The clinical utility of the local inflammatory response in colorectal cancer

Prognostic Value of Immunoscore in Colorectal Carcinomas

Aims. Immunoscore, based on the evaluation of CD3+ and CD8+ densities in the center of the tumor and its invasive margin, is currently considered as a potential prognostic factor, particularly in colorectal carcinomas. In the current study, we aimed to assess the prognostic value of immunoscore in colorectal cancer stage I to IV, through a survival study. Methods and Results. It was a descriptive and retrospective study involving 104 cases of colorectal cancer. Data were collected over 3 years (2014-2016). An immunohistochemical study (anti-CD3, anti-CD8) by the tissue microarray technique was carried out in the areas of "hot spot" in the tumor center and invasive margin. A percentage was assigned to each marker and within each region. Then, the density was classified as "low" or "high," according to a cutoff fixed at the median of percentages. immunoscore was calculated by the method described by Galon et al. The prognostic value of the immunoscore was assessed through a survival study. The mean age of patients was 61.6 years. immunoscore was low in 60.6% (n = 63). Our study had shown that low immunoscore significantly deteriorates survival and a high immunoscore enhances survival significantly (P < .001). We found a correlation between immunoscore and T stage (P = .026). A multivariate showed that the predictive factors for survival were immunoscore (P = .001) and age (P = .035). Conclusions. Our study highlights the potential role of immunoscore as a prognostic factor in colorectal cancer. Its reproducibility and reliability allow its introduction into daily practice for better therapeutic management.

Investigating the Role of Tumor-Infiltrating Lymphocytes as Predictors of Lymph Node Metastasis in Deep Submucosal Invasive Colorectal Cancer: A Retrospective Cross-Sectional Study

The role of tumor-infiltrating T cells (TILs) in colorectal cancer (CRC) and their significance in early-stage CRC remain unknown. We investigated the role of TILs in early-stage CRC, particularly in deep submucosal invasive (T1b) CRC. Sixty patients with CRC (20 each with intramucosal [IM group], submucosal invasive [SM group], and advanced cancer [AD group]) were randomly selected. We examined changes in TILs with tumor invasion and the relationship between TILs and LN metastasis risk. Eighty-four patients with T1b CRC who underwent initial surgical resection with LN dissection or additional surgical resection with LN dissection after endoscopic resection were then selected. TIL phenotype and number were evaluated using triple immunofluorescence for CD4, CD8, and Foxp3. All subtypes were more numerous according to the degree of CRC invasion and more abundant at the invasive front of the tumor (IF) than in the center of the tumor (CT) in the SM and AD groups. The increased Foxp3 cells at the IF and high ratios of Foxp3/CD4 and Foxp3/CD8 positively correlated with LN metastasis. In conclusion, tumor invasion positively correlated with the number of TILs in CRC. The number and ratio of Foxp3 cells at the IF may predict LN metastasis in T1b CRC.

Early-Onset/Young-Onset Colorectal Carcinoma: A Comparative Analysis of Morphological Features and Biomarker Profile

Introduction Colorectal carcinoma (CRC) is one of the most common cancers that involve the human body. Young-onset CRC (YO-CRC) or early-onset CRC (EO-CRC) is defined as CRC that develops before the age of 50 years, as opposed to CRC that is diagnosed after the age of 50, referred to as late-onset CRC (LO-CRC). EO-CRC is sparsely studied in our population. Therefore, in this study, we evaluated the clinicopathological parameters and biomarker profile of EO-CRC and compared them with those of LO-CRC. Methods This was a retrospective study conducted at the Department of Histopathology, Liaquat National Hospital, Karachi, Pakistan. A total of 254 biopsy-proven cases of CRC, reported over a period of nine years, were enrolled in the study. The specimens collected during surgery were sent to the laboratory for histopathological and immunohistochemical (IHC) status examinations. IHC staining of the specimens was performed using antibodies, namely, MutL protein homolog 1 (MLH1), postmeiotic segregation increased 2 (PMS2), MutS homolog 2 (MSH2), MutS homolog 6 (MSH6), and human epidermal growth factor receptor 2 (HER2/neu), on representative tissue blocks. A comparison of morphological and biomarker profiles between EO-CRC and LO-CRC was performed. Results The mean age at diagnosis was 46.27±17.75 years, with female predominance (59.8%). A significant difference between the two groups (EO-CRC and LO-CRC) was noted with respect to laterality, tumor site, tumor grade, tumor type, presence of pre-existing polyps, perineural invasion (PNI), lymphovascular invasion (LVI), and IHC markers. EO-CRC (as opposed to LO-CRC) significantly affected the left colon (92.6% vs. 72.9%, p<0.001), with the rectosigmoid being the most common site in the majority of cases (72.1% in EO-CRC vs. 61% in LO-CRC). EO-CRC showed a higher frequency of PNI and LVI than LO-CRC (42.6% vs. 23.7%, p=0.001; 29.4% vs. 18.6%, p=0.046, respectively). A significantly higher proportion of EO-CRCs were mucinous (42.6%) and medullary carcinoma (11.8%). Although the majority (54.4%) of cases of EO-CRC were grade 2 tumors at the time of diagnosis, a significantly higher proportion of them were grade 3 (44.1%) compared with LO-CRC. IHC comparisons between the two age groups showed that a significantly higher proportion of cases of EO-CRC showed positive HER2/neu expression (27.1%) compared with LO-CRC (13.2%). Conversely, the loss of expression of microsatellite instability (MSI) markers was more commonly seen in LO-CRS compared with EO-CRC. Conclusions We found a relatively higher frequency of EO-CRC in our population. Moreover, compared with LO-CRCs, EO-CRCs were associated with prognostically poor histological parameters, such as mucinous and medullary carcinoma, high-grade, PNI, and LVI. Similarly, EO-CRC had a higher positive expression of HER2/neu with intact MSI markers compared with AO-CRC; all these characteristics indicate poor biological behavior in EO-CRC.

Immune Response and Immune Checkpoint Molecules in Patients with Rectal Cancer Undergoing Neoadjuvant Chemoradiotherapy: A Review

It is well-established that tumor antigens and molecules expressed and secreted by cancer cells trigger innate and adaptive immune responses. These two types of anti-tumor immunity lead to the infiltration of the tumor's microenvironment by immune cells with either regulatory or cytotoxic properties. Whether this response is associated with tumor eradication after radiotherapy and chemotherapy or regrowth has been a matter of extensive research through the years, mainly focusing on tumor-infiltrating lymphocytes and monocytes and their subtypes, and the expression of immune checkpoint and other immune-related molecules by both immune and cancer cells in the tumor microenvironment. A literature search has been conducted on studies dealing with the immune response in patients with rectal cancer treated with neoadjuvant radiotherapy or chemoradiotherapy, assessing its impact on locoregional control and survival and underlying the potential role of immunotherapy in the treatment of this cancer subtype. Here, we provide an overview of the interactions between local/systemic anti-tumor immunity, cancer-related immune checkpoint, and other immunological pathways and radiotherapy, and how these affect the prognosis of rectal cancer patients. Chemoradiotherapy induces critical immunological changes in the tumor microenvironment and cancer cells that can be exploited for therapeutic interventions in rectal cancer.

CD8 + T-cell Density Is an Independent Predictor of Survival and Response to Adjuvant Chemotherapy in Stage III Colon Cancer

We assessed CD8 + T-cell density in 351 resected stage II to III colon cancers from 2011 to 2015 and correlated the findings with disease-free survival and survival effect of adjuvant chemotherapy. Most tumors (70%) had high/intermediate CD8 + T-cell density, and this was significantly associated with mismatch repair deficiency compared with tumors with low CD8 + T-cell density (28% vs. 13%, P =0.003). Fewer tumors with high/intermediate CD8 + T-cell density had adverse histologic features compared with tumors with low CD8 + T-cell density including high tumor budding (16% vs. 27%) and venous (22% vs. 35%), lymphatic (54% vs. 65%), and perineural (23% vs. 33%) invasion (all with P <0.05). In the stage III cohort, high/intermediate CD8 + T-cell density was an independent predictor of disease-free survival on multivariate analysis (hazard ratio: 0.39, 0.21 to 0.71 95% CI, P =0.002). For stage III patients with high/intermediate CD8 + T-cell density, adjuvant chemotherapy was significantly associated with improved disease-free survival (hazard ratio: 0.28, 0.11 to 0.74 95% CI, P =0.01) whereas stage III patients with low CD8 + T-cell density did not have improved survival with adjuvant chemotherapy. In conclusion, in stage III colon cancer, CD8 + T-cell density is an independent prognostic biomarker for disease-free survival and may help to identify patients who benefit from adjuvant chemotherapy.

High tissue expression of TLRs combined with high density of tumor infiltrating lymphocytes predicts a better prognosis in colorectal cancer patients

BACKGROUND

Colorectal cancer causes 935,000 cancer deaths yearly. High local immune cell infiltration serves as a positive prognostic factor in CRC. Toll-like receptors (TLRs) induce innate immune responses and lead to adaptive immune system activation. TLRs play protumorigenic and antitumorigenic roles. We aimed to explore the relationship between TLR immunoexpressions and the infiltration densities of T-lymphocytes in CRC.

METHODS

Immunohistochemical TLR2, TLR4, TLR5, and TLR7 positivity and the density of CD3- and CD8-positive cells in tumoral and stromal tissue were evaluated from the tissue microarray slides of 549 consecutive CRC surgical patients treated at Helsinki University Hospital, Finland, between 1998 and 2005. We calculated the associations and correlations using Pearson's chi-square and Spearman's correlation tests, generating survival curves using the Kaplan-Meier method.

RESULTS

Positive intratumoral CD3 and CD8 densities associated with a high TLR2 expression (p < 0.001 and p = 0.001, respectively) and a high TLR4 expression (p = 0.013 and p = 0.025). A low TLR5 immunoexpression associated with negative intratumoral CD3 (p = 0.001) and CD8 (p = 0.011) and a low stromal CD3 (p = 0.001). No association or correlation emerged between TLR7 immunoexpression and CD3 or CD8 cell density. A low CD3-CD8 tumor-stroma index indicated a worse prognosis among all TLR subgroups, except the TLR7-negative subgroup.

CONCLUSIONS

We detected significant associations and correlations between high tissue TLR2, TLR4, and TLR5 immunoexpressions and high densities of CD3- and CD8-positive cells. Combining these markers may improve the prognostic evaluation of CRC patients.

Expression Pattern and Prognostic Value of CTLA-4, CD86, and Tumor-Infiltrating Lymphocytes in Rectal Cancer after Neoadjuvant Chemo(radio)therapy

The synergistic effect of combining immune checkpoint inhibitors (ICIs) with neoadjuvant chemo(radio)therapy (nCRT) in colorectal cancer is still limited. We aimed to understand the impact of nCRT on the tumor microenvironment and to explore favorable immune markers of this combination. Herein, we investigated the expression of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), CD86, CD4, and CD8 after nCRT and its association with clinicopathological characteristics. Immunostaining of immune-related molecules was performed in 255 surgically resected specimens from rectal cancer patients treated with nCRT. CD4 and CD8 expression on the tumor (tCD4/CD8), stroma (sCD4/CD8), and invasive front (iCD4/CD8) was evaluated. The expression levels of immune-related molecules were significantly lower in the nCRT-treated group, except for CTLA-4 and sCD8. However, patients with higher sCD8⁺ cell density and CTLA-4 expression had better progression-free survival (PFS) and distant metastasis-free survival (DMFS). In addition, higher CD86 expression was associated with poorer overall survival (OS). Higher CTLA-4 expression was associated with higher tCD8⁺ cell density, whereas CD86 expression was correlated with the cell density of t/sCD8. Prognostic analysis confirmed that the relationships between CTLA-4 and DMFS as well as CD86 and OS were significantly correlated in low rather than high CD8⁺ cell density. Further the combination of CD8⁺ cell density and CD86 expression was shown to be an independent prognostic factor of OS, whereas the combination of CTLA-4 was not for DMFS. Together, these results demonstrate significant correlations between CD86 expression and t/sCD8⁺ cell density in rectal cancer after nCRT and could potentially have clinical implications for combining ICIs and nCRT.

Immune Response in Colorectal Carcinoma: A Review of Its Significance as a Predictive and Prognostic Biomarker

Colorectal carcinoma is a leading cause of cancer-related death worldwide. There is significant prognostic heterogeneity in stage II and III tumours, necessitating the development of new biomarkers to better identify patients at risk of disease progression. Recently, the tumour immune environment, particularly the type and quantity of T lymphocytes, has been shown to be a useful biomarker in predicting prognosis for patients with colorectal carcinoma. In this review, the significance of the immune response in colorectal carcinoma, including its influence on prognosis and response to therapy, will be detailed.

Lag3: From Bench to Bedside

The introduction of immune checkpoint inhibitors represented a breakthrough treatment for metastatic melanoma, but the effect of these agents is not limited to a single cancer type. Promising results have been reported in various solid tumors, for example, lung cancer. The success of these drugs depends on the activation of tumor-infiltrating lymphocytes and primary and acquired resistance have been reported alongside a high rate of immune-related adverse events when agents targeting different immune checkpoints are given in combination. Numerous other targets have been investigated to overcome the resistance, improve the activity, and reduce the toxicity of checkpoint inhibitor therapy. Among these, the most promising is Lymphocyte-activation gene 3 (LAG-3), a transmembrane protein involved in cytokine release and inhibitory signaling in T cells. Preclinical data showed that LAG-3 is a negative regulator of both CD4⁺ T cell and CD8⁺ T cell and the activity on CD8⁺ T cell is independent of CD4⁺ activation. On the CD8⁺ T cell, LAG-3 activation abrogates the antigen presentation whereas on the CD4⁺ T cell, arrests the S phase of the cell cycle. The blockade of LAG-3 has been tested in several combination therapies, and recent clinical data showed a good safety profile and a synergistic effect with anti-PD-1, suggesting that this combination could become a standard treatment for metastatic melanoma. In this review, we report the available preclinical data and the new clinical data on LAG-3 blockade in different solid tumors, and we discuss LAG-3 as potential prognostic and predictive factor, together with possible future applications.

Comparison of Immune Response Assessment in Colon Cancer by Immunoscore (Automated Digital Pathology) and Pathologist Visual Scoring

Simple Summary

The immune response to colon cancer (CC) is highly variable among patients and is clinically relevant. In this study, we compared the immune response assessment for early-stage CC, as measured by Immunoscore (IS), to pathologist visual scoring of the CD3+ and CD8+ T-cell densities at the tumor site (T-score). The objectives were to determine the inter-observer agreement between pathologists and the concordance between the two methods. Agreement between pathologists was minimal to weak. Moreover, a weak concordance between the two methods was observed, leading to misclassification of 48% of cases by pathologist scoring. Due to the high level of immune infiltrate heterogeneity resulting in disagreement of interpretation among pathologists, IS is unlikely to be reproduced via non-standardized methods.

Abstract

Adjunction of immune response into the TNM classification system improves the prediction of colon cancer (CC) prognosis. However, immune response measurements have not been used as robust biomarkers of pathology in clinical practice until the introduction of Immunoscore (IS), a standardized assay based on automated artificial intelligence assisted digital pathology. The strong prognostic impact of the immune response, as assessed by IS, has been widely validated and IS can help to refine treatment decision making in early CC. In this study, we compared pathologist visual scoring to IS. Four pathologists evaluated tumor specimens from 50 early-stage CC patients and classified the CD3+ and CD8+ T-cell densities at the tumor site (T-score) into 2 (High/Low) categories. Individual and overall pathologist scoring of immune response (before and after training for immune response assessment) were compared to the reference IS (High/Low). Pathologists’ disagreement with the reference IS was observed in almost half of the cases (48%) and training only slightly improved the accuracy of pathologists’ classification. Agreement among pathologists was minimal with a Kappa of 0.34 and 0.57 before and after training, respectively. The standardized IS assay outperformed expert pathologist assessment in the clinical setting.

Density of CD3+ and CD8+ Cells in the Microenvironment of Colorectal Cancer according to Prediagnostic Physical Activity

BACKGROUND

Physical activity is associated not only with a decreased risk of developing colorectal cancer but also with improved survival. One putative mechanism is the infiltration of immune cells in the tumor microenvironment. Experimental findings suggest that physical activity may mobilize immune cells to the tumor. We hypothesized that higher levels of physical activity prior to colorectal cancer diagnosis are associated with higher densities of tumor-infiltrating T-lymphocytes in colorectal cancer patients.

METHODS

The study setting was a northern Swedish population-based cohort, including 109,792 participants with prospectively collected health- and lifestyle-related data. For 592 participants who later developed colorectal cancer, archival tumor tissue samples were used to assess the density of CD3⁺ and CD8⁺ cytotoxic T cells by IHC. Odds ratios for associations between self-reported, prediagnostic recreational physical activity and immune cell infiltration were estimated by ordinal logistic regression.

RESULTS

Recreational physical activity >3 times per week was associated with a higher density of CD8⁺ T cells in the tumor front and center compared with participants reporting no recreational physical activity. Odds ratios were 2.77 (95% CI, 1.21-6.35) and 2.85 (95% CI, 1.28-6.33) for the tumor front and center, respectively, after adjustment for sex, age at diagnosis, and tumor stage. The risk estimates were consistent after additional adjustment for several potential confounders. For CD3, no clear associations were found.

CONCLUSIONS

Physical activity may promote the infiltration of CD8⁺ immune cells in the tumor microenvironment of colorectal cancer.

IMPACT

The study provides some evidence on how physical activity may alter the prognosis in colorectal cancer.

Tumor Microenvironmental Prognostic Risk in Primary Operable Small Intestinal Adenocarcinoma

The tumor microenvironment (TME) has become an important area of investigation with respect to improving prognosis in malignancies. Here we evaluated TME prognostic risk in small intestinal adenocarcinomas based on histologic assessment of tumor budding at the peritumoral-invasive front (pTB) and stromal tumor-infiltrating lymphocytes (sTILs). pTB and sTILs were analyzed in 230 surgically resected small intestinal adenocarcinomas, as recommended by the International Tumor Budding Consensus Conference (ITBCC) and the International TILs Working Group (ITWG). On the basis of high levels of pTB count (≥10) and sTIL density (≥20%), we combined pTB and sTIL to produce a collective TME-based prognostic risk index: low-risk (pTBLow/sTILHigh; n=39, 17.0%), intermediate-risk (pTBLow/sTILLow or pTBHigh/sTILHigh; n=99, 43.0%), and high-risk groups (pTBHigh/sTILLow; n=92, 40.0%). TME risk index provided better prognostic stratification than the individual pTB and sTIL (14.9 vs. 6.7 vs. 10.3). Tumors with higher TME prognostic risk were associated with an infiltrative growth pattern and nonintestinal immunophenotype (both P=0.001), pancreatic invasion (P=0.010), lymphovascular (P<0.001) or perineural invasion (P=0.006), higher T-category (P<0.001), N-category (P=0.004), and stage grouping (P=0.002), and KRAS mutation (P=0.008). In multivariate analysis, higher TME prognostic risk index (P<0.001), distal tumor location and nonintestinal immunophenotype (both P=0.001), higher N-category (P<0.001), and microsatellite stable (P=0.015) were worse-independent prognosticators. TME prognostic risk index consistently stratified patient survival regardless of tumor location (P<0.001 in proximal; P=0.002 in distal), stages (P<0.001 in lower stages I to II; P=0.028 in stage III), and DNA mismatch repair gene status (P<0.001 in microsatellite stable; P=0.001 in microsatellite instability). TME risk index is a powerful prognostic predictor for risk stratification of patients with small intestinal adenocarcinoma.

Improving Risk Stratification of Early Oral Tongue Cancer with TNM-Immune (TNM-I) Staging System

Simple Summary

Some patients with early-stage oral tongue cancer suffer from poor survival. The currently used classification requires further improvement to better predict the prognosis. Immune-related parameters (such as assessment of infiltrating lymphocytes) can be used as a modifier for the classification and that can aid in improving the prognostication. We included 290 cases of early-stage oral tongue cancer in this study. Lymphocytes were scored and divided as low or high and incorporated in the traditional tumor-node-metastasis (TNM) classification to form our proposed TNM-Immune staging system. The TNM-Immune staging system allowed for a significant distinction between T1 and T2. The TNM-Immune staging system showed a powerful ability to identify cases with poor survival. TNM-Immune staging forms a step towards a more personalized classification of early-stage oral tongue cancer.

Abstract

Although patients with early-stage oral tongue squamous cell carcinoma (OTSCC) show better survival than those with advanced disease, there is still a number of early-stage cases who will suffer from recurrence, cancer-related mortality and worse overall survival. Incorporation of an immune descriptive factor in the staging system can aid in improving risk assessment of early OTSCC. A total of 290 cases of early-stage OTSCC re-classified according to the American Joint Committee on Cancer (AJCC 8) staging were included in this study. Scores of tumor-infiltrating lymphocytes (TILs) were divided as low or high and incorporated in TNM AJCC 8 to form our proposed TNM-Immune system. Using AJCC 8, there were no significant differences in survival between T1 and T2 tumors (p > 0.05). Our proposed TNM-Immune staging system allowed for significant discrimination in risk between tumors of T1N0M0-Immune vs. T2N0M0-Immune. The latter associated with a worse overall survival with hazard ratio (HR) of 2.87 (95% CI 1.92–4.28; p < 0.001); HR of 2.41 (95% CI 1.26–4.60; p = 0.008) for disease-specific survival; and HR of 1.97 (95% CI 1.13–3.43; p = 0.017) for disease-free survival. The TNM-Immune staging system showed a powerful ability to identify cases with worse survival. The immune response is an important player which can be assessed by evaluating TILs, and it can be implemented in the staging criteria of early OTSCC. TNM-Immune staging forms a step towards a more personalized classification of early OTSCC.

Low level of stromal lectin-like oxidized LDL receptor 1 and CD8+ cytotoxic T-lymphocytes indicate poor prognosis of colorectal cancer

Background

Lectin‐like oxidized LDL receptor‐1 (LOX‐1) has been identified as a new marker for functional myeloid‐derived suppressor cells (MDSCs) that exhibit an immunosuppressive phenotype in the tumor microenvironment (TME). However, the role of LOX‐1⁺ cells in the TME of colorectal cancer (CRC) remains unknown.

Aim

This study aimed to determine the expression and significance of LOX‐1 in the TME of clinical CRC specimens.

Methods and results

We performed immunohistochemical and genetic analyses of LOX‐1, CD8, KRAS, and BRAF in 128 resected CRC specimens and determined the expression of IFN‐γ and IL‐10 using real‐time reverse transcription‐polymerase chain reaction. We analyzed the correlation between LOX‐1, TME factors, gene alteration, clinicopathological factors, and disease prognosis. The co‐expression pattern of LOX‐1, hematopoietic markers, and a fibroblast marker was evaluated using multiplex immunofluorescence staining. Low stromal LOX‐1 expression and low intratumoral CD8⁺ cytotoxic T‐lymphocyte (CTL) status correlated with poor prognosis. Moreover, stromal LOX‐1‐low/CD8⁺ CTL‐low status was the most important independent prognostic factor of poor overall survival. Most of the LOX‐1⁺ stromal cells were positive for CD163⁺, indicating they were CD163⁺ M2 macrophages.

Conclusions

The MDSC marker, LOX‐1, was mainly expressed by M2 macrophages in CRC tissues. LOX‐1⁺ macrophages and CD8⁺ CTLs may serve as useful biomarkers for predicting the prognosis of CRC.

Distribution of tumor-infiltrating-T-lymphocytes and possible tumor-escape mechanisms avoiding immune cell attack in locally advanced adenocarcinomas of the esophagus

Introduction

The inflammatory microenvironment has emerged as one of the focuses of cancer research. Little is known about the immune environment in esophageal adenocarcinoma (EAC) and possible tumor-escape mechanisms to avoid immune cell attack.

Patients and methods

We measured T cell inflammation (CD3, CD8) in the microenvironment using a standardized software-based evaluation algorithm considering different predefined tumor areas as well as expression of MHC class 1 and PD-L1 on 75 analyzable primarily resected and locally advanced (≥ pT2) EACs. We correlated these findings statistically with clinical data.

Results

Patients with high amounts of T cell infiltration in their tumor center showed a significant survival benefit of 41.4 months compared to 16.3 months in T cell poor tumors (p = 0.025), although CD3 fails to serve as an independent prognostic marker in multivariate analysis. For the invasion zone, a correlation between number of T-cells and overall survival was not detectable. Loss of MHC1 protein expression on tumor cells was seen in 32% and PD-L1 expression using the combined positive score (CPS) in 21.2%. Most likely due to small numbers of cases, both markers are not prognostically relevant, even though PD-L1 expression correlates with advanced tumor stages.

Discussion

Our analyses reveal an outstanding, though not statistically independent, prognostic relevance of T-cell-rich inflammation in our group of EACs, in particular driven by the tumor center. For the first time, we describe that the inner part of the invasion zone in EACs shows significantly fewer T-cells than other tumor segments and is prognostically irrelevant. We also demonstrate that the loss of antigen presenting ability via MHC1 downregulation by the carcinoma cells is a common escape mechanism in EACs. Future work will need to show whether tumors with MHC class 1 loss respond less well to immunotherapy.

The Role of Tumor Microenvironment Cells in Colorectal Cancer (CRC) Cachexia

Cancer cachexia (CC) is a multifactorial syndrome in patients with advanced cancer characterized by weight loss via skeletal-muscle and adipose-tissue atrophy, catabolic activity, and systemic inflammation. CC is correlated with functional impairment, reduced therapeutic responsiveness, and poor prognosis, and is a major cause of death in cancer patients. In colorectal cancer (CRC), cachexia affects around 50–61% of patients, but remains overlooked, understudied, and uncured. The mechanisms driving CC are not fully understood but are related, at least in part, to the local and systemic immune response to the tumor. Accumulating evidence demonstrates a significant role of tumor microenvironment (TME) cells (e.g., macrophages, neutrophils, and fibroblasts) in both cancer progression and tumor-induced cachexia, through the production of multiple procachectic factors. The most important role in CRC-associated cachexia is played by pro-inflammatory cytokines, including the tumor necrosis factor α (TNFα), originally known as cachectin, Interleukin (IL)-1, IL-6, and certain chemokines (e.g., IL-8). Heterogeneous CRC cells themselves also produce numerous cytokines (including chemokines), as well as novel factors called “cachexokines”. The tumor microenvironment (TME) contributes to systemic inflammation and increased oxidative stress and fibrosis. This review summarizes the current knowledge on the role of TME cellular components in CRC-associated cachexia, as well as discusses the potential role of selected mediators secreted by colorectal cancer cells in cooperation with tumor-associated immune and non-immune cells of tumor microenvironment in inducing or potentiating cancer cachexia. This knowledge serves to aid the understanding of the mechanisms of this process, as well as prevent its consequences.

The Glasgow Microenvironment Score associates with prognosis and adjuvant chemotherapy response in colorectal cancer

BACKGROUND

The Glasgow Microenvironment Score (GMS) combines peritumoural inflammation and tumour stroma percentage to assess interactions between tumour and microenvironment. This was previously demonstrated to associate with colorectal cancer (CRC) prognosis, and now requires validation and assessment of interactions with adjuvant therapy.

METHODS

Two cohorts were utilised; 862 TNM I-III CRC validation cohort, and 2912 TNM II-III CRC adjuvant chemotherapy cohort (TransSCOT). Primary endpoints were disease-free survival (DFS) and relapse-free survival (RFS). Exploratory endpoint was adjuvant chemotherapy interaction.

RESULTS

GMS independently associated with DFS (p = 0.001) and RFS (p < 0.001). GMS significantly stratified RFS for both low risk (GMS 0 v GMS 2: HR 3.24 95% CI 1.85-5.68, p < 0.001) and high-risk disease (GMS 0 v GMS 2: HR 2.18 95% CI 1.39-3.41, p = 0.001). In TransSCOT, chemotherapy type (pinteraction = 0.013), but not duration (p = 0.64) was dependent on GMS. Furthermore, GMS 0 significantly associated with improved DFS in patients receiving FOLFOX compared with CAPOX (HR 2.23 95% CI 1.19-4.16, p = 0.012).

CONCLUSIONS

This study validates the GMS as a prognostic tool for patients with stage I-III colorectal cancer, independent of TNM, with the ability to stratify both low- and high-risk disease. Furthermore, GMS 0 could be employed to identify a subset of patients that benefit from FOLFOX over CAPOX.

Comparison of Immune Microenvironment Between Colon and Liver Metastatic Tissue in Colon Cancer Patients with Liver Metastasis

BACKGROUND

Liver metastasis is an indicator of unfavorable responses to immunotherapy in colorectal cancer patients. However, the difference of immune microenvironment between primary tumors and liver metastases has not been well understood.

PATIENTS AND METHODS

Fifty-four colon cancer with liver metastasis patients who received resection of both primary and metastasis lesions have been analyzed. The immune score is based on the density of infiltrating immune cells (CD3+ cell, CD8+ cell, CD11b+ cell, CD11c+ cell, and CD33+ cell) in the center and margin of the tumor. The expression of immune markers between the primary tumor and hepatic metastases was analyzed using Wilcoxon's signed rank test.

RESULTS

All the five markers had higher expression in tumor margins than center tumor in both primary tumor and hepatic metastases lesions. The expression of CD11c and CD11b had no difference between metastatic lesions and primary tumor. In tumor margins, except CD11b, all the other 4 markers expressed significantly higher in hepatic metastases than in primary tumor. Intra-tumor, CD3 had higher expression in primary tumor than in hepatic metastases, while CD33 had higher expression in hepatic metastases than in primary tumor. CD8+ CD3+ cells of the total CD8+ cell population in primary tumor was significantly higher than in hepatic metastases (36.42% vs. 24.88%, p = 0.0069).

CONCLUSIONS

The immune microenvironment between primary tumor and hepatic metastasis is different. More immunosuppressing cells in liver may partially explain why immunotherapy in colon cancer is less effective with liver metastatic disease.

Relationship between immune checkpoint proteins, tumour microenvironment characteristics, and prognosis in primary operable colorectal cancer

The tumour microenvironment is an important factor for colorectal cancer prognosis, affecting the patient's immune response. Immune checkpoints, which regulate the immune functions of lymphocytes, may provide prognostic power. This study aimed to investigate the prognostic value of the immune checkpoints TIM‐3, LAG‐3 and PD‐1 in patients with stage I–III colorectal cancer. Immunohistochemistry was employed to detect TIM‐3, LAG‐3, PD‐1 and PD‐L1 in 773 patients with stage I–III colorectal cancer. Immune checkpoint protein expression was assessed in tumour cells using the weighted histoscore, and in immune cells within the stroma using point counting. Scores were analysed for associations with survival and clinical factors. High tumoural LAG‐3 (hazard ratio [HR] 1.45 95% confidence interval [CI] 1.00–2.09, p = 0.049) and PD‐1 (HR 1.34 95% CI 1.00–1.78, p = 0.047) associated with poor survival, whereas high TIM‐3 (HR 0.60 95% CI 0.42–0.84, p = 0.003), LAG‐3 (HR 0.58 95% CI 0.40–0.87, p = 0.006) and PD‐1 (HR 0.65 95% CI 0.49–0.86, p = 0.002) on immune cells within the stroma associated with improved survival, while PD‐L1 in the tumour (p = 0.487) or the immune cells within the stroma (p = 0.298) was not associated with survival. Furthermore, immune cell LAG‐3 was independently associated with survival (p = 0.017). Checkpoint expression scores on stromal immune cells were combined into a Combined Immune Checkpoint Stromal Score (CICSS), where CICSS 3 denoted all high, CICSS 2 denoted any two high, and CICSS 1 denoted other combinations. CICSS 3 was associated with improved patient survival (HR 0.57 95% CI 0.42–0.78, p = 0.001). The results suggest that individual and combined high expression of TIM‐3, LAG‐3, and PD‐1 on stromal immune cells are associated with better colorectal cancer prognosis, suggesting there is added value to investigating multiple immune checkpoints simultaneously.

Prognostic and Predictive Cross-Roads of Microsatellite Instability and Immune Response to Colon Cancer

Understanding molecular features of colon cancer has shed light on its pathogenesis and progression. Over time, some of these features acquired clinical dignity and were incorporated in decision making. Namely, microsatellite instability (MSI) due to mismatch repair of defects, which primarily was adopted for the diagnosis of Lynch syndrome, became recognized as the biomarker of a different disease type, showing a less aggressive behavior. MSI tumors harbor high amounts of tumor infiltrating lymphocytes (TILs) due to their peculiar load in neoantigens. However, microsatellite stable colon cancer may also show high amounts of TILs, and this feature is as well associated with better outcomes. High TIL loads are in general associated with a favorable prognosis, especially in stage II colon cancer, and therein identifies a patient subset with the lowest probability of relapse. With respect to post-surgical adjuvant treatment, particularly in stage III, TILs predictive ability seems to weaken along with the progression of the disease, being less evident in high risk patients. Moving from cohort studies to the analysis of a series from clinical trials contributed to increase the robustness of TILs as a biomarker. The employment of high TIL densities as an indicator of good prognosis in early-stage colon cancers is strongly advisable, while in late-stage colon cancers the employment as an indicator of good responsiveness to post-surgical therapy requires refinement. It remains to be clarified whether TILs could help in identifying those patients with node-positive cancers to whom adjuvant treatment could be spared, at least in low-risk groups as defined by the TNM staging system.

Differences in circulating γδ T cells in patients with primary colon cancer and relation with prognostic factors

Downregulation of the T cell system has been proposed as a mechanism to block immunity in colonic cancer (CC). However, little has been studied about circulating αβ and γδ T cells and their immunological status in newly diagnosed patients. The aim of this study was to characterize the αβ and γδ T cell subsets in peripheral blood of patients with CC matched with healthy volunteers. In this prospective case-control study, blood samples were obtained from 96 patients with newly diagnosed treatment-naïve infiltrating colonic adenocarcinoma and 48 healthy volunteers. Pathological report at surgery was obtained from all CC patients. A significant decrease in CD3+ γδ T cells and CD3+CD8+ γδ T cells (p<0.001) were observed in CC patients. Apoptosis was significantly increased in all conventional and both αβ and γδ T cell subsets in patients with CC vs healthy subjects. γδ T cells were decreased in peripheral blood of patients with microscopic infiltration in tissues, history of cancer and synchronous colon cancer (p < 0.05). IFN-γ was significantly reduced in CC patients compared to controls. Cytotoxic effector γδ T cells TEMRA (CD8 and CD56) are the proportionally most abundant T cells in peripheral blood of CC patients. Patients with CC present a deep downregulation in the systemic T-cell immunity. These variations are evident through all tumor stages and suggest that a deficiency in γδ T cell populations could be preventing control of tumor progression. This fact prove the role of immunomodulation on CC carcinogenesis.

Automated Quantitation of CD8-positive T Cells Predicts Prognosis in Colonic Adenocarcinoma With Mucinous, Signet Ring Cell, or Medullary Differentiation Independent of Mismatch Repair Protein Status

Despite their association with DNA mismatch repair (MMR) protein deficiency, colonic adenocarcinomas with mucinous, signet ring cell, or medullary differentiation have not been associated with improved survival compared with conventional adenocarcinomas in most studies. Recent studies indicate that increased T-cell infiltration in the tumor microenvironment has a favorable prognostic effect in colonic adenocarcinoma. However, the prognostic effect of tumor-associated T cells has not been evaluated in histologic subtypes of colonic adenocarcinoma. We evaluated CD8-positive T-cell density in 259 patients with colonic adenocarcinoma, including 113 patients with tumors demonstrating mucinous, signet ring cell, or medullary differentiation, using a validated automated quantitative digital image analysis platform and correlated CD8-positive T-cell density with histopathologic variables, MMR status, molecular alterations, and survival. CD8-positive T-cell densities were significantly higher for MMR protein-deficient tumors (P<0.001), BRAF V600E mutant tumors (P=0.004), and tumors with medullary differentiation (P<0.001) but did not correlate with mucinous or signet ring cell histology (P>0.05 for both). In the multivariable model of factors predicting disease-free survival, increased CD8-positive T-cell density was associated with improved survival both in the entire cohort (hazard ratio=0.34, 95% confidence interval, 0.15-0.75, P=0.008) and in an analysis of patients with tumors with mucinous, signet ring cell, or medullary differentiation (hazard ratio=0.06, 95% confidence interval, 0.01-0.54, P=0.01). The prognostic effect of CD8-positive T-cell density was independent of tumor stage, MMR status, KRAS mutation, and BRAF mutation. Venous invasion was the only other variable independently associated with survival in both the entire cohort and in patients with tumors with mucinous, signet ring cell, or medullary differentiation. In summary, our results indicate that the prognostic value of MMR protein deficiency is most likely attributed to increased tumor-associated CD8-positive T cells and that automated quantitative CD8 T-cell analysis is a better biomarker of patient survival, particularly in patients with tumors demonstrating mucinous, signet ring cell, or medullary differentiation.

The role of tumor budding in colorectal adenocarcinoma: Possible involvement of the intestinal cancer stem cell marker Lgr5

Background

Tumor budding (TB) is a promising prognostic factor in colorectal cancer (CRC) that is independent of tumor-node-metastasis (TNM) staging. Leucine-rich repeat-containing G-protein-coupled receptor 5 (Lgr5) is a stem cell marker and a member of the canonical Wnt-signaling cascade. It is involved in colorectal carcinogenesis. However, its role in CRC progression and TB needs to be clarified.

Materials and Methods

TB was assessed in both H and E and CK immunostained sections of 92 CRC cases. Associations between TB grade and different clinicopathological parameters were evaluated. Lgr5 expression in CRC cases and its association with TB grade and other clinicopathological features was also evaluated.

Results

H and E stained sections revealed low- and high-grade budding in 55 (59.8%) and 37 (40.2%) tumors, respectively, whereas Cytokeratin Immunohistochemistry (CK-IHC) showed low- and high-grade budding in 31 (33.7%) and 61 (66.3%) tumors, respectively. TB grade (in H and E and CK stained sections) was significantly associated with adverse pathological prognostic variables including vascular invasion (P = 0.03 and 0.001), lymph node metastasis (P = 0.001 and 0,001), advanced Dukes (P = 0.000 and 0.000), and TNM (P = 0.001 and 0.000) stages and inversely associated with Tumor infiltrating lymphocytes (TILS) (P = 0.02 and 0.0001) which is known to be a good prognostic indicator. Lgr5 protein was positively expressed in 52.2% (48/92) of the CRCs. Immunoreactivity of Lgr5 was significantly associated with histological grade (P = 0.01), lymph node metastasis (P = 0.002), vascular invasion (P = 0.02), TNM stage (P = 0.000), Dukes stage (P = 0.000), and TILS (P = 0.03). Furthermore, Lgr5 was found to be significantly associated with TB estimated in both H and E and CK stained tumors (P = 0.003 and 0.001 respectively).

Conclusion

This study supported the relevance of TB in the assessment of CRC aggressiveness. It also revealed that Lgr5 expression is related to morphologic features in the invasive front of CRC. Lgr5 could have an important role in forming a morphologic feature at the invasive front associated with the aggressiveness of the tumor.

Histological phenotypic subtypes predict recurrence risk and response to adjuvant chemotherapy in patients with stage III colorectal cancer

Histological 'phenotypic subtypes' that classify patients into four groups (immune, canonical, latent and stromal) have previously been demonstrated to stratify survival in a stage I-III colorectal cancer (CRC) pilot cohort. However, clinical utility has not yet been validated. Therefore, this study assessed prognostic value of these subtypes in additional patient cohorts along with associations with risk of recurrence and response to chemotherapy. Two independent stage I-III CRC patient cohorts (internal and external cohort) were utilised to investigate phenotypic subtypes. The primary endpoint was disease-free survival (DFS) and the secondary endpoint was recurrence risk (RR). Stage II-III patients, from the SCOT adjuvant chemotherapy trial, were utilised to further validate prognostic value and for exploratory analysis assessing associations with adjuvant chemotherapy. In an 893-patient internal cohort, phenotypic subtype independently associated with DFS (p = 0.025) and this was attenuated in stage III patients (p = 0.020). Phenotypic subtype also independently associated with RR (p < 0.001) in these patients. In a 146-patient external cohort, phenotypic subtype independently stratified patients by DFS (p = 0.028), validating their prognostic value. In 1343 SCOT trial patients, the effect of treatment type significantly depended on phenotypic subtype (pinteraction = 0.011). Phenotypic subtype independently associated with DFS in stage III patients receiving FOLFOX (p = 0.028). Furthermore, the immune subtype significantly associated with better response to FOLFOX compared to CAPOX adjuvant chemotherapy in stage III patients (p = 0.013). In conclusion, histological phenotypic subtypes are an effective prognostic classification in patients with stage III CRC that associates with risk of recurrence and response to FOLFOX adjuvant chemotherapy.

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.

The prognostic role of tissue TLR2 and TLR4 in colorectal cancer

Colorectal cancer (CRC), the second most common cancer globally, resulted in 881,000 deaths in 2018. Toll-like receptors (TLRs) are crucial to detecting pathogen invasion and inducing the host’s immune response. This study aimed to explore the prognostic value of TLR2 and TLR4 tumor expressions in colorectal cancer patients. We studied the immunohistochemical expressions of TLR2 and TLR4 using tissue microarray specimens from 825 patients undergoing surgery in the Department of Surgery, Helsinki University Hospital, between 1982 and 2002. We assessed the relationships between TLR2 and TLR4 expressions and clinicopathological variables and patient survival. We generated survival curves using the Kaplan-Meier method, determining significance with the log-rank test. Among patients with lymph node–positive disease and no distant metastases (Dukes C), a strong TLR2 immunoactivity associated with a better prognosis (p < 0.001). Among patients with local Dukes B disease, a strong TLR4 immunoactivity associated with a worse disease-specific survival (DSS; p = 0.017). In the multivariate survival analysis, moderate TLR4 immunoactivity compared with strong TLR4 immunoactivity (hazard ratio (HR) 0.66, 95% confidence interval (CI) 0.49–0.89, p = 0.007) served as an independent prognostic factor. In the multivariate analysis for the Dukes subgroups, moderate TLR2 immunoactivity (HR 2.63, 95% CI 1.56–4.44, p < 0.001) compared with strong TLR2 immunoactivity served as an independent negative prognostic factor in the Dukes C subgroup. TLR2 and TLR4 might be new prognostic factors to indicate which CRC patients require adjuvant therapy and which could spare from an unnecessary follow-up, but further investigations are needed.

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 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.

Preoperative, biopsy-based assessment of the tumour microenvironment in patients with primary operable colorectal cancer

The tumour microenvironment (TME) is recognised as an important prognostic characteristic and therapeutic target in patients with colorectal cancer (CRC). However, assessment generally utilises surgically resected specimens, precluding neoadjuvant targeting. The present study investigated the feasibility of intra‐epithelial CD3⁺ T‐lymphocyte density and tumour stroma percentage (TSP) assessment using preoperative colonoscopic biopsies from 115 patients who had undergone resection of stages I–III CRC, examining the relationship between biopsy and surgically resected specimen‐based assessment, and the relationship with cancer‐specific survival (CSS). High biopsy CD3⁺ density was associated with high CD3⁺ density in the invasive margin, cancer stroma and intra‐epithelial compartments of surgically resected specimens (area under the curve > 0.62, p < 0.05 for all) and with high Immunoscore. High biopsy TSP predicted high TSP in resected specimens (p = 0.001). Intra‐class correlation coefficient for both measures was >0.7 (p < 0.001), indicating excellent concordance between individuals. Biopsy CD3⁺ density (hazard ratio [HR] 0.23, p = 0.002) and TSP (HR 2.23, p = 0.029) were independently associated with CSS; this was comparable to the prognostic value of full section assessment (HR 0.21, p = 0.004, and HR 2.25, p = 0.033 respectively). These results suggest that assessment of the TME is comparable in biopsy and surgically resected specimens from patients with CRC, and biopsy‐based assessment could allow for stratification prior to surgery or commencement of therapy targeting the TME.

The relationship between members of the canonical NF-kB pathway, tumour microenvironment and cancer specific survival in colorectal cancer patients

BACKGROUND

The aim of this study was to investigate the role of the upstream kinase TAK1 and the canonical NF-κB pathway colorectal in cancer (CRC). Immunohistochemistry was used to assess the expression of TAK1/pTAK1 and canonical NF-κB pathway members in a tissue microarray of 242 patients. The relationship between expression, the tumour microenvironment and cancer-specific survival were examined.

RESULTS

All the investigated members of the pathway were expressed in CRC tissue. In addition, cytoplasmic pTAK1 was associated with the tumour microenvironment (P=0.045) and cancer-specific survival (CSS) (P=0.032). When cytoplasmic pTAK1 was stratified by BRAF status, cytoplasmic pTAK1 expression association with CSS was strengthened (P=0.014). Cytoplasmic IKKβ was significantly associated with the inflammatory cell infiltrate (P=0.015) as graded by Klintrup Makinen grade, systemic inflammation as assessed by neutrophil-lymphocyte ratio (P=0.03) and CSS (P=0.046). On multivariate analysis cytoplasmic IKKβ was independently associated with CSS (HR 1.75,95%CI 1.05-2.91, P=0.033).

CONCLUSION

Cytoplasmic pTAK1 was significantly associated with CSS and this was enhanced in patients with tumours that expressed wild type BRAF. High expression of cytoplasmic IKKβ was significantly associated with decreased CSS and with markers of the tumour microenvironment. These results support the hypothesis that NF-κB pathway members are poor prognostic markers in patients with CRC, but this requires to be validated in a large independent cohort.

Impact of tumor-infiltrating LAMP-3 dendritic cells on the prognosis of esophageal squamous cell carcinoma

BACKGROUND

Dendritic cells (DCs) are the most potent antigen-presenting cells to induce cytotoxic T lymphocytes in the tumor environment. After acquiring antigens, DCs undergo maturation and their expression of MHC and co-stimulation molecules are enhanced, along with lysosome-associated membrane glycoprotein 3 (LAMP-3), which is a specific marker of mature DCs. In general, mature DCs are usually considered to be immunostimulatory in the cancer microenvironment. In addition, it is known that tumor-infiltrating lymphocytes (TILs) are associated with a good prognosis in esophageal squamous cell carcinoma (ESCC). However, few studies have targeted the interaction between DCs and TILs in the local immunity of ESCC. We investigated the localization of mature DCs within ESCC tissue and their relationship to TILs as well as the clinical outcome.

METHODS

We evaluated 80 ESCC patients who underwent surgical treatment without preoperative treatment, using immunohistochemistry with LAMP-3 and CD8.

RESULTS

The results showed that LAMP-3 DCs were predominantly observed in the peritumoral area. Intratumoral CD8 T cells were found to be associated with a favorable prognosis, and the number of infiltrating LAMP-3 DCs was correlated with the number of intratumoral CD8 T cells.

CONCLUSION

At the local tumor site, mature LAMP-3 DCs might be associated with increasing tumor infiltrating CD8 T cells.

Clinical significance of tumor-infiltrating lymphocytes and neutrophil-to-lymphocyte ratio in patients with stage III colon cancer who underwent surgery followed by FOLFOX chemotherapy

Local tumor immune response and host immunity have been suggested as important prognosticators respectively in colorectal cancer. However, the utility of combination of these parameters remains inconclusive. The aim of this study was to investigate the combinational impact of local and host tumor immune response, as determined by tumor-infiltrating lymphocytes (TILs) and neutrophil-to-lymphocyte ratio (NLR), in patients with stage III colon cancer. Patients with stage III colon cancer homogeneously treated with surgery followed by FOLFOX chemotherapy between Jan 2007 and Aug 2013 were included retrospectively. Hematoxylin and eosin (H&E) stained tumor sections of local inflammatory infiltrate (TILs) were classified as 0–3 by the Klintrup-Mäkinen grading method. NLR was measured within 1 month of surgery. The association of NLR and TILs with survival, alone or combined, were measured using multivariate Cox proportional hazard regression analysis. Among 137 patients, 75 (54.7%) were identified as the high TIL group (TILs 2 and 3) and 97 (70.8%) as the low NLR group (NLR < 3). Of the patients with high TILs, 51 (68%) had a low NLR. In univariate analysis, operation time, complications, lymph node ratio (LNR), stage, TILs, and high TILs with low NLR were significantly associated with overall survival(OS). Multivariate Cox regression identified operation time, stage, and TILs as independent risk factors for OS. When high TILs with low NLR vs. others was entered into multivariate analysis, this also proved to be a significant predictor of OS (HR 4.1, 95% CI 1.1–14.2, P = 0.025), with an increased C-index and lower AIC value compared to TILs. Measuring TILs using H&E stained sections could stratify the prognosis of stage III colon cancer. Considering host immunity, using the combination of TILs and NLR, allowed the prognosis to be stratified in more detail.

The prognostic value of tumor-infiltrating lymphocytes in colorectal cancer differs by anatomical subsite: a systematic review and meta-analysis

PURPOSE

In colorectal cancer (CRC), whether the immune score can be used to predict the clinical prognosis of the patient has not been completely established. Besides, the prognostic values of tumor-infiltrating lymphocytes (TILs) in different anatomical locations, counting sites, and subtypes have been controversial. The purpose of this meta-analysis is to analyze and determine the prognostic value of TILs indices including TIL subsets, infiltrating sites, and anatomical sites.

METHODS

Relevant literature was obtained by searching PubMed and Google Scholar. The pooled hazard ratio (HR) of the overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) was computed to investigate the prognostic significance of CD3+, CD8+, CD45RO+, and FOXP3+ T cells.

RESULTS

A total of 22 studies involving 5108 patients were included in the meta-analysis. In CC, based on T cell subtypes analysis, the final results indicated that CD8+ and FOXP3+ infiltrating cells, but not CD3+ T cells were prognostic markers for DFS and OS. In addition, with regard to the counting location of TILs, subgroup analysis revealed that only high FOXP3+ infiltrates in the tumor stroma (ST) were significantly associated with OS (HR = 0.38, 95% confidence interval (CI) = 0.22-0.67, P = 0.0007), whereas in invasive margin (IM), high density of CD3+ infiltrating cells indicated increased DFS (HR = 0.76, 95% CI = 0.62-0.93, P = 0.008). At the tumor center (TC), high CD8+ T cells infiltration was associated with improved DFS (HR = 0.50, 95% CI = 0.38-0.65, P < 0.00001). In RC, whether CSS or OS, high-density TIL was associated with improved prognosis.

CONCLUSION

In a single counting site, high-density TILs reflect favorable prognostic value in CC or RC. For CC, more prospective studies are needed to verify whether different anatomical sites affect the distribution of TILs and thus the prognosis of patients. For RC, further studies should analyze the prognostic value of the immune score.

Systemic and local inflammation in colorectal cancer

Background

Colorectal cancer (CRC) is the third most common cancer in the world. The cornerstone of CRC treatment is surgical resection. However, patients in the same TNM stage show different recurrence rates and survival. Of patients with a local disease without lymph node or a distant metastasis, 20-25% still develop recurrence. There is evidence that inflammatory reaction is one of the key elements in tumour development.

Materials and methods

We reviewed literature on colorectal cancer and its relationships with the immune system, with special focus on local and systemic inflammatory reaction. The Pubmed and ClinicalKey databases were searched using the key words colorectal cancer, local inflammation, systemic inflammation, markers of inflammation. The relevant literature was reviewed and included in the article.

Results

The immune system has two-sided relationships with cancer, so it not only performs anti-tumour activities, but can also promote tumour growth and spread. Research has shown that signs of local inflammation are associated with a better prognosis in CRC. Systemic inflammation has been associated with more aggressive behaviour and a worse prognosis for patients with several cancers, including CRC.

Conclusions

Recent findings in tumour biology have improved our understanding of colorectal cancer and of the natural course of this disease. Several markers of local and systemic inflammatory reaction have been identified. The next step is to find the most accurate and applicable marker, so that this promising tool can be used in clinical practice and aid in decision making.

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.

The association between markers of tumour cell metabolism, the tumour microenvironment and outcomes in patients with colorectal cancer

Tumour cell anaerobic metabolism has been reported to be a prognostic factor in colorectal cancer. The present study investigated the association between monocarboxylate transporter (MCT) 1, MCT 2, lactate dehydrogenase (LDH) 1 and LDH 5, the tumour microenvironment, and outcome in patients with colorectal cancer. A cohort of 150 patients with stage I-III CRC were utilised to assess tumour cell expression of MCT-1, MCT-2, LDH-1 and LDH-5 by immunohistochemistry. Expression levels were dichotomised and associations with tumour factors, the tumour microenvironment and survival analysed. Nuclear LDH-5 associates with poor prognosis (HR 1.68 95% CI 0.99-2.84, p = 0.050) and trends toward increased tumour stroma percentage (TSP, p = 0.125). Cytoplasmic MCT-2 also trends toward increased TSP (p = 0.081). When combined into a single score; nuclear LDH-5 + TSP significantly associated with decreased survival independent of stage (HR 2.61 95% CI 1.27-5.35, p = 0.009), increased tumour budding (p = 0.002) and decreased stromal T-lymphocytes (p = 0.014). Similarly, cytoplasmic MCT-2 + TSP significantly associated with decreased survival (HR 2.32 95% CI 1.31-4.11, p = 0.003), decreased necrosis (p = 0.039), and increased tumour budding (p = 0.004). The present study reports that the combination of TSP and nuclear LDH-5 was significantly associated with survival, increased tumour budding, and decreased stromal T-lymphocytes. This supports the hypothesis that increased stromal invasion promotes tumour progression via modulation of tumour metabolism. Moreover, MCT-2 and LDH-5 may provide promising therapeutic targets for patients with stromal-rich CRC.

Signal interaction between the tumour and inflammatory cells in patients with gastrointestinal cancer: Implications for treatment

Over the last 15 years there has been a change in how we understand the impact of the interaction between the tumour and the host on cancer outcomes. From the simplistic view that the make-up of tumours cells largely determines their aggressiveness to a more complex view that the interaction between the products of tumour and host cell signal transduction pathways is crucial in determining whether the tumour cell is eliminated or survives in the host. Of the host cells, those with an immune/inflammatory function are most well documented to inhibit or promote tumour cell proliferation and dissemination. It is only in the last few years that there has been greater recognition of the impact of intracellular, cellular and systemic immune/inflammatory phenotypes on patient outcomes independent of current tumour staging and that these phenotypes are useful in informing oncological research and practice. In the present review we will examine the importance of inflammatory phenotypes at the intra-cellular, cellular and systemic levels on outcomes in patients with gastrointestinal cancer with focus on colorectal cancer. Based on these phenotypes we will examine and discuss the prospects for therapeutic intervention.

A novel tumor-based epithelial-to-mesenchymal transition score that associates with prognosis and metastasis in patients with Stage II/III colorectal cancer

It is increasingly appreciated that host factors within the tumor center and microenvironment play a key role in dictating colorectal cancer (CRC) outcomes. As a result, the metastatic process has now been defined as a result of epithelial-mesenchymal transition (EMT). Establishment of the role of EMT within the tumor center and its effect on the tumor microenvironment would be beneficial for prognosis and therapeutic intervention in CRC. The present study assessed five immunohistochemical EMT markers within the tumor center on a 185 Stage II/III CRC patient tissue microarray. In 185 patients with CRC, cytoplasmic snail (HR 1.94 95% confidence interval [CI] 1.15-3.29, p = 0.012) and a novel combined EMT score (HR 3.86 95% CI 2.17-6.86, p < 0.001) were associated with decreased cancer-specific survival. The combined EMT score was also associated with increased tumor budding (p = 0.046), and systemic inflammation (p = 0.007), as well as decreased memory T-cells within the stroma (p = 0.030) and at the invasive margin (p = 0.035). Furthermore, the combined EMT score was associated with cancer-specific survival independent of TNM-stage (HR 4.12 95% CI 2.30-7.39, p < 0.001). In conclusion, a novel combined EMT score stratifies patient's survival in Stage II/III CRC and associates with key factors of tumor metastasis. Therefore, the combined EMT score could be used to identify patients at risk of micrometastases and who may benefit from standard adjuvant therapy, potentially in combination with EMT blockade.

ERK and p38MAPK combine to improve survival in patients with BRAF mutant colorectal cancer

BACKGROUND

In colorectal cancer (CRC), BRAF mutations influence tumour progression. In mismatch repair-deficient (dMMR) tumours, BRAF mutations are associated with a good prognosis, whereas in MMR-competent tumours, they are detrimental. The differential expression of the downstream MAPK pathway members, which are constitutively activated in BRAF mutant patients, may account for these differences.

METHODS

Phosphorylation of ERK, p38MAPK and JNK was assessed by immunohistochemistry, utilising CRC tissue microarrays. A discovery cohort (n = 187) and a validation cohort (n = 801) were analysed for associations with BRAF mutations, clinicopathological characteristics and cancer-specific survival (CSS).

RESULTS

In 801 CRC patients, nuclear ERK phosphorylation (HR 0.65 95% CI 0.48-0.88, p = 0.004) and the combined nuclear pERK/p-p38 score (HR 0.61 95% CI 0.45-0.82, p = 0.001) were independently associated with CSS, and were further associated with increased BRAF mutations (p = 0.003 and p = 0.002). When stratified for BRAF status, only MMR-competent patients harbouring the mutation and a strong combined nuclear pERK/p-p38 score (HR 0.49 95% CI 0.27-0.89, p = 0.016) demonstrated improved CSS. This improvement in CSS was specific to stage III CRC (HR 0.25 95% CI 0.10-0.64, p = 0.002).

CONCLUSIONS

MMR-competent stage III tumours harbouring BRAF mutations have an improved prognosis when strong nuclear phosphorylation of both ERK and p38MAPK is present.

Prognostic value of intra-tumoral CD8+ /FoxP3+ lymphocyte ratio in patients with resected colorectal cancer liver metastasis

Background and Objectives

Patients with isolated colorectal‐cancer‐liver‐metastases (CRCLM) frequently undergo metastatectomy. Tumor‐infiltrating‐lymphocytes (TILs) have prognostic potential in the setting of primary colorectal cancer, however, their role in CRCLM is less studied. We aimed to study the spatial distribution and prognostic role of tumor‐infiltrating CD8⁺ cytotoxic T‐cells and FoxP3⁺ regulatory T‐cells at the metastatic site of CRCLM patients.

Methods

TILs were isolated from fresh metastatic tissues of 47 patients with CRCLM. Archived paraffin‐embedded tissue, from the same patients, was retrieved. CD8⁺ and FoxP3⁺ cells, both in the intra‐tumoral and the peri‐tumoral compartments, were measured by immunohistochemistry on full tissue sections. Proportions of cytotoxic T‐cells (CD8⁺) and regulatory T‐cells (CD4⁺CD25⁺FoxP3⁺), within CD45⁺TILs, were measured by flow‐cytometry.

Results

By immunohistochemistry, individual densities of intra‐tumoral or peri‐tumoral CD8⁺ and FoxP3⁺ cells were not prognostic of survival. However, the intra‐tumoral, but not the peri‐tumoral, CD8⁺/FoxP3⁺ ratio was an independent predictor of survival (HR 0.43, 95%CI 0.19‐0.95, P = 0.032). By flow cytometry, the intra‐tumoral CD8⁺/regulatory T‐cell ratio was also an independent predictor of survival (HR 0.45, 95%CI 0.20‐0.99, P = 0.044).

Conclusions

The ratio of cytotoxic (CD8⁺) to regulatory (FoxP3⁺) T‐cells, in the intra‐tumoral compartment, but not in the peri‐tumoral compartment, can predict survival after resection of CRCLM.

Verification of the methodology for evaluating tumor-infiltrating lymphocytes in colorectal cancer

Background

The density of tumor-infiltrating lymphocytes (TILs) have been reported to reflect antitumor immune response and correlate with prognosis in malignancy. However, the methodology for evaluating the density of TILs by an immunohistochemical analysis differs among reports. The aim of this study was to verify the methodology for evaluating the density of TILs by immunohistochemical analysis and thereby identify the optimum methodology in clinical setting.

Methods

Three-hundred-thirteen patients who underwent curative operation for stage II/III colorectal cancer were enrolled. We retrospectively examined the density of TILs using immunohistochemical staining according to each method as follows: 1) subset of lymphocytes (i.e. CD4⁺/CD8⁺), 2) selected fields (i.e. at random or focusing on hot spots), 3) location in low-power field (i.e. the invasive margin [TILs^IM] or the center of the tumor [TILs^CT] or the surface of the tumor [TILs^ST]), and 4) location in high-power field (i.e. in tumor stroma [sTILs] or intra-tumor cells [iTILs] or total TILs [tTILs: sTILs+iTILs]). We then assessed the prognostic value of the density of TILs^IM evaluated as described above. We also evaluated the correlation between the density of TILs^IM and that of TILs^CT/TILs^ST.

Results

Only the densities of CD8⁺sTILs^IM and CD8⁺tTILs^IM evaluated in randomly selected fields were significantly associated with the survival. Furthermore, the density of CD8⁺TILs^IM was significantly associated with that of CD8⁺TILs^CT and CD8⁺TILs^ST.

Conclusions

We concluded that best and easiest way to evaluate the density of TILs in the clinical setting may be to assess the density of CD8⁺tTILs^IM in randomly selected fields.

Relationship between tumour PTEN/Akt/COX-2 expression, inflammatory response and survival in patients with colorectal cancer

In patients with colorectal cancer (CRC), local and systemic inflammatory responses have been extensively reported to associate with cancer survival. However, the specific signalling pathways responsible for inflammatory responses are not clear. The PTEN/Akt pathway is a plausible candidate as it may play a role in mediating inflammation via COX-2, and has been associated with cancer progression. This study therefore examined the relationship between tumour PTEN/Akt/COX-2 expression, inflammatory responses and survival in CRC patients using a tissue microarray.

In 201 CRC patients, activation of tumour-specific PTEN/Akt significantly associated with poorer CSS (12.0yrs v 7.3yrs, P=0.032), poorer differentiation (P=0.032), venous invasion (P=0.008) and peritoneal involvement (P=0.004). Patients were stratified for peri-nuclear expression of COX-2 to examine associations with inflammatory responses. In patients with absent peri-nuclear COX-2 expression, activation of tumour-specific PTEN/Akt significantly associated with poorer CSS (11.9yrs v 5.4yrs, P=0.001), poorer differentiation (P=0.018), venous invasion (P=0.003) and peritoneal involvement (P=0.001). However, no associations were seen with either the local or systemic inflammatory responses.

In CRC patients, tumour-specific PTEN/Akt pathway activation was significantly associated with poorer CSS, particularly when peri-nuclear COX-2 expression was absent. However, activation of the PTEN/Akt pathway appears not to be responsible for the regulation of inflammatory responses.

The relationship between right-sided tumour location, tumour microenvironment, systemic inflammation, adjuvant therapy and survival in patients undergoing surgery for colon and rectal cancer

Background:

There has been an increasing interest in the role of tumour location in the treatment and prognosis of patients with colorectal cancer (CRC), specifically in the adjuvant setting. Together with genomic data, this has led to the proposal that right-sided and left-sided tumours should be considered as distinct biological and clinical entities. The aim of the present study was to examine the relationship between tumour location, tumour microenvironment, systemic inflammatory response (SIR), adjuvant chemotherapy and survival in patients undergoing potentially curative surgery for stage I–III colon and rectal cancer.

Methods:

Clinicopathological characteristics were extracted from a prospective database. MMR and BRAF status was determined using immunohistochemistry. The tumour microenvironment was assessed using routine H&E pathological sections. SIR was assessed using modified Glasgow Prognostic Score (mGPS), neutrophil:lymphocyte ratio (NLR), neutrophil:platelet score (NPS) and lymphocyte:monocyte ratio (LMR).

Results:

Overall, 972 patients were included. The majority were over 65 years (68%), male (55%), TNM stage II/III (82%). In all, 40% of patients had right-sided tumours and 31% had rectal cancers. Right-sided tumour location was associated with older age (P=0.001), deficient MMR (P=0.005), higher T stage (P<0.001), poor tumour differentiation (P<0.001), venous invasion (P=0.021), and high CD3⁺ within cancer cell nests (P=0.048). Right-sided location was consistently associated with a high SIR, mGPS (P<0.001) and NPS (P<0.001). There was no relationship between tumour location, adjuvant chemotherapy (P=0.632) or cancer-specific survival (CSS; P=0.377). In those 275 patients who received adjuvant chemotherapy, right-sided location was not associated with the MMR status (P=0.509) but was associated with higher T stage (P=0.001), venous invasion (P=0.036), CD3⁺ at the invasive margin (P=0.033) and CD3⁺ within cancer nests (P=0.012). There was no relationship between tumour location, SIR or CSS in the adjuvant group.

Conclusions:

Right-sided tumour location was associated with an elevated tumour lymphocytic infiltrate and an elevated SIR. There was no association between tumour location and survival in the non-adjuvant or adjuvant setting in patients undergoing potentially curative surgery for stage I–III colon and rectal cancer.

Progress and challenges of predictive biomarkers of anti PD-1/PD-L1 immunotherapy: A systematic review

Despite the marked success of applications of PD-1/PD-L1 checkpoint blockades in clinical, the efficacy and responsiveness of these agents varies greatly among different tumor types and across individual patients. Therefore, establishment of predictive biomarkers for checkpoint blockades is of the most importance to maximize the therapeutic benefits. In this review, we discuss the current progress and challenges of developing predictive biomarkers of immunotherapy responsiveness, aiming to provide some directions for future studies. PD-L1 expression is a logical biomarker for the prediction of response to anti-PD-(L)1 immunotherapies. However, the predictive values of PD-L1 expressions for immunotherapy are currently debating and challenging. Multiplex detecting methods and combined biomarkers may provide new strategies. For example, tumor mutation and neoantigens burden, some oncogene mutations, like EGFR, ALK, KRAS and STK11. In addition, with development of new probes and tracers, immuno-PET provide a new, non-invasive and quantitative strategy to monitor treatment response. As current evidence of those potential predictors, a consensus and standardization is needed to establish to widely applied in future studies. Multiplex detecting methods and combined biomarkers may provide new strategies.

Neoadjuvant radiochemotherapy decreases the total amount of tumor infiltrating lymphocytes, but increases the number of CD8+/Granzyme B+ (GrzB) cytotoxic T-cells in rectal cancer

Although neoadjuvant radiochemotherapy (nRCTx) is an established oncological treatment in patients with advanced rectal cancer, little is known about its effects on the tumor microenvironment. Quantity and composition of tumor infiltrating lymphocytes (TILs) are known to influence patients' prognosis but nRCTx-induced modifications are still unclear. We determined the composition of the immune cell infiltrate in rectal cancer after nRCTx and its influence on tumor regression, local recurrence rate and survival. We investigated density and composition of tumor infiltrating CD3⁺ and CD8⁺ T-cells and the quantity and ratio of CD8⁺/GrzB⁺ T-cells to CD8⁺ T-cells in 130 rectal cancers after nRCTx compared to a cohort of 30 primarily resected rectal cancers. Furthermore, we analyzed 22 pretherapeutic rectal cancer biopsies, later treated with nRCTx and surgery to evaluate nRCTx-induced modifications of the tumor microenvironment. The total numbers of CD3⁺ and CD8⁺ T-cells in tumor stroma (p < 0.001) and tumor epithelium (p < 0.001 CD3; 0.002 CD8) were significantly lower in rectal cancers after nRCTx compared to primarily resected cases, while the ratio of CD8⁺/GrzB⁺ T-cells to CD8⁺ T-cells was significantly increased in the nRCTx cohort (p < 0.001). In multivariate analyses, CD8⁺/GrzB⁺ T-cells in the tumor stroma were significantly associated with high regression grade and a lower likelihood of local recurrence (p = 0.029). nRCTx modifies the tumor microenvironment of rectal cancer leading to a total decrease of TILs, but a relative increase in CD8⁺/GrzB⁺ T-cells in the tumor stroma. CD8⁺/GrzB⁺ T-cells may contribute to local tumor control and the better outcome.

Assessing Tumor-Infiltrating Lymphocytes in Solid Tumors: A Practical Review for Pathologists and Proposal for a Standardized Method from the International Immuno-Oncology Biomarkers Working Group: Part 2: TILs in Melanoma, Gastrointestinal Tract Carcinomas, Non-Small Cell Lung Carcinoma and Mesothelioma, Endometrial and Ovarian Carcinomas, Squamous Cell Carcinoma of the Head and Neck, Genitourinary Carcinomas, and Primary Brain Tumors

Assessment of the immune response to tumors is growing in importance as the prognostic implications of this response are increasingly recognized, and as immunotherapies are evaluated and implemented in different tumor types. However, many different approaches can be used to assess and describe the immune response, which limits efforts at implementation as a routine clinical biomarker. In part 1 of this review, we have proposed a standardized methodology to assess tumor-infiltrating lymphocytes (TILs) in solid tumors, based on the International Immuno-Oncology Biomarkers Working Group guidelines for invasive breast carcinoma. In part 2 of this review, we discuss the available evidence for the prognostic and predictive value of TILs in common solid tumors, including carcinomas of the lung, gastrointestinal tract, genitourinary system, gynecologic system, and head and neck, as well as primary brain tumors, mesothelioma and melanoma. The particularities and different emphases in TIL assessment in different tumor types are discussed. The standardized methodology we propose can be adapted to different tumor types and may be used as a standard against which other approaches can be compared. Standardization of TIL assessment will help clinicians, researchers and pathologists to conclusively evaluate the utility of this simple biomarker in the current era of immunotherapy.

Prognostic role of tumor infiltrating lymphocytes in EBV positive and EBV negative nasopharyngeal carcinoma

OBJECTIVES

Tumor infiltrating lymphocytes (TILs) correlate with both better and worse prognosis in solid tumors. As therapeutic modalities for nasopharyngeal carcinoma (NPC) are limited, immunotherapy could be a potential alternative. Up till now there is limited prognostic data on the role of TILs in NPC, so we assessed the prognostic role of TILs in Epstein-Barr-virus (EBV) positive and negative NPC.

METHODS

Tissue of 92 NPCs was assessed for CD3, CD4, CD8, PD1 and PDL1 expression in the tumor's micro-environment. Correlations between clinicopathological characteristics was assessed using the Pearson X² test, Fisher's exact test and ANOVA. Survival was analyzed with the Kaplan-Meier method and Cox regression. Differences in CD3, CD4, CD8, PD1, PDL1 counts/(co)expression between EBV positive and negative NPCs were evaluated using the Mann-Whitney U test. Two-tailed P values below 0.05 were considered statistically significant.

RESULTS

EBV positive NPC contains significantly more CD3, CD4 and CD8 TILs than EBV negative NPC. In the whole NPC group, increased CD8 count is associated with better overall survival (OS) (HR 0.219 (95%CI 0.075-0.640)), but also in cases with PDL1 co-expression (HR 0.073 (95%CI 0.010-0.556)). In EBV positive NPC co-expression of CD8 and PDL1 showed better disease free survival (HR 0.407 (95%CI 0.195-0.850)) and OS (HR 0.170 (95%CI 0.037-0.787)).

CONCLUSIONS

Although TILs are significantly different between EBV positive and negative NPCs, it is especially composition of the infiltrate which determines prognosis. Effects of PD1 and CD8 need more study, because these findings show much potential in using immunotherapeutic modalities in NPC treatment.

Tumour invasiveness, the local and systemic environment and the basis of staging systems in colorectal cancer

Background:

The present study aimed to examine the relationship between tumour invasiveness (T stage), the local and systemic environment and cancer-specific survival (CSS) of patients with primary operable colorectal cancer.

Methods:

The tumour microenvironment was examined using measures of the inflammatory infiltrate (Klintrup-Makinen (KM) grade and Immunoscore), tumour stroma percentage (TSP) and tumour budding. The systemic inflammatory environment was examined using modified Glasgow Prognostic Score (mGPS) and neutrophil:lymphocyte ratio (NLR). A 5-year CSS was examined.

Results:

A total of 331 patients were included. Increasing T stage was associated with colonic primary, N stage, poor differentiation, margin involvement and venous invasion (P<0.05). T stage was significantly associated with KM grade (P=0.001), Immunoscore (P=0.016), TSP (P=0.006), tumour budding (P<0.001), and elevated mGPS and NLR (both P<0.05). In patients with T3 cancer, N stage stratified survival from 88 to 64%, whereas Immunoscore and budding stratified survival from 100 to 70% and from 91 to 56%, respectively. The Glasgow Microenvironment Score, a score based on KM grade and TSP, stratified survival from 93 to 58%.

Conclusions:

Although associated with increasing T stage, local and systemic tumour environment characteristics, and in particular Immunoscore, budding, TSP and mGPS, are stage-independent determinants of survival and may be utilised in the staging of patients with primary operable colorectal cancer.