Expression of scavenger receptor MARCO defines a targetable tumor-associated macrophage subset in non-small cell lung cancer.

Tumor-associated macrophages (TAMs) are attractive targets for immunotherapy. Recently, studies in animal models showed that treatment with an anti-TAM antibody directed against the scavenger receptor MARCO resulted in suppression of tumor growth and metastatic dissemination. Here we investigated the expression of MARCO in relation to other macrophage markers and immune pathways in a non-small cell lung cancer (NSCLC) cohort (n = 352). MARCO, CD68, CD163, MSR1 and programmed death ligand-1 (PD-L1) were analyzed by immunohistochemistry and immunofluorescence, and associations to other immune cells and regulatory pathways were studied in a subset of cases (n = 199) with available RNA-seq data. We observed a large variation in macrophage density between cases and a strong correlation between CD68 and CD163, suggesting that the majority of TAMs present in NSCLC exhibit a protumor phenotype. Correlation to clinical data only showed a weak trend toward worse survival for patients with high macrophage infiltration. Interestingly, MARCO was expressed on a distinct subpopulation of TAMs, which tended to aggregate in close proximity to tumor cell nests. On the transcriptomic level, we found a positive association between MARCO gene expression and general immune response pathways including strong links to immunosuppressive TAMs, T-cell infiltration and immune checkpoint molecules. Indeed, a higher macrophage infiltration was seen in tumors expressing PD-L1, and macrophages residing within tumor cell nests co-expressed MARCO and PD-L1. Thus, MARCO is a potential new immune target for anti-TAM treatment in a subset of NSCLC patients, possibly in combination with available immune checkpoint inhibitors.

Inconsistent results in the analysis of ALK rearrangements in non-small cell lung cancer.

BACKGROUND: Identification of targetable EML4-ALK fusion proteins has revolutionized the treatment of a minor subgroup of non-small cell lung cancer (NSCLC) patients. Although fluorescence in situ hybridization (FISH) is regarded as the gold standard for detection of ALK rearrangements, ALK immunohistochemistry (IHC) is often used as screening tool in clinical practice. In order to unbiasedly analyze the diagnostic impact of such a screening strategy, we compared ALK IHC with ALK FISH in three large representative Swedish NSCLC cohorts incorporating clinical parameters and gene expression data. METHODS: ALK rearrangements were detected using FISH on tissue microarrays (TMAs), including tissue from 851 NSCLC patients. In parallel, ALK protein expression was detected using IHC, applying the antibody clone D5F3 with two different protocols (the FDA approved Ventana CDx assay and our in house Dako IHC protocol). Gene expression microarray data (Affymetrix) was available for 194 patients. RESULTS: ALK rearrangements were detected in 1.7 % in the complete cohort and 2.0 % in the non-squamous cell carcinoma subgroup. ALK protein expression was observed in 1.8 and 1.4 % when applying the Ventana assay or the in house Dako protocol, respectively. The specificity and accuracy of IHC was high (> 98 %), while the sensitivity was between 69 % (Ventana) and 62 % (in house Dako protocol). Furthermore, only 67 % of the ALK IHC positive cases were positive with both IHC assays. Gene expression analysis revealed that 6/194 (3 %) tumors showed high ALK gene expression (≥ 6 AU) and of them only three were positive by either FISH or IHC. CONCLUSION: The overall frequency of ALK rearrangements based on FISH was lower than previously reported. The sensitivity of both IHC assays was low, and the concordance between the FISH and the IHC assays poor, questioning current strategies to screen with IHC prior to FISH or completely replace FISH by IHC.

Endoscopic papillectomy and KRAS expression in the treatment of adenoma in the major duodenal papilla.

OBJECTIVE: The use of endoscopic papillectomy for resecting adenomas in the major duodenal papilla is increasing. This study focuses on the following three issues: Can endoscopic papillectomy be performed as a safe diagnostic and/or therapeutic procedure in biopsy-verified or suspected ampullary adenoma? Does expression of mutated KRAS in resected adenomatous tissue predict long-term outcome? What other factors may affect long-term outcome and should, therefore, be considered in decision making prior to endoscopic papillectomy? MATERIAL AND METHODS: Thirty-six prospectively collected patients who underwent endoscopic papillectomy at Karolinska University Hospital between 2005 and 2014 were analyzed. RESULTS: The rate of exact agreement between the histomorphological grading of the endoscopic biopsies and the papillectomy specimens was low (48%). Obstructive jaundice at presentation increased the risk of undetected adenocarcinoma (RR = 3.98; 95% CI = 1.46-10.85, p = 0.007). Lesions with malignancies were significantly larger (mean 30.6 mm) than those where only adenomas were found (mean 14.4 mm, p = 0.001). Mutated KRAS was detected in 9 of the 36 post-papillectomy specimens, including 4 of the 5 cases of ampullary adenocarcinoma. Eighteen cases were endoscopically cured after a mean follow-up period of 47 months (range 16-92 months). CONCLUSIONS: Endoscopic papillectomy is a valuable staging tool because of the limitations of endoscopic biopsy. Endoscopic papillectomy concomitantly offers a curative treatment for most patients with adenoma in the major duodenal papilla. Jaundice at presentation and large adenomas may indicate the presence of more advanced disease. Determination of mutated KRAS seems to be of limited value in predicting long-term outcome.

Identification of sample annotation errors in gene expression datasets.

The comprehensive transcriptomic analysis of clinically annotated human tissue has found widespread use in oncology, cell biology, immunology, and toxicology. In cancer research, microarray-based gene expression profiling has successfully been applied to subclassify disease entities, predict therapy response, and identify cellular mechanisms. Public accessibility of raw data, together with corresponding information on clinicopathological parameters, offers the opportunity to reuse previously analyzed data and to gain statistical power by combining multiple datasets. However, results and conclusions obviously depend on the reliability of the available information. Here, we propose gene expression-based methods for identifying sample misannotations in public transcriptomic datasets. Sample mix-up can be detected by a classifier that differentiates between samples from male and female patients. Correlation analysis identifies multiple measurements of material from the same sample. The analysis of 45 datasets (including 4913 patients) revealed that erroneous sample annotation, affecting 40 % of the analyzed datasets, may be a more widespread phenomenon than previously thought. Removal of erroneously labelled samples may influence the results of the statistical evaluation in some datasets. Our methods may help to identify individual datasets that contain numerous discrepancies and could be routinely included into the statistical analysis of clinical gene expression data.

Diagnostic gastrointestinal markers in primary lung cancer and pulmonary metastases.

Histopathological diagnosis of pulmonary tumors is essential for treatment decisions. The distinction between primary lung adenocarcinoma and pulmonary metastasis from the gastrointestinal (GI) tract may be difficult. Therefore, we compared the diagnostic value of several immunohistochemical markers in pulmonary tumors. Tissue microarrays from 629 resected primary lung cancers and 422 resected pulmonary epithelial metastases from various sites (whereof 275 colorectal cancer) were investigated for the immunohistochemical expression of CDH17, GPA33, MUC2, MUC6, SATB2, and SMAD4, for comparison with CDX2, CK20, CK7, and TTF-1. The most sensitive markers for GI origin were GPA33 (positive in 98%, 60%, and 100% of pulmonary metastases from colorectal cancer, pancreatic cancer, and other GI adenocarcinomas, respectively), CDX2 (99/40/100%), and CDH17 (99/0/100%). In comparison, SATB2 and CK20 showed higher specificity, with expression in 5% and 10% of mucinous primary lung adenocarcinomas and both in 0% of TTF-1-negative non-mucinous primary lung adenocarcinomas (25-50% and 5-16%, respectively, for GPA33/CDX2/CDH17). MUC2 was negative in all primary lung cancers, but positive only in less than half of pulmonary metastases from mucinous adenocarcinomas from other organs. Combining six GI markers did not perfectly separate primary lung cancers from pulmonary metastases including subgroups such as mucinous adenocarcinomas or CK7-positive GI tract metastases. This comprehensive comparison suggests that CDH17, GPA33, and SATB2 may be used as equivalent alternatives to CDX2 and CK20. However, no single or combination of markers can categorically distinguish primary lung cancers from metastatic GI tract cancer.

Spatial immunophenotyping of the tumour microenvironment in non-small cell lung cancer.

INTRODUCTION: Immune cells in the tumour microenvironment are associated with prognosis and response to therapy. We aimed to comprehensively characterise the spatial immune phenotypes in the mutational and clinicopathological background of non-small cell lung cancer (NSCLC). METHODS: We established a multiplexed fluorescence imaging pipeline to spatially quantify 13 immune cell subsets in 359 NSCLC cases: CD4 effector cells (CD4-Eff), CD4 regulatory cells (CD4-Treg), CD8 effector cells (CD8-Eff), CD8 regulatory cells (CD8-Treg), B-cells, natural killer cells, natural killer T-cells, M1 macrophages (M1), CD163+ myeloid cells (CD163), M2 macrophages (M2), immature dendritic cells (iDCs), mature dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs). RESULTS: CD4-Eff cells, CD8-Eff cells and M1 macrophages were the most abundant immune cells invading the tumour cell compartment and indicated a patient group with a favourable prognosis in the cluster analysis. Likewise, single densities of lymphocytic subsets (CD4-Eff, CD4-Treg, CD8-Treg, B-cells and pDCs) were independently associated with longer survival. However, when these immune cells were located close to CD8-Treg cells, the favourable impact was attenuated. In the multivariable Cox regression model, including cell densities and distances, the densities of M1 and CD163 cells and distances between cells (CD8-Treg-B-cells, CD8-Eff-cancer cells and B-cells-CD4-Treg) demonstrated positive prognostic impact, whereas short M2-M1 distances were prognostically unfavourable. CONCLUSION: We present a unique spatial profile of the in situ immune cell landscape in NSCLC as a publicly available data set. Cell densities and cell distances contribute independently to prognostic information on clinical outcomes, suggesting that spatial information is crucial for diagnostic use.

FGFR1 overexpression in non-small cell lung cancer is mediated by genetic and epigenetic mechanisms and is a determinant of FGFR1 inhibitor response.

Amplification of fibroblast growth factor receptor 1 (FGFR1) in non-small cell lung cancer (NSCLC) has been considered as an actionable drug target. However, pan-FGFR tyrosine kinase inhibitors did not demonstrate convincing clinical efficacy in FGFR1-amplified NSCLC patients. This study aimed to characterise the molecular context of FGFR1 expression and to define biomarkers predictive of FGFR1 inhibitor response. In this study, 635 NSCLC samples were characterised for FGFR1 protein expression by immunohistochemistry and copy number gain (CNG) by in situ hybridisation (n = 298) or DNA microarray (n = 189). FGFR1 gene expression (n = 369) and immune cell profiles (n = 309) were also examined. Furthermore, gene expression, methylation and microRNA data from The Cancer Genome Atlas (TCGA) were compared. A panel of FGFR1-amplified NSCLC patient-derived xenograft (PDX) models were tested for response to the selective FGFR1 antagonist M6123. A minority of patients demonstrated FGFR1 CNG (10.5%) or increased FGFR1 mRNA (8.7%) and protein expression (4.4%). FGFR1 CNG correlated weakly with FGFR1 gene and protein expression. Tumours overexpressing FGFR1 protein were typically devoid of driver alterations (e.g. EGFR, KRAS) and showed reduced infiltration of T-lymphocytes and lower PD-L1 expression. Promoter methylation and microRNA were identified as regulators of FGFR1 expression in NSCLC and other cancers. Finally, NSCLC PDX models demonstrating FGFR1 amplification and FGFR1 protein overexpression were sensitive to M6123. The unique molecular and immune features of tumours with high FGFR1 expression provide a rationale to stratify patients in future clinical trials of FGFR1 pathway-targeting agents.

Identification and functional characterization of new missense SNPs in the coding region of the TP53 gene.

Infrequent and rare genetic variants in the human population vastly outnumber common ones. Although they may contribute significantly to the genetic basis of a disease, these seldom-encountered variants may also be miss-identified as pathogenic if no correct references are available. Somatic and germline TP53 variants are associated with multiple neoplastic diseases, and thus have come to serve as a paradigm for genetic analyses in this setting. We searched 14 independent, globally distributed datasets and recovered TP53 SNPs from 202,767 cancer-free individuals. In our analyses, 19 new missense TP53 SNPs, including five novel variants specific to the Asian population, were recurrently identified in multiple datasets. Using a combination of in silico, functional, structural, and genetic approaches, we showed that none of these variants displayed loss of function compared to the normal TP53 gene. In addition, classification using ACMG criteria suggested that they are all benign. Considered together, our data reveal that the TP53 coding region shows far more polymorphism than previously thought and present high ethnic diversity. They furthermore underline the importance of correctly assessing novel variants in all variant-calling pipelines associated with genetic diagnoses for cancer.

Evaluation of NTRK immunohistochemistry as a screening method for NTRK gene fusion detection in non-small cell lung cancer.

PURPOSE: The small molecule inhibitors larotrectinib and entrectinib have recently been approved as cancer agnostic drugs in patients with tumours harbouring a rearrangement of the neurotrophic tropomyosin receptor kinase (NTRK). These oncogenic fusions are estimated to occur in 0.1-3 % of non-small cell lung cancers (NSCLC). Although molecular techniques are most reliable for fusion detection, immunohistochemical analysis is considered valuable for screening. Therefore, we evaluated the newly introduced diagnostic immunohistochemical assay (clone EPR17341) on a representative NSCLC cohort. METHODS: Cancer tissue from 688 clinically and molecularly extensively annotated NSCLC patients were comprised on tissue microarrays and stained with the pan-TRK antibody clone EPR17341. Positive cases were further analysed with the TruSight Tumor 170 RNA assay (Illumina). Selected cases were also tested with a NanoString NTRK fusion assay. For 199 cases, NTRK RNA expression data were available from previous RNA sequencing analysis. RESULTS: Altogether, staining patterns for 617 NSCLC cases were evaluable. Of these, four cases (0.6 %) demonstrated a strong diffuse cytoplasmic and membranous staining, and seven cases a moderate staining (1.1 %). NanoString or TST170-analysis could not confirm an NTRK fusion in any of the IHC positive cases, or any of the cases with high mRNA levels. In the four cases with strong staining intensity in the tissue microarray, whole section staining revealed marked heterogeneity of NTRK protein expression. CONCLUSION: The presence of NTRK fusion genes in non-small cell lung cancer is exceedingly rare. The use of the immunohistochemical NTRK assay will result in a small number of false positive cases. This should be considered when the assay is applied as a screening tool in clinical diagnostics.

Comprehensive analysis of RNA binding motif protein 3 (RBM3) in non-small cell lung cancer.

AIMS: High expression of the RNA-binding motif protein 3 (RBM3) correlates with improved prognosis in several major types of cancer. The aim of the present study was to examine the prognostic value of RBM3 protein and mRNA expression in non-small cell lung cancer (NSCLC). METHODS AND RESULTS: Immunohistochemical expression of RBM3 was evaluated in surgically treated NSCLC from two independent patient populations (n = 213 and n = 306). Staining patterns were correlated with clinicopathological parameters, overall survival (OS), and recurrence-free interval (RFI). Cases with high nuclear RBM3 protein expression had a prolonged 5-year OS in both cohorts when analyzing adenocarcinomas separately (P = .02 and P = .01). RBM3 remained an independent prognostic factor for OS in multivariable analysis of cohort I (HR 0.44, 95% CI 0.21-0.90) and for RFI in cohort II (HR 0.38, 95% CI 0.22-0.74). In squamous cell carcinoma, there was instead an insignificant association to poor prognosis. Also, the expression levels of RBM3 mRNA were investigated in 2087 lung adenocarcinomas and 899 squamous cell carcinomas assembled from 13 and 8 public gene expression microarray datasets, respectively. The RBM3 mRNA levels were not clearly associated with patient outcome in either adenocarcinomas or squamous cell carcinomas. CONCLUSIONS: The results from this study support that high protein expression of RBM3 is linked to improved outcome in lung adenocarcinoma.

Diagnostic Value of Insulinoma-Associated Protein 1 (INSM1) and Comparison With Established Neuroendocrine Markers in Pulmonary Cancers.

CONTEXT.­: The diagnostic distinction of pulmonary neuroendocrine (NE) tumors from non-small cell lung carcinomas (NSCLCs) is clinically relevant for prognostication and treatment. Diagnosis is based on morphology and immunohistochemical staining. OBJECTIVE.­: To determine the diagnostic value of insulinoma-associated protein 1 (INSM1), in comparison with established NE markers, in pulmonary tumors. DESIGN.­: Fifty-four pulmonary NE tumors and 632 NSCLCs were stained for INSM1, CD56, chromogranin A, and synaptophysin. In a subset, gene expression data were available for analysis. Also, 419 metastases to the lungs were stained for INSM1. A literature search identified 39 additional studies with data on NE markers in lung cancers from the last 15 years. Seven of these included data on INSM1. RESULTS.­: A positive INSM1 staining was seen in 39 of 54 NE tumors (72%) and 6 of 623 NSCLCs (1%). The corresponding numbers were 47 of 54 (87%) and 14 of 626 (2%) for CD56, 30 of 54 (56%) and 6 of 629 (1%) for chromogranin A, and 46 of 54 (85%) and 49 of 630 (8%) for synaptophysin, respectively. Analysis of literature data revealed that CD56 and INSM1 were the best markers for identification of high-grade NE pulmonary tumors when considering both sensitivity and specificity, while synaptophysin also showed good sensitivity. INSM1 gene expression was clearly associated with NE histology. CONCLUSIONS.­: The solid data of both our and previous studies confirm the diagnostic value of INSM1 as a NE marker in pulmonary pathology. The combination of CD56 with INSM1 and/or synaptophysin should be the first-hand choice to confirm pulmonary high-grade NE tumors. INSM1 gene expression could be used to predict NE tumor histology.

WITHDRAWN: Characterization of Patterns of Immune Cell Infiltration in NSCLC.

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Immunohistochemical profiles in primary lung cancers and epithelial pulmonary metastases.

Correct diagnosis of pulmonary tumors is essential for treatment decision and often relies on immunohistochemical markers. We stained tissue microarrays from resected primary lung cancer (n = 665) and pulmonary metastases (n = 425) for CK7, CK20, CDX2, CK5, p40, p63, TTF-1, napsin A, GATA3, and PAX8 to systematically assess the diagnostic value of these markers. Primary lung adenocarcinomas expressed TTF-1 in 90% and napsin A in 84% of the cases, whereas 10% were positive for p63, 7% for CDX2, 2% for CK20, and 2% for GATA3. Only 68% of the lung adenocarcinomas were positive for CK7, TTF-1, and napsin A and negative for all other markers. Primary lung squamous cell carcinomas expressed CK5, p40, and p63 in 94%-97% of cases, whereas 44% were positive for CK7, 20% for GATA3, 7% for CDX2, and 3% for TTF-1. Rare cases expressed PAX8, CK20, or napsin A. Pulmonary metastases of colorectal cancer were positive for CK20 in 83% and CDX2 in 99% of the cases. Rare cases expressed CK7, p63, or PAX8, whereas 4% expressed TTF-1. Pulmonary metastases of renal cell carcinomas were positive for PAX8 in 74%, napsin A in 7%, and CK7 in 7% of the cases. Pulmonary metastases of breast cancer were positive for GATA3 in 93% and CK7 in 78% of the cases, whereas 15% expressed CK5. Information on expression and patterns of immunohistochemical markers facilitates histopathological diagnostics. Evidently, unusual immune profiles occur and may lead to incorrect diagnosis.

Prognostic Impact of Tumor Cell Programmed Death Ligand 1 Expression and Immune Cell Infiltration in NSCLC.

INTRODUCTION: Infiltration of T and B/plasma cells has been linked to NSCLC prognosis, but this has not been thoroughly investigated in relation to the expression of programmed death ligand 1 (PD-L1). Here, we determine the association of lymphocytes and PD-L1 with overall survival (OS) in two retrospective cohorts of operated NSCLC patients who were not treated with checkpoint inhibitors targeting the programmed death 1/PD-L1 axis. Moreover, we evaluate how PD-L1 positivity and clinicopathologic factors affect the prognostic association of lymphocytes. METHODS: Cluster of differentiation (CD) 3 (CD3)-, CD8-, CD4-, forkhead box P3 (FOXP3)-, CD20-, CD79A-, and immunoglobulin kappa constant (IGKC)-positive immune cells, and tumor PD-L1 positivity, were determined by immunohistochemistry on tissue microarrays (n = 705). Affymetrix data was analyzed for a patient subset, and supplemented with publicly available transcriptomics data (N = 1724). Associations with OS were assessed by Kaplan-Meier plots and uni- and multivariate Cox regression. RESULTS: Higher levels of T and B plasma cells were associated with longer OS (p = 0.004 and p < 0.001, for CD8 and IGKC, respectively). Highly proliferative tumors with few lymphocytes had the worst outcome. No association of PD-L1 positivity with OS was observed in a nonstratified patient population; however, a significant association with shorter OS was observed in never-smokers (p = 0.009 and p = 0.002, 5% and 50% cutoff). Lymphocyte infiltration was not associated with OS in PD-L1-positive tumors (50% cutoff). The prognostic association of lymphocyte infiltration also depended on the patients' smoking history and histologic subtype. CONCLUSIONS: Proliferation, PD-L1 status, smoking history, and histology should be considered if lymphocyte infiltration is to be used as a prognostic biomarker.

Detection of autoantibodies against cancer-testis antigens in non-small cell lung cancer.

OBJECTIVES: Cancer-testis antigens (CTAs) are defined as proteins that are specifically expressed in testis or placenta and their expression is frequently activated in cancer. Due to their ability to induce an immune response, CTAs may serve as suitable targets for immunotherapy. The aim of this study was to evaluate if there is reactivity against CTAs in the plasma of non-small cell lung cancer (NSCLC) patients through the detection of circulating antibodies. MATERIALS AND METHODS: To comprehensively analyze autoantibodies against CTAs the multiplexing capacities of suspension bead array technology was used. Bead arrays were created with 120 protein fragments, representing 112 CTAs. Reactivity profiles were measured in plasma samples from 133 NSCLC patients and 57 cases with benign lung diseases. RESULTS: Altogether reactivity against 69 antigens, representing 81 CTAs, was demonstrated in at least one of the analyzed samples. Twenty-nine of the antigens (45 CTAs) demonstrated exclusive reactivity in NSCLC samples. Reactivity against cancer-testis antigen family 47; member A (CT47A) genes, P antigen family member 3 (PAGE3), variable charge X-linked (VCX), melanoma antigen family B1 (MAGEB1), lin-28 homolog B (LIN28B) and chromosome 12 open reading frame 54 (C12orf54) were only found in NSCLC patients at a frequency of 1%-4%. The presence of autoantibodies towards these six antigens was confirmed in an independent group of 34 NSCLC patients. CONCLUSION: We identified autoantibodies against CTAs in the plasma of lung cancer patients. The reactivity pattern of autoantibodies was higher in cancer patients compared to the benign group, stable over time, but low in frequency of occurrence. The findings suggest that some CTAs are immunogenic and that these properties can be utilized as immune targets.

Comparison of Three Different TTF-1 Clones in Resected Primary Lung Cancer and Epithelial Pulmonary Metastases.

OBJECTIVES: Immunohistochemical staining against thyroid transcription factor 1 (TTF-1) is often used to distinguish lung adenocarcinoma from squamous cell carcinoma and pulmonary metastasis. METHODS: TTF-1 expression was examined using the antibody clones 8G7G3/1, SPT24, and SP141 on tissue microarrays from 665 cases of resected lung cancers and 428 pulmonary metastases. RESULTS: Most lung adenocarcinomas, 89%, 93%, and 93%, were positive with TTF-1 clones 8G7G3/1, SPT24, and SP141, respectively. The corresponding figures for lung squamous cell carcinomas were 0%, 6%, and 8%. In total, five (2%), 19 (7%), and 21 (8%) of the pulmonary metastases from colorectal adenocarcinomas were positive with clones 8G7G3/1, SPT24, and SP141, respectively. Other TTF-1-positive pulmonary metastases (n = 8) were thyroid, urothelial, pancreatic, small bowel, and cervix carcinomas. CONCLUSIONS: TTF-1 expression in lung cancer and pulmonary metastases differs between clones, with 8G7G3/1 being more specific but less sensitive compared with SPT24 and SP141.

Various Antibody Clones of Napsin A, Thyroid Transcription Factor 1, and p40 and Comparisons With Cytokeratin 5 and p63 in Histopathologic Diagnostics of Non-Small Cell Lung Carcinoma.

Histopathologic classification of cancer in the lung is important for choice of treatment. Cytokeratin 5 (CK5), p63, and p40 are commonly used immunohistochemical markers for squamous cell carcinoma, and napsin A (NAPA) and thyroid transcription factor 1 (TTF-1) are markers for adenocarcinoma of the lung. The aim of the present study was to evaluate these 5 markers and to compare different commercially available antibody clones in lung cancer. Tissue microarrays including 557 cases of surgically treated primary tumors and 73 matched metastases of non-small cell lung carcinoma were stained with CK5, p63, p40 (monoclonal and polyclonal), NAPA (5 different clones/protocols), and TTF-1 (2 different clones). The sensitivity and specificity to separate squamous cell carcinomas from non-small cell carcinomas of nonsquamous type were 95% and 97%, respectively, for CK5, 95% and 87% for p63, 94% and 96% for p40, 75% to 79% and 96% to 98% for the NAPA clones/protocols and 80% to 85% and 95% to 97% for the TTF-1 clones. A combination of NAPA and TTF-1 resulted in a higher sensitivity (85% to 88%), whereas combining CK5 and p40 did not increase the diagnostic performance. The sensitivity was generally lower in evaluation of lung cancer metastases. The κ-values for comparison of staining results between monoclonal and polyclonal p40 and between the 5 NAPA clones/protocols were 0.97 to 1.0, whereas the corresponding figure for the 2 TTF-1 clones was 0.91 to 0.93. Conclusively, CK5 and p40 are good diagnostic markers for squamous cell carcinoma and superior to p63. In addition, it may be useful to combine NAPA and TTF-1 for increased sensitivity in lung cancer diagnostics. There is no substantial difference between monoclonal and polyclonal p40 and between different NAPA clones, whereas there is a difference between the TTF-1 clones 8G7G3/1 and SPT24.

Prognostic impact of COX-2 in non-small cell lung cancer: a comprehensive compartment-specific evaluation of tumor and stromal cell expression.

Cyclooxygenase-2 (COX-2) is an enzyme that has been extensively investigated as a prognostic marker in cancer. In non-small cell lung cancer (NSCLC) previous results regarding the prognostic impact of COX-2 expression are inconsistent. Therefore we evaluated the association between transcript levels and overall survival in nine publicly available gene expression data sets (total n = 1337) and determined in situ compartment-specific tumor and stromal cell protein expression in two independent cohorts (n = 616). Gene expression did not show any correlation with clinical parameters or with overall survival. Protein expression in tumor and stromal cells did not correlate with any clinical parameter or with overall survival in one of the analyzed cohorts, while a significant association of high stromal expression with longer survival was observed in both univariate and multivariate analysis in the other cohort. Stromal expression of COX-2 has not been separately evaluated in NSCLC previously and may be a subject of further investigation, whereas the presented findings from this comprehensive compartment specific evaluation clearly reject the hypothesis of COX-2 tumor cell expression having a prognostic value in NSCLC.