Immune system and prognosis in colorectal cancer: a detailed immunohistochemical analysis

Tumor-Infiltrating Immune Cells in Colorectal Cancer

Colorectal cancer encompasses a heterogeneous group of malignancies that differ in pathophysiological mechanisms, immune response and infiltration, therapeutic response, and clinical prognosis. Numerous studies have highlighted the clinical relevance of tumor-infiltrating immune cells among different types of colorectal tumors yet vary in cell type definitions and cell identification strategies. The distinction of immune signatures is particularly challenging when several immune subtypes are involved but crucial to identify novel intercellular mechanisms within the tumor microenvironment. In this review, we compile human and non-human studies on tumor-infiltrating immune cells and provide an overview of immune subtypes, their pathophysiological functions, and their prognostic role in colorectal cancer. We discuss how differentiating immune signatures can guide the development of immunotherapeutic targets and personalized treatment regimens. We analyzed comprehensive human protein biomarker profiles across the entire immune spectrum to improve interpretability and application of tumor studies and to ultimately enhance immunotherapy and advance precision medicine for colorectal cancer patients.

Role of chemokine receptors in gastrointestinal mucosa

Chemokine receptors are essential for the immune response in the oral and gut mucosa. The gastrointestinal mucosa is characterized by the presence of immune populations because it is susceptible to inflammatory and infectious diseases, necessitating immune surveillance. Chemokine receptors are expressed on immune cells and play a role in gastrointestinal tissue-homing, although other non-immune cells also express them for various biological functions. CCR9, CXCR3 and CXCR6 play an important role in the T cell response in inflammatory and neoplastic conditions of the gastrointestinal mucosa. However, CXCR6 could also be found in gastric cancer cells, highlighting the different roles of chemokine receptors in different pathologies. On the other hand, CCR4 and CCR8 are critical for Treg migration in gastrointestinal tissues, correlating with poor prognosis in mucosal cancers. Other chemokine receptors are also important in promoting myeloid infiltration with context-dependent roles. Further, CXCR4 and CXCR7 are also present in gastrointestinal tumor cells and are known to stimulate proliferation, migration, and invasion into other tissues, among other pro-tumorigenic functions. Determining the processes underlying mucosal immunity and creating tailored therapeutic approaches for gastrointestinal diseases requires an understanding of the complex interactions that occur between chemokine receptors and their ligands in these mucosal tissues.

Clinical impact of heterogeneously distributed tumor-infiltrating lymphocytes on the prognosis of colorectal cancer

Background

Tumor-infiltrating lymphocytes (TILs) exist in various malignancies, and have been viewed as a promising biomarker to predict the efficacy and outcome of treatment. However, the marked inter- and intra-tumor heterogeneity of TILs has resulted in some confusion regarding their impact on the prognosis of colorectal cancer (CRC).

Methods

In this study, 78 CRC patients were enrolled and the CD3+ and CD8+ TILs densities at the tumor center (TC), the invasive margin (IM) and the tumor stroma (TS) were assessed by immunohistochemical staining. Their associations with clinicopathological features and progression free survival (PFS) were analyzed to evaluate the predictive and prognostic values of TILs.

Results

TILs were mainly distributed along the invasive margin. High density of TILs in tumor center and invasive margin was associated with smaller tumor size (CD3+TILsIM), reduced tumor invasion (CD3+TILsIM), absence of lymph node metastasis (CD3+TILsIM and CD8+TILsTC), earlier stage (CD3+TILsIM and CD8+TILsIM), and lower tumor grade (CD3+TILsIM and CD8+TILsTC). However, stromal TILs were not associated with any clinicopathological features. Kaplan-Meier survival analysis revealed that high densities of TILs always correlated with prolonged patient survival. The pathological N stage, CD3+ TILsIM and CD8+ TILsTC were found to be independent prognostic indicators. Additionally, early-stage CRC patients who developed recurrence after surgery, showed a higher CD3+/CD8+ TILs ratio in invasive margin. In the present study, it was clarified that CD3+ and CD8+ TILs were heterogeneously distributed in tumor tissues of CRC. The increase in intratumoral and peritumoral TILs had been shown to be strongly predictive of improved clinical outcome. More importantly, the immune signatures enabled to stratify early-stage CRC patients with high risk of recurrence, highlighting the prognostic power of TILs.

Prognostic and predictive value of tumor infiltrating lymphocytes in combination with systemic inflammatory markers in colon cancer

OBJECTIVE

Systemic inflammatory indices and CD8(+) tumor infiltrating lymphocytes (TILs) in the tumor microenvironment are highly prognostic in colon cancer (CC) but combined assessment is less well studied. The purpose of this study was to investigate the prognostic and predictive value of CD8(+) TILs in combination with systemic inflammatory indices in patients with resected stage II-III colon cancer.

PATIENTS AND METHODS

Patients with stage II-III CC (n = 304) diagnosed between 2008 and 2016 were included. Pan-immune inflammation value (PIV) was used as a comprehensive inflammatory index and was calculated as: [neutrophil count × platelet count × monocyte count]/lymphocyte count. The mean density of CD8+ TILs in the periphery and center of the tumor was assessed and dichotomized at the 75th percentile. Combined inflammation score (CIS) was classified as "high" in patients with high PIV (>median) plus low mean CD8(+) TILs density, and CIS "low" in the remaining patients.

RESULTS

5-year DFS was 71% (78% in stage II, 63.4% in stage III). PIV was higher in right colon tumors, T4 tumors and in patients with obstruction / perforation. CD8(+) TIL density was lower in node positive tumors. High PIV and low CD8(+) TILs were associated with shorter disease-free survival (DFS). In multivariate analysis; age > 65 years, stage III disease and high CIS (PIVhigh / CD8low) were associated with shorter DFS. Among patients with stage II disease, patients with high CIS (PIVhigh / CD8low) derived significant benefit from adjuvant chemotherapy while those with low CIS derived no benefit.

CONCLUSION

Combined inflammation score may represent a new prognostic factor for localized colon cancer and predictor of chemotherapy response in patients with stage II disease.

TMEM123 a key player in immune surveillance of colorectal cancer

Colorectal cancer (CRC) is a leading cause of cancer-associated death. In the tumor site, the interplay between effector immune cells and cancer cells determines the balance between tumor elimination or outgrowth. We discovered that the protein TMEM123 is over-expressed in tumour-infiltrating CD4 and CD8 T lymphocytes and it contributes to their effector phenotype. The presence of infiltrating TMEM123+ CD8+ T cells is associated with better overall and metastasis-free survival. TMEM123 localizes in the protrusions of infiltrating T cells, it contributes to lymphocyte migration and cytoskeleton organization. TMEM123 silencing modulates the underlying signaling pathways dependent on the cytoskeletal regulator WASP and the Arp2/3 actin nucleation complex, which are required for synaptic force exertion. Using tumoroid-lymphocyte co-culture assays, we found that lymphocytes form clusters through TMEM123, anchoring to cancer cells and contributing to their killing. We propose an active role for TMEM123 in the anti-cancer activity of T cells within tumour microenvironment.

High abundance of Lachnospiraceae in the human gut microbiome is related to high immunoscores in advanced colorectal cancer

INTRODUCTION

The tumor microenvironment (TME) in colorectal cancer (CRC) includes the gut microbiome, immune cells, angiogenic factors, and fibroblasts and plays a major role in cancer progression. The Immunoscore (IS) is based on tumor infiltration by immune cells that are known prognostic biomarkers for CRC. However, the interrelation between the IS, microbiome, and other TME factors in human CRC remains unclear.

PATIENTS AND METHODS

A cohort of 94 patients with CRC was examined at the Shiga University of Medical Science Hospital in Japan. The expression levels of CD3, CD8, CD31, and alpha-smooth muscle actin (α-SMA) in the primary tumor were evaluated by immunohistochemistry. The IS was calculated based on the results of the CD3 and CD8 staining assays. Microbiomes in patients with CRC were examined by amplicon sequencing.

RESULTS

The expression levels of α-SMA and tumor-infiltrating lymphocytes in patients with CRC were negatively correlated (P = 0.006). A high IS was associated with high abundance of Lachnospiraceae in the microbiomes of patients with CRC.

CONCLUSION

Lymphocyte infiltration into the primary tumor was marked by reduced density of cancer-associated fibroblasts and enrichment of the Lachnospiraceae family in the gut microbiome, which may influence CRC progression.

Effect of Peripheral Blood Lymphocytes on Prognosis of Multiple Cancers

BACKGROUND

In the era of immunotherapy, the immune function of patients with cancer has attracted increasingly more attention. The immune scoring system is an important supplement to the classical tumor staging and classification process. The immune system plays a controversial role in the development of cancer. Meanwhile, the prognostic significance of peripheral blood lymphocytes is still controversial. The present study aimed to assess the prognostic significance of peripheral blood lymphocytes in eight types of cancers.

METHODS

We performed a retrospective analysis of 32731 patients with cancer hospitalized in Shanxi Cancer Hospital from January 2012 to December 2016. The percentages of CD3+, CD4+, CD8+, CD19+, CD56+, and CD127+ lymphocytes in the peripheral blood of all patients were examined using flow cytometry. The immune cell subsets of patients with cancer were classified into three groups using the K-means clustering method via the R language software. Differences in the overall survival rate were analyzed using the Kaplan-Meier method. The Cox regression model was utilized for univariate and multivariate analysis.

RESULTS

The mean survival time of patients with liver cancer, rectal cancer, gastric cancer, breast cancer, esophageal cancer, colon cancer, ovarian cancer, and lymphoma was 30.25, 21.74, 37.67, 16.28, 21.62, 30.25, 31.43, and 34.27 months, respectively. The survival curves showed that the most prognostically beneficial immune state of the patients was when the expression of the immune cells in the peripheral blood was in equilibrium. Moreover, Cox proportional hazards regression model analysis revealed that the factors affecting the overall survival (OS) of patients with eight different kinds of cancer were not identical. However, CD19+ lymphocytes had the most significant impact on the prognosis of these patients.

CONCLUSIONS

Cancer occurrence and development were associated with the density of lymphocyte infiltration. Thus, immune homeostasis could be an effective indicator to evaluate prognosis and judge cancer treatment.

Neoadjuvant Chemotherapy Improves the Immunosuppressive Microenvironment of Bladder Cancer and Increases the Sensitivity to Immune Checkpoint Blockade

Although tumor immune microenvironment plays an important role in antitumor therapy, few studies explored the gene signatures associated with the tumor immune microenvironment of bladder cancer after neoadjuvant chemotherapy. We examined and analyzed differentially expressed genes from 9 patients with stage I-III bladder cancer by RNA immune-oncology profiling platform. After neoadjuvant chemotherapy, the expressions of 43 genes in 19 pathways and 10 genes in 5 pathways were upregulated and downregulated, respectively. Neoadjuvant chemotherapy also promoted the expression of genes related to the activation of antitumor immune responses and decreased the expression of genes related to tumor proliferation pathways. In addition, neoadjuvant chemotherapy improved tumor response to immune checkpoint blockade. Furthermore, this study also identified several genes that can be used to predict the efficacy of neoadjuvant chemotherapy and their possible molecular mechanisms. In conclusion, neoadjuvant chemotherapy may promote the activation of antitumor effects, improve the suppressive tumor immune microenvironment, and increase the sensitivity of bladder cancer to immune checkpoint blockade.

ZhenQi FuZheng formula inhibits the growth of colorectal tumors by modulating intestinal microflora-mediated immune function

Zhenqi Fuzheng formula (ZQFZ), of which the main ingredients are Astragalus membranaceus and Ligustrum lucidum, has immune system regulatory functions and potential anti-tumor bioactivity. The inhibition of colorectal tumor growth by ZQFZ was analyzed in inflammatory cells and B6/JGpt-Apc^em1Cin(MinC)/Gpt (Apc^Min/+) mice. ZQFZ exhibited anti-inflammatory activity by decreasing the phosphorylation of nuclear factor-kappa B (NF-κB) pathway-related proteins in lipopolysaccharide-induced RAW264.7 cells. After 56 days of treatment, ZQFZ alleviated the progression of colorectal cancer (CRC) and increased the body weight and thymic index values of the Apc^Min/+ mice. An analysis of the intestinal microflora showed that ZQFZ affected the abundance of certain immune-related bacteria, which may explain its immunomodulatory effects. Moreover, the percentages of T cells and NK cells in peripheral blood were significantly increased and 15 immune-related cytokines were regulated in serum or the colon or both. ZQFZ upregulated the levels of CD4 and CD8 in the spleen and colorectal tumors and decreased the expression levels of cytotoxic T-lymphocyte-associated protein 4 and programmed death-ligand 1 in colorectal tumors. ZQFZ promoted an anti-tumor immune response and inhibited the occurrence and development of CRC by regulating the immune system. This study provides the experimental basis for the application of ZQFZ as a therapeutic agent for CRC.

Systematic construction and external validation of an immune-related prognostic model for nasopharyngeal carcinoma

BACKGROUND

We attempted to identify the most reliable immune-related index for predicting nasopharyngeal carcinoma (NPC) prognosis and to reveal its precise and integrated relationship with NPC progression.

METHOD

One thousand seven hundred and six patients with newly diagnosed NPC (1320 from the primary cohort and 386 from the validated cohort) from January 2010 to March 2014 were enrolled. Clinical features and 12 immune-related variables were analyzed.

RESULTS

A high absolute lymphocyte count (ALC; >3.2 × 10⁹ /L) correlated with a poor prognosis of patients with NPC. Significant OS differences were discovered between patients with high ALC and no ALC elevation (p < 0.05, in primary cohort), showing similar prognostic risk to patients with advanced NPC (p > 0.05, in validated cohort). ALC improved the predictive performance of the basic tumor-node-metastasis prognostic model (p = 0.025), which was reliably validated in the external independent cohort.

CONCLUSION

High ALC is a surrogate marker for improved prognostic risk stratification in NPC.

Metastatic colorectal cancer in both sides of Aegean sea: practice patterns and outcome

OBJECTIVE

The successful results obtained in trials may not necessarily translate into prolonged survival of metastatic colorectal cancer (mCRC) patients in real life. This multinational registry study aimed to evaluate the real-life data effecting the survival of patients with mCRC.

METHODS

This is a multinational, retrospective registry study. Turkish and Greek mCRC patients diagnosed between 2005 and 2012, with at least 3 years of follow-up data or who died before 3 years of follow-up were included in the study.

RESULTS

A total of 364 were included in the study. RAS and BRAF mutation rates were found to be 36% and 39%, respectively. As first-line therapy, 196 (54%) patients received bevacizumab and Anti-EGFR treatments in combination with chemotherapy. The objective response rate was 42% (n = 152) and 32% (n = 78) for 1^st line and 2^nd line treatments, respectively. While the median progression-free survival (PFS) with the 1^st line treatment was 10 months, it was 7 months with the 2^nd line treatments. In the total study population median PFS and overall survival (OS) were 10 (95% CI, 8.3-11.6) and 35 (95% CI, 30.7-39.2) months, respectively. In Turkish and Greek patients, median OS (36 months versus 29 months, p = .81) and PFS (10.2 versus 9.2, p = .42) were not different. In multivariate analysis, ECOG PS of ≥2 and having metastases in more than one region decreased overall survival (p = .002 and p = .003), it was found that wild RAS and BRAF mutations and second metastasectomy contributed to overall survival (p = .047 and p < .001).

CONCLUSION

In conclusion, it seems that the patient's performance status, tumor location, number of metastatic lesions at the time of diagnosis affect the prognosis of mCRC. Although access to molecular tests and first-line treatments differ between Greece and Turkey, no significant difference was found in survival times.

Tumor-Infiltrating Lymphocytes in Colorectal Cancer: The Fundamental Indication and Application on Immunotherapy

The clinical success of immunotherapy has revolutionized the treatment of cancer patients, bringing renewed attention to tumor-infiltrating lymphocytes (TILs) of various cancer types. Immune checkpoint blockade is effective in patients with mismatched repair defects and high microsatellite instability (dMMR-MSI-H) in metastatic colorectal cancer (CRC), leading the FDA to accelerate the approval of two programmed cell death 1 (PD-1) blocking antibodies, pembrolizumab and nivolumab, for treatment of dMMR-MSI-H cancers. In contrast, patients with proficient mismatch repair and low levels of microsatellite stability or microsatellite instability (pMMR-MSI-L/MSS) typically have low tumor-infiltrating lymphocytes and have shown unsatisfied responses to the immune checkpoint inhibitor. Different TILs environments reflect different responses to immunotherapy, highlighting the complexity of the underlying tumor-immune interaction. Profiling of TILs fundamental Indication would shed light on the mechanisms of cancer-immune evasion, thus providing opportunities for the development of novel therapeutic strategies. In this review, we summarize phenotypic diversities of TILs and their connections with prognosis in CRC and provide insights into the subsets-specific nature of TILs with different MSI status. We also discuss current clinical immunotherapy approaches based on TILs as well as promising directions for future expansion, and highlight existing clinical data supporting its use.

Cross-Talk Between Tumor Cells Undergoing Epithelial to Mesenchymal Transition and Natural Killer Cells in Tumor Microenvironment in Colorectal Cancer

Tumor cells undergoing epithelial to mesenchymal transition (EMT) and immune cells in tumor microenvironment (TME) reciprocally influence each other. Immune cells, by supplying TME with bioactive molecules including cytokines, chemokines, enzymes, metabolites, and by physical interactions with tumor cells via their receptors, represent an important factor that affects EMT. Chronical inflammation in TME favorizes tumor growth and invasiveness and stimulates synthesis of EMT promoting transcription factors. Natural killer (NK) cells, owing to their unique ability to exert cytotoxic function independent of major histocompatibility (MHC)-mediated antigen presentation, play a significant role in the control of metastasis in colorectal cancer (CRC). Although, the cross-talk between immune cells and tumor cells in general favors the induction of EMT and inhibition of antitumor immune responses, there are some changes in the immunogenicity of tumor cells during EMT of CRC cells that increase their susceptibility to NK cell cytotoxic lysis. However, suppressive TME downmodulates the expression of activating NK cell receptors, decreases the expression of activating and increases the expression of inhibitory NK cell ligands on tumor cells, and impairs NK cell metabolism that altogether negatively affects the overall NK cell function. Furthermore, process of EMT is often associated with increased expression of programmed cell death ligand (PD-L) and expression of immune checkpoint molecules PD-1, TIGIT, and TIM3 on functionally exhausted NK cells in TME in CRC. In this review we discuss modalities of cross-talk between tumor cells and NK cells, with regard of EMT-driven changes.

Prognostic value of LINC02560 in colorectal cancer correlates with tumor microenvironment immunity

Background: LINC02560 is a new 477 bp long non-coding RNA located in 19q13.43. However, the expression of LINC02560 in colorectal cancer (CRC) has not been reported, and its correlation with tumor development and function is still unclear. Methods: The expression of LINC02560 in CRC was first analyzed in the cancer genome atlas (TCGA) combined with The Genotype-Tissue Expression(GTEx) databases and then validated by clinical CRC samples and cell lines. The association between LINC02560 expression and clinicopathologic variables was analyzed by the Wilcoxon Rank SUM test. Cox regression analysis and Kaplan-Meier plots were used to assess the prognostic value of LINC02560 in CRC. The correlation between the expression level of LINC02560 and the 24 immune cells in tumor microenvironment (TME) was analyzed by single sample gene set enrichment analysis (ssGSEA). Gene set enrichment analysis (GSEA) was conducted to detect potential biological processes associated with LINC02560 in CRC. Results: LINC02560 was significantly up-regulated in CRC in comparison to normal samples. There are significant differences in the expression of LINC02560 in different subgroups of N stage, M stage, carcinoembryonic antigen (CEA) level, residual tumor, TP53 status and pathological stage. The high LINC02560 expression indicated poor overall survival (OS) and progress free interval (PFI) in patients with CRC. Moreover, the multivariate Cox analysis demonstrated that the expression of LINC02560 was an independent prognosis-predicting factor for OS in CRC patients. GSEA indicated that high expression of LINC02560 was involved in MAPK, Wnt, and PPAR signaling pathways and participated in humoral immune processes. We also identified that LINC02560 expression had a negative correlation with 4 kinds of immune cells. Conclusions: In summary, our research results indicate that LINC02560 may be a potential prognostic biomarker. It is involved in the occurrence and development of CRC and may affect the prognosis of CRC patients by regulating immune cells in the TME.

Tumour heterogeneity and evolutionary dynamics in colorectal cancer

Colorectal cancer (CRC) has a global burden of disease. Our current understanding of CRC has progressed from initial discoveries which focused on the stepwise accumulation of key driver mutations, as encapsulated in the Vogelstein model, to one in which marked heterogeneity leads to a complex interplay between clonal populations. Current evidence suggests that an initial explosion, or “Big Bang”, of genetic diversity is followed by a period of neutral dynamics. A thorough understanding of this interplay between clonal populations during neutral evolution gives insights into the roles in which driver genes may participate in the progress from normal colonic epithelium to adenoma and carcinoma. Recent advances have focused not only on genetics, transcriptomics, and proteomics but have also investigated the ecological and evolutionary processes which transform normal cells into cancer. This review first describes the role which driver mutations play in the Vogelstein model and subsequently demonstrates the evidence which supports a more complex model. This article also aims to underscore the significance of tumour heterogeneity and diverse clonal populations in cancer progression.

Prognostic Relevance of CD4+, CD8+ and FOXP3+ TILs in Oral Squamous Cell Carcinoma and Correlations with PD-L1 and Cancer Stem Cell Markers

This study investigates the relevance of tumor-infiltrating lymphocytes (TILs) in oral squamous cell carcinoma (OSCC). Immunohistochemical analysis of stromal/tumoral CD4⁺, CD8⁺ and FOXP3⁺ TILs is performed in 125 OSCC patients. Potential relationships with the expression of tumoral PD-L1 and cancer stem cell (CSC) markers (NANOG, SOX2, OCT4, Nestin and Podoplanin (PDPN)) are assessed. CD4⁺ and CD8⁺ TILs are significantly associated with smoking and alcohol habits. CD4⁺ and CD8⁺ TILs show an inverse relationship with NANOG and SOX2 expression, and FOXP3⁺ TILs is significantly correlated with Nestin and PDPN expression. High infiltration of CD4⁺ and CD8⁺ TILs and a high tumoral CD8⁺/FOXP3⁺ ratio are significantly associated with tumors harboring positive PD-L1 expression. Infiltration of stromal/tumoral FOXP3⁺ TILs and a low stromal CD8⁺/FOXP3⁺ ratio are significantly associated with better disease-specific survival. Multivariate analysis reveals that the stromal CD8⁺/FOXP3⁺ TILs ratio is a significant independent prognostic factor. Regarding OSCC patient survival, the CD8⁺/FOXP3⁺ TILs ratio is an independent prognostic factor. TILs may act as biomarkers and potential therapeutic targets for OSCC.

Therapeutic applications of the cancer immunoediting hypothesis

Since the late 19th century, the immune system has increasingly garnered interest as a novel avenue for cancer therapy, particularly given scientific breakthroughs in recent decades delineating the fundamental role of the immune system in tumorigenesis. The immunoediting hypothesis has articulated this role, describing three phases of the tumor-immune system interaction: Elimination, Equilibrium, and Escape wherein tumors progress from active immunologic surveillance and destruction through dynamic immunologic stasis to unfettered growth. The primary goals of immunotherapy are to restrict and revert progression through these phases, thereby improving the immune system's ability to control tumor growth. In this review, we detail the development and foundation of the cancer immunoediting hypothesis and apply this hypothesis to the dynamic immunotherapy field that includes checkpoint blockade, vaccine therapy, and adoptive cell transfer.

HLA class I loss in colorectal cancer: implications for immune escape and immunotherapy

T cell-mediated immune therapies have emerged as a promising treatment modality in different malignancies including colorectal cancer (CRC). However, only a fraction of patients currently respond to treatment. Understanding the lack of responses and finding biomarkers with predictive value is of great importance. There is evidence that CRC is a heterogeneous disease and several classification systems have been proposed that are based on genomic instability, immune cell infiltration, stromal content and molecular subtypes of gene expression. Human leukocyte antigen class I (HLA-I) plays a pivotal role in presenting processed antigens to T lymphocytes, including tumour antigens. These molecules are frequently lost in different types of cancers, including CRC, resulting in tumour immune escape from cytotoxic T lymphocytes during the natural history of cancer development. The aim of this review is to (i) summarize the prevalence and molecular mechanisms behind HLA-I loss in CRC, (ii) discuss HLA-I expression/loss in the context of the newly identified CRC molecular subtypes, (iii) analyze the HLA-I phenotypes of CRC metastases disseminated via blood or the lymphatic system, (iv) discuss strategies to recover/circumvent HLA-I expression/loss and finally (v) review the role of HLA class II (HLA-II) in CRC prognosis.

The local immunological microenvironment in colorectal cancer as a prognostic factor for treatment decisions in the clinic: The way ahead

Analysis of the local immunological microenvironment in colorectal cancer lesions yielded prognostic markers. Harnessing these insights for clinical application however requires the use of sophisticated technology and algorithms, especially the robust and reproducible quantification of immune cells. These technologies are available and will allow individualized treatment decisions beyond the current standard.

Trial watch: Prognostic and predictive value of the immune infiltrate in cancer

Solid tumors are constituted of a variety of cellular components, including bona fide malignant cells as well as endothelial, structural and immune cells. On one hand, the tumor stroma exerts major pro-tumorigenic and immunosuppressive functions, reflecting the capacity of cancer cells to shape the microenvironment to satisfy their own metabolic and immunological needs. On the other hand, there is a component of tumor-infiltrating leucocytes (TILs) that has been specifically recruited in the attempt to control tumor growth. Along with the recognition of the critical role played by the immune system in oncogenesis, tumor progression and response to therapy, increasing attention has been attracted by the potential prognostic and/or predictive role of the immune infiltrate in this setting. Data from large clinical studies demonstrate indeed that a robust infiltration of neoplastic lesions by specific immune cell populations, including (but not limited to) CD8⁺ cytotoxic T lymphocytes, Th1 and Th17 CD4⁺ T cells, natural killer cells, dendritic cells, and M1 macrophages constitutes an independent prognostic indicator in several types of cancer. Conversely, high levels of intratumoral CD4⁺CD25⁺FOXP3⁺ regulatory T cells, Th2 CD4⁺ T cells, myeloid-derived suppressor cells, M2 macrophages and neutrophils have frequently been associated with dismal prognosis. So far, only a few studies have addressed the true predictive potential of TILs in cancer patients, generally comforting the notion that—at least in some clinical settings—the immune infiltrate can reliably predict if a specific patient will respond to therapy or not. In this Trial Watch, we will summarize the results of clinical trials that have evaluated/are evaluating the prognostic and predictive value of the immune infiltrate in the context of solid malignancies.

Gene co-expression network analysis reveals immune cell infiltration as a favorable prognostic marker in non-uterine leiomyosarcoma

The present study aimed to improve the understanding of non-uterine leiomyosarcoma (NULMS) prognostic genes through system biology approaches. This cancer is heterogeneous and rare. Moreover, gene interaction networks have not been reported in NULMS yet. The datasets were obtained from the public gene expression databases. Seven co-expression modules were identified from 5000 most connected genes; using weighted gene co-expression network analysis. Using Cox regression, the modules showed favorable (HR = 0.6, 95% CI = 0.4-0.89, P = 0.0125), (HR = 0.65, 95% CI = 0.44-0.98, P = 0.04) and poor (HR = 1.55, 95% CI = 1.06-2.27, P = 0.025) prognosis to the overall survival (OS) (time = 3740 days). The first one was significant in multivariate HR estimates (HR = 0.4, 95% CI = 0.28-0.69, P = 0.0004). Enriched genes through the Database for Annotation, Visualization, and Integrated Discovery (DAVID) revealed significant immune-related pathways; suggesting immune cell infiltration as a favorable prognostic factor. The most significant protective genes were ICAM3, NCR3, KLRB1, and IL18RAP, which were in one of the significant modules. Moreover, genes related to angiogenesis, cell-cell adhesion, protein glycosylation, and protein transport such as PYCR1, SRM, and MDFI negatively affected the OS and were found in the other related module. In conclusion, our analysis suggests that NULMS might be a good candidate for immunotherapy. Moreover, the genes found in this study might be potential candidates for targeted therapy.

NK cell infiltration is associated with improved overall survival in solid cancers: A systematic review and meta-analysis

The immune landscape of a tumor is highly connected to patient prognosis and response to treatment, but little is known about how natural killer (NK) cells predict overall survival (OS) among patients with solid tumors. We present the first meta-analysis on NK cell infiltration into solid tumors as a prognostic indicator for OS, considering cancer types independently, and together. Samples were collected from 1973 to 2016 with results published between 1989 and 2020. From 53 studies, we found that NK cell infiltration corresponds with decreased risk of death (HR=0.34, 95% CI: 0.26-0.46; p<0.0001). Among studies that investigated the prognostic potential of NK cells in specific regions of the tumor, intraepithelial infiltration was better predictive of OS than NK infiltration in the tumor-adjacent stroma. Generally, NK cell infiltration is lower in advanced-stage and lower-grade tumors; nevertheless, it remains prognostically beneficial. This meta-analysis highlights an important prognostic role of NK cells in solid tumors, but exposes that few studies have considered the contributions of NK cells. Toward NK cell-based immunotherapies, it will be important to understand the conditions under which NK cells can be effective agents of tumor control.

The immune contexture and Immunoscore in cancer prognosis and therapeutic efficacy

The international American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) tumour-node-metastasis (TNM) staging system provides the current guidelines for the classification of cancer. However, among patients within the same stage, the clinical outcome can be very different. More recently, a novel definition of cancer has emerged, implicating at all stages a complex and dynamic interaction between tumour cells and the immune system. This has enabled the definition of the immune contexture, representing the pre-existing immune parameters associated with patient survival. Even so, the role of distinct immune cell types in modulating cancer progression is increasingly emerging. An immune-based assay named the 'Immunoscore' was defined to quantify the in situ T cell infiltrate and was demonstrated to be superior to the AJCC/UICC TNM classification for patients with colorectal cancer. This Review provides a broad overview of the main immune parameters positively or negatively shaping cancer development, including the Immunoscore, and their prognostic and predictive value. The importance of the immune system in cancer control is demonstrated by the requirement for a pre-existing intratumour adaptive immune response for effective immunotherapies, such as checkpoint inhibitors. Finally, we discuss how the combination of multiple immune parameters, rather than individual ones, might increase prognostic and/or predictive power.

Prognostic Significance of Tumor-Infiltrating Natural Killer Cells in Solid Tumors: A Systematic Review and Meta-Analysis

Background: Tumor-infiltrating natural killer (NK) cells (TINKs) are crucial immune cells in tumor defense, and might be related to tumor prognosis. However, the results were discrepant among different studies. The present meta-analysis was performed to comprehensively assess the prognostic value of NK cell markers in solid tumor tissues.

Methods: PubMed, Web of Science, and EMBASE were searched to identify original researches reporting the prognostic significance of TINKs in solid tumors. NK cell markers CD56, CD57, NKp30, and NKp46 were included in the analysis. The hazard ratios (HRs) and 95% confidence intervals (CIs) of pooled overall survival (OS), disease-free survival (DFS), metastasis-free survival (MFS), progression-free survival (PFS), and recurrence-free survival (RFS) were calculated by STATA software 14.0 to assess the prognostic significance.

Results : Of the 56 included studies, there were 18 studies on CD56, 31 studies on CD57, 1 study on NKp30, and 7 studies on NKp46. High levels of CD56, CD57, NKp30, and NKp46 were significantly correlated with better OS of patients with solid malignancies (HR = 0.473, 95%CI: 0.315–0.710, p < 0.001; HR = 0.484, 95%CI: 0.380–0.616, p < 0.001; HR = 0.34, 95%CI: 0.14–0.80, p = 0.014; HR = 0.622, 95%CI: 0.470–0.821, p < 0.001, respectively). Our results also revealed that CD56, CD57, and NKp46 could act as independent prognostic predictors for favorable OS (HR = 0.372, 95%CI: 0.261–0.531, p < 0.001; HR = 0.525, 95%CI: 0.346–0.797, p = 0.003; HR = 0.559, 95%CI: 0.385–0.812, p = 0.002, respectively).

Conclusions : Our results indicated that high levels of NK cell markers in solid tumor tissues could predict favorable prognosis for solid tumor patients.

Sex-Specific Differences in Primary CNS Lymphoma

Sex-specific differences have been increasingly recognized in many human diseases including brain cancer, namely glioblastoma. Primary CNS lymphoma (PCNSL) is an exceedingly rare type of brain cancer that tends to have a higher incidence and worse outcomes in male patients. Yet, relatively little is known about the reasons that contribute to these observed sex-specific differences. Using a population-representative cohort of patients with PCNSL with dense magnetic resonance (MR) imaging and digital pathology annotation (n = 74), we performed sex-specific cluster and survival analyses to explore possible associations. We found three prognostically relevant clusters for females and two for males, characterized by differences in (i) patient demographics, (ii) tumor-associated immune response, and (iii) MR imaging phenotypes. Upon a multivariable analysis, an enhanced FoxP3+ lymphocyte-driven immune response was associated with a shorter overall survival particularly in female patients (HR 1.65, p = 0.035), while an increased extent of contrast enhancement emerged as an adverse predictor of outcomes in male patients (HR 1.05, p < 0.01). In conclusion, we found divergent prognostic constellations between female and male patients with PCNSL that suggest differential roles of tumor-associated immune response and MR imaging phenotypes. Our results further underline the importance of continued sex-specific analyses in the field of brain cancer.

Perioperative COX2 and β-adrenergic blockade improves biomarkers of tumor metastasis, immunity, and inflammation in colorectal cancer: A randomized controlled trial

BACKGROUND

Preclinical studies have implicated excess release of catecholamines and prostaglandins in the mediation of prometastatic processes during surgical treatment of cancer. In this study, we tested the combined perioperative blockade of these pathways in patients with colorectal cancer (CRC).

METHODS

In a randomized, double-blind, placebo-controlled biomarker trial involving 34 patients, the β-blocker propranolol and the COX2-inhibitor etodolac were administered for 20 perioperative days, starting 5 days before surgery. Excised tumors were subjected to whole genome messenger RNA profiling and transcriptional control pathway analyses.

RESULTS

Drugs were well-tolerated, with minor complications in both the treatment group and the placebo group. Treatment resulted in a significant improvement (P < .05) of tumor molecular markers of malignant and metastatic potential, including 1) reduced epithelial-to-mesenchymal transition, 2) reduced tumor infiltrating CD14⁺ monocytes and CD19⁺ B cells, and 3) increased tumor infiltrating CD56⁺ natural killer cells. Transcriptional activity analyses indicated a favorable drug impact on 12 of 19 a priori hypothesized CRC-related transcription factors, including the GATA, STAT, and EGR families as well as the CREB family that mediates the gene regulatory impact of β-adrenergic- and prostaglandin-signaling. Alterations observed in these transcriptional activities were previously associated with improved long-term clinical outcomes. Three-year recurrence rates were assessed for long-term safety analyses. An intent-to-treat analysis revealed that recurrence rates were 12.5% (2/16) in the treatment group and 33.3% (6/18) in the placebo group (P = .239), and in protocol-compliant patients, recurrence rates were 0% (0/11) in the treatment group and 29.4% (5/17) in the placebo group (P = .054).

CONCLUSIONS

The favorable biomarker impacts and clinical outcomes provide a rationale for future randomized placebo-controlled trials in larger samples to assess the effects of perioperative propranolol/etodolac treatment on oncological clinical outcomes.

Tissue-Infiltrating Lymphocytes as a Predictive Factor for Recurrence in Patients with Curatively Resected Colon Cancer: A Propensity Score Matching Analysis

BACKGROUND

In patients with colorectal cancer, the rate of recurrence increases as the histologic stage progresses. However, the prediction of recurrence in individual patients is difficult. Many studies have reported on the relation between outcomes and tissue-infiltrating lymphocytes (TILs). The aim of our study was to clarify the relation between TILs and oncologic outcomes in patients with colon cancer using propensity score matching analysis.

METHODS

The study group comprised 513 patients with colon cancer who received curative resection. By using propensity score matching for sex, age, tumor location, T stage, N stage, histologic type, and adjuvant therapy as conventional prognostic factors, 61 patients with recurrence and 61 patients with no recurrence were selected. Hematoxylin-eosin staining and immunohistochemical staining using CD3, CD8, CD4, and FoxP3 were performed for lymphocytes in the primary tissue. The results were evaluated separately in the whole tumor, the central part, and the invasive margin.

RESULTS

The median follow-up period was 53 months. Among the 513 patients, 70 had recurrence and 443 had no recurrence. In the comparison of outcomes between the 61 patients with recurrence and the 61 patients with no recurrence, univariate analysis showed that the disease-free survival rate was significantly higher among the patients with positive TILs in the whole tumor and in the invasive margin (p = 0.016 and p = 0.012, respectively) and with CD8+ cells in the central part (p = 0.039) than among those with negative results. A multivariate analysis showed that TILs in the invasive margin (hazard ratio 1.81; 95% confidence interval, 1.03-3.05; p = 0.037) and CD8+ cell density in the central part (hazard ratio 1.76; 95% confidence interval, 1.07-2.93; p = 0.023) were prognostic factors that were independent from conventional prognostic factors.

CONCLUSIONS

In patients with curatively resected colon cancer, TILs in the invasive margin and CD8+ cell density in the central part may be prognostic factors suggesting host antitumor immune response.

MED15, transforming growth factor beta 1 (TGF-β1), FcγRIII (CD16), and HNK-1 (CD57) are prognostic biomarkers of oral squamous cell carcinoma

Owing to the high incidence and mortality of oral squamous cell carcinoma (OSCC), knowledge of its diagnostic and prognostic factors is of significant value. The biomarkers 'CD16, CD57, transforming growth factor beta 1 (TGF-β1), and MED15' can play crucial roles in tumorigenesis, and hence might contribute to diagnosis, prognosis, and treatment. Since there was no previous study on MED15 in almost all cancers, and since the studies on diagnostic/prognostic values of the other three biomarkers were a few in OSCC (if any) and highly controversial, this study was conducted. Biomarker expressions in all OSCC tissues and their adjacent normal tissues available at the National Tumor Bank (n = 4 biomarkers × [48 cancers + 48 controls]) were estimated thrice using qRT-PCR. Diagnostic values of tumors were assessed using receiver-operator characteristic (ROC) curves. Factors contributing to patients' survival over 10 years were assessed using multiple Cox regressions. ROC curves were used to estimate cut-off points for significant prognostic variables (α = 0.05). Areas under the curve pertaining to diagnostic values of all markers were non-significant (P > 0.15). Survival was associated positively with tumoral upregulation of TGF-β1 and downregulation of CD16, CD57, and MED15. It was also associated positively with younger ages, lower histological grades, milder Jacobson clinical TNM stages (and lower pathological Ns), smaller and thinner tumors, and surgery cases not treated with incisional biopsy (Cox regression, P < 0.05). The cut-off point for clinical stage -as the only variable with a significant area under the curve- was between the stages 2 and 3. Increased TGF-β1 and reduced CD16, CD57, and MED15 expressions in the tumor might independently favor the prognosis. Clinical TNM staging might be one of the most reliable prognostic factors, and stages above 2 can predict a considerably poorer prognosis.

High-dimensional cytometric analysis of colorectal cancer reveals novel mediators of antitumour immunity

OBJECTIVE

A comprehensive understanding of anticancer immune responses is paramount for the optimal application and development of cancer immunotherapies. We unravelled local and systemic immune profiles in patients with colorectal cancer (CRC) by high-dimensional analysis to provide an unbiased characterisation of the immune contexture of CRC.

DESIGN

Thirty-six immune cell markers were simultaneously assessed at the single-cell level by mass cytometry in 35 CRC tissues, 26 tumour-associated lymph nodes, 17 colorectal healthy mucosa and 19 peripheral blood samples from 31 patients with CRC. Additionally, functional, transcriptional and spatial analyses of tumour-infiltrating lymphocytes were performed by flow cytometry, single-cell RNA-sequencing and multispectral immunofluorescence.

RESULTS

We discovered that a previously unappreciated innate lymphocyte population (Lin^-CD7⁺CD127^-CD56⁺CD45RO⁺) was enriched in CRC tissues and displayed cytotoxic activity. This subset demonstrated a tissue-resident (CD103⁺CD69⁺) phenotype and was most abundant in immunogenic mismatch repair (MMR)-deficient CRCs. Their presence in tumours was correlated with the infiltration of tumour-resident cytotoxic, helper and γδ T cells with highly similar activated (HLA-DR⁺CD38⁺PD-1⁺) phenotypes. Remarkably, activated γδ T cells were almost exclusively found in MMR-deficient cancers. Non-activated counterparts of tumour-resident cytotoxic and γδ T cells were present in CRC and healthy mucosa tissues, but not in lymph nodes, with the exception of tumour-positive lymph nodes.

CONCLUSION

This work provides a blueprint for the understanding of the heterogeneous and intricate immune landscape of CRC, including the identification of previously unappreciated immune cell subsets. The concomitant presence of tumour-resident innate and adaptive immune cell populations suggests a multitargeted exploitation of their antitumour properties in a therapeutic setting.

The Prognostic Implications of Tumor Infiltrating Lymphocytes in Colorectal Cancer: A Systematic Review and Meta-Analysis

Tumor-infiltrating lymphocytes (TILs) are an important histopathologic feature of colorectal cancer that confer prognostic information. Previous clinical and epidemiologic studies have found that the presence and quantification of tumor-infiltrating lymphocytes are significantly associated with disease-specific and overall survival in colorectal cancer. We performed a systematic review and meta-analysis, establishing pooled estimates for survival outcomes based on the presence of TILs in colon cancer. PubMed (Medline), Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov were searched from inception to April 2017. Studies were included, in which the prognostic significance of intratumoral tumor infiltrating lymphocytes, as well as subsets of CD3, CD8, FOXP3, CD45R0 lymphocytes, were determined within the solid tumor center, the invasive margin, and tumor stroma. Random-effects models were calculated to estimated summary effects using hazard ratios. Forty-three relevant studies describing 21,015 patients were included in our meta-analysis. The results demonstrate that high levels of generalized TILS as compared to low levels had an improved overall survival (OS) with a HR of 0.65 (p = <0.01). In addition, histologically localized CD3+ T-cells at the tumor center were significantly associated with better disease-free survival (HR = 0.46, 95% CI 0.36–0.61, p = 0.05), and CD3 + cells at the invasive margin were associated with improved disease-free survival (HR = 0.57, 95% CI 0.38–0.86, p = 0.05). CD8+ T-cells at the tumor center had statistically significant prognostic value on cancer-specific survival and overall survival with HRs of 0.65 (p = 0.02) and 0.71 (p < 0.01), respectively. Lastly, FOXP3+ T-cells at the tumor center were associated with improved prognosis for cancer-specific survival (HR = 0.65, p < 0.01) and overall survival (HR = 0.70, p < 0.01). These findings suggest that TILs and specific TIL subsets serve as prognostic biomarkers for colorectal cancer.

The role of Human leukocyte antigen class I on patient survival in Gastrointestinal cancers: a systematic review and meta- analysis

The prognostic role of Human leukocyte antigen class I (HLA- I) in gastrointestinal cancers has been remained controversial. We performed a meta-analysis to determine the role of classical HLA-I in predicting survival of patients. In addition, the relationship between HLA- I and some clinicopathological factors was evaluated. Published studies investigated HLA-I expression effect on gastrointestinal cancers were evaluated to determine association between HLA- I and overall survival (OS) and recurrence-free survival (RFS) in patients. The used effect sizes were hazard ratio (HR) and Odds ratio (OR) with 95% confidence interval (CI). A total of ten studies included 1307 patients were analyzed. The pooled results revealed that HLA- I overexpression was positively related to OS (HR: 0.72; 95% CI: 0.53-0.96) and demonstrated little association for RFS (HR: 0.70; 95% CI: 0.46-1.08). HLA-I overexpression is negative associated with poorer differentiation of tumor (OR: 0.53; 95% CI (0.43-0.81) and also higher stages of cancer (OR: 0.29; 95% CI (0.13-0.64). HLA- I overexpression was related to a better prognosis on OS and probably had little impact on RFS.

The Role of the Immune Infiltrate in Distinct Cancer Types and Its Clinical Implications : Lymphocytic Infiltration in Colorectal Cancer

Colorectal cancer (CRC) represents a major public health challenges, with one of the highest incidences worldwide. The two affected anatomical sites in CRC, i.e. the colon and the rectum, share important underlying features, but often differ in terms of therapeutic management. Current guidelines for CRC define its clinical stratification according to classical, tumor cell-based and pathological parameters. Novel ground-breaking findings in the recent years revealed the prominent role of the immune system in shaping CRC development. This chapter provides a detailed overview of the main genomic and immune features driving (or hampering) CRC progression, with a focus on the main immune cells and factors shaping its evolution. Furthermore, we discuss how tumor-infiltrating immunity could be leveraged both for therapeutic and stratification purposes.

The local inflammatory response in colorectal cancer - Type, location or density? A systematic review and meta-analysis

INTRODUCTION

The host anti-tumour inflammatory response is a strong prognostic indicator, and tumour infiltrating lymphocytes (TILs) are believed to have a complimentary role alongside TNM assessment in dictating future management. However, there is wide disagreement regarding the most efficacious and cost-effective method of assessment.

METHODS

A comprehensive literature search was performed of EMBASE, MedLine and PubMed as well as an assessment of references to identify all relevant studies relating to the assessment of the peri-tumoural inflammatory response or TILs and prognosis in colorectal cancer (CRC). A meta-analysis was performed of 67 studies meeting the REMARK criteria using RevMan software.

RESULTS

Intratumoural assessment of both CD3 and CD8 in CRC were significant for disease-free survival (DFS) (combined HRs 0.46; 95%CI: 0.39-0.54 and 0.54; 95%CI: 0.45-0.65), as well as overall survival (OS) and disease-specific survival (DSS). The same was true for assessment of CD3 and CD8 at the invasive margin (DFS: combined HRs 0.45; 95%CI: 0.33-0.61 and 0.51; 95%CI: 0.41-0.62). However, similar fixed effects summaries were also observed for H&E-based methods, like Klintrup-Makinen grade (DFS: HR 0.62; 95%CI: 0.43-0.88). Furthermore, inflammatory assessments were independent of MSI status.

CONCLUSION

The evidence suggests that it is the density of a co-ordinated local inflammatory infiltrate that confers survival benefit, rather than any individual immune cell subtype. Furthermore, the location of individual cells within the tumour microenvironment does not appear to influence survival. The authors advocate a standardised assessment of the local inflammatory response, but caution against emphasizing the importance of any individual immune cell subtype.

Local Inflammatory Response Can Predict Clinical Outcome in Patients with Curatively Resected Stage-IIB Colon Cancer: An Advanced Methodological Study

PURPOSE

Although local inflammatory response (LIR) is a reliable survival marker in colon cancers (CCs), there is no consensus on its use in daily practice. We investigated the prognostic value of LIR in a highly homogeneous population with a well-designed methodology.

METHODS

Eighty stage-IIB CC patients operated between 2002 and 2012 were included in the study. Standardization was investigated for extra-biopsy evaluation methods (magnification, staining, and counting). Model A was used for intra-biopsy evaluation methods (block, section, and focus). So, this study makes important contributions to the standardization of pathological evaluations.

RESULTS

In method 1, the following analyzes showed more successful results for LIR: relationship with prognostic factors [tumour deposits (p=0.017), Crohn's-like reaction (p=0.019), advanced grade, (p=0.012), positive surgical margin (p=0.019), perineural invasion (p=0.025), mismatch repair proteins-proficiency (p=0.031)], reproducibility of the study (Kappa=0.49-0.73, Intra-class correlation=0.442-0.724), and correlation of estimates (r=0.704). The cut-off value was also quite useful (area of under ROC=0.820 [0.694-0.920]). In univariate analysis, low LIR was related to poor overall survival (OS; p<0.001) and poor relapse-free survival (RFS, p=0.001) . Multivariate analysis confirmed that low LIR is an independent poor survival marker for OS (Hazard Ratio [HR]=1.32 [1.08-1.61, p=0.005) and RFS (HR=1.50 [1.22-1.85], p<0.001).

CONCLUSIONS

Our results showed that low LIR had an independent prognostic significance in stage -IIB CCs. We also recommend using model A and method 1 for successful results and standardization.

Targeting of the Cancer-Associated Fibroblast-T-Cell Axis in Solid Malignancies

The introduction of a wide range of immunotherapies in clinical practice has revolutionized the treatment of cancer in the last decade. The majority of these therapeutic modalities are centered on reinvigorating a tumor-reactive cytotoxic T-cell response. While impressive clinical successes are obtained, the majority of cancer patients still fail to show a clinical response, despite the fact that their tumors express antigens that can be recognized by the immune system. This is due to a series of other cellular actors, present in or attracted towards the tumor microenvironment, including regulatory T-cells, myeloid-derived suppressor cells and cancer-associated fibroblasts (CAFs). As the main cellular constituent of the tumor-associated stroma, CAFs form a heterogeneous group of cells which can drive cancer cell invasion but can also impair the migration and activation of T-cells through direct and indirect mechanisms. This singles CAFs out as an important next target for further optimization of T-cell based immunotherapies. Here, we review the recent literature on the role of CAFs in orchestrating T-cell activation and migration within the tumor microenvironment and discuss potential avenues for targeting the interactions between fibroblasts and T-cells.

Prognostic role of tumour-infiltrating T lymphocytes in stage IIA (T3N0) colon cancer: A broad methodological study in a fairly homogeneous population

AIM

Tumour-infiltrating T lymphocytes (TIL) are considered to be a reliable prognostic marker in CC, but the use in daily practice is unclear. We investigated the survival effect of TIL methodologically in a highly homogeneous population.

METHODS

Seventy-two stage IIA (T3N0) CC patients who underwent surgical resection from 2000 to 2014 were included. CD3 and CD8 were separately scored for different blocks, areas and foci. To the best of our knowledge, this study has the most comprehensive methodology in the literature.

RESULTS

Foremost, we searched for the optimal evaluation method. We found better results with Model A (deepest invasive block&hot spot area&invasive margin focus), e.g. for CD3, the relationship with prognostic factors [Crohn's-like reaction (p = 0.015), positive surgical margin (p = 0.019), Mismatch repair proteins deficiency (p = 0.003), advanced grade (p = 0.015)], the correlation of distinct estimates (r = 0.708), the reproducibility of research (Κappa = 0.60-0.71), and the usefulness of cut-off value (area of under ROC = 0.800 [0.683-0.917]) were best. Then, survival analysis was performed with two better methods including Model A. In univariate analysis, low TIL with Model A was associated with worse OS (CD3, p < 0.001; CD8, p = 0.023) and RFS (CD3, p < 0.001; CD8, p = 0.005). Multivariate analyses confirmed low TIL with same method as an independent worse prognostic marker for OS (CD3, Hazard ratio [HR] = 1.42 [1.10-1.85], p = 0.005) and RFS (CD3, HR = 1.46 [1.17-1.83], p = 0.001; CD8, HR = 1.32 [1.05-1.64], p = 0.032).

CONCLUSIONS

Our results confirm that low TIL is an independent worse prognostic marker in stage IIA (T3N0) CC and that the use of CD3 with Model A can contribute to improving the prognostication of early CCs.

Prognostic Impact of Tumor-Infiltrating Lymphocytes in Primary and Metastatic Colorectal Cancer: A Systematic Review and Meta-analysis

BACKGROUND

There is increasing literature emerging on the significance of tumor-infiltrating lymphocytes in colorectal cancer. However, there have been inconsistent findings, secondary to small patient numbers and varied methods for identifying these lymphocytes.

OBJECTIVE

The aim of this study was to determine the prognostic and predictive power of tumor-infiltrating lymphocytes in colon, rectal (in neoadjuvant setting), and metastatic colorectal cancer.

DATA SOURCES

A comprehensive search of PubMed and Embase was undertaken from January 2006 to December 2016.

STUDY SELECTION

The inclusion criteria included a description of the tumor-infiltrating lymphocyte subset(s) assessed with reporting of associated short- and long-term outcomes.

MAIN OUTCOME MEASURES

The main outcome measures, were disease-free and overall survival.

RESULTS

A total of 25 studies were included, 15 for primary colorectal cancer (4719 patients), 7 for locally advanced rectal cancer (727 patients), and 3 studies for metastatic colorectal cancer (418 patients). High CD3, CD8, FoxP3, and CD45RO densities were associated with improved overall survival for primary colorectal cancer, with pooled estimated HRs of 0.88, 0.81, 0.70, and 0.63 (all p < 0.001) respectively. Furthermore, in locally advanced rectal cancer, the levels of CD8 cells were a significant predictor of good tumor regression grade after chemoradiotherapy.

LIMITATIONS

The retrospective nature of included studies and the significant interstudy heterogeneity were limitations.

CONCLUSIONS

There is increasing evidence that tumor-infiltrating lymphocytes play an important role in predicting prognosis in colorectal cancer and tumor regression after neoadjuvant chemoradiotherapy in locally advanced rectal cancer. Clinical researchers are now in a unique position to build on this work to identify robust predictive markers to stratify patients not only to currently available therapies but also to immunotherapy, which has demonstrated success in improving patient outcomes.

Tumor-infiltrating CD8+ T-cell density is an independent prognostic marker for oral squamous cell carcinoma

BACKGROUND

The presence of tumor-infiltrating lymphocytes (TILs) is associated with improved survival in head and neck squamous cell carcinoma. However, the prognostic value of TILs remains unclear in oral squamous cell carcinoma (OSCC).

METHODS

We evaluated the associations between tumor-infiltrating CD8⁺ T-cell density and survival in five distinct compartments in 139 OSCC cases.

RESULTS

There was a significant association between increased tumor-infiltrating CD8⁺ T cells and their distribution. High parenchymal CD8⁺ T-cell density at the invading tumor edge was associated with improved overall survival (OS) and disease-specific survival (DSS; P < 0.01 and P < 0.01, respectively). High stromal CD8⁺ T-cell density at the tumor periphery was also associated with improved recurrence-free survival (RFS; P < 0.01). Cox regression analysis revealed that high stromal CD8⁺ T-cell density at the tumor periphery and high parenchymal CD8⁺ T-cell density at the invading edge were independent prognostic makers (hazard ratio: 0.38 and 0.19, 95% confidence interval, 0.18-0.80 and 0.05-0.72, P = 0.01 and 0.01, respectively) for RFS and OS, respectively.

CONCLUSIONS

Assessment of CD8⁺ T cells at the parenchyma of the invading edge and peripheral stroma provides an indicator of tumor recurrence and prognosis.

Immune regulation and anti-cancer activity by lipid inflammatory mediators

Rodent and clinical studies have documented that myeloid cell infiltration of tumors is associated with poor outcomes, neutrophilia and lymphocytopenia. This contrasts with increased lymphocyte infiltration of tumors, which is correlated with improved outcomes. Lifestyle parameters, such as obesity and diets with high levels of saturated fat and/or omega (ω)-6 polyunsaturated fatty acids (PUFAs), can influence these inflammatory parameters, including an increase in extramedullary myelopoiesis (EMM). While tumor secretion of growth factors (GFs) and chemokines regulate tumor-immune-cell crosstalk, lifestyle choices also contribute to inflammation, abnormal pathology and leukocyte infiltration of tumors. A relationship between obesity and high-fat diets (notably saturated fats in Western diets) and inflammation, tumor incidence, metastasis and poor outcomes is generally accepted. However, the mechanisms of dietary promotion of an inflammatory microenvironment and targeted drugs to inhibit the clinical sequelae are poorly understood. Thus, modifications of obesity and dietary fat may provide preventative or therapeutic approaches to control tumor-associated inflammation and disease progression. Currently, the majority of basic and clinical research does not differentiate between obesity and fatty acid consumption as mediators of inflammatory and neoplastic processes. In this review, we discuss the relationships between dietary PUFAs, inflammation and neoplasia and experimental strategies to improve our understanding of these relationships. We conclude that dietary composition, notably the ratio of ω-3 vs ω-6 PUFA regulates tumor growth and the frequency and sites of metastasis that together, impact overall survival (OS) in mice.

Immunological environment in colorectal cancer: a computer-aided morphometric study of whole slide digital images derived from tissue microarray

Cancer research has moved from investigating tumour cells to including analysis of the tumour microenvironment as well. The aim of this study was to assess the cellular infiltrate of colorectal cancer (CRC) using computer-aided analysis of whole slide digital image derived from tissue microarray (TMA). TMA slides from 31 CRC patients were immunostained for forkhead box protein 3 (FOXP3) and immunomodulatory enzyme indoleamine 2,3-dioxygenase (IDO) at four sites: centre (C) and invasive front (F) of the tumour, proximal non-metastatic draining lymph node (N-), tumour-draining lymph node with metastasis (N+) and healthy mucosa at 10 cm from the cancer (M). We analysed the proportion of IDO+ tissue areas in the lamina propria or in the non-epithelial area of the lymph node and in epithelial cells in each site. The normal mucosa of patients operated on for benign disease was also analysed. The proportion (%) of FOXP3+ tissue area in C, F, N-, N+ and M were 2.3 ± 1.8, 2.6 ± 2.9, 6.0 ± 2.9, 14.2 ± 5.8 and 1.2 ± 0.8 (p < 0.001). The proportion (%) of IDO+ tissue area in the lamina propria of C, F, N-, N+ and M were 1.6 ± 3.1, 1.1 ± 1.3, 3.4 ± 2.5, 9.1 ± 8.5 and 6.7 ± 5.4 (p < 0.001). IDO+ tissue area in the lamina propria was not significantly different between healthy mucosa of patients with cancer than without (1.8 ± 3 vs 1.1 ± 0.95). The proportion of IDO positive tissue area in the epithelium was significantly higher in healthy mucosa of patients with cancer than without (5.4 ± 13.8 vs 2.1 ± 2.4). The FOXP3+ tissue area was increased in healthy mucosa of CRC patients in comparison with healthy mucosa of patients with colorectal resection for disease other than cancer: 1.20 ± 1.81 versus 0.81 ± 0.51 (p < 0.05). The proportion of IDO+ tissue area in lymph node (N-) was correlated with the proportion of FOXP3+ tissue area in tumour area (r = 0.44, p < 0.01). TMA technique permits simultaneous analysis of FOXP3+ and IDO+ cells at different sites including tumour, draining non-metastatic lymph node, metastatic lymph node and normal mucosa.

Tumor-Infiltrating Lymphocytes and Colorectal Cancer Survival in African American and Caucasian Patients

Background: Compared with Caucasian Americans (CAs), African Americans (AAs) with colorectal cancer have poorer survival, especially younger-age patients. A robust lymphocytic reaction within colorectal cancers is strongly associated with better survival, but whether immune response impacts the disparity in colorectal cancer survival is unknown.Methods: The study population was comprised of 211 histologically confirmed colorectal cancers at the Medical University of South Carolina (Charleston, SC; 159 CAs and 52 AAs) diagnosed between Jan 01, 2000, and June 30, 2013. We constructed a lymphocyte score based on blinded pathologic assessment of the four different types of lymphocytic reactions. Cox proportional hazards regression was used to evaluate the association between the lymphocyte score and risk of death by race.Results: Colorectal cancers in AAs (vs. CAs) had a stronger lymphocytic reaction at diagnosis. A high lymphocyte score (vs. the lowest) was associated with better survival in AAs [HR 0.19; 95% confidence interval (CI), 0.04-0.99] and CAs (HR 0.47; 95% CI, 0.15-1.45). AAs with no lymphocytic reaction (vs. other categories) had poor survival HR 4.48 (1.58-12.7) whereas no difference was observed in CAs. The risk of death in AAs (vs. CA) was more pronounced in younger patients (HR 2.92; 95% CI, 1.18-7.22) compared with older (HR 1.20; 95% CI, 0.54-2.67), especially those with lymphocytic poor colorectal cancers.Conclusions: The lymphocytic reaction in tumor impacted the racial disparity in survival.Impact: Our results confirm the importance of the lymphocytic score on survival and highlight the need to fully characterize the immune environment of colorectal cancers by race. Cancer Epidemiol Biomarkers Prev; 27(7); 755-61. ©2018 AACR.

Evolving notions on immune response in colorectal cancer and their implications for biomarker development

INTRODUCTION

Colorectal cancer (CRC) still represents the third most commonly diagnosed type of cancer in men and women worldwide. CRC is acknowledged as a heterogeneous disease that develops through a multi-step sequence of events driven by clonal selections; this observation is sustained by the fact that histologically similar tumors may have completely different outcomes, including a varied response to therapy.

METHODS

In "early" and "intermediate" stage of CRC (stages II and III, respectively) there is a compelling need for new biomarkers fit to assess the metastatic potential of their disease, selecting patients with aggressive disease that might benefit from adjuvant and targeted therapies. Therefore, we review the actual notions on immune response in colorectal cancer and their implications for biomarker development.

RESULTS

The recognition of the key role of immune cells in human cancer progression has recently drawn attention on the tumor immune microenvironment, as a source of new indicators of tumor outcome and response to therapy. Thus, beside consolidated histopathological biomarkers, immune endpoints are now emerging as potential biomarkers.

CONCLUSIONS

The introduction of immune signatures and cellular and molecular components of the immune system as biomarkers is particularly important considering the increasing use of immune-based cancer therapies as therapeutic strategies for cancer patients.

A new method for evaluating tumor-infiltrating lymphocytes (TILs) in colorectal cancer using hematoxylin and eosin (H-E)-stained tumor sections

Purpose

Numerous reports indicate that tumor-infiltrating lymphocytes (TILs) are a prognostic factor in various cancers and that they must be good biomarkers. However, the methods of evaluating TILs differ in each study; thus, there is not yet a standardized methodology for evaluating TILs. The purpose of this study is to evaluate the prognostic significance of tumor-infiltrating lymphocytes (TILs) in patients with colorectal cancer (CRC) using the new method proposed by the International TILs Working Group in breast cancer and to standardize the method of evaluating TILs in CRC.

Methods

We retrospectively reviewed a database of 160 patients with Stage II or III CRC. The density of TILs was assessed by measuring the area occupied by mononuclear cells over the stromal area on hematoxylin and eosin (H-E)-stained sections. We set 42% as the cut-off percentage of the area occupied by TILs according to the receiver operating characteristic curve, and we classified patients into the high-TILs and the low-TILs groups.

Results

The rates of relapse-free survival (RFS) and overall survival (OS) in the high-TILs group were significantly higher than those in the low-TILs group. A multivariate analysis showed that the density of TILs was independently associated with RFS and OS. Moreover, the density of TILs assessed by an observer was significantly associated with the density of TILs assessed by the automated imaging software program.

Conclusions

The new method for evaluating TILs, which was recommended by the International TILs Working Group in breast cancer, might be a useful predictive factor in colorectal cancer patients.

Prognostic role of tumor-infiltrating CD57-positive lymphocytes in solid tumors: a meta-analysis

The prognostic role of tumor-infiltrating CD57-positive lymphocytes (CD57⁺ lymphocytes) in human solid tumors remains controversial. Herein, we conducted a meta-analysis including 26 published studies with 7656 patients identified from PubMed and EBSCO to assess the prognostic impact of tumor-infiltrating CD57⁺ lymphocytes in human solid tumors. We found that CD57⁺ lymphocyte infiltration significantly improved overall survival (OS) including 1 – year, 3 – year and 5 – year survival, and disease – free survival (DFS) in all types of solid tumors. In stratified analyses, CD57⁺ lymphocyte infiltration was significantly associated with better OS in hepatocellular, esophageal, head and neck carcinoma, non-small cell lung cancer, 5 – year survival in colorectal cancer, and 3 – year and 5 – year survival in gastric cancer, but not with 1 – year survival in gastric cancer, or 1 – year or 3 – year survival in colorectal cancer. In addition, high density of intratumoral CD57⁺ lymphocytes was significantly inversely correlated with lymph node metastasis and TNM stage of solid tumor. In conclusion, CD57⁺ lymphocyte infiltration leads to a favorable clinical outcome in solid tumors, implicating that it is a useful biomarker for prognosis and adoptive immunotherapy based on these cells may be a promising choice for treatment.

Immunotherapy as a Potential Treatment for Chordoma: a Review

Chordoma is a locally aggressive primary malignancy of the axial skeleton. The gold standard for treatment is en bloc resection, with some centers now advocating for the use of radiation to help mitigate the risk of recurrence. Local recurrence is common, and salvaging local failures is quite difficult. Chemotherapy has been ineffective and small molecule targeted therapy has had only marginal benefits in small subsets of patients with rare tumor phenotypes or refractory disease. Recent successes utilizing immunotherapy in a variety of cancers has led to a resurgence of interest in modifying the host immune system to develop new ways to treat tumors. This review will discuss these studies and will highlight the early studies employing immune strategies for the treatment of chordoma.

Black Raspberries Enhance Natural Killer Cell Infiltration into the Colon and Suppress the Progression of Colorectal Cancer

Natural killer (NK) cells are an essential component of innate immunity against cancer development. Many studies have been conducted to evaluate immune-modulating effects using dietary compounds. Our laboratory has been investigating the chemopreventive potential of black raspberries (BRBs) and previously demonstrated their beneficial modulation of genetic and epigenetic biomarkers in patients with colorectal cancer (CRC). The current study investigated their potential on modulating NK cells. To avoid the excessive inflammation caused by the dextran sulfate sodium (DSS) treatment that leads to colitis, we treated the mice with overnight DSS so that it would slightly irritate the colon but still promote colon carcinogenesis with 100% incidence in both the Apc^Min/+ mice and azoxymethane (AOM)-treated mice. A significant decrease of tissue-infiltrating NK cells along the progression of microadenoma-to-adenoma and adenoma-to-adenocarcinoma was observed in the Apc^Min/+ /DSS and AOM/DSS mice, respectively. Depletion of NK cells significantly promoted the development of CRC, suggesting a critical role of NK cells in combating CRC progression. BRBs significantly suppressed the CRC progression and increased the number of tissue-infiltrating NK cells in both mouse models. Moreover, we further determined BRBs' effects on NK cells in the human biopsy specimens collected from our previously completed clinical trial, in which CRC patients consumed BRBs for an average of 4 weeks during a presurgical window. We observed an increased number and an enhanced cytotoxicity of NK cells by BRB intervention. The current study provides evidence that BRBs have the potential to enhance the tumor immunesurveillance of NK cells that can be beneficial in the setting of CRC prevention and treatment.

Diagnostic value of inflammatory cell infiltrates, tumor stroma percentage and disease-free survival in patients with colorectal cancer

The anticancer immune defense mechanism involves humoral and cellular responses. The main effector mechanisms of antitumor responses involve the following: the activity of cytotoxic T cells; the activation of macrophages and neutrophils; the activity of cytokines secreted by T cells; and natural killer cell activity. Selected cell populations are responsible for the stimulation or suppression of the immune system against tumor cells. Therefore, the aim of the present study was to evaluate the location, extent and composition of the cellular inflammatory infiltration of tumors in patients with colorectal cancer (CRC). In addition, the correlation between cellular inflammatory infiltration, and anatomoclinical and histopathological features of patients was evaluated. The study involved 160 patients diagnosed with primary operable CRC. The local inflammatory infiltrate was assessed in the invasive front and center of the tumor using light microscopy with hematoxylin and eosin (H&E) staining, according to the Klintrup-Makinen criteria, tumor stroma percentage, and Glasgow microenvironment score. The inflammatory infiltrate in the invasive front of the tumor was correlated with gender (P=0.018), the invasion of blood vessels (P=0.020) and lymph vessels (P=0.038), the presence of tumor-infiltrating lymphocytes in the invasive front (P=0.033) and center (P<0.001) of the tumor, fibrosis (P<0.001), and the degree of desmoplasmic stroma (P=0.004). In contrast, inflammatory infiltration in the center of the tumor was associated with the tumor node metastasis stage (P=0.012), Dukes' stage (P=0.009), primary tumor stage (P=0.036), lymph node status (P=0.005), number of lymph nodes (P=0.006), invasion of lymph node pouches (P=0.021), size of lymph node metastasis (P=0.025) and the degree of desmoplasmic stroma (P=0.002). The low-group, who demonstrated an absent or weak inflammatory cell infiltrate in the invasive front of the tumor, had a statistically significant shorter disease-free survival (DFS) time (P=0.004). Inflammatory cell infiltrate in the invasive front was identified as an independent predictive factor in CRC (P=0.041). In conclusion, the degree of inflammatory cell infiltration in the invasive front of the primary tumor significantly affects various variables that determine disease progression and DFS rates of patients with CRC. Furthermore, the routine histopathological assessment of this parameter in tissue stained with H&E may have potential prognostic value.

Loss of Fas expression and high expression of HLA-E promoting the immune escape of early colorectal cancer cells

Previous studies have investigated the mechanisms of immune evasion of tumor cells in numerous types of advanced solid malignant tumor, and several types of immune preparations have been administered as antitumor adjuvant therapies. However, in the majority of studies, the efficacy of therapies has been revealed to be limited. The present study aimed to investigate the immune evasion mechanisms employed by early colorectal cancer cells and the expression of the molecules associated with immune evasion during the malignant transformation process of normal colorectal epithelial cells to measure the effects of immune intervention for early colorectal cancer, and to improve the efficacy of immunotherapy. A total of 60 colorectal tissues, including 15 normal mucosa, 15 adenoma, 15 early cancer and 15 advanced cancer tissues, from patients undergoing endoscopic procedures in Huadong Hospital Affiliated to Fudan University (Shanghai, China) were collected. A comparison of baseline characteristics among these four groups was performed. The expression levels of human leukocyte antigen-A (HLA-A), apoptosis antigen 1 (Fas), c-c chemokine receptor type 5 (CCR5), Fas ligand (FasL) and HLA-E in each group were detected by immunohistochemical analysis. Furthermore, 15 patients with advanced colorectal cancer were enrolled into the present study. Advanced cancer and paracancer tissues (normal mucosal tissues 3 cm away from the margin of cancer tissues) were collected from each patient by colonoscopic biopsy. The expression levels of HLA-A, Fas, CCR5, FasL and HLA-E in each group were detected by western blot analysis. During the malignant transformation process of normal colorectal epithelial cells, the expression levels of CCR5, FasL and HLA-E increased significantly (P<0.001), whilst the expression levels of Fas reduced significantly (P=0.0271). In the early cancer group, the expression levels of Fas reduced significantly (P=0.0239), whilst the expression levels of HLA-E increased significantly (P<0.001) compared with adenoma group. In conclusion, a loss of Fas expression and high expression levels of HLA-E may promote the immune evasion of early colorectal cancer cells.

Detailed resolution analysis reveals spatial T cell heterogeneity in the invasive margin of colorectal cancer liver metastases associated with improved survival

On a broader scale, T cell density and localization in colorectal cancer liver metastases have prognostic and predictive implications. As T cell distribution at higher resolutions has not been fully investigated, a detailed resolution analysis of T cell distribution was performed. Patient tissues were divided into 10 µm distance classes between the tumor border and adjacent normal liver. Thereby, distinct density patterns of T cell localization in relation to the malignant tissue could be detected. At a distance of 20 to 30 µm to the tumor, a decrease of CD3 T cells is common. Within this area, cytotoxic Granzyme B and CD8⁺ T cells were found to be significantly reduced as well as CD163 macrophages were increased and identified to be in close contact with T cells. Our data suggests a physical or functional border within this region. Survival analysis revealed improved overall survival in patients with high T cells numbers at the direct tumor border. Interestingly, the decreased T cells in the 20 to 30 µm region were also found to be significantly associated with improved survival. Consequently, the detailed localization of T cells, despite blockade, could be associated with improved clinical outcome. The high-resolution analysis represents new insights into relevant heterogenous T cell distributions especially related to clinical responses. As the paradoxical observation of localization-dependent prognostic relevance of T cell densities is only detectable by detailed spatial analyses, this investigation of spatial profiles at higher resolutions is suggested as a new biomarker for survival and response to therapies.

Lipid Inflammatory Mediators in Cancer Progression and Therapy

Rodent and clinical studies have documented that myeloid cell infiltration of tumors is associated with neutrophilia, lymphocytopenia and poor patient outcomes. This contrasts with lymphocyte infiltration of tumors, which is associated with improved outcomes. Lifestyle parameters such as high fat diet s and omega (ω)-6 polyunsaturated fatty acids (PUFA) intake may influence these inflammatory parameters including extramedullary myelopoiesis that can contribute to a metastatic "niche". While, tumor secretion of growth factors (GFs) and chemokines regulate tumor-immune-cell crosstalk, in this chapter, we also emphasize how lifestyle choices, including, obesity, high-fat and high ω-6 PUFA dietary content, contribute to inflammation and myeloid cell infiltration of tumors. A relationship between obesity and high-fat diets (notably the saturated fats in Western diets) and tumor incidence, metastasis, and poor outcomes is generally accepted. However, the mechanisms of dietary promotion of inflammatory microenvironments and targeted drugs to inhibit the clinical sequel remain an unmet challenge. One approach, modification of dietary intake may have a preventative or therapeutic approach to regulate tumor-associated inflammation and remains an attractive, but little studied intervention.