SMARCA4 deficiency and mutations are frequent in large cell lung carcinoma and are prognostically significant

SMARCA4 mutation has emerged as a marker of poor prognosis in lung cancer and has potential predictive value in cancer treatment, but recommendations for which patients require its investigation are lacking. We comprehensively studied SMARCA4 alterations and the clinicopathological significance in a large cohort of immunohistochemically-subtyped non-small cell lung cancer (NSCLC). A total of 1416 patients was studied for the presence of SMARCA4 deficiency by immunohistochemistry (IHC). Thereafter, comprehensive sequencing of tumours was performed for 397 of these patients to study the mutational spectrum of SWI/SNF and SMARCA4 aberrations. IHC evidence of SMARCA4 deficiency was found in 2.9% of NSCLC. Of the sequenced tumours, 38.3% showed aberration in SWI/SNF complex, and 9.3% had SMARCA4 mutations. Strikingly, SMARCA4 aberrations were much more prevalent in large cell carcinoma (LCC) than other histological tumour subtypes. SMARCA4-deficient and SMARCA4-mutated tumours accounted for 40.5% and 51.4% of all LCC, respectively. Multivariable analyses confirmed SMARCA4 mutation was an independent prognostic factor in lung cancer. The immunophenotype of a subset of these tumours frequently showed TTF1 negativity and HepPAR1 positivity. SMARCA4 mutation or its deficiency was associated with positive smoking history and poor prognosis. It also demonstrated mutual exclusion with EGFR mutation. Taken together, the high incidence of SMARCA4 aberrations in LCC may indicate its diagnostic and prognostic value. Our study established the necessity of SMARCA4 IHC in the identification of SMARCA4-aberrant tumours, and this may be of particular importance in LCC and tumours without known driver events.

Characterization of two transcriptomic subtypes of marker-null large cell carcinoma of the lung suggests different origin and potential new therapeutic perspectives

Pulmonary large cell carcinoma (LCC) is an undifferentiated neoplasm lacking morphological, histochemical, and immunohistochemical features of small cell lung cancer, adenocarcinoma (ADC), or squamous cell carcinoma (SCC). The available molecular information on this rare disease is limited. This study aimed to provide an integrated molecular overview of 16 cases evaluating the mutational asset of 409 genes and the transcriptomic profiles of 20,815 genes. Our data showed that TP53 was the most frequently inactivated gene (15/16; 93.7%) followed by RB1 (5/16; 31.3%) and KEAP1 (4/16; 25%), while CRKL and MYB genes were each amplified in 4/16 (25%) cases and MYC in 3/16 (18.8%) cases; transcriptomic analysis identified two molecular subtypes including a Pure-LCC and an adenocarcinoma like-LCC (ADLike-LCC) characterized by different activated pathways and cell of origin. In the Pure-LCC group, POU2F3 and FOXI1 were distinctive overexpressed markers. A tuft cell-like profile and the enrichment of a replication stress signature, particularly involving ATR, was related to this profile. Differently, the ADLike-LCC were characterized by an alveolar-cell transcriptomic profile and association with AIM2 inflammasome complex signature. In conclusion, our study split the histological marker-null LCC into two different transcriptomic entities, with POU2F3, FOXI1, and AIM2 genes as differential expression markers that might be probed by immunohistochemistry for the differential diagnosis between Pure-LCC and ADLike-LCC. Finally, the identification of several signatures linked to replication stress in Pure-LCC and inflammasome complex in ADLike-LCC could be useful for designing new potential therapeutic approaches for these subtypes.

Patient-derived tumoroid models of pulmonary large-cell neuroendocrine carcinoma: a promising tool for personalized medicine and developing novel therapeutic strategies

Pulmonary large-cell neuroendocrine carcinoma (LCNEC), a disease with poor prognosis, is classified as pulmonary high-grade neuroendocrine carcinoma, along with small-cell lung cancer. However, given its infrequent occurrence, only a limited number of preclinical models have been established. Here, we established three LCNEC tumoroids for long-term culture. Whole-exome sequencing revealed that these tumoroids inherited genetic mutations from their parental tumors; two were classified as small-cell carcinoma (S-LCNEC) and one as non-small cell carcinoma (N-LCNEC). Xenografts from these tumoroids in immunodeficient mice mimicked the pathology of the parent LCNEC, and one reproduced the mixed-tissue types of combined LCNEC with a component of adenocarcinoma. Drug sensitivity tests using these LCNEC tumoroids enabled the evaluation of therapeutic agent efficacy. Based on translational research, we found that a CDK4/6 inhibitor might be effective for N-LCNEC and that Aurora A kinase inhibitors might be suitable for S-LCNEC or LCNEC with MYC amplification. These results highlight the value of preclinical tumoroid models in understanding the pathogenesis of rare cancers and developing treatments. LCNEC showed a high success rate in tumoroid establishment, indicating its potential application in personalized medicine.

Genomic and transcriptomic profiling of combined small-cell lung cancer through microdissection: unveiling the transformational pathway of mixed subtype

BACKGROUND

Combined small-cell lung carcinoma (cSCLC) represents a rare subtype of SCLC, the mechanisms governing the evolution of cancer genomes and their impact on the tumor immune microenvironment (TIME) within distinct components of cSCLC remain elusive.

METHODS

Here, we conducted whole-exome and RNA sequencing on 32 samples from 16 cSCLC cases.

RESULTS

We found striking similarities between two components of cSCLC-LCC/LCNEC (SCLC combined with large-cell carcinoma/neuroendocrine) in terms of tumor mutation burden (TMB), tumor neoantigen burden (TNB), clonality structure, chromosomal instability (CIN), and low levels of immune cell infiltration. In contrast, the two components of cSCLC-ADC/SCC (SCLC combined with adenocarcinoma/squamous-cell carcinoma) exhibited a high level of tumor heterogeneity. Our investigation revealed that cSCLC originated from a monoclonal source, with two potential transformation modes: from SCLC to SCC (mode 1) and from ADC to SCLC (mode 2). Therefore, cSCLC might represent an intermediate state, potentially evolving into another histological tumor morphology through interactions between tumor and TIME surrounding it. Intriguingly, RB1 inactivation emerged as a factor influencing TIME heterogeneity in cSCLC, possibly through neoantigen depletion.

CONCLUSIONS

Together, these findings delved into the clonal origin and TIME heterogeneity of different components in cSCLC, shedding new light on the evolutionary processes underlying this enigmatic subtype.

An in-silico analysis reveals further evidence of an aggressive subset of lung carcinoids sharing molecular features of high-grade neuroendocrine neoplasms

Little is known as to whether there may be any pathogenetic link between pulmonary carcinoids and neuroendocrine carcinomas (NECs). A gene signature we previously found to cluster pulmonary carcinoids, large cell neuroendocrine carcinoma (LCNEC) and small cell lung carcinoma (SCLC), and which encompassed MEN1, MYC, MYCL1, RICTOR, RB1, SDHA, SRC and TP53 mutations or copy number variations (CNVs), was used to reclassify an independent cohort of 54 neuroendocrine neoplasms (NENs) [31 typical carcinoids (TC), 11 atypical carcinoids (AC) and 12 SCLC], by means of transcriptome and mutation data. Unsupervised clustering analysis identified two histology-independent clusters, namely CL1 and CL2, where 17/42 (40.5%) carcinoids and all the SCLC samples fell into the latter. CL2 carcinoids affected survival adversely, were enriched in T to G transversions or T > C/C > T transitions in the context of specific mutational signatures, presented with at least 1.5-fold change (FC) increase of gene mutations including TSC2, SMARCA2, SMARCA4, ERBB4 and PTPRZ1, differed for gene expression and showed epigenetic changes in charge of MYC and MTORC1 pathways, cellular senescence, inflammation, high-plasticity cell state and immune system exhaustion. Similar results were also found in two other independent validation sets comprising 101 lung NENs (24 carcinoids, 21 SCLC and 56 LCNEC) and 30 carcinoids, respectively. We herein confirmed an unexpected sharing of molecular traits along the spectrum of lung NENs, with a subset of genomically distinct aggressive carcinoids sharing molecular features of high-grade neuroendocrine neoplasms.

Real-World comprehensive genomic profiling data for diagnostic clarity in pulmonary Large-Cell neuroendocrine carcinoma

BACKGROUND

Pulmonary large-cell neuroendocrine carcinoma (LCNEC) is an uncommon subtype of lung cancer believed to represent a spectrum of tumors sharing characteristics of both small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Other groups have proposed genomic LCNEC subtypes, including small cell-like, non-small cell-like, and carcinoid-like subtypes. The primary goal of this study was to better define the NSCLC-like subtype with comprehensive genomic profiling (CGP).

METHODS

An institutional database was queried to identify tissue specimens (TBx, N = 1,426) and liquid biopsies (LBx, N = 39) submitted for CGP during routine clinical care (8/2014 - 7/2023) with a disease ontology of LCNEC. TBx were profiled with FoundationOne® (F1) or F1CDx, using hybrid-capture technology to detect genomic alterations (GAs).

RESULTS

1,426 LCNEC samples were genomically profiled. The presence of RB1 and TP53 genomic alterations (GAs) were used to define a SCLC-like subtype (n = 557). A carcinoid-like group was defined by the presence of MEN1 mutation in the absence of TP53 GAs (n = 25). The remaining 844 samples were compared to the SCLC-like group and GAs enriched relative to the SCLC-like samples with a false discovery rate (FDR) < 0.0001 were used to define a NSCLC-like group. These NSCLC-like subtype-defining GAs included SMARCA4, KRAS, FGF3/4/19, STK11, CDKN2A/B, MTAP, and CCND1. Under this schema, 530 samples were classified as NSCLC-like and 314 remained unclassified.

CONCLUSIONS

Large-scale CGP can better characterize biologically distinct molecular subtypes in LCNEC. Further studies to define how these molecular subtypes may help inform treatment decisions in this complex and challenging malignancy are warranted.

Exploring the molecular features and genetic prognostic factors of pulmonary high-grade neuroendocrine carcinomas

Molecular research on large-cell neuroendocrine carcinoma (LCNEC) and small-cell lung cancer (SCLC) has progressed significantly. However, there are still fewer molecular markers related to prognostic/therapeutic strategies for these conditions compared to those for adenocarcinoma. We therefore investigated the molecular characteristics of neuroendocrine carcinomas (NECs). We enrolled patients surgically diagnosed with NECs between 2011 and 2019, with complete follow-up records. All were analyzed using whole exome sequencing and p53/Rb immunohistochemistry (IHC). A total of 92 cases, comprising 45 pure SCLC, 15 combined SCLC, 27 pure LCNEC, and 5 combined LCNEC, were included. TP53 (78.3%) and RB1 (34.8%) were the most common molecular alterations, followed by KMT2D, LRP1B, FAT3, NCOR2, SPTA1, and NOTCH1. The mutation frequency for EGFR was 10.9%. Sixteen patients with LCNEC who had TP53/RB1 co-alterations were SCLC-like, while the remaining were NSCLC-like. There was no statistically significant difference between the groups regarding overall survival (OS; p = 0.458) and progression-free survival (PFS; p = 0.157). The frequency of the loss of Rb expression by IHC in SCLC-like LCNEC was 100%. Significant pathway alterations unique to SCLC included Notch and AMPK, while HIF-1 was enriched exclusively in LCNEC. NCOR2 mutation was linked to worse OS (p = 0.029) and PFS (p = 0.015), while wild-type SPTA1 was associated with poor PFS (p = 0.018). IHC for Rb was reliable for predicting LCNEC molecular subtypes, indicating its clinical value. NCOR2 and SPTA1 alterations were identified as prognostic factors that may provide therapeutic targets for patients with NEC.

Novel Mouse Cell Lines and In Vivo Models for Human High-Grade Neuroendocrine Lung Carcinoma, Small Cell Lung Carcinoma (SCLC), and Large Cell Neuroendocrine Carcinoma (LCNEC)

There is a clear need to expand the toolkit of adequate mouse models and cell lines available for preclinical studies of high-grade neuroendocrine lung carcinoma (small cell lung carcinoma (SCLC) and large cell neuroendocrine carcinoma (LCNEC)). SCLC and LCNEC are two highly aggressive tumor types with dismal prognoses and few therapeutic options. Currently, there is an extreme paucity of material, particularly in the case of LCNEC. Given the lack of murine cell lines and transplant models of LCNEC, the need is imperative. In this study, we generated and examined new models of LCNEC and SCLC transplantable cell lines derived from our previously developed primary mouse LCNEC and SCLC tumors. RNA-seq analysis demonstrated that our cell lines and syngeneic tumors maintained the transcriptome program from the original transgenic primary tumor and displayed strong similarities to human SCLC or LCNEC. Importantly, the SCLC transplanted cell lines showed the ability to metastasize and mimic this characteristic of the human condition. In summary, we generated mouse cell line tools that allow further basic and translational research as well as preclinical testing of new treatment strategies for SCLC and LCNEC. These tools retain important features of their human counterparts and address the lack of LCNEC disease models.

Comparative study of the genomic landscape and tumor microenvironment among large cell carcinoma of the lung, large cell neuroendocrine of the lung, and small cell lung cancer

Deciphering the genomic profiles and tumor microenvironment (TME) in large cell carcinomas of the lung (LCC), large cell neuroendocrine of the lung (LCNEC), and small cell lung cancer (SCLC) might contribute to a better understanding of lung cancer and then improve outcomes. Ten LCC patients, 12 LCNEC patients, and 18 SCLC patients were enrolled. Targeted next-generation sequencing was used to investigate the genomic profiles of LCC, LCNEC, and SCLC. Tumor-infiltrating lymphocytes (TILs) within cancer cell nests and in cancer stroma were counted separately. Precise 60% of LCNEC patients harbored classical non-small cell lung cancer driver alterations, occurring in BRAF, KRAS, ROS1, and RET. More than 70% of SCLC patients harbored TP53-RB1 co-alterations. Moreover, 88.9%, 40%, and 77.8% of LCC, LCNEC, and SCLC cases had a high tumor mutation burden level with more than 7 mutations/Mb. Furthermore, high index of CD68+ CD163+ (TILs within cancer cell nests/ TILs within cancer cell nests and in cancer stroma, P = .041, 548 days vs not reached) and CD163+ TILs (P = .041, 548 days vs not reached) predicted a shorter OS in SCLC. Our findings revealed the distinct genomic profiles and TME contexture among LCC, LCNEC, and SCLC. Our findings suggest that stratifying LCNEC/SCLC patients based on TME contexture might help clinical disease management.

Comprehensive Characterization of the Genomic Landscape in Chinese Pulmonary Neuroendocrine Tumors Reveals Prognostic and Therapeutic Markers (CSWOG-1901)

BACKGROUND

Pulmonary neuroendocrine tumors (pNETs) include typical carcinoid (TC), atypical carcinoid (AC), large cell neuroendocrine carcinoma (LCNEC), and small cell lung carcinoma (SCLC). The optimal treatment strategy for each subtype remains elusive, partly due to the lack of comprehensive understanding of their molecular features. We aimed to explore differential genomic signatures in pNET subtypes and identify potential prognostic and therapeutic biomarkers.

METHODS

We investigated genomic profiles of 57 LCNECs, 49 SCLCs, 18 TCs, and 24 ACs by sequencing tumor tissues with a 520-gene panel and explored the associations between genomic features and prognosis.

RESULTS

Both LCNEC and SCLC displayed higher mutation rates for TP53, PRKDC, SPTA1, NOTCH1, NOTCH2, and PTPRD than TC and AC. Small cell lung carcinoma harbored more frequent co-alterations in TP53-RB1, alterations in PIK3CA and SOX2, and mutations in HIF-1, VEGF and Notch pathways. Large cell neuroendocrine carcinoma (12.7 mutations/Mb) and SCLC (11.9 mutations/Mb) showed higher tumor mutational burdens than TC (2.4 mutations/Mb) and AC (7.1 mutations/Mb). 26.3% of LCNECs and 20.8% of ACs harbored alterations in classical non-small cell lung cancer driver genes. The presence of alterations in the homologous recombination pathway predicted longer progression-free survival in advanced LCNEC patients with systemic therapy (P = .005) and longer overall survival (OS) in SCLC patients with resection (P = .011). The presence of alterations in VEGF (P = .048) and estrogen (P = .018) signaling pathways both correlated with better OS in patients with resected SCLC.

CONCLUSION

We performed a comprehensive genomic investigation on 4 pNET subtypes in the Chinese population. Our data revealed distinctive genomic signatures in subtypes and provided new insights into the prognostic and therapeutic stratification of pNETs.

Undifferentiated large cell/rhabdoid carcinoma presenting in the intestines of patients with concurrent or recent non-small cell lung cancer (NSCLC): clinicopathologic and molecular analysis of 14 cases indicates an unusual pattern of dedifferentiated metastases

Undifferentiated carcinoma metastatic to the bowel is uncommon in surgical pathology practice and might be confused with primary gastrointestinal carcinoma, melanoma, lymphoma, and others. We present 14 cases of uni- (n = 9) or multifocal (n = 5) undifferentiated large cell/rhabdoid carcinoma presenting in the bowel of patients with concurrent (n = 9) or recent (diagnosed 1 to 25 months earlier; median, 4) non-small cell lung cancer (NSCLC). Patients were 6 females and 8 males, aged 52 to 85 years. Primary NSCLC was verified histologically in 10 cases and by imaging in 4. The undifferentiated histology was present in the lung biopsy in 4/10 patients (as sole pattern in 3 and combined with adenocarcinoma in 1) and was limited to the intestinal metastases in the remainder. PDL1 was strongly expressed in 7/9 cases (CPS: 41 to 100). Loss of at least one SWI/SNF subunit was detected in 7/13 cases (54%). SMARCA2 loss (n = 6) was most frequent and was combined with SMARCA4 loss in one case. PBRM1 loss was observed in one tumor. Successful molecular testing of 11 cases revealed BRAF mutations in 4 (3 were non-V600E variants), KRAS mutations in 3, and wildtype in 4. None had EGFR mutations. Analysis of 4 paired samples revealed concordant KRAS (2) and BRAF (1) mutations or wildtype (1). Our study indicates that undifferentiated carcinoma within the intestines of patients with concurrent/recent NSCLC represents dedifferentiated metastasis from the NSCLC. Recognition of this unusual presentation is cardinal to avoid misdiagnosis with inappropriate therapeutic and prognostic implications.

MMP1 drives tumor progression in large cell carcinoma of the lung through fibroblast senescence

Large cell carcinoma (LCC) is a rare and aggressive lung cancer subtype with poor prognosis and no targeted therapies. Tumor-associated fibroblasts (TAFs) derived from LCC tumors exhibit premature senescence, and coculture of pulmonary fibroblasts with LCC cell lines selectively induces fibroblast senescence, which in turn drives LCC cell growth and invasion. Here we identify MMP1 as overexpressed specifically in LCC cell lines, and we show that expression of MMP1 by LCC cells is necessary for induction of fibroblast senescence and consequent tumor promotion in both cell culture and mouse models. We also show that MMP1, in combination with TGF-β1, is sufficient to induce fibroblast senescence and consequent LCC promotion. Furthermore, we implicate PAR-1 and oxidative stress in MMP1/TGF-β1-induced TAF senescence. Our results establish an entirely new role for MMP1 in cancer, and support a novel therapeutic strategy in LCC based on targeting senescent TAFs.

An immune gene expression signature distinguishes central nervous system metastases from primary tumours in non-small-cell lung cancer

BACKGROUND

Dissemination of non-small-cell lung cancer (NSCLC) in the central nervous system is a frequent and challenging clinical problem. Systemic or local therapies rarely prolong survival and have modest activity regarding local control. Alterations in gene expression in brain metastasis versus primary tumour may increase aggressiveness and impair therapeutic efforts.

METHODS

We identified 25 patients with surgically removed NSCLC brain metastases in two different patient cohorts. For 13 of these patients, primary tumour samples were available. Gene expression analysis using the nCounter® PanCancer Immune Profiling gene expression panel (nanoString technologies Inc.) was performed in brain metastases and primary tumour samples. Identification of differentially expressed genes was conducted on normalized data using the nSolver analysis software.

RESULTS

We compared gene expression patterns in brain metastases with primary tumours. Brain metastasis samples displayed a distinct clustering pattern compared to primary tumour samples with a statistically significant downregulation of genes related to immune response and immune cell activation. Results from KEGG term analysis on differentially expressed genes revealed a concomitant enrichment of multiple KEGG terms associated with the immune system. We identified a 12-gene immune signature that clearly separated brain metastases from primary tumours.

CONCLUSIONS

We identified a unique gene downregulation pattern in brain metastases compared with primary tumours. This finding may explain the lower intracranial efficacy of systemic therapy, especially immunotherapy, in brain metastasis of patients with NSCLC.

Comprehensive Next-Generation Sequencing Unambiguously Distinguishes Separate Primary Lung Carcinomas From Intrapulmonary Metastases: Comparison with Standard Histopathologic Approach

PURPOSE

In patients with >1 non-small cell lung carcinoma (NSCLC), the distinction between separate primary lung carcinomas (SPLCs) and intrapulmonary metastases (IPMs) is a common diagnostic dilemma with critical staging implications. Here, we compared the performance of comprehensive next-generation sequencing (NGS) with standard histopathologic approaches for distinguishing NSCLC clonal relationships in clinical practice.

EXPERIMENTAL DESIGN

We queried 4,119 NSCLCs analyzed by 341-468 gene MSK-IMPACT NGS assay for patients with >1 surgically resected tumor profiled by NGS. Tumor relatedness predicted by prospective histopathologic assessment was contrasted with comparative genomic profiling by subsequent NGS.

RESULTS

Sixty patients with NGS performed on >1 NSCLCs were identified, yielding 76 tumor pairs. NGS classified tumor pairs into 51 definite SPLCs (median, 14; up to 72 unique somatic mutations per pair), and 25 IPMs (24 definite, one high probability; median, 5; up to 16 shared somatic mutations per pair). Prospective histologic prediction was discordant with NGS in 17 cases (22%), particularly in the prediction of IPMs (44% discordant). Retrospective review highlighted several histologic challenges, including morphologic progression in some IPMs. We subsampled MSK-IMPACT data to model the performance of less comprehensive assays, and identified several clinicopathologic differences between NGS-defined tumor pairs, including increased risk of subsequent recurrence for IPMs.

CONCLUSIONS

Comprehensive NGS allows unambiguous delineation of clonal relationship among NSCLCs. In comparison, standard histopathologic approach is adequate in most cases, but has notable limitations in the recognition of IPMs. Our results support the adoption of broad panel NGS to supplement histology for robust discrimination of NSCLC clonal relationships in clinical practice.

Independent prognostic value of ultra-sensitive quantification of tumor pre-treatment T790M subclones in EGFR mutated non-small cell lung cancer (NSCLC) treated by first/second generation TKI, depends on variant allele frequency (VAF): Results of the French cooperative thoracic intergroup (IFCT) biomarkers France project

OBJECTIVES

T790M mutations inEGFR-mutated non-small cell lung cancer (NSCLC) account for nearly 50% of acquired resistance mechanisms to EGFR-TKIs. Earlier studies suggested that tumor T790M could also be detected in TKI-naïve EGFR-mutated NSCLC. The aim of the study is to assess the prevalence and clinical significance of quantification of tumor pre-treatment T790M subclones.

MATERIALS AND METHODS

We analyzed 366 EGFR-mutated NSCLC patients of the real-life IFCT Biomarkers France study with available pre-treatment formalin-fixed paraffin-embedded (FFPE) tumor DNA before treatment by first/second-generation EGFR-TKI. We used ultra-sensitive Droplet Digital Polymerase Chain Reaction (ddPCR) QX200 (BIO-RAD®, Hercules, CA, USA). All samples were tested in duplicate.

RESULTS

ddPCR identified T790M in 19/240 specimens (8%). T790M-positive and T790M-negative populations were not different for clinical baseline characteristics. T790M Variant Allele Frequency (VAF) was > 0.01% <0.1%, > 0.1% <1%, > 1% <10%, and >10% in five (26.3%), six (31.6%), six (31.6%), and two (10.5%) patients, respectively. T790M VAF was >0.1% in 11/13 (84%) patients with rapid (<3 months) or usual progression (3-20 months) compared to 0/3 with low progression (>20 months) (p = 0.02). In a Cox model, T790M mutation positivity was correlated with overall survival (OS) and progression-free survival (PFS) for 10% > VAF >1% (hazard ratio [HR] = 2.83, 95% confidence interval [CI] 1.13-7.07, p = 0.03; HR=3.62, 95%CI 1.43-4.92, p = 0.007, respectively) and for VAF >10% (HR = 19.14, 95%CI 4.35-84.26, p < 0.001; HR = 17.89, 95%CI 2.21-144.86, p = 0.007, respectively).

CONCLUSION

Ultra-sensitive detection of tumor T790M mutation concerned 8% of EGFR-mutated TKI-naïve NSCLC patients and has a negative prognostic value only for T790M VAF over 1%.

DLL3 expression in large cell neuroendocrine carcinoma (LCNEC) and association with molecular subtypes and neuroendocrine profile

OBJECTIVES

For stage IV pulmonary large cell neuroendocrine carcinoma (LCNEC), the only therapeutic option is palliative chemotherapy. DLL3 is a new therapeutic target, which seems to be often expressed in SCLC and LCNEC. It has recently been reported that DLL3 mRNA expression is particularly upregulated in the LCNEC subgroup with STK11/KEAP1 and TP53 co-mutations, in contrast to lower expression levels in RB1 and TP53 co-mutated LCNEC. Our aim was to investigate DLL3 protein expression in stage IV LCNEC and correlate data with mutational profiles (i.e.STK11/KEAP1/RB1), immunostaining results (pRb, NE markers) and clinical characteristics.

MATERIALS AND METHODS

Immunohistochemical analysis for DLL3 (SC16.65) and ASCL1 (SC72.201) was performed on 94 and 51 FFPE tissue sections, respectively, of pathologically reviewed stage IV LCNEC. DLL3 and ASCL1 were scored positive if ≥1% of the tumor cells showed cytoplasmic/membranous or dotlike (DLL3) or nuclear (ASCL1) immunostaining. Data were correlated with available sequencing (TP53, RB1, STK11, KEAP1), immunostaining (pRb, NE markers) and clinical data.

RESULTS

DLL3 was expressed in 70/94 (74%) LCNEC, 56 (80%) of which showed cytoplasmic/membranous staining. Median H-score was 55 (interquartile range 0-160). DLL3 staining was not different in pRb immunohistochemistry negative and positive patients (DLL3+ in 53/70 (76%) vs. 14/21 (67%), p = 0.409) or RB1 mutated and wildtype patients (DLL3+ in 27/34 (79%) vs. 23/33 (70%), p = 0.361). Nevertheless, 6/6 (100%) STK11 mutated, 10/11 (91%) KEAP1 mutated and 9/9 (100%) TP53 wildtype tumors were DLL3+ . Furthermore, DLL3 expression was associated with expression of ASCL1 and at least 2 out of 3 neuroendocrine markers.

CONCLUSION

The high percentage (74%) of DLL3 expression in stage IV LCNEC denotes the potential of DLL3 targeted therapy in this patient group.

Integrative and comparative genomic analyses identify clinically relevant pulmonary carcinoid groups and unveil the supra-carcinoids

The worldwide incidence of pulmonary carcinoids is increasing, but little is known about their molecular characteristics. Through machine learning and multi-omics factor analysis, we compare and contrast the genomic profiles of 116 pulmonary carcinoids (including 35 atypical), 75 large-cell neuroendocrine carcinomas (LCNEC), and 66 small-cell lung cancers. Here we report that the integrative analyses on 257 lung neuroendocrine neoplasms stratify atypical carcinoids into two prognostic groups with a 10-year overall survival of 88% and 27%, respectively. We identify therapeutically relevant molecular groups of pulmonary carcinoids, suggesting DLL3 and the immune system as candidate therapeutic targets; we confirm the value of OTP expression levels for the prognosis and diagnosis of these diseases, and we unveil the group of supra-carcinoids. This group comprises samples with carcinoid-like morphology yet the molecular and clinical features of the deadly LCNEC, further supporting the previously proposed molecular link between the low- and high-grade lung neuroendocrine neoplasms.

Identification of key modules and hub genes for small-cell lung carcinoma and large-cell neuroendocrine lung carcinoma by weighted gene co-expression network analysis of clinical tissue-proteomes

Small-cell lung carcinoma (SCLC) and large-cell neuroendocrine lung carcinoma (LCNEC) are high-grade lung neuroendocrine tumors (NET). However, comparative protein expression within SCLC and LCNEC remains unclear. Here, protein expression profiles were obtained via mass spectrometry-based proteomic analysis. Weighted gene co-expression network analysis (WGCNA) identified co-expressed modules and hub genes. Of 34 identified modules, six were significant and selected for protein–protein interaction (PPI) network analysis and pathway enrichment. Within the six modules, the activation of cellular processes and complexes, such as alternative mRNA splicing, translation initiation, nucleosome remodeling and deacetylase (NuRD) complex, SWItch/Sucrose Non-Fermentable (SWI/SNF) superfamily-type complex, chromatin remodeling pathway, and mRNA metabolic processes, were significant to SCLC. Modules enriched in processes, including signal recognition particle (SRP)-dependent co-translational protein targeting to membrane, nuclear-transcribed mRNA catabolic process of nonsense-mediated decay (NMD), and cellular macromolecule catabolic process, were characteristically activated in LCNEC. Novel high-degree hub genes were identified for each module. Master and upstream regulators were predicted via causal network analysis. This study provides an understanding of the molecular differences in tumorigenesis and malignancy between SCLC and LCNEC and may help identify potential therapeutic targets.

Ferritin heavy subunit enhances apoptosis of non-small cell lung cancer cells through modulation of miR-125b/p53 axis

Ferritin is a nanocage protein composed by the variable assembly of 24 heavy and light subunits. As major intracellular iron storage protein, ferritin has been studied for many years in the context of iron metabolism. However, recent evidences have highlighted its role, in particular that of the heavy subunit (FHC), in pathways related to cancer development and progression, such as cell proliferation, growth suppressor evasion, cell death inhibition, and angiogenesis. At least partly, the involvement in these pathways is due to the ability of FHC to control the expression of a repertoire of oncogenes and oncomiRNAs. Moreover, the existence of a feedback loop between FHC and the tumor suppressor p53 has been demonstrated in different cell types. Here, we show that ectopic over-expression of FHC induces the promoter hypermethylation and the down-regulation of miR-125b that, in turn, enhances p53 protein expression in non-small cell lung cancer (NSCLC) cell lines. Notably, analysis by absolute quantitative RT-PCR of FHC, miR-125b, and p53 strongly suggests that this axis might be active in human NSCLC tissue specimens. In vitro, FHC over-expression attenuates survival of NSCLC cells by inducing p53-mediated intrinsic apoptosis that is partially abrogated upon miR-125b re-expression. Overall, our findings demonstrate that FHC acts as a tumor suppressor gene, thus providing a potential molecular strategy for induction of NSCLC apoptotic cell death.

Development of novel real-time RT-qPCR methodologies for quantification of the COL11A1 mRNA general and C transcripts and evaluation in non-small cell lung cancer specimens

PURPOSE

The purpose of this study was the development of new quantitative methodologies for the general (total) COL11A1 gene and the C transcript (RT-qPCR methods for A and E transcripts have already been developed by our group previously), the quantification of all COL11A1 transcripts and the investigation for the first time of their potential association with histopathological prognostic factors in lung cancer.

METHODS

Real-time RT-qPCR methodologies with dual hybridization probes were developed on the Light Cycler 1.5 platform (Roche,Germany). All COL11A1 transcripts were measured in 27 cDNA lung tissue specimens in a blinded fashion (8 control and 19 non-small cell lung cancer (NSCLC) tissues with known histopathological data). Statistical analysis was performed with the IBM SPSS program.

RESULTS

The novel real-time RT-qPCR methodologies were appropriately validated. All 19 NSCLC samples were positive for the general COL11A1 transcript (range 11.2-1198.0 copies/μg total RNA, while 5 out of 8 control samples were negative: mean values were also statistically significantly different (p<0.001). In 4 tumor samples (21%), no specific COL11A1 transcript was detected. Transcript C was detected in only 3 tumor samples. Regarding transcripts A and E, 13 out of 19 tumor samples were positive for either one (68%) and 11 for both (58%).

CONCLUSIONS

No other statistically significant association of the specific transcripts with histopathological data was observed, most probably due to the limited number of samples. As the number of general COL11A1 transcripts/µg exceeds the sum of A+E+C transcripts in all samples, there is opportunity for discovery and identification of other transcripts as well.

Hybrid Capture-Based Genomic Profiling of Circulating Tumor DNA from Patients with Advanced Non-Small Cell Lung Cancer

INTRODUCTION

Genomic profiling informs selection of matched targeted therapies as part of routine clinical care in NSCLC. Tissue biopsy is the criterion standard; however, genomic profiling of blood-derived circulating tumor DNA (ctDNA) has emerged as a minimally invasive alternative.

METHODS

Hybrid capture-based genomic profiling of 62 genes was performed on blood-based ctDNA from 1552 patients with NSCLC.

RESULTS

Evidence of ctDNA was detected in 80% of samples, and in 86% of these cases, at least one reportable genomic alteration (GA) was detected. Frequently altered genes were tumor protein p53 gene (TP53) (59%), EGFR (25%), and KRAS (17%). Comparative analysis with a tissue genomic database (N = 21,500) showed similar frequencies of GAs per gene, although KRAS mutation and EGFR T790M were more frequent in tissue and ctDNA, respectively (both p < 0.0001), likely reflecting the use of liquid versus tissue biopsy after relapse during targeted therapy. In temporally matched ctDNA and tissue samples from 33 patients with evidence of ctDNA in their blood, 64% of GAs detected in tissue were also detected in ctDNA, including 78% of short variants (58 of 74) and 100% of rearrangements (four of four), but only 16% of amplifications (four of 25).

CONCLUSIONS

Genomic profiling of ctDNA detected clinically relevant GAs in a significant subset of NSCLC cases. Most alterations detected in matched tissue were also detected in ctDNA. These results suggest the utility of ctDNA testing in advanced NSCLC as a complementary approach to tissue testing. Blood-based ctDNA testing may be particularly useful at the time of progression during targeted therapy.

Establishment, functional and genetic characterization of a colon derived large cell neuroendocrine carcinoma cell line

AIM

To establish cell line and patient-derived xenograft (PDX) models for neuroendocrine carcinomas (NEC) which is highly desirable for gaining insight into tumor development as well as preclinical research including biomarker testing and drug response prediction.

METHODS

Cell line establishment was conducted from direct in vitro culturing of colonic NEC tissue (HROC57). A PDX could also successfully be established from vitally frozen tumor samples. Morphological features, invasive and migratory behavior of the HROC57 cells as well as expression of neuroendocrine markers were vastly analyzed. Phenotypic analysis was done by microscopy and multicolor flow cytometry. The extensive molecular-pathological profiling included mutation analysis, assessment of chromosomal and microsatellite instability; and in addition, fingerprinting (i.e., STR analysis) was performed from the cell line in direct comparison to primary patient-derived tissues and the PDX model established. Drug responsiveness was examined for a panel of chemotherapeutics in clinical use for the treatment of solid cancers.

RESULTS

The established cell line HROC57 showed distinct morphological and molecular features of a poorly differentiated large-cell NEC with KI-67 > 50%. Molecular-pathological analysis revealed a CpG island promoter methylation positive cell line with microsatellite instability being absent. The following mutation profile was observed: KRAS (wt), BRAF (mut). A high sensitivity to etoposide, cisplatin and 5-FU could be demonstrated while it was more resistant towards rapamycin.

CONCLUSION

We successfully established and characterized a novel patient-derived NEC cell line in parallel to a PDX model as a useful tool for further analysis of the biological characteristics and for development of novel diagnostic and therapeutic options for NEC.

Large-Scale EGFR Mutation Testing in Clinical Practice: Analysis of a Series of 18,920 Non-Small Cell Lung Cancer Cases

We make use of a very large dataset of non-small cell lung cancer specimens to examine the molecular epidemiology of EGFR mutations, particularly with respect to rare and compound mutations, and to non-adenocarcinoma histological subtypes. We also demonstrate the feasibility of large-scale EGFR mutation screening using the full range of specimens encountered in routine practice. We retrospectively reviewed 18,920 unselected EGFR mutation results from our centre between July 2009 and October 2016, using Qiagen's therascreen EGFR RGQ PCR Kit. Mutation rates were correlated with patient demographics and tumour histology. Our testing success rate was 93.9%, with similar success rates using histological and cytological specimens. Rare, potentially-targetable mutations accounted for 9.5% of all mutations detected. We identified a 2.5% mutation rate in tumours diagnosed as squamous cell carcinomas. There was a trend towards increasing EGFR mutation rates with increasing age, and while Del19 was the commonest mutation in the young, L858R predominated in the elderly. We found that EGFR mutation heterogeneity is rare within tumours and between primary and metastatic deposits. Our data demonstrate that large-scale, reflex EGFR mutation testing is feasible and affordable in the context of a publicly-funded health system. Furthermore, we have shown that the use of techniques sensitive only to classical mutations and selection of patients on the grounds of age, sex and histology denies patients access to potentially beneficial TKI therapy.

Methylation of L1RE1, RARB, and RASSF1 function as possible biomarkers for the differential diagnosis of lung cancer

Background

Lung cancer is the major cause of cancer-related deaths worldwide. Differential diagnosis can be difficult, especially when only small samples are available. Epigenetic changes are frequently tissue-specific events in carcinogenesis and hence may serve as diagnostic biomarkers.

Material and methods

138 representative formalin-fixed, paraffin-embedded (FFPE) tissues (116 lung cancer cases and 22 benign controls) were used for targeted DNA methylation analysis via pyrosequencing of ten literature-derived methylation markers (APC, CDH1, CDKN2A, EFEMP1, FHIT, L1RE1, MGMT, PTEN, RARB, and RASSF1). Methylation levels were analyzed with the Classification and Regression Tree Algorithm (CART), Conditional Interference Trees (ctree) and ROC. Validation was performed with additional 27 lung cancer cases and 38 benign controls. TCGA data for 282 lung cancer cases was included in the analysis.

Results

CART and ctree analysis identified the combination of L1RE1 and RARB as well as L1RE1 and RASSF1 as independent methylation markers with high discriminative power between tumor and benign tissue (for each combination, 91% specificity and 100% sensitivity). L1RE1 methylation associated significantly with tumor type and grade (p<0.001) with highest methylation in the control group. The opposite was found for RARB (p<0.001). RASSF1 methylation increased with tumor type and grade (p<0.001) with strongest methylation in neuroendocrine tumors (NET).

Conclusion

Hypomethylation of L1RE1 is frequent in tumors compared to benign controls and associates with higher grade, whereas increasing methylation of RARB is an independent marker for tumors and higher grade. RASSF1 hypermethylation was frequent in tumors and most prominent in NET making it an auxiliary marker for separation of NSCLC and NET. L1RE1 in combination with either RARB or RASSF1 could function as biomarkers for separating lung cancer and non-cancerous tissue and could be useful for samples of limited size such as biopsies.

Large Cell Neuroendocrine Carcinoma Harboring an Anaplastic Lymphoma Kinase (ALK) Rearrangement with Response to Alectinib

Anaplastic lymphoma kinase (ALK) rearrangement is most commonly observed in lung adenocarcinoma in a subset of lung cancer. Large cell neuroendocrine carcinoma (LCNEC) harboring an ALK rearrangement is very rare. Based on the findings from a transbronchial lung biopsy, a 75-year-old non-smoking woman was diagnosed with LCNEC with multiple liver and bone metastases. After seven cycles of cytotoxic chemotherapy, her genotype testing demonstrated ALK rearrangement. Subsequently, she was administered alectinib and exhibited a partial response.

Pulmonary large cell neuroendocrine carcinoma with adenocarcinoma-like features: napsin A expression and genomic alterations

Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a highly aggressive malignancy, which was recently found to comprise three major genomic subsets: small cell carcinoma-like, non-small cell carcinoma (predominantly adenocarcinoma)-like, and carcinoid-like. To further characterize adenocarcinoma-like subset, here we analyzed the expression of exocrine marker napsin A, along with TTF-1, in a large series of LCNECs (n=112), and performed detailed clinicopathologic and genomic analysis of napsin A-positive cases. For comparison, we analyzed napsin A expression in other lung neuroendocrine neoplasms (177 carcinoids, 37 small cell carcinomas) and 60 lung adenocarcinomas. We found that napsin A was expressed in 15% of LCNEC (17/112), whereas all carcinoids and small cell carcinomas were consistently negative. Napsin A reactivity in LCNEC was focal in 12/17 cases, and weak or moderate in intensity in all cases, which was significantly lower in the extent and intensity than seen in adenocarcinomas (P<0.0001). The combination of TTF-1-diffuse/napsin A-negative or focal was typical of LCNEC but was rare in adenocarcinoma, and could thus serve as a helpful diagnostic clue. The diagnosis of napsin A-positive LCNECs was confirmed by classic morphology, diffuse labeling for at least one neuroendocrine marker, most consistently synaptophysin, and the lack of distinct adenocarcinoma component. Genomic analysis of 14 napsin A-positive LCNECs revealed the presence of mutations typical of lung adenocarcinoma (KRAS and/or STK11) in 11 cases. In conclusion, LCNECs are unique among lung neuroendocrine neoplasms in that some of these tumors exhibit low-level expression of exocrine marker napsin A, and harbor genomic alterations typical of adenocarcinoma. Despite the apparent close biological relationship, designation of adeno-like LCNEC as a separate entity from adenocarcinoma is supported by their distinctive morphology, typically diffuse expression of neuroendocrine marker(s) and aggressive behavior. Further studies are warranted to assess the clinical utility and optimal method of identifying adenocarcinoma-like and other subsets of LCNEC in routine practice.

MMP-2 and MMP-13 affect vasculogenic mimicry formation in large cell lung cancer

Matrix metalloproteinases (MMPs) have critical functions in tumour vasculogenic mimicry (VM). This study explored the mechanisms underlying MMP-13 and MMP-2 regulation of tumour VM formation in large cell lung cancer (LCLC). In our study, laminin5 (Ln-5) fragments cleaved by MMP-2 promoted tubular structure formation by the LCLC cell lines H460 and H661 in three-dimensional (3D) cultures. Transient up-regulation of MMP-13 or treatment with recombinant MMP-13 protein abrogated tubular structure formation of H460 cells in 3D culture. Treated cells with Ln-5 fragments cleaved by MMP-2 stimulated EGFR and F-actin expression. Ln-5 fragments cleaved by MMP-13 decreased EGFR/F-actin expression and disrupted VM formation. MMP-13 expression was negatively correlated with VM, Ln-5 and EGFR in LCLC tissues and xenograft. In vivo experiments revealed that VM was decreased when the number of endothelium-dependent vessels (EDVs) increased during xenograft tumour growth, whereas MMP-13 expression was progressively increased. In conclusion, MMP-2 promoted and MMP-13 disrupted VM formation in LCLC by cleaving Ln-5 to influence EGFR signal activation. MMP-13 may regulate VM and EDV formation.

Histological Transformation to Large Cell Neuroendocrine Carcinoma from Lung Adenocarcinoma Harboring an EGFR Mutation: An Autopsy Case Report

We herein report a 58-year-old Japanese woman who survived 14 years after surgery for lung adenocarcinoma harboring an epidermal growth factor receptor (EGFR) exon 19 deletion. She developed recurrence, for which she underwent multimodal therapy, including EGFR-tyrosine kinase inhibitor (TKI) administration. She ultimately died from a rapidly progressive right lung tumor that was resistant to EGFR-TKI. According to the autopsy findings, she had combined large-cell neuroendocrine carcinoma (LCNEC) and adenocarcinoma in the right lung, which retained an EGFR exon 19 deletion in both components. Therefore, the histological transformation to LCNEC can be a mechanism of acquired EGFR-TKI resistance.

Large Cell Neuroendocrine Carcinoma of the Lung: Clinico-Pathologic Features, Treatment, and Outcomes

BACKGROUND

Large cell neuroendocrine carcinoma (LCNEC) accounts for approximately 3% of lung cancers. Pathologic classification and optimal therapies are debated. We report the clinicopathologic features, treatment and survival of a series of patients with stage IV LCNEC.

MATERIALS AND METHODS

Cases of pathologically-confirmed stage IV LCNEC evaluated at Memorial Sloan Kettering Cancer Center from 2006 to 2013 were identified. We collected demographic, treatment, and survival data. Available radiology was evaluated by Response Evaluation Criteria In Solid Tumors (RECIST) 1.1 criteria.

RESULTS

Forty-nine patients with stage IV LCNEC were identified. The median age was 64 years, 63% of patients were male, and 88% were smokers. Twenty-three patients (n = 23/49; 47%) had brain metastases, 17 at diagnosis and 6 during the disease course. Seventeen LCNEC patients (35%) had molecular testing, of which 24% had KRAS mutations (n = 4/17). Treatment data for first-line metastatic disease was available on 37 patients: 70% (n = 26) received platinum/etoposide and 30% (n = 11) received other regimens. RECIST was completed on 23 patients with available imaging; objective response rate was 37% (95% confidence interval, 16%-62%) with platinum/etoposide, while those treated with other first-line regimens did not achieve a response. Median overall survival was 10.2 months (95% confidence interval, 8.6-16.4 months) for the entire cohort.

CONCLUSION

Patients with stage IV LCNEC have a high incidence of brain metastases. KRAS mutations are common. Patients with stage IV LCNEC do not respond as well to platinum/etoposide compared with historic data for extensive stage small-cell lung cancer; however, the prognosis is similar. Prospective studies are needed to define optimum therapy for stage IV LCNEC.

Dabrafenib plus trametinib in patients with previously treated BRAF(V600E)-mutant metastatic non-small cell lung cancer: an open-label, multicentre phase 2 trial

BACKGROUND

BRAF mutations act as an oncogenic driver via the mitogen-activated protein kinase (MAPK) pathway in non-small cell lung cancer (NSCLC). BRAF inhibition has shown antitumour activity in patients with BRAF(V600E)-mutant NSCLC. Dual MAPK pathway inhibition with BRAF and MEK inhibitors in BRAF(V600E)-mutant NSCLC might improve efficacy over BRAF inhibitor monotherapy based on observations in BRAF(V600)-mutant melanoma. We aimed to assess the antitumour activity and safety of dabrafenib plus trametinib in patients with BRAF(V600E)-mutant NSCLC.

METHODS

In this phase 2, multicentre, non-randomised, open-label study, we enrolled adult patients (aged ≥18 years) with pretreated metastatic stage IV BRAF(V600E)-mutant NSCLC who had documented tumour progression after at least one previous platinum-based chemotherapy and had had no more than three previous systemic anticancer therapies. Patients with previous BRAF or MEK inhibitor treatment were ineligible. Patients with brain metastases were allowed to enrol only if the lesions were asymptomatic, untreated (or stable more than 3 weeks after local therapy if treated), and measured less than 1 cm. Enrolled patients received oral dabrafenib (150 mg twice daily) plus oral trametinib (2 mg once daily) in continuous 21-day cycles until disease progression, unacceptable adverse events, withdrawal of consent, or death. The primary endpoint was investigator-assessed overall response, which was assessed by intention to treat in the protocol-defined population (patients who received second-line or later treatment); safety was also assessed in this population and was assessed at least once every 3 weeks, with adverse events, laboratory values, and vital signs graded according to the Common Terminology Criteria for Adverse Events version 4.0. The study is ongoing but no longer recruiting patients. This trial is registered with ClinicalTrials.gov, number NCT01336634.

FINDINGS

Between Dec 20, 2013, and Jan 14, 2015, 59 patients from 30 centres in nine countries across North America, Europe, and Asia met eligibility criteria. Two patients who had previously been untreated due to protocol deviation were excluded; thus, 57 eligible patients were enrolled. 36 patients (63·2% [95% CI 49·3-75·6]) achieved an investigator-assessed overall response. Serious adverse events were reported in 32 (56%) of 57 patients and included pyrexia in nine (16%), anaemia in three (5%), confusional state in two (4%), decreased appetite in two (4%), haemoptysis in two (4%), hypercalcaemia in two (4%), nausea in two (4%), and cutaneous squamous cell carcinoma in two (4%). The most common grade 3-4 adverse events were neutropenia in five patients (9%), hyponatraemia in four (7%), and anaemia in three (5%). Four patients died during the study from fatal adverse events judged to be unrelated to treatment (one retroperitoneal haemorrhage, one subarachnoid haemorrhage, one respiratory distress, and one from disease progression that was more severe than typical progression, as assessed by the investigator).

INTERPRETATION

Dabrafenib plus trametinib could represent a new targeted therapy with robust antitumour activity and a manageable safety profile in patients with BRAF(V600E)-mutant NSCLC.

FUNDING

GlaxoSmithKline.

Genomic architecture of lung cancers

PURPOSE OF REVIEW

Lung cancer remains the most frequent cancer worldwide and the leading cause of cancer death in most countries. The molecular characteristics of lung tumors play an important role in clinical decisions, which ultimately affect patients' survival. This review aims to summarize the most recent genomic discoveries made on lung cancer.

RECENT FINDINGS

A relatively comprehensive molecular characterization has been achieved for the three major types of lung cancer: adenocarcinoma, squamous-cell carcinoma, and small-cell carcinoma. Little is still known about large-cell neuroendocrine carcinoma and carcinoid tumors. A major finding has been the nonnegligible inter and intratumor heterogeneity of lung cancer and their impact in the clinical management of this disease.

SUMMARY

The high load of mutations, the frequent inactivation of major tumor suppressor genes, and the huge heterogeneity of lung cancer tumors may complicate long-lasting therapeutic responses. The development of strategies for the early detection of lung cancer might translate into an increase of the number of surgical resectable tumors, and therefore contribute to improve the survival rate of these patients.

Singapore Cancer Network (SCAN) Lung Cancer Workgroup. Singapore Cancer Network (SCAN) Guidelines for the Use of Systemic Therapy in Advanced Non-Small Cell Lung Cancer

INTRODUCTION

The SCAN lung cancer workgroup aimed to develop Singapore Cancer Network (SCAN) clinical practice guidelines for the use of systemic therapy in advanced non-small cell lung cancer (NSCLC) in Singapore.

MATERIALS AND METHODS

The workgroup utilised a modified ADAPTE process to calibrate high quality international evidence-based clinical practice guidelines to our local setting.

RESULTS

Five international guidelines were evaluated- those developed by the National Comprehensive Cancer Network (2014), the European Society of Medical Oncology (2014), the National Institute of Clinical Excellence (2012), the Scottish Intercollegiate Guidelines Network (2014) and Cancer Care Council Australia (2012). Recommendations on systemic treatment for advanced NSCLC were produced.

CONCLUSION

These adapted guidelines form the SCAN guidelines 2015 for systemic therapy of advanced or metastatic NSCLC.

Methylation of the DCLK1 promoter region in circulating free DNA and its prognostic value in lung cancer patients

INTRODUCTION

The possibility of detection of suppressor genes methylation in circulating free DNA (cf-DNA) of cancer patients and the lack of methylation in healthy individuals makes this epigenetic alternation an ideal diagnostic marker of neoplastic processes. Moreover, hypermethylation in several genes promoter was described as a biomarker of lung cancer. Methylation in the gene encoding doublecortin-like kinase 1 (DCLK1) is observed in patients with colorectal cancer and cholangiocarcinoma. However, there are no studies concerning DCLK1 methylation in lung cancer patients. The aims of the study was to evaluate the frequency of DCLK1 promoter methylation in cf-DNA of lung cancer patients and of healthy persons as well as the usefulness of this test for predicting the lung cancer course.

MATERIALS AND METHODS

DCLK1 methylation status was evaluated in DNA isolated from peripheral blood plasma from 65 lung cancer patients and 95 healthy individuals. After DNA bisulfitation, DCLK1 methylation was determined using the qMSP-PCR technique. Moreover, the presence of DCLK1 methylation was correlated with the overall survival (OS) probability of lung cancer patients.

RESULTS

DCLK1 promoter methylation was detected in 32 lung cancer patients (49.2 %) and 8 healthy individuals (8.4 %). The methylation of the region before transcription start site (TSS) and the region after TSS of DCLK1 gene was detected in 28 and 11 patients, respectively. In seven cases (10.8 %), the DCLK1 promoter methylation in both regions was reported simultaneously. The methylation was observed slightly frequently in patients with small cell lung cancer (75 % of SCLC patients). The median overall survival of patients with DCLK1 promoter methylation was lower than that of patients without DCLK1 gene modification (p = <0.001, HR = 4.235).

CONCLUSIONS

The evaluation of DCLK1 promoter region methylation may be useful in both early diagnosis and prediction of the course of lung cancer.

STK33 plays an important positive role in the development of human large cell lung cancers with variable metastatic potential

Serine/threonine kinase 33 (STK33) is a novel protein that has attracted considerable interest in recent years. Previous research has revealed that STK33 expression plays a special role in cancer cell proliferation. However, the mechanisms of STK33 induction of cancer cells remain largely unknown. In this study, it is demonstrated that STK33 expression varies in NL9980 and L9981 cells which are homogeneous cell lines with similar genetic backgrounds. STK33 can promote cell migration and invasion and suppress p53 gene expression in the NL9980 and L9981 cells. In addition, this protein also promotes epithelial-mesenchymal transition (EMT). Moreover, STK33 knockdown decreases tumor-related gene expression and inhibits cell migration, invasion, and EMT, suggesting that STK33 may be a mediator of signaling pathways that are involved in cancer. In conclusion, our results suggest that STK33 may be an important prognostic marker and a therapeutic target for the metastatic progression of human lung cancer.

RARβ Promoter Methylation as an Epigenetic Mechanism of Gene Silencing in Non-small Cell Lung Cancer

The retinoid acid receptor-p (RARβ) gene is one of the tumor suppressor genes (TSGs), which is frequently deleted or epigenetically silenced at an early stage of tumor progression. In this study we investigated the promoter methylation and expression status of the RARβ gene in 60 surgically resected non-small cell lung cancer (NSCLC) tissue samples and 60 corresponding unchanged lung tissue samples, using methylation-specific PCR and real-time-polymerase chain reaction (qPCR) techniques. We correlated the results with the pathological features of tumors and clinical characteristics of patients. qPCR analysis detected a significantly lower RARβ expression in the patients with adenocarcinoma (AC) and large cell carcinoma (LCC) than in those with squamous cell carcinoma (SCC) (AC vs. SCC, p = 0.032; AC and LCC vs. SCC, p = 0.0 13). Additionally, significantly lower expression of the RARβ gene was revealed in the patients with non-squamous cell cancer with a history of smoking assessed as pack-years (PY < 40 vs. PY ≥ 40, p = 0.045). Regarding RARβ promoter methylation, we found significant differences in the methylation index in the SCC group when considering pTNM staging; with higher index values in T1a + T1b compared with T2a + T2b and T3 + T4 groups (p = 0.024). There was no correlation between the methylation status and expression level of the RARβ gene, which suggests that other molecular mechanisms influence the RARβ expression in NSCLC patients. In conclusion, different expression of the RARβ gene in SCC and NSCC makes the RARβ gene a valuable diagnostic marker for differentiating the NSCLC subtypes.

Knocking Down Nucleolin Expression Enhances the Radiosensitivity of Non-Small Cell Lung Cancer by Influencing DNA-PKcs Activity

Nucleolin (C23) is an important anti-apoptotic protein that is ubiquitously expressed in exponentially growing eukaryotic cells. In order to understand the impact of C23 in radiation therapy, we attempted to investigate the relationship of C23 expression with the radiosensitivity of human non-small cell lung cancer (NSCLC) cells. We investigated the role of C23 in activating the catalytic subunit of DNA-dependent protein kinase (DNA- PKcs), which is a critical protein for DNA double-strand breaks (DSBs) repair. As a result, we found that the expression of C23 was negatively correlated with the radiosensitivity of NSCLC cell lines. In vitro clonogenic survival assays revealed that C23 knockdown increased the radiosensitivity of a human lung adenocarcinoma cell line, potentially through the promotion of radiation-induced apoptosis and adjusting the cell cycle to a more radiosensitive stage. Immunofluorescence data revealed an increasing quantity of γ-H2AX foci and decreasing radiation-induced DNA damage repair following knockdown of C23. To further clarify the mechanism of C23 in DNA DSBs repair, we detected the expression of DNA-PKcs and C23 proteins in NSCLC cell lines. C23 might participate in DNA DSBs repair for the reason that the expression of DNA-PKcs decreased at 30, 60, 120 and 360 minutes after irradiation in C23 knockdown cells. Especially, the activity of DNA-PKcs phosphorylation sites at the S2056 and T2609 was significantly suppressed. Therefore we concluded that C23 knockdown can inhibit DNA-PKcs phosphorylation activity at the S2056 and T2609 sites, thus reducing the radiation damage repair and increasing the radiosensitivity of NSCLC cells. Taken together, the inhibition of C23 expression was shown to increase the radiosensitivity of NSCLC cells, as implied by the relevance to the notably decreased DNA-PKcs phosphorylation activity at the S2056 and T2609 clusters. Further research on targeted C23 treatment may promote effectiveness of radiotherapy and provide new targets for NSCLC patients.

Relevance of insulin-like growth factor 1 receptor gene expression as a prognostic factor in non-small-cell lung cancer

PURPOSE

Signalling through the insulin-like growth factor 1 receptor (IGF-1R) is implicated in carcinogenesis, metastasis, and resistance to cytotoxic cancer therapies. The purpose of this study was to investigate the prognostic role of IGF-1R expression in surgically resected non-small-cell lung cancer (NSCLC), and responses to IGF-1R tyrosine kinase inhibitor NVP-ADW742 in a panel of lung cancer cell lines.

METHODS

Insulin-like growth factor 1 receptor (IGF-1R) expression was evaluated by quantitative RT-PCR in 115 NSCLC samples and in a panel of 6 NSCLC cell lines. Cytotoxicity experiments with IGF-1R inhibitor and conventional systemic drugs such as paclitaxel in cell lines were realised.

RESULTS

Insulin-like growth factor 1 receptor (IGF-1R) was differentially expressed across histologic subtypes, with the lowest levels observed in squamous cell tumours. Median survival was longer in patients with squamous tumour histology expressing low IGF-1R levels. In multivariable analysis, ageing and high tumour stage were significant predictors of worse overall survival. The hazard of death was lower in patients with squamous histology and low IGF-1R gene expression. There was no correlation between IGF-1R expression and response to tyrosine kinase inhibitor in cell lines tested. However, combination drug treatment resulted in synergistically enhanced antiproliferative effects on several cell lines.

CONCLUSIONS

These findings suggest that IGF-1R is a potential target for therapy in NSCLC patients. Combination therapies will have an important role in treatment.

Allelic imbalance in the miR-31 host gene locus in lung cancer--its potential role in carcinogenesis

Small non-protein coding RNA, microRNA (miR), which regulate messenger RNA levels, have recently been identified, and may play important roles in the pathogenesis of various diseases. The present study focused on miR-31 and investigated its potential involvement in lung carcinogenesis. The expression of miR-31 was altered in lung cancer cells through either the amplification or loss of the host gene locus. The strong expression of miR-31 in large cell carcinomas was attributed to the gene amplification. Meanwhile, the loss of miR-31 expression was more frequently observed in aggressive adenocarcinomas. Thus, miR-31 may play a pleiotropic role in the development of lung cancers among different histological types. To the best of our knowledge, this is the first study to show the potential causative mechanism of the altered expression of miR-31 and suggest its potentially diverse significance in the different histological types of lung cancers.

Insulin-like growth factor receptor 1 mRNA expression as a prognostic marker in advanced non-small cell lung cancer

BACKGROUND

The insulin-like growth factor 1 receptor (IGF1R) has yet to be established as a biomarker in non-small cell lung cancer (NSCLC) but could prove useful in customized chemotherapy. We explored its prognostic value using both quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC).

MATERIALS AND METHODS

Analyses of IGF1R were performed on patients with advanced NSCLC, included in a randomized chemotherapy trial, having large, representative tissue samples. IGF1R mRNA and protein expression were correlated to clinical end-points.

RESULTS

Surgical tissue samples were available from 33 patients deemed inoperable. IGF1R status varied according to histopathology. Patients with tumors positive for IGF1R mRNA expression had a shorter progression-free and overall survival when compared to the negative sub-group (6.1 vs. 7.4 months, p=0.039 and 10.9 vs. 14.3 months, p=0.038, respectively). IGF1R protein expression showed a similar, although non-significant tendency.

CONCLUSION

IGF1R mRNA expression may be a prognostic biomarker in advanced NSCLC and should be investigated in a larger population.

[Expression and significance of UNC-112 protein in lung cancer]

OBJECTIVE

To investigate the expression of UNC-112 protein in lung cancer and discuss its value.

METHODS

The method of immunohistochemical SP was employed to detect the expression of UNC-112 protein in 210 cases of lung cancer, and evaluate its correlation with pathological classification.

RESULTS

UNC-112A and UNC-112B protein were highly expressed in non-small cell lung cancer, not expressed or expressed at very low levels in small cell lung cancer(P < 0.05);the expression of UNC-112A protein in squamous cell carcinoma was significantly higher than those in adenocarcinoma (P < 0.001)and large cell lung cancer (P < 0.01), but there is no significant difference between adenocarcinoma and large cell lung cancer (P = 0.18).UNC-112A protein expression level was positively correlated with the differentiation of squamous cell carcinoma(P = 0.0024). The expression of UNC-112B protein was significantly higher in large cell lung cancer than those in adenocarcinoma (P = 0.002) and squamous cell carcinoma (P < 0.01), and it was significantly higher in adenocarcinoma than squamous cell carcinoma (P = 0.005).

CONCLUSIONS

UNC-112 protein may be related to the heterogeneity of lung cancer, UNC-112A and UNC-112B protein play different roles in invasion and migration of lung cancer.

Urinary bladder urothelial carcinoma with expression of KIT and PDGFRA and showing diverse differentiations into plasmacytoid, clear cell, acantholytic, nested, and spindle variants, and into adenocarcinoma, signet-ring cell carcinoma, small cell carcinoma, large cell carcinoma, and pleomorphic carcinoma

Various tumors can arise in the urinary bladder (UB); most common is urothelial carcinoma (UC). UC of the UB have many variants. Other types of carcinomas such as adenocarcinoma (AC) and small cell carcinoma (SmCC) can occur in UB carcinomas. Expression of KIT and PDGFRA has not been reported. A 66-year-old man admitted to our hospital because of hematuria. Cystoscopy revealed papillary invasive tumor and a transurethral bladder tumorectomy (TUR-BT) was performed. The TUR-BT showed UC, AC, SmCC, large cell carcinoma (LCC), and pleomorphic carcinoma (PC). The UC component showed plasmacytoid, spindle, nested, clear cell, acantholytic variants. The AC element showed tubular adenocarcinoma and signet-ring cell carcinoma (Sig). Immunohistochemically, all of these subtypes were positive for cytokeratin (CK) AE1/3, CK CAM5.2, CK34BE12, CK5, CK6, CK7, CK8, CK18, CK19, CK20, EMA, CEA, p63, CA19-9, p53 (positive 45%), MUC1, NSE, NCAM, KIT, PDGFRA, and Ki-67 (87%). They were negative for vimentin, chromogranin, synaptophysin, S100 protein, CD34, CD14, α-smooth muscle actin, CD31, caldesmon, CD138, CD45, κ-chain, λ-chain, MUC2, MUC5AC and MUC6. Mucin histochemistry revealed mucins in AC element including Sig. A molecular genetic analysis using PCR-direct sequencing method identified no mutations of KIT (exons 9, 11, 13, and 17) and PDGFRA (exons 12 and 18) genes. The carcinoma was highly aggressive and invaded into muscular layer. The nuclear grade was very high, and there were numerous lymphovascular permeations were seen. The surface showed carcinoma in situ involving von-Brunn's nests. This case shows that carcinoma of UB can show diverse differentiations into numerous histological types and variants, and can express KIT and PDGFRA. The both genes showed no mutations in the present case.

Human lung cancer-associated fibroblasts enhance motility of non-small cell lung cancer cells in co-culture

The metastatic potential of non-small cell lung cancer (NSCLC) cells has been shown to be associated with the tumor microenvironment. Cancer-associated fibroblasts (CAFs) are a major component of the tumor microenvironment, regulating tumor cell function by secreting growth factors, chemokines, and extracellular matrix (ECM). In this study, we examined the role of CAFs in the tumor progression of NSCLC. Firstly, we established primary cultures of CAFs and matched normal fibroblasts (NFs) from patients with resected NSCLC. CAFs exhibited greater expression of the pan-mesenchymal marker α-smooth muscle actin (α-SMA) than did NFs, although they displayed similar morphology. Furthermore, we employed a direct co-culture assay with human NSCLC A549 and H358 cells, and found that CAFs were more potent in inducing the epithelial-to-mesenchymal transition (EMT) phenotype than NFs, as indicated by an elongated and disseminated appearance. CAF-induced EMT led to an increase in motility and a decrease in proliferation of NSCLC cells through SMAD family number-3 (SMAD3)-dependent up-regulation of the growth inhibitory gene p21(CIP1) [cyclin-dependent kinase inhibitor-1A (CDKN1A)] and α-SMA. Taken together, these findings provide evidence that lung CAFs have tumor-promoting capacity distinct from NFs and might play a significant role in the metastatic potential of NSCLC.

Distinct profile of driver mutations and clinical features in immunomarker-defined subsets of pulmonary large-cell carcinoma

Pulmonary large-cell carcinoma-a diagnostically and clinically controversial entity-is defined as a non-small-cell carcinoma lacking morphologic differentiation of either adenocarcinoma or squamous cell carcinoma, but suspected to represent an end stage of poor differentiation of these tumor types. Given the recent advances in immunohistochemistry to distinguish adenocarcinoma and squamous cell carcinoma, and the recent insights that several therapeutically relevant genetic alterations are distributed differentially in these tumors, we hypothesized that immunophenotyping may stratify large-cell carcinomas into subsets with distinct profiles of targetable driver mutations. We therefore analyzed 102 large-cell carcinomas by immunohistochemistry for TTF-1 and ΔNp63/p40 as classifiers for adenocarcinoma and squamous cell carcinoma, respectively, and correlated the resulting subtypes with nine therapeutically relevant genetic alterations characteristic of adenocarcinoma (EGFR, KRAS, BRAF, MAP2K1/MEK1, NRAS, ERBB2/HER2 mutations and ALK rearrangements) or more common in squamous cell carcinoma (PIK3CA and AKT1 mutations). The immunomarkers classified large-cell carcinomas as variants of adenocarcinoma (n=62; 60%), squamous cell carcinoma (n=20; 20%) or marker-null (n=20; 20%). Genetic alterations were found in 38 cases (37%), including EGFR (n=1), KRAS (n=30), BRAF (n=2), MAP2K1 (n=1), ALK (n=3) and PIK3CA (n=1). All molecular alterations characteristic of adenocarcinoma occurred in tumors with immunoprofiles of adenocarcinoma or marker-null, but not in tumors with squamous immunoprofiles (combined mutation rate 50% vs 30% vs 0%, respectively; P<0.001), whereas the sole PIK3CA mutation occurred in a tumor with squamous profile (5%). Furthermore, marker-null large-cell carcinomas were associated with significantly inferior disease-free (P<0.001) and overall (P=0.001) survival. In conclusion, the majority (80%) of large-cell carcinomas can be classified by immunomarkers as variants of adenocarcinoma or squamous cell carcinoma, which stratifies these tumors into subsets with a distinct distribution of driver mutations and distinct prognoses. These findings have practical implications for diagnosis, predictive molecular testing and therapy selection.

Identification and characterization of cells with cancer stem cell properties in human primary lung cancer cell lines

Lung cancer (LC) with its different subtypes is generally known as a therapy resistant cancer with the highest morbidity rate worldwide. Therapy resistance of a tumor is thought to be related to cancer stem cells (CSCs) within the tumors. There have been indications that the lung cancer is propagated and maintained by a small population of CSCs. To study this question we established a panel of 15 primary lung cancer cell lines (PLCCLs) from 20 fresh primary tumors using a robust serum-free culture system. We subsequently focused on identification of lung CSCs by studying these cell lines derived from 4 representative lung cancer subtypes such as small cell lung cancer (SCLC), large cell carcinoma (LCC), squamous cell carcinoma (SCC) and adenocarcinoma (AC). We identified a small population of cells strongly positive for CD44 (CD44^high) and a main population which was either weakly positive or negative for CD44 (CD44^low/−). Co-expression of CD90 further narrowed down the putative stem cell population in PLCCLs from SCLC and LCC as spheroid-forming cells were mainly found within the CD44^highCD90⁺ sub-population. Moreover, these CD44^highCD90⁺ cells revealed mesenchymal morphology, increased expression of mesenchymal markers N-Cadherin and Vimentin, increased mRNA levels of the embryonic stem cell related genes Nanog and Oct4 and increased resistance to irradiation compared to other sub-populations studied, suggesting the CD44^highCD90⁺ population a good candidate for the lung CSCs. Both CD44^highCD90⁺ and CD44^highCD90⁻ cells in the PLCCL derived from SCC formed spheroids, whereas the CD44^low/− cells were lacking this potential. These results indicate that CD44^highCD90⁺ sub-population may represent CSCs in SCLC and LCC, whereas in SCC lung cancer subtype, CSC potentials were found within the CD44^high sub-population.

Elevated microsatellite alterations at selected tetra-nucleotide (EMAST) in non-small cell lung cancers--a potential determinant of susceptibility to multiple malignancies

The present study evaluated the potential clinicopathologic significance of elevated microsatellite alteration at selected tetra-nucleotide (EMAST) in non-small cell lung cancer (NSCLC). Sixty-five NSCLCs (19 squamous cell carcinomas, 39 adenocarcinomas, one adenosquamous cell carcinoma, and 6 large cell carcinomas) were examined for EMAST in the ten selected tetra-nucleotide markers. Traditional microsatellite instability (MSI) in the five mono- or di-nucleotide markers of the Bethesda panel was also examined, and compared with EMAST. The incidence of EMAST was higher than that of traditional MSI, as 64.6% (42/65) and 12.3% (8/65) tumors respectively exhibited EMAST and traditional MSI in at least one marker. EMAST and traditional MSI appear to occur independently, as no significant association in their incidence was found (Fisher's exact test, P = 0.146). Subjects who exhibited EMAST in two or more markers had a significantly higher incidence of history of other malignant neoplasms (42.9% [9/21]), compared to those with less than two markers (16.3% [7/43] (Chi-square test, P = 0.021)). Taken together, impairment of molecular machinery for maintaining stable replication of the tetra-nucleotide-repeating regions, which would differ from machinery for mono- or di-nucleotide-repeating regions, may elevate susceptibility to NSCLCs and certain neoplastic diseases. Elucidation of the potential molecular mechanism of EMAST is expected to lead to a discovery of a novel genetic background determining susceptibility to NSCLC and other multiple neoplasms. This is the first report describing a clinicopathologic significance of EMAST in NSCLC.

Applications of array-CGH for lung cancer

This chapter summarizes the current knowledge on gene copy number changes found in lung tumors, and their application in the diagnosis, prognostication, and prediction of response to chemotherapy. Examples of the identification of specific "driver" oncogenes within amplified DNA segments are described. A model of how array-CGH could be integrated clinically into the routine workup of lung cancers in clinical laboratory is proposed.

Identification of Wnt pathway, uPA, PAI-1, MT1-MMP, S100A4 and CXCR4 associated with enhanced metastasis of human large cell lung cancer by DNA microarray

AIM

The aim of this paper was to investigate the differentially expressed genes in large cell lung cancer cell lines with different metastatic potential, and to screen out new candidate genes related to metastasis of lung cancer.

METHODS

The total RNAs of low and high metastatic large cell lung cancer cell lines (NL9980 and L9981) were extracted and processed, then hybridized to Affymetrix HG U133 Plus 2.0 array. The hybridization signals were scanned and compared to find out the differentially expressed genes. Chosen genes were verified by Western Blot. Bioinformatics were used to analyze the functions and related pathways of the genes.

RESULTS

There were 933 differentially expressed genes between NL9980 and L9981 cell lines. In the high metastatic cell line L9981, 672 genes were up-regulated and 260 genes were down-regulated compared with the low metastatic cell line NL9980. The differentially expressed genes were mainly associated with binding, catalytic activity, signal transducer activity and transporter activity, and mainly involved in pathways including, pathways in cancer, focal adhesion, regulation of actin cytoskeleton, ECM-receptor interaction.

CONCLUSION

Differentially expressed genes with the functions including binding, catalytic activity, signal transducer activity and transporter activity may promote metastasis of lung cancer cells through complicated networks including Wnt pathway and metastasis-related genes such as uPA, PAI-1, MT1-MMP, S100A4 and CXCR4.

Impact of collection and storage of lung tumor tissue on whole genome expression profiling

Gene expression profiling could assist in revealing biomarkers of lung cancer prognosis and progression. The handling of biological samples may strongly influence global gene expression, a fact that has not been addressed in many studies. We sought to investigate the changes in gene expression that may occur as a result of sample processing time and conditions. Using Illumina Human WG-6 arrays, we quantified gene expression in lung carcinoma samples from six patients obtained at chest opening before and immediately after lung resection with storage in RNAlater [T1a((CO)) and T1b((LR))], after receipt of the sample for histopathology, placed in RNAlater [T2a((HP))]; snap frozen [T2b((HP.SF))]; or snap frozen and stored for 1 week [T2c((HP.SFA))], as well as formalin-fixed, paraffin-embedded (FFPE) block samples. Sampling immediately after resection closely represented the tissue obtained in situ, with only 1% of genes differing more than twofold [T1a((CO)) versus T1b((LR))]. Delaying tissue harvest for an average of 30 minutes from the operating theater had a significant impact on gene expression, with approximately 25% of genes differing between T1a((CO)) and T2a((HP)). Many genes previously identified as lung cancer biomarkers were altered during this period. Examination of FFPE specimens showed minimal correlation with fresh samples. This study shows that tissue collection immediately after lung resection with conservation in RNAlater is an optimal strategy for gene expression profiling.

Clinical application of MAGE A1-6 RT-nested PCR for diagnosis of lung cancer invisible by bronchoscopy

BACKGROUND

The main goal of this study was to evaluate the diagnostic efficacy of melanoma-associated antigen (MAGE) A1-6 reverse transcriptase-nested polymerase chain reaction (RT-nested PCR) of bronchial washing fluid for the detection of lung cancer invisible by bronchoscopy.

PATIENTS AND METHODS

To determine the expression of MAGE A1-6 gene in 75 lung carcinomas diagnosed by conventional fluoroscopy-guided lung biopsy and 58 cancer-free controls, RT-nested PCR was performed of bronchial washing fluid. MAGE A1-6 RT-nested PCR data was analyzed according to tumor histology, stage, size, and compared with cytological data.

RESULTS

MAGE A1-6 RT-nested PCR displayed higher sensitivity (64.0%) than that of conventional cytology (14.7%). There was no significant correlation between MAGE gene expression and histological types or clinical stage. For tumor size, detection rates were 74.0% in tumor smaller than 3 cm and 58.7% in these larger than 3 cm.

CONCLUSIONS

MAGE A1-6 RT-nested PCR of bronchial washing fluid may be a useful method for diagnosis of peripheral lung cancer in clinical practice.