The nonsmokers' and smokers' pathways in lung adenocarcinoma: Histological progression and molecular bases.

There could be two carcinogenetic pathways for lung adenocarcinoma (LADC): the nonsmokers' pathway and the smokers' pathway. This review article describes the two pathways with special reference to potential relationships between histological subtypes, malignant grades, and driver mutations. The lung is composed of two different tissue units, the terminal respiratory unit (TRU) and the central airway compartment (CAC). In the nonsmokers' pathway, LADCs develop from the TRU, and their histological appearances change from lepidic to micropapillary during the progression process. In the smokers' pathway, LADCs develop from either the TRU or the CAC, and their histological appearances vary among cases in the middle of the progression process, but they are likely converged to acinar/solid at the end. On a molecular genetic level, the nonsmokers' pathway is mostly driven by EGFR mutations, whereas in the smokers' pathway, approximately one-quarter of LADCs have KRAS mutations, but the other three-quarters have no known driver mutations. p53 mutations are an important factor triggering the progression of both pathways, with unique molecular alterations associated with each, such as MUC21 expression and chromosome 12p13-21 amplification in the nonsmokers' pathway, and HNF4α expression and TTF1 mutations in the smokers' pathway. However, investigation into the relationship between histological progression and genetic alterations is in its infancy. Tight cooperation between traditional histopathological examinations and recent molecular genetics can provide valuable insight to better understand the nature of LADCs.

A method to obtain reproducible Ki-67 indices in lung adenocarcinoma.

AIMS: Proliferative activity, evaluated from the Ki-67 index, is a strong prognostic factor in lung adenocarcinoma (LADC). Here, we optimised a procedure to measure the Ki-67 index and establish the best cut-off value. METHODS AND RESULTS: We examined 342 stage I LADCs for the immunohistochemical expression of Ki-67 using different antibodies, MIB1 and SP6. The results revealed the superior specificity of SP6; therefore, SP6 was used in subsequent analyses. Slides were scanned with a virtual slide system. Using software, tumour cells were counted in a whole tumour. Thereafter, the tumour was evenly subdivided into 0.25-mm2 tiles. The frequency of positive cells was counted in each tile of an invasive area or the whole tumour. We calculated the number of tumour cells required to produce a 95% confidence interval (CI) <0.05. Additionally, we calculated coverage probabilities (CP) using two different methods, counting any number or 200 cells per tile. The results showed that we could meet our goal by counting 2000 cells from 10 random tiles (200 cells each) in invasive areas. CONCLUSIONS: We successfully developed an optimal procedure for determination of the Ki-67 labelling index using an SP6 antibody, which provided CP > 70% and CI of <0.05 in more than 90% of cases. Furthermore, we identified an optimal cut-off value of 0.12 with an alternative of 0.15, based on disease recurrence. This procedure and the cut-off values may be used in the routine pathological diagnosis of LADC.

[Postoperative Relapse of Combined Large‒Cell Neuroendocrine Carcinoma of the Lung with a Remarkable Transient Response to Amrubicin Monotherapy in an Elderly Patient-A Case Report].

An 86‒year‒old man with chronic kidney disease underwent surgical resection for combined large‒cell neuroendocrine carcinoma of the left lower lobe of the lung(pT2aN1M0, stage ⅡB). Five months later, multiple liver and bone metastases and mediastinal lymph node recurrence were detected. After 9 courses of amrubicin monotherapy(32 mg/m2 for 3 consecutive days), his tumor marker levels normalized, and radiological examination revealed a complete tumor response. Adverse events occurred, but they were tolerable except a decrease in the neutrophil count. The patient remained in good condition for several months but died of tumor relapse 22 months after the initial recurrence. Amrubicin monotherapy was considered to be one of the treatment choices for recurrent large‒cell neuroendocrine carcinoma of the lung in elderly patients.

Validating margin status in lung wedge resection for clinical stage I non-small cell lung cancer.

Stage I non-small cell lung cancer (NSCLC) is a localized disease without metastasis; therefore, it can be treated effectively with local therapies. Pulmonary resection is the most frequent treatment, performed as pulmonary wedge resection, segmentectomy, lobectomy, or pneumonectomy. Some retrospective clinical studies of pulmonary wedge resection suggest that its outcome may be inferior to that of anatomical pulmonary resection, whereas other recent studies, which assess surgical margin status, leveled acceptable outcomes. Since the outcome of pulmonary wedge resection for lung cancer may depend on tumor size, distance from the surgical margin to the tumor, tumor size/margin distance ratio, and margin cytology results, a prospective study assessing these parameters is ongoing. This will allow us to identify the clinical implications of these factors and predict which patients are likely to have a good outcome.

The pathological features of idiopathic interstitial pneumonia-associated pulmonary adenocarcinomas.

AIMS: To investigate the pathological features of idiopathic interstitial pneumonia (IIP)-associated pulmonary adenocarcinoma. METHODS AND RESULTS: Surgically resected adenocarcinomas associated with IIP (the IIP group) and adenocarcinomas without IIP (the non-IIP group) were subjected to analysis. Adenocarcinomas in the IIP group were subdivided into two groups: one group included tumours connected to bronchiolar metaplasia in honeycomb lesions (the H-IIP group), and the other included tumours unrelated to honeycomb lesions (the NH-IIP group). Histomorphological appearance and immunohistochemical expression were compared among the H-IIP group, the NH-IIP group, and the non-IIP group. Most of the tumour cells in the H-IIP group had a tall, columnar shape that showed similar features to proximal bronchial epithelium, whereas tumour cells in the NH-IIP group and the non-IIP group had a club-like shape that showed similar features to respiratory bronchiolar/alveolar epithelium. Adenocarcinomas in the H-IIP group tended to be negative for thyroid transcription factor-1 (TTF-1) and positive for hepatocyte nuclear factor-4α (HNF-4α). The frequency of EGFR mutations was significantly lower in adenocarcinomas in the H-IIP group, although the frequencies of KRAS and ALK mutations did not differ among the three groups. CONCLUSIONS: Idiopathic interstitial pneumonia-associated pulmonary adenocarcinomas, especially those arising from honeycomb lesions, have distinct pathological features.

The potential significance of alpha-enolase (ENO1) in lung adenocarcinomas - A utility of the immunohistochemical expression in pathologic diagnosis.

We herein analyzed the relationships among the immunohistochemical expression of alpha-enolase (ENO1) and clinicopathological factors in order to define the significance of ENO1 in lung adenocarcinomas (ADCs). ENO1 expression was detected in most of the ADCs examined (95.8%), but not in bronchial and alveolar epithelia. ENO1 expression was typically observed in the cytoplasm among most ADCs (95.8%), but was also detected in the nucleus (56.3%). The levels were significantly higher in terminal respiratory unit (TRU) cytological subtype ADCs. Neither cytoplasmic nor nuclear expression was associated with any other clinicopathological factors including post-operative survival and growth activity. These results suggest that ENO1 is a crucial factor promoting neoplastic transformation exclusively in TRU subtype ADCs. We also investigated the potential utility of the immunohistochemical expression of ENO1 to differentiate TRU-type ADC cells from the reactive hyperplasia of pneumocytes and bronchiolar epithelial cells because difficulties are associated with discriminating these lesions in small biopsy specimens. The sensitivity and specificity of ENO1 (cytoplasmic/nuclear) were 87.5%/37.5% and 88.9%/100%, respectively, which are superior to those of p53 (18.8% and 100%). ENO1 has potential as a biomarker to assist in the histopathological detection of TRU subtype ADC cells.

Alterations in cathepsin L expression in lung cancers.

We herein investigated the potential role of cathepsin L in lung carcinogenesis. Lung cancer cell lines and surgically resected tumors were examined for the expression of the cathepsin L protein and copy number alterations in its gene locus. Cathepsin L was stably expressed in bronchiolar epithelial cells. Neoplastic cells expressed cathepsin L at various levels, whereas its expression was completely lost in most of the lung cancer cell lines (63.6%, 7/11) examined. Furthermore, expression levels were lower in a large fraction of lung tumors (69.5%, 139/200) than in bronchiolar epithelia. The expression of cathepsin L was lost in some tumors (16.0%, 32/200). In adenocarcinomas, expression levels were significantly lower in high-grade tumors than in low-grade tumors (one-way ANOVA, P < 0.0500). Copy number alterations were found in 18.0% (36 [32 gain + 4 loss] /200) of lung tumors. No relationship existed between cathepsin L protein expression levels and the copy number of its gene locus (Spearman's rank-order correlation, P = 0.3096). Collectively, these results suggest that the down-regulated expression of cathepsin L, which is caused by an undefined mechanism other than copy number alterations, is involved in the progression of lung adenocarcinomas.

Simultaneously Detected Liver and Lung Metastases from Colorectal Carcinoma: A Potential Treatment Strategy.

BACKGROUND/AIM: No clear treatment strategy for simultaneously detected liver and lung metastases (SLLM) of colorectal carcinoma has been established, to date. We aimed to identify the prognostic factors for SLLM and propose an appropriate treatment option. PATIENTS AND METHODS: This retrospective study included 64 patients with SLLM: 32 underwent pulmonary resection after hepatectomy in 32, while the other 32 underwent hepatectomy alone in 32. Poor prognostic factors and a suitable strategy for SLLM were assessed. RESULTS: Multivariate analysis showed that preoperative carcinoembryonic antigen (CEA) level ≥20 ng/ml (p=0.001) and unresected lung metastases (p=0.001) were independent prognostic factors for poor overall survival. Compared with the non-pulmonary resection group, the rate of R1 resection of liver tumors (46.8% vs. 15.6%; p=0.007), incidence of complications after hepatectomy (Clavien-Dindo grade ≥III: 21.8% vs. 0%; p=0.005) and having four or more metastatic lung nodules (40.6% vs. 3.2%; p=0.001) were significantly higher in the group that underwent hepatectomy only. CONCLUSION: Preoperative CEA ≥20 ng/ml and unresectable pulmonary nodules were prognostic factors for poor survival of patients with SLLM. Furthermore, the presence of more than four pulmonary nodules was a preoperative predictive factor for unresectable pulmonary nodules. R1 resection and the occurrence of complications after hepatectomy should be avoided; a smooth transition from hepatectomy to pulmonary resection is important.

Favourable surgical outcomes for either second primary lung cancer or intrapulmonary metastasis after resection of non-small-cell lung cancer.

OBJECTIVES: Metachronous lung cancer arising after resection of non-small-cell lung cancer is either a second primary lung cancer (SPLC) or intrapulmonary metastasis (IPM) of the initial lung cancer; however, differential diagnosis is difficult. We evaluated the surgical outcomes of metachronous lung cancer in a combined population of patients with SPLC and IPM. METHODS: A retrospective study of 3534 consecutive patients with resected non-small-cell lung cancer between 1992 and 2016 was conducted at 4 institutions. RESULTS: A total of 105 patients (66 males; median age, 70 years) who underwent a second pulmonary resection for metachronous lung cancer were included. Most patients (81%) underwent sublobar resection, and there was no 30-day mortality. All metachronous lung cancers were cN0, 5 were pN1-2. The postoperative comprehensive histologic assessment revealed SPLC (n = 77) and IPM (n = 28). The 5-year overall survival rate after the second resection was 70.6% (median follow-up: 69.7 months). A multivariable analysis showed that age >70 years at the second resection (P = 0.013), male sex (P = 0.003), lymph node involvement in metachronous cancer (P < 0.001), pathological invasive size of metachronous cancer >15 mm (P < 0.001) and overlapping squamous cell carcinoma histology of the initial and metachronous cancers (P = 0.003) were significant prognostic factors for poor survival after the second resection, whereas histological IPM was not (P = 0.065). CONCLUSIONS: Surgery for cN0 metachronous lung cancer is safe and shows good outcomes. There were no statistically significant differences in the SPLC and IPM results. Caution should be exercised when operating on patients with overlapping squamous cell carcinoma.

Prognostic value of the IASLC/ATS/ERS classification of lung adenocarcinoma in stage I disease of Japanese cases.

A new classification of adenocarcinoma (ADC) was proposed by the International Association for the Study of Lung Cancer, the American Thoracic Society, and the European Respiratory Society (IASLC/ATS/ERS) in 2011. The present study evaluates its prognostic value in stage I disease of Japanese cases. One-hundred-and-seventy-nine cases with pathological stage I ADC were classified according to the new classification system and their association with disease recurrence was analyzed. Eighteen (10.1%) and 24 (13.4%) cases were adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA), respectively. One-hundred-and-thirty-seven cases (76.5%) were invasive adenocarcinoma (IVA), in which 43 (24.0%) were lepidic (LEP), 59 (33.0%) were acinar (ACN), 16 (8.9%) were papillary (PAP), 1 (0.6%) was micropapillary (MPAP), 12 (6.7%) were solid predominant subtypes (SOL), and 6 (3.4%) were invasive mucinous adenocarcinoma (MUC). The5-year disease-free survivals (DFS) of patients with AIS and MIA were 100%. Those of LEP, ACN, PAP, SOL and MUC were 93.5%, 83.7%, 75.0%, 44.4% and 62.5%, respectively. Multivariate analysis showed that high-histological grade (SOL, MPAP, MUC) had an independent prognostic value to predict post-operative recurrence (HR 3.661, 95% CI 1.421-9.437, P = 0.007). In conclusion, the present study demonstrates a prognostic value of the 2011 IASLC/ATS/ERS classification of ADC in Japanese cases.

Expression of the potential cancer stem cell markers, CD133, CD44, ALDH1, and ß-catenin, in primary lung adenocarcinoma--their prognostic significance.

The present study investigated expression profiles of the potential CSC markers including CD133, CD44, ALDH1, and ß-catenin, and evaluated their prognostic value in lung adenocarcinomas. One-hundred-and-seventy-seven tumors (stage I) were immunohistochemically examined for the expression of these markers, and thresholds to subdivide expression levels were determined using receiver operating characteristics curves. Tumors with high levels of CD133 (adjusted hazard ratio (HR) 4.55 (95% confidence interval (CI) 1.26-16.40, P = 0.021), CD44 (HR 3.73, 95% CI 1.20-11.58, P = 0.023) or ALDH1 (HR 3.61, 95% CI 1.09-12.3, P = 0.036), but not ß-catenin (HR 2.43, 95% CI 0.59-10.8, P = 0.220), showed a significantly higher risk of recurrence than the corresponding low expressers. In conclusion, levels of CD133, CD44, and ALDH1 had independent prognostic value to predict the recurrence of lung adenocarcinoma.

Early growth response-1 induces and enhances vascular endothelial growth factor-A expression in lung cancer cells.

Vascular endothelial growth factor-A (VEGF-A) is crucial for angiogenesis, vascular permeability, and metastasis during tumor development. We demonstrate here that early growth response-1 (EGR-1), which is induced by the extracellular signal-regulated kinase (ERK) pathway activation, activates VEGF-A in lung cancer cells. Increased EGR-1 expression was found in adenocarcinoma cells carrying mutant K-RAS or EGFR genes. Hypoxic culture, siRNA experiment, luciferase assays, chromatin immunoprecipitation, electrophoretic mobility shift assays, and quantitative RT-PCR using EGR-1-inducible lung cancer cells demonstrated that EGR-1 binds to the proximal region of the VEGF-A promoter, activates VEGF-A expression, and enhances hypoxia inducible factor 1alpha (HIF-1alpha)-mediated VEGF-A expression. The EGR-1 modulator, NAB-2, was rapidly induced by increased levels of EGR-1. Pathology samples of human lung adenocarcinomas revealed correlations between EGR-1/HIF-1alpha and VEGF-A expressions and relative elevation of EGR-1 and VEGF-A expression in mutant K-RAS- or EGFR-carrying adenocarcinomas. Both EGR-1 and VEGF-A expression increased as tumors dedifferentiated, whereas HIF-1alpha expression did not. Although weak correlation was found between EGR-1 and NAB-2 expressions on the whole, NAB-2 expression decreased as tumors dedifferentiated, and inhibition of DNA methyltransferase/histone deacetylase increased NAB-2 expression in lung cancer cells despite no epigenetic alteration in the NAB-2 promoter. These findings suggest that EGR-1 plays important roles on VEGF-A expression in lung cancer cells, and epigenetic silencing of transactivator(s) associated with NAB-2 expression might also contribute to upregulate VEGF-A expression.

Insulin-like growth factor binding protein-4 gene silencing in lung adenocarcinomas.

Gene silencing by promoter hypermethylation plays an important role in molecular pathogenesis. We previously reported that insulin-like growth factor (IGF) binding protein-4 (IGFBP-4), which inhibits IGF-dependent growth, is expressed via early growth response-1 (EGR-1) and is often silenced in cultivated lung cancer cells. The purpose of the present study was to clarify clinicopathological factors associated with IGFBP-4 gene silencing in lung adenocarcinomas. Seventy-six surgically resected adenocarcinomas (20 well-, 35 moderately-, and 21 poorly-differentiated) were subjected to methylation-specific polymerase chain reaction (PCR) analysis for EGR-1-binding sites located in the IGFBP-4 promoter and immunohistochemistry for IGFBP-4, EGR-1, and Ki-67. Thirty-two adenocarcinomas (42%) revealed IGFBP-4 promoter hypermethylation, and the severity inversely correlated with the level of IGFBP-4 expression (P < 0.0001) and tumor differentiation (well versus poor, P = 0.0278; well/moderate versus poor, P = 0.0395). Furthermore, there was a negative correlation between Ki-67 labeling index and IGFBP-4 expression (P = 0.0361). These findings suggest that the expression of IGFBP-4 in adenocarcinoma cells in vivo is downregulated by epigenetic silencing in association with tumor differentiation, resulting in disruption of the mechanism of IGFBP-4-mediated growth inhibition.

Down-regulation of FXYD3 expression in human lung cancers: its mechanism and potential role in carcinogenesis.

FXYD3 is a FXYD-containing Na,K-ATPase ion channel regulator first identified as a protein overexpressed in murine breast tumors initiated by oncogenic ras or neu. However, our preliminary study revealed that FXYD3 expression was down-regulated in oncogenic KRAS-transduced airway epithelial cells. This contradiction led us to investigate the role of FXYD3 in carcinogenesis of the lung. FXYD3 mRNA and protein levels were lower in most of the lung cancer cell lines than in either the noncancerous lung tissue or airway epithelial cells. Protein levels were also lower in a considerable proportion of primary lung cancers than in nontumoral airway epithelia; FXYD3 expression levels decreased in parallel with the dedifferentiation process. Also, a somatic point mutation, g55c (D19H), was found in one cell line. Forced expression of the wild-type FXYD3, but not the mutant, restored the well-demarcated distribution of cortical actin in cancer cells that had lost FXYD3 expression, suggesting FXYD3 plays a role in the maintenance of cytoskeletal integrity. However, no association between FXYD3 expression and its promoter's methylation status was observed. Therefore, inactivation of FXYD3 through a gene mutation or unknown mechanism could be one cause of the atypical shapes of cancer cells and play a potential role in the progression of lung cancer.

Down-regulation of DUSP6 expression in lung cancer: its mechanism and potential role in carcinogenesis.

Our preliminary studies revealed that oncogenic KRAS (KRAS/V12) dramatically suppressed the growth of immortalized airway epithelial cells (NHBE-T, with viral antigen-inactivated p53 and RB proteins). This process appeared to be a novel event, different from the so-called premature senescence that is induced by either p53 or RB, suggesting the existence of a novel tumor suppressor that functions downstream of oncogenic KRAS. After a comprehensive search for genes whose expression levels were modulated by KRAS/V12, we focused on DUSP6, a pivotal negative feedback regulator of the RAS-ERK pathway. A dominant-negative DUSP6 mutant, however, failed to rescue KRAS/V12-induced growth suppression, but conferred a stronger anchorage-independent growth activity to the surviving subpopulation of cells generated from KRAS/V12-transduced NHBE-T. DUSP6 expression levels were found to be weaker in most lung cancer cell lines than in NHBE-T, and DUSP6 restoration suppressed cellular growth. In primary lung cancers, DUSP6 expression levels decreased as both growth activity and histological grade of the tumor increased. Loss of heterozygosity of the DUSP6 locus was found in 17.7% of cases and was associated with reduced expression levels. These results suggest that DUSP6 is a growth suppressor whose inactivation could promote the progression of lung cancer. We have here identified an important factor involved in carcinogenesis through a comprehensive search for downstream targets of oncogenic KRAS.

Neuroendocrine cancer-specific up-regulating mechanism of insulin-like growth factor binding protein-2 in small cell lung cancer.

Small cell lung cancer (SCLC) exhibits insulin-like growth factor-dependent growth. SCLC is the most aggressive among known in vivo lung cancers, whereas in vitro growth of SCLC is paradoxically slow as compared with that of non-SCLC (NSCLC). In this study, we demonstrate that SCLC cells overexpress insulin-like growth factor binding protein (IGFBP)-2 via NeuroD, a neuroendocrine cell-specific transcription factor. Chromatin immunoprecipitation, electrophoretic mobility shift, and IGFBP-2 promoter assays all revealed that NeuroD binds to the E-box in the 5'-untranslated region of IGFBP-2. A NeuroD transgene in both airway epithelial and NSCLC cells up-regulated the transcription of IGFBP-2 and retarded cell growth. Recombinant IGFBP-2 repressed the growth of both airway epithelial and NSCLC cells in a dose-dependent manner. A NeuroD-specific small interfering RNA repressed IGFBP-2 expression in SCLC, and neutralization of IGFBP-2 and an IGFBP-2-specific small interfering RNA increased SCLC cell growth. Pathological samples of SCLC also expressed IGFBP-2 abundantly, as compared with NSCLC, and showed only rare (8%) IGFBP-2 promoter methylation, whereas the IGFBP-2 promoter was methylated in 71% of adenocarcinomas and 29% of squamous cell carcinomas. These findings suggest that 1) SCLC has an IGFBP-2 overexpression mechanism distinct from NSCLC, 2) secreted IGFBP-2 contributes to the slow growth of SCLC in vitro, and 3) the epigenetic alterations in the IGFBP-2 promoter contribute to the striking differences in IGFBP-2 expression between SCLC and NSCLC in vivo.

KRAS gene mutations in lung cancer: particulars established and issues unresolved.

Lung cancer, like other cancers, is considered to develop through the accumulation of genetic alterations. Mutation of the KRAS gene is one of the most important events in carcinogenesis of the lung. The KRAS gene, belonging to the RAS gene family, encodes a membrane-bound 21-kd guanosine triphosphate (GTP)-binding protein. Single point mutations in this protein result in continuous activation to transmit excessive signals, promoting a variety of biological events. In lung cancers, the mutations concentrate at codon 12 and mostly affect adenocarcinomas (ADCs). They also affect atypical adenomatous hyperplasia, the precursor of ADCs. Therefore, mutation of the KRAS gene is suggested to confer a growth advantage to airway epithelial cells enabling them to expand clonally early in the development of ADCs. The mutation is also a reliable marker of an unfavorable response to certain molecular-targeting therapies. Furthermore, patients with ADCs affected by mutations have been reported to exhibit a significantly higher risk of postoperative disease recurrence. Thus, the significance of KRAS gene mutations has been investigated extensively. However, not all the details emerged. In this review, particulars that have been established are introduced, and important issues remaining to be resolved are discussed, with special reference to carcinogenesis of the lung.

Detection of gastric cancer cells in the blue lymph node and lymphaticus under sentinel lymph node biopsy using dye technique alone.

BACKGROUND/AIMS: We investigated whether or not there are cancer cells in the blue node (BN) and the sentinel lymphaticus (SL), which is detected using sentinel node biopsy (SNB). METHODOLOGY: Patent blue (1%) is injected submucosally into 4 to 5 different sites at 1 mL per site around the primary tumor. Blue-stained lymphatics and lymph nodes can be seen by turning over the greater omentum and lesser omentum extraperitoneally. If blue nodes or lymphaticus are found, biopsy is performed at this point. The study was conducted in 14 patients (11 males and 3 females, mean age 65.7 y/o) with a preoperative diagnosis of T1 tumor invasion and NO that there is no lymph node metastasis. Informed consent was obtained from the patients for SNB after patent blue staining and investigation of CEAmRNA and CK20mRNA. RESULTS: Of the 14 patients in whom BN and SL were identified, 1 (7.1%) had positive CEAmRNA and positive CK20mRNA of SL. CONCLUSION: Our present study shows the possibility for the existence of cancer cells in the lymphaticus from the tumor to BN. We should avoid the cut of lymphaticus when we perform gastrectomy.

Multicentre randomised phase II study of the perioperative administration of flurbiprofen axetil in patients with non-small cell lung cancer: study protocol of the FLAX Study.

INTRODUCTION: In patients with non-small cell lung cancer, surgical treatment with postoperative adjuvant chemotherapy is performed. However, the improvement of overall survival achieved by postoperative adjuvant chemotherapy may be insufficient in consideration of the deterioration of quality of life (QOL). Considering the relationships among surgical treatments, inflammation and carcinogenesis, non-steroidal anti-inflammatory drugs (NSAIDs) are a candidate postoperative treatment for preventing recurrence and maintaining QOL. In this study, we investigate the effects of the perioperative administration of flurbiprofen axetil on postoperative recurrence in patients with non-small cell lung cancer. METHODS AND ANALYSIS: This study is a multicentre, parallel group, open label, randomised controlled trial. Patients clinically suspected of non-small cell lung cancer are randomly assigned to the flurbiprofen axetil group or the no-NSAIDs group. A total of 420 patients (210 per group) will be registered. The primary analysis will evaluate the treatment effect of flurbiprofen axetil on postoperative recurrence. ETHICS AND DISSEMINATION: The study protocol was approved by the Clinical Research Review Board of Saitama Medical University in September 2019 (No. 192002) and will be approved by each institutional review board of all participating institutions before patient enrolment. This study complies with the latest version of the Declaration of Helsinki, Clinical Trial Act and related notifications. Results will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: Japan Registry of Clinical Trials (jRCTs031190167; Pre-results) (https://jrct.niph.go.jp/).

Clinical Significance of Tumour CD44v and MIST1 Expression in Patients With Non-small-cell Lung Cancer.

BACKGROUND: Cancer stem cells (CSCs) are involved in cancer metastasis and relapse. Therefore, identification of CSC biomarkers might help determine the success of a treatment. In this study, we examined the expression of four CSC markers: Cluster of differentiation 44 variant (CD44v), leucine-rich repeat-containing G-protein-coupled receptor 5 (LGR5), frizzled 7 (FZD7), and muscle, intestine and stomach expression 1 (MIST1), in cancer tissues of patients with non-small-cell lung cancer at >5 years after resection, and its clinical significance. PATIENTS AND METHODS: We examined the expression of each CSC marker in 360 patients with NSCLC (n=360) who underwent curative resection by immunohistochemical analysis of tissue microarrays, and determined its relationship with survival. RESULTS: High expression of MIST1 was related to better overall survival (p<0.05); high CD44v expression was associated with poor overall and recurrence-free survival (p<0.001 for both) and thus, CD44v was defined as an independent prognostic factor (p<0.05), according to a multivariate analysis. CONCLUSION: Tumoral CD44v expression might be a useful prognostic marker for patients after curative resection of NSCLC.