Sigve Andersen

The Role of Tumor Stroma in Cancer Progression and Prognosis: Emphasis on Carcinoma-Associated Fibroblasts and Non-small Cell Lung Cancer

Maintenance of both normal epithelial tissues and their malignant counterparts is supported by the host tissue stroma. The tumor stroma mainly consists of the basement membrane, fibroblasts, extracellular matrix, immune cells, and vasculature. Although most host cells in the stroma possess certain tumor-suppressing abilities, the stroma will change during malignancy and eventually promote growth, invasion, and metastasis. Stromal changes at the invasion front include the appearance of carcinoma-associated fibroblasts (CAFs). CAFs constitute a major portion of the reactive tumor stroma and play a crucial role in tumor progression. The main precursors of CAFs are normal fibroblasts, and the transdifferentiation of fibroblasts to CAFs is driven to a great extent by cancer-derived cytokines such as transforming growth factor-&bgr;. During recent years, the crosstalk between the cancer cells and the tumor stroma, highly responsible for the progression of tumors and their metastasis, has been increasingly unveiled. A better understanding of the host stroma contribution to cancer progression will increase our knowledge about the growth promoting signaling pathways and hopefully lead to novel therapeutic interventions targeting the tumor stroma. This review reports novel data on the essential crosstalk between cancer cells and cells of the tumor stroma, with an emphasis on the role played by CAFs. Furthermore, it presents recent literature on relevant tumor stroma- and CAF-related research in non-small cell lung cancer.

The role of tumor-infiltrating immune cells and chronic inflammation at the tumor site on cancer development, progression, and prognosis: emphasis on non-small cell lung cancer.

In addition to malignant neoplastic cells, cancer tissues also include immune cells, fibroblasts, and endothelial cells, including an abundant collection of growth factors, proangiogenic mediators, cytokines, chemokines, and components of the extracellular matrix. The main physiological function of the immune cells is to monitor tissue homeostasis, to protect against invading pathogens, and to eliminate transformed or damaged cells. Between immune cells and malignant cells in the tumor stroma, there is in fact a complex interaction which has significant prognostic relevance as the immune system has both tumor-promoting and -inhibiting roles. In non-small cell lung cancer (NSCLC), there is a marked infiltration of different types of immune cells, and the distribution, tissue localization, and cell types are significantly associated with progression and survival. Cancer immunotherapy has seen a significant progress during the last decade. An increased understanding of the mechanisms by which lung cancer cells escape the immune system, and the recognition of the key tumor antigens and immune system components in tumor ignorance have led to the development of several lung cancer vaccines. As the NSCLC prognosis in general is dismal, one may hope that future immunotherapy may be an effective adjunct to standard therapy, reversing immunologic tolerance in the tumor microenvironment. This review reports on the tumor stroma and in particular tumor-suppressing and -promoting roles of the immune system. Furthermore, it presents recent literature on relevant immune cell-related research in NSCLC.

Prognostic Impact of Notch Ligands and Receptors in Nonsmall Cell Lung Cancer Coexpression of Notch-1 and Vascular Endothelial Growth Factor-A Predicts Poor Survival

Notch signaling plays a key role in embryonic vascular development and angiogenesis. The authors aimed to study the prognostic role of the angiogenesis‐related Notch ligands and receptors and investigate the prognostic impact of the coexpression of vascular endothelial growth factor‐A (VEGF‐A) and Notch signaling.

Prognostic Impact of Platelet-Derived Growth Factors in Non-small Cell Lung Cancer Tumor and Stromal Cells

Background: In tumor angiogenesis there is a complex interplay between endothelial, stromal, and tumor cells (neoplastic epithelial cells). Platelet-derived growth factors (PDGFs) and receptors (PDGFRs) are pivotal in this interaction, and important targets in novel antiangiogenic therapies. This study investigates the prognostic impact of these molecular markers in tumor cells and tumor stroma of resected non-small cell lung cancer (NSCLC) tumors. Methods: Tumor tissue samples from 335 resected patients with stage I to IIIA NSCLC were obtained and tissue microarrays were constructed from duplicate cores of tumor cells and tumor-related stroma from each specimen. Immunohistochemistry was used to evaluate the expression of the molecular markers PDGF-A, -B, -C, and -D and PDGFR-&agr; and -&bgr;. Results: In univariate analyses, high tumor cell expression of PDGF-B (p = 0.001), PDGF-C (p = 0.01), and PDGFR-&agr; (p = 0.026) were negative prognostic indicators for disease-specific survival. In tumor stroma, high expression of PDGF-A (p = 0.009), PDGF-B (p = 0.04), PDGF-D (p = 0.019), and PDGFR-&agr; (p = 0.019) correlated with good prognosis. In multivariate analyses, high tumor cell PDGF-B (p = 0.001) and PDGFR-&agr; (p = 0.047) expression were independent negative prognostic factors for disease-specific survival, whereas in stromal cells high PDGF-A (p = 0.001) expression had an independent positive survival impact. Conclusion: Our results indicate PDGF-B and PDGFR-&agr; inhibition as an interesting approach in NSCLC treatment, but also demonstrates the importance of understanding the cellular crosstalk between endothelial, stromal, and tumor cells when targeting PDGF markers.

MicroRNA Signatures in Tumor Tissue Related to Angiogenesis in Non-Small Cell Lung Cancer

Background Angiogenesis is regarded as a hallmark in cancer development, and anti-angiogenic treatment is presently used in non-small cell lung cancer (NSCLC) patients. MicroRNAs (miRs) are small non-coding, endogenous, single stranded RNAs that regulate gene expression. In this study we aimed to identify significantly altered miRs related to angiogenesis in NSCLC. Methods From a large cohort of 335 NSCLC patients, paraffin-embedded samples from 10 patients with a short disease specific survival (DSS), 10 with a long DSS and 10 normal controls were analyzed. The miRs were quantified by microarray hybridization and selected miRs were validated by real-time qPCR. The impacts of different pathways, including angiogenesis, were evaluated by Gene Set Enrichment Analysis (GSEA) derived from Protein ANalysis THrough Evolutionary Relationship (PANTHER). One of the most interesting candidate markers, miR-155, was validated by in situ hybridization (ISH) in the total cohort (n = 335) and correlation analyses with several well-known angiogenic markers were done. Results 128 miRs were significantly up- or down-regulated; normal versus long DSS (n = 68) and/or normal versus short DSS (n = 63) and/or long versus short DSS (n = 37). The pathway analysis indicates angiogenesis-related miRs to be involved in NSCLC. There were strong significant correlations between the array hybridization and qPCR validation data. The significantly altered angiogenesis-related miRs of high interest were miR-21, miR-106a, miR-126, miR-155, miR-182, miR-210 and miR-424. miR-155 correlated significantly with fibroblast growth factor 2 (FGF2) in the total cohort (r = 0.17, P = 0.002), though most prominent in the subgroup with nodal metastasis (r = 0.34, P<0.001). Conclusions Several angiogenesis-related miRs are significantly altered in NSCLC. Further studies to understand their biological functions and explore their clinical relevance are warranted.

Stromal CD8+ T-cell Density—A Promising Supplement to TNM Staging in Non–Small Cell Lung Cancer

Purpose: Immunoscore is a prognostic tool defined to quantify in situ immune cell infiltrates, which appears to be superior to the tumor–node–metastasis (TNM) classification in colorectal cancer. In non–small cell lung cancer (NSCLC), no immunoscore has been established, but in situ tumor immunology is recognized as highly important. We have previously evaluated the prognostic impact of several immunological markers in NSCLC, yielding the density of stromal CD8+ tumor-infiltrating lymphocytes (TIL) as the most promising candidate. Hence, we validate the impact of stromal CD8+ TIL density as an immunoscore in NSCLC. Experimental Design: The prognostic impact of stromal CD8+ TILs was evaluated in four different cohorts from Norway and Denmark consisting of 797 stage I–IIIA NSCLC patients. The Tromso cohort (n = 155) was used as training set, and the results were further validated in the cohorts from Bodo (n = 169), Oslo (n = 295), and Denmark (n = 178). Tissue microarrays and clinical routine CD8 staining were used for all cohorts. Results: Stromal CD8+ TIL density was an independent prognostic factor in the total material (n = 797) regardless of the endpoint: disease-free survival (P < 0.001), disease-specific survival (P < 0.001), or overall survival (P < 0.001). Subgroup analyses revealed significant prognostic impact of stromal CD8+ TIL density within each pathologic stage (pStage). In multivariate analysis, stromal CD8+ TIL density and pStage were independent prognostic variables. Conclusions: Stromal CD8+ TIL density has independent prognostic impact in resected NSCLC, adds prognostic impact within each pStage, and is a good candidate marker for establishing a TNM-Immunoscore. Clin Cancer Res; 21(11); 2635–43. ©2015 AACR.

Prognostic Impact of MiR-155 in Non-Small Cell Lung Cancer Evaluated by in Situ Hybridization

BackgroundIn recent years, microRNAs (miRNAs) have been found to play an essential role in tumor development. In lung tumorigenesis, targets and pathways of miRNAs are being revealed, and further translational research in this field is warranted. MiR-155 is one of the miRNAs most consistently involved in various neoplastic diseases. We aimed to investigate the prognostic impact of the multifunctional miR-155 in non-small cell lung cancer (NSCLC) patients.MethodsTumor tissue samples from 335 resected stage I to IIIA NSCLC patients were obtained and tissue microarrays (TMAs) were constructed with four cores from each tumor specimen. In situ hybridization (ISH) was used to evaluate the expression of miR-155.ResultsThere were 191 squamous cell carcinomas (SCCs), 95 adenocarcinomas (ACs), 31 large cell carcinomas and 18 bronchioalveolar carcinomas. MiR-155 expression did not have a significant prognostic impact in the total cohort (P = 0.43). In ACs, high miR-155 expression tended to a significant negative prognostic effect on survival in univariate analysis (P = 0.086) and was an independent prognostic factor in multivariate analysis (HR 1.87, CI 95% 1.01 - 3.48, P = 0.047). In SCC patients with lymph node metastasis, however, miR-155 had a positive prognostic impact on survival in univariate (P = 0.034) as well as in multivariate (HR 0.45, CI 95% 0.21-0.96, P = 0.039) analysis.ConclusionsThe prognostic impact of miR-155 depends on histological subtype and nodal status in NSCLC.

Independent and Tissue-Specific Prognostic Impact of miR-126 in Nonsmall Cell Lung Cancer

Angiogenesis is pivotal in tumor development. Vascular endothelial growth factor‐A (VEGF‐A) is considered one of the most important angiogenic factors, but lately several microRNAs (miRs) have been associated with vascular development. miR‐126 has been related to tumor angiogenesis and in the regulation of VEGF‐A. The authors aimed to investigate the prognostic impact of miR‐126 and its co‐expression with VEGF‐A in nonsmall cell lung cancer (NSCLC) patients.

The Role of Tumor-Infiltrating Lymphocytes in Development, Progression, and Prognosis of Non-Small Cell Lung Cancer.

ABSTRACT A malignant tumor is not merely an accumulation of neoplastic cells, but constitutes a microenvironment containing endothelial cells, fibroblasts, structural components, and infiltrating immune cells that impact tumor development, invasion, metastasis, and outcome. Hence, the evolution of cancers reflects intricate cellular and molecular interactions between tumor cells and constituents of the tumor microenvironment. Recent studies have shed new light on this complex interaction between tumor and host immune cells and the resulting immune response. The composition of the immune microenvironment differs across patients as well as in cancers of the same type, including various populations of T cells, B cells, dendritic cells, natural killer cells, myeloid‐derived suppressor cells, neutrophils, and macrophages. The type, density, location, and organization of immune cells within solid tumors define the immune contexture, which has proved to be a major determinant of tumor characteristics and patient outcome. Lung cancer consists mostly of non–small cell lung cancer (85%); it is our most deadly malignant disease, with the 5‐year survival rate being merely 15%. This review focuses on the immune contexture; the tumor‐suppressing roles of tumor‐infiltrating lymphocytes; and the relevance of this immune contexture for cancer diagnostics, prognostication, and treatment allocation, with an emphasis on non–small cell lung cancer.

Combination of Low Vascular Endothelial Growth Factor A (VEGF-A)/VEGF Receptor 2 Expression and High Lymphocyte Infiltration Is a Strong and Independent Favorable Prognostic Factor in Patients With Nonsmall Cell Lung Cancer

There seems to be a close interplay between angiogenesis and the immune system. The authors of this report investigated the prognostic role of angiogenic markers in coexpression with immune system markers in patients with nonsmall cell lung cancer (NSCLC).