulmonary DNA single strand break (DNA-SSB) as well as nuclear thiobarbituric acid reactive substances (TBARS) in connection with the increase of nuclear nonheme iron level. In contrast, nuclear alpha-tocopherol levels in the iron-loaded group significantly decreased as compared to that in the control group. Pulmonary ODC and SAT activities showed increasing tendency on feeding excess iron for 28 weeks. These results suggest that dietary iron stimulates spontaneous lung tumor promotion in A/J mice, partly due to the enhancement of oxidative damage to the pulmonary nuclei.

The present study was designed to evaluate whether vitamin E could be a useful chemopreventive agent to reduce spontaneous lung tumorigenesis in mice. Starting at 6 weeks of age, groups were divided into three groups, i.e. A/J mice fed a control diet (A/J control), A/J mice fed a vitamin E-supplemented diet (A/J vitamin E) and ddY mice fed a control diet (ddY control). At the 28th experimental week, nuclear NADPH-driven active oxygen generation, thiobarbituric acid reactive substances (TBARS) and DNA single strand breaks (DNA-SSB) in A/J mice fed a control diet were significantly higher than those in the ddY control group. A/J mice fed Vitamin E for 28 weeks could decrease the levels of TBARS and DNA-SSB with a significant difference, as compared with those in A/J control mice. The nuclear alpha-tocopherol levels in A/J controls were significantly lower than those in ddY controls, on the contrary, the vitamin feeding to A/J mice increased nuclear alpha-tocopherol levels more than that in the ddY controls. At the 40th experimental week, lung tumor incidence and tumor multiplicity (percentage of mice with tumors) in A/J controls were reduced and brought close to those in ddY control mice by vitamin E. Then the alpha-tocopherol level in plasma of A/J controls was significantly lower than the level in plasma of ddY controls, and the level in tumor-bearing mice in A/J controls also showed a lower level with significant difference as compared to that in non-tumor-bearing mice of A/J controls. These results suggest that the difference in susceptibility to spontaneous lung tumorigenesis between A/J and ddY mice partly depends on the difference of oxidative stress on the pulmonary nuclei, and vitamin E can act as a useful chemopreventive agent to reduce spontaneous lung tumorigenesis in mice.