Shunichiro Iwasawa

Chronic obstructive pulmonary disease as a risk factor for lung cancer

The association between chronic obstructive pulmonary disease (COPD) and lung cancer has long been a subject of intense debate. The high prevalence of COPD in elderly smokers inevitably strengthens their coincidence. In addition to this contingent coincidence, recent studies have revealed a close association between the two diseases that is independent of the smoking history; that is, the existence of COPD is an independent risk factor for the development of lung cancer. Molecular-based evidence has been accumulating as a result of the efforts to explain the underlying mechanisms of this association. These mechanisms may include the following: the retention of airborne carcinogens followed by the activation of oncogenes and the suppression of tumor suppressor genes; the complex molecular mechanism associated with chronic inflammation in the distal airways of patients with COPD; the possible involvement of putative distal airway stem cells; and genetic factors that are common to both COPD and lung cancer. The existence of COPD in patients with lung cancer may potentially affect the process of diagnosis, surgical resection, radiotherapy, chemotherapy, and end-of-life care. The comprehensive management of COPD is extremely important for the appropriate treatment of lung cancer. Surgical resections with the aid of early interventions for COPD are often possible, even for patients with mild-to-moderate COPD. New challenges, such as lung cancer CT screening for individuals at high risk, are now in the process of being implemented. Evaluating the risk of lung cancer in patients with COPD may be warranted in community-based lung cancer screening.

Upregulation of thioredoxin reductase 1 in human oral squamous cell carcinoma

Thioredoxin reductase 1 (TrxR1) catalyzes the nicotinamide adenine dinucleotide phosphate-dependent reduction of oxidized thioredoxin (Trx). Trx, which is over-expressed in many human tumors, is a selenocysteine-containing protein associated with cell proliferation and apoptosis inhibition. This selenium-containing redox system regulates the activity of various enzymes and counteracts oxidative stress in cells such as hypoxia and cytotoxic agents. Consequently, TrxR1 could play an important role in tumor progression and resistance to chemotherapy due to its anti-apoptotic functions. To characterize cancer-related gene expression changes in oral squamous cell carcinomas (OSCC), we compared the gene expression profiles in OSCC primary tumors with patient-matched normal oral epithelium. Microarray analysis showed TrxR1 upregulation in primary tumors. Gene ontology analysis showed highly significant cancer-related function. The TrxR1 expression examined by immunohistochemistry was correlated with regional lymph node metastasis (P<0.05) and the clinical stages of 50 patients (P<0.01). Overexpression of TrxR1 could contribute to cancer progression and might be a potential molecular marker for therapy.

Drug resistance originating from a TGF-β/FGF-2-driven epithelial-to-mesenchymal transition and its reversion in human lung adenocarcinoma cell lines harboring an EGFR mutation

Epithelial-to-mesenchymal transition (EMT) is a malignant cancer phenotype characterized by augmented invasion and metastasis, chemoresistance, and escape from host-immunity. This study sought to identify efficient methods for inducing EMT reversion, to evaluate alterations in chemosensitivity and immune-protectiveness, and to elucidate the underlying mechanisms. In this study, the human lung adenocarcinoma cell lines PC-9 and HCC-827, harboring an EGFR mutation, were treated with TGF-β and FGF-2 to induce EMT. The phenotypic alterations were evaluated by RT-PCR, fluorescent immunohistochemistry, cell-mobility, and flow cytometry. Chemosensitivity to gefitinib and cisplatin was evaluated using an MTT assay and apoptosis. Immune-protectiveness was evaluated by PD-L1 expression. A combination of TGF-β and FGF-2 efficiently induced EMT in both cell lines: through Smad3 pathway in PC-9, and through Smad3, MEK/Erk, and mTOR pathways in HCC-827. The mTOR inhibitor PP242, metformin, and DMSO reverted EMT to different extent and through different pathways, depending on the cell lines. EMT induction reduced the sensitivity to gefitinib in both cell lines and to cisplatin in HCC-827, and it increased PD-L1 expression in both cell lines. EMT reversion using each of the 3 agents partly restored chemosensitivity and suppressed PD-L1 expression. Thus, chemoresistance and increased PD-L1 expression caused by EMT can be successfully reverted by EMT-reverting agents.

Incidence, Risk Factors and Treatment Outcomes of Extravasation of Cytotoxic Agents in an Outpatient Chemotherapy Clinic

OBJECTIVE Extravasation, the accidental leakage of an anticancer agent from a vessel into the surrounding tissues, can lead to irreversible local injuries and severe disability. Despite its considerable clinical importance, evidence-based information on extravasation in chemotherapy is lacking. This study characterized the clinical features of extravasation and identified issues to be resolved in current cancer chemotherapy performed in outpatient settings. METHODS We retrospectively reviewed the medical charts of patients who received chemotherapy and sustained extravasation in our Outpatient Chemotherapy Clinic from April 2007 to August 2012. Chemotherapy administration and extravasation management procedures were standardized using the in-house chemotherapy guideline. RESULTS Among 43 557 patients who received chemotherapy, 35 (0.08%) experienced extravasation. The duration between the start of infusion and extravasation was >2 h in 28 (80.0%) patients. The severity of extravasation was Grades 1, 2 and 3 in 28, 2 and 5 patients, respectively-three of whom were associated with port trouble. The contributing factor for extravasation was walking in 11 (31.4%) patients. All extravasations were cured without surgical intervention by management according to our guidelines. CONCLUSIONS The incidence of extravasation is as low as 0.08%, using our in-house chemotherapy guideline. Extravasation from implanted ports tends to be severe.

Safety of a short hydration method for cisplatin administration in comparison with a conventional method—a retrospective study

OBJECTIVE Cisplatin is administered in combination with massive hydration to avoid renal toxicity, making its administration difficult in an outpatient setting. Although a short hydration protocol for cisplatin has been recently developed, its safety is not fully understood. METHODS Consecutive patients with lung or other cancer and an Eastern Cooperative Oncology Group performance status of 0-2 who were receiving chemotherapy containing cisplatin at a dose of ≥60 mg/m(2) in a single administration were evaluated. Seventy-four patients were treated with a short hydration protocol consisting of 1750-2250 ml of hydration with mannitol and magnesium supplementation over a period of 3.75-4.75 h on Day 1. Sixty-nine patients were treated with a conventional hydration protocol consisting of 2100-2600 ml of hydration over 6.5-7.5 h on Day 1 with pre- and post-hydration on Days 0, 2 and 3. Toxicity was then compared between the two groups. RESULTS An elevated serum creatinine level ≥grade 1 was significantly less frequent in the group receiving the short hydration protocol than in the group receiving conventional hydration. Other toxicities were similar between the two groups. Consequently, the completion rate for the planned treatment in the short hydration group (73.0%, 54/74) was significantly higher than that in the conventional hydration group (53.6%, 37/69). CONCLUSIONS Short hydration is safe, making cisplatin-containing chemotherapy easier to perform.

Overdiagnosis in Lung Cancer Screening with Low-Dose Computed Tomography

Overdiagnosis in Lung Cancer Screening with Low-Dose Computed Tomography We appreciate the comments by Dr. Poullis regarding our recent study examining outcomes in patients with clinical stage IIIA(N2) non–small-cell lung cancer. We agree that the elimination of patients who did not survive 4 months from the analysis was a limitation of the study. The use of Cox–Aalen regression may have mitigated this bias, however, it would not control for potential time biases because of differences in the duration of time it takes to complete certain treatment categories. Dr. Poullis states that there were several covariates affecting survival, such as age, laterality, and histology not included in the Cox regression analysis. In the Methods section we state that these variables were included in our model and were controlled by stratification because of the violation of proportional hazard for these variables. This allows for calculation of hazard ratio for those variables that do not violate the proportional hazard assumption but it does preclude the generation of hazard ratio estimates for variables that do violate the proportional hazard assumption. Therefore, covariates including age, laterality, and histology were included as covariates in the model; however, specific hazard ratios for each of these variables are unavailable. Table 3 reveals an overlap between the confidence intervals for patients who underwent neoadjuvant + lobectomy versus lobectomy followed by adjuvant therapy. However, this table only included patients diagnosed in 2003–2004 (N = 4025) and the purpose of these results was to examine whether comorbidity significantly affected outcomes, which it did not. Our initial cohort with a larger number of patients (N = 10,058) revealed a significant In Response:

Antitumor activity of satraplatin in cisplatin-resistant oral squamous cell carcinoma cells

The aim of the current study was to identify the antitumor activity of satraplatin in paired cisplatin (CDDP)‐resistant oral squamous cell carcinoma (OSCC) cell line and its parental cell line.

Crizotinib-Induced Abnormal Signal Processing in the Retina.

Molecular target therapy for cancer is characterized by unique adverse effects that are not usually observed with cytotoxic chemotherapy. For example, the anaplastic lymphoma kinase (ALK)-tyrosine kinase inhibitor crizotinib causes characteristic visual disturbances, whereas such effects are rare when another ALK-tyrosine kinase inhibitor, alectinib, is used. To elucidate the mechanism responsible for these visual disturbances, the responses to light exhibited by retinal ganglion cells treated with these agents were evaluated using a C57BL6 mouse ex vivo model. Both crizotinib and alectinib changed the firing rate of ON and OFF type retinal ganglion cells. However, the ratio of alectinib-affected cells (15.7%) was significantly lower than that of crizotinib-affected cells (38.6%). Furthermore, these drugs changed the response properties to light stimuli of retinal ganglion cells in some of the affected cells, i.e., OFF cells responded to both ON and OFF stimuli, etc. Finally, the expressions of ALK (a target receptor of both crizotinib and alectinib) and of MET and ROS1 (additional target receptors of crizotinib) were observed at the mRNA level in the retina. Our findings suggest that these drugs might target retinal ganglion cells and that the potency of the drug actions on the light responses of retinal ganglion cells might be responsible for the difference in the frequencies of visual disturbances observed between patients treated with crizotinib and those treated with alectinib. The present experimental system might be useful for screening new molecular target agents prior to their use in clinical trials.

Alveolar Hemorrhage Associated with Pemetrexed Administration

We herein describe a 67-year-old man with advanced adenocarcinoma of the lung who developed an alveolar hemorrhage (AH) associated with pemetrexed. He received four courses of pemetrexed therapy with carboplatin and seven courses of pemetrexed maintenance therapy. One week after the last pemetrexed administration, the patient developed hemoptysis with deteriorating dyspnea and anemia. Chest images showed diffuse ground-glass attenuation. The diagnosis of AH was based on findings of bloody bronchoalveolar lavage (BAL) fluid, hemosiderin-laden macrophages in the BAL fluid, and a transbronchial lung biopsy sample. This report is the first to describe AH associated with pemetrexed.

Pirfenidone may revert the epithelial-to-mesenchymal transition in human lung adenocarcinoma

The epithelial-to-mesenchymal transition (EMT) in cancer is associated with invasion, metastasis and chemoresistance. Recent studies have revealed the increased expression of programmed death-ligand 1 (PD-L1) in cells undergoing EMT. The underlying mechanism of EMT involves transforming growth factor-β (TGF-β) and fibroblast growth factor-2 (FGF-2). Pirfenidone and the known EMT-suppressor nintedanib suppress pulmonary fibrosis partially through suppression of TGF-β. The present study aimed to determine whether pirfenidone has the potential to induce EMT-reversion, using nintedanib as a reference. The human lung adenocarcinoma cell lines A-549, HCC-827, and PC-9 were treated with TGF-β and FGF-2 to induce EMT. The EMT-induced cells were further treated with pirfenidone or nintedanib. Phenotypic alterations associated with EMT were assessed by examining the following: i) The expression levels of E-cadherin, vimentin, fibronectin and slug, using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and fluorescent immunohistochemistry; ii) cell motility via wound-healing assays; and iii) the expression of PD-L1 using RT-qPCR. The combination of TGF-β and FGF-2 successfully induced EMT in all three cell lines, characterized by a significant reduction in E-cadherin expression in the A-549 and HCC-827 cells, increased expression levels of vimentin, fibronectin, slug and PD-L1, and increased cell motility in all three cell lines. Pirfenidone and nintedanib reverted all of these phenotypes, with the exception of unaltered E-cadherin expression in all three cell lines, and inconsistent expression of vimentin in the HCC-827 and PC-9 cells. Thus, pirfenidone and nintedanib have the ability to induce EMT-reversion in human lung adenocarcinoma.