Low infiltration of peritumoral regulatory T cells predicts worse outcome following resection of colorectal liver metastases

The role of CD8+ T-cells in colorectal cancer immunotherapy

Immunotherapy has been an advanced and effective approach to treating various types of solid tumors in recent years, and the most successful strategy is immune checkpoint inhibitors (ICIs), which have shown beneficial effects in patients with colorectal cancer (CRC). Drug resistance to ICIs is usually associated with CD8+ T-cells targeting tumor antigens; thus, CD8+ T-cells play an important role in immunotherapy. Unfortunately, Under continuous antigen stimulation, tumor microenvironment(TME), hypoxia and other problems it leads to insufficient infiltration of CD8+ T-cells, low efficacy and mechanism exhaustion, which have become obstacles to immunotherapy. Thus, this article describes the relationship between CRC and the immune system, focuses on the process of CD8+ T-cells production, activation, transport, killing, and exhaustion, and expounds on related mechanisms leading to CD8+ T-cells exhaustion. Finally, this article summarizes the latest strategies and methods in recent years, focusing on improving the infiltration, efficacy, and exhaustion of CD8+ T-cells, which may help to overcome the barriers to immunotherapy.

Tissue adaptation of CD4 T lymphocytes in homeostasis and cancer

The immune system is traditionally classified as a defense system that can discriminate between self and non-self or dangerous and non-dangerous situations, unleashing a tolerogenic reaction or immune response. These activities are mainly coordinated by the interaction between innate and adaptive cells that act together to eliminate harmful stimuli and keep tissue healthy. However, healthy tissue is not always the end point of an immune response. Much evidence has been accumulated over the years, showing that the immune system has complex, diversified, and integrated functions that converge to maintaining tissue homeostasis, even in the absence of aggression, interacting with the tissue cells and allowing the functional maintenance of that tissue. One of the main cells known for their function in helping the immune response through the production of cytokines is CD4+ T lymphocytes. The cytokines produced by the different subtypes act not only on immune cells but also on tissue cells. Considering that tissues have specific mediators in their architecture, it is plausible that the presence and frequency of CD4+ T lymphocytes of specific subtypes (Th1, Th2, Th17, and others) maintain tissue homeostasis. In situations where homeostasis is disrupted, such as infections, allergies, inflammatory processes, and cancer, local CD4+ T lymphocytes respond to this disruption and, as in the healthy tissue, towards the equilibrium of tissue dynamics. CD4+ T lymphocytes can be manipulated by tumor cells to promote tumor development and metastasis, making them a prognostic factor in various types of cancer. Therefore, understanding the function of tissue-specific CD4+ T lymphocytes is essential in developing new strategies for treating tissue-specific diseases, as occurs in cancer. In this context, this article reviews the evidence for this hypothesis regarding the phenotypes and functions of CD4+ T lymphocytes and compares their contribution to maintaining tissue homeostasis in different organs in a steady state and during tumor progression.

A prognostic nomogram for predicting recurrence-free survival of stage I-III colon cancer based on immune-infiltrating Treg-related genes

PURPOSE

A high postoperative recurrence rate seriously impedes colon cancer (CC) patients from achieving long-term survival. Here, we aimed to develop a Treg-related classifier that can help predict recurrence-free survival (RFS) and therapy benefits of stage I-III colon cancer.

METHODS

A Treg-related prognostic classifier was built through a variety of bioinformatic methods, whose performance was assessed by KM survival curves, time-dependent receiver operating characteristic (tROC), and Harrell's concordance index (C-index). A prognostic nomogram was generated using this classifier and other traditional clinical parameters. Moreover, the predictive values of this classifier for immunotherapy and chemotherapy therapeutic efficacy were tested using multiple immunotherapy sets and R package "pRRophetic".

RESULTS

A nine Treg-related classifier categorized CC patients into high- and low-risk groups with distinct RFS in the multiple datasets (all p < 0.05). The AUC values of 5-year RFS were 0.712, 0.588, 0.669, and 0.662 in the training, 1st, 2nd, and entire validation sets, respectively. Furthermore, this classifier was identified as an independent predictor of RFS. Finally, a nomogram combining this classifier and three clinical variables was generated, the analysis of tROC, C-index, calibration curves, and the comparative analysis with other signatures confirmed its predictive performance. Moreover, KM analysis exhibited an obvious discrepancy in the subgroups, especially in different TNM stages and with adjuvant chemotherapy. We detected the difference between the two risk subsets of immune cell sub-population and the response to immunotherapy and chemotherapy.

CONCLUSIONS

We built a robust Treg-related classifier and generated a prognostic nomogram that predicts recurrence-free survival in stage I-III colon cancer that can identify high-risk patients for more personalized and effective therapy.

Distinct role of tumor-infiltrating lymphocytes between synchronous and metachronous colorectal cancer

PURPOSE

Tumor-infiltrating lymphocytes (TILs) may influence the prognosis of colorectal liver metastasis (CRLM). We assessed the prognostic value of evaluating TILs in the primary and metastatic sites of synchronous CRLM as well as metachronous CRLM.

METHODS

We examined 90 patients who underwent curative primary and liver metastasis resection for colorectal cancer. CD8+ TILs (cytotoxic T cells) or CD45RO+ TILs (memory T cells) in both primary and metastatic sites were simultaneously evaluated by immunohistochemistry.

RESULTS

Fifty-one patients had synchronous CRLM, and 39 patients had metachronous CRLM. In synchronous cases, the overall survival (OS) was significantly worse in patients with low CD8+ or CD45RO+ TILs in a metastatic site than in those with high CD8+ or CD45RO+ TILs (P = 0.017 and P = 0.005, respectively). Multivariate analysis showed that age ≥ 65 years (P = 0.043), maximum tumor size ≥ 30 mm (P = 0.003), primary N2-3 (P = 0.019), and low CD8+ TILs in metastatic site (P = 0.046) were independent poor prognostic factors. In contrast, in metachronous cases, OS was significantly worse in patients with low CD45RO+ TILs in a primary site than in those with high CD45RO+ TILs (P = 0.021). CD45RO+ TILs in a primary site (P = 0.044) were determined to be independent prognostic factor on multivariate analysis.

CONCLUSIONS

The immune microenvironment between synchronous and metachronous CRLM might be different, and these differences may affect its prognosis.

Histological tumor response to neoadjuvant chemotherapy correlates to Immunoscore in colorectal cancer liver metastases patients

BACKGROUND

This study investigated the correlation between tumor regression grade (TRG) score and Immunoscore, and prognostic values of TRG score and a risk score in colorectal cancer liver metastases (CRLMs) patients after neoadjuvant chemotherapy.

METHODS

Patients undergoing neoadjuvant chemotherapy from 2014 to 2019 were selected. TRG score and Immunoscore were evaluated in 200 CRLMs. A risk score combining TRG score, Immunoscore, and clinical risk score (CRS) was defined and divided patients into the low-, medium-, and high-risk groups. Differences in relapse-free survival (RFS) and overall survival (OS) between groups were determined.

RESULTS

The densities of CD3⁺ and CD8⁺ immune cells were higher in TRG1-3 group than in TRG4-5 group, and the ratio of high Immunoscores was higher in TRG1-3 group than in TRG4-5 group (60.0% vs. 15.8%, p < 0.001). Patients in TRG1-3 group had significantly longer RFS and OS than those in TRG4-5 group. The low-risk group shows a significantly higher 2-year RFS and 5-year OS rate than the medium- and high-risk group (RFS: 59.9%, 36.2%, and 6.4%, p < 0.001; OS: 82.0%, 41.0%, and 16.9%, p < 0.001).

CONCLUSION

TRG score may be proposed to evaluate the prognosis of neoadjuvant chemotherapy and may be used for predicting the postoperative survival of CRLMs.

Abundant intratumoral fibrosis prevents lymphocyte infiltration into peritoneal metastases of colorectal cancer

BACKGROUND

Tumor-infiltrating lymphocytes (TILs) have been reported to reflect the anti-tumor immune status. However, recent investigations have demonstrated that intratumoral fibrosis is important as a factor affecting the infiltration of TILs. This study investigated the organ specificities of TIL infiltration and intratumoral fibrosis in primary colorectal cancer and distant metastases, as well as the relationship between the distribution of TILs and intratumoral fibrosis.

METHODS

Patients who underwent resection of primary tumors or distant metastases for colorectal cancer with distant metastases were enrolled. We evaluated the TIL infiltration by immunohistochemical staining with CD3&CD8 and intratumoral fibrosis by immunohistochemical staining with α-SMA positive cancer-associated fibroblasts and Masson's trichrome staining against collagen fibers. The "ImageJ" was used to evaluate fibrosis, and the density of TILs in the dense and sparse areas of fibrosis was calculated. The Immunoscore (IS) was obtained based on the density of CD3+/CD8+TILs in the tumor center and invasive margin of the primary tumor.

RESULTS

The degree of CD3+/CD8+TIL infiltration in peritoneal metastases was significantly lower than that in liver and lung metastases. The area ratio of α-SMA positive cancer-associated fibroblasts and collagen fibers in peritoneal metastases was significantly higher than that of liver and lung metastases. Furthermore, the density of TILs in the high-fibrosis area was significantly lower than that in the low-fibrosis area. In the high-IS group of primary tumors, the degree of TIL infiltration in distant metastases was significantly higher than that in the low-IS group.

CONCLUSION

The infiltration of T lymphocytes into tumors is prevented in peritoneal metastases of colorectal cancer due to the high intratumoral fibrosis, which may lead to treatment resistance and a poor prognosis.

Relationship between stromal regulatory T cells and the response to neoadjuvant chemotherapy for locally advanced rectal cancer

BACKGROUND

In addition to the direct power of anticancer drugs, the effectiveness of anticancer therapy depends on the host immune function. The present study investigated whether or not the reduction rate and histological response of preoperative chemotherapy were related to the immune microenvironment surrounding a primary tumor of the rectum.

METHODS

Sixty-five patients received preoperative chemotherapy followed by resection from 2012 to 2014; all of these patients were retrospectively analyzed. CD3, CD8, and FoxP3 were immunohistochemically examined as markers for T lymphocytes, cytotoxic T lymphocytes, and regulatory T lymphocytes (Treg), respectively. The correlation between the tumor-infiltrating lymphocyte composition and the tumor reduction rate and histological response to neoadjuvant chemotherapy was investigated.

RESULTS

The average tumor reduction rate was 41.5% ± 18.8%. According to RECIST, 47 patients (72.3%) achieved a partial response (PR), and 1 patient (1.5%) achieved a complete response (CR). Eight patients (12.3%) showed a grade 2 histological response, and 2 (3.1%) showed a grade 3 response. A multivariate analysis demonstrated that a low Treg infiltration in stromal cell areas was significantly associated with the achievement of a PR or CR [odds ratio (OR) 7.69; 95% confidence interval (CI) 1.96-33.33; p < 0.01] and a histological grade 2 or 3 response (OR 11.11; 95% CI 1.37-98.04; p = 0.02).

CONCLUSION

A low Treg infiltration in the stromal cell areas may be a marker of a good response to neoadjuvant chemotherapy in patients with locally advanced rectal cancer.

Heterogeneity of Colorectal Cancer Progression: Molecular Gas and Brakes

The review begins with molecular genetics, which hit the field unveiling the involvement of oncogenes and tumor suppressor genes in the pathogenesis of colorectal cancer (CRC) and uncovering genetic predispositions. Then the notion of molecular phenotypes with different clinical behaviors was introduced and translated in the clinical arena, paving the way to next-generation sequencing that captured previously unrecognized heterogeneity. Among other molecular regulators of CRC progression, the extent of host immune response within the tumor micro-environment has a critical position. Translational sciences deeply investigated the field, accelerating the pace toward clinical transition, due to its strong association with outcomes. While the perturbation of gut homeostasis occurring in inflammatory bowel diseases can fuel carcinogenesis, micronutrients like vitamin D and calcium can act as brakes, and we discuss underlying molecular mechanisms. Among the components of gut microbiota, Fusobacterium nucleatum is over-represented in CRC, and may worsen patient outcome. However, any translational knowledge tracing the multifaceted evolution of CRC should be interpreted according to the prognostic and predictive frame of the TNM-staging system in a perspective of clinical actionability. Eventually, we examine challenges and promises of pharmacological interventions aimed to restrain disease progression at different disease stages.

An Efficient Prognostic Immune Scoring System For Colorectal Cancer Patients With Peritoneal Metastasis

Immunoscore can accurately predict the prognosis of patients with stage I–III colorectal cancer. However, whether it can be used to predict the prognosis of colorectal cancer peritoneal metastases (CRCPM) remains to be validated. We analyzed peritoneal and ovarian metastases in 68 patients with CRCPM. The immunoscore (IS) was based on the infiltration level of CD3+ and CD8+ T cells, whereas the TBM score was derived from the infiltration level of CD3+, CD8+, CD20+ and CD163+ cells to tumor microenvironment (TME). The predictive value of IS and TBM scores for relapse-free survival (RFS) and overall survival (OS) of patients with CRCPM was analyzed using Kaplan Meier curve and Cox multivariate models. Significant difference in the infiltration levels of different immune cell subtypes in primary lesions, peritoneal metastasis and ovarian metastasis were compared using t-test.CRCPM patients with high IS (>1), high TBM1 score (≥2) or high TBM2 score (≥2) had a significantly longer OS (IS: median OS, not reached vs 23 months, p = .0078; TBM1: not reached vs 21.5 months, p = .013; TBM2: 39.3 months vs 15.2 months, p = .001). On the other hand, patients with high IS had a trend of improved RFS (13.4 months vs 11.0 months, p = .067). However, TBM1 and TBM2 score has no predictive utility for RFS. Multivariate analysis revealed that IS, TBM1 and TBM2 can accurately predict OS, but not RFS. Finally, the infiltration level of CD3+ T cells, CD8+ T cells, CD20+ B cells, and CD68+ macrophage was significantly higher in peritoneal metastatic tissue and ovarian metastatic tissue, relative to primary tumor tissues.The IS and TBM score of peritoneal metastases could effectively predict OS of patients with CRCPM. Peritoneal metastasis of colorectal cancer decreased the infiltration level of T and B cells.

Histopathological and Immune Prognostic Factors in Colo-Rectal Liver Metastases

Simple Summary

Clinical management of colo-rectal liver metastasis would benefit from a refined stratification of patients in prognostic groups, in order to identify the best therapeutic option. Efforts are ongoing in the definition of parameters associated with clinical behaviors, which could help classifying patients in clinically relevant groups. Here we aimed at discussing the recent advances in this field, and we introduced current and new promising candidates, such as morphological tumor features and immune components, which have been showing significant association with survival. Some of these parameters are slowly reaching the clinic and further efforts are ongoing in the attempt to combine them in multiparametric scores.

Abstract

Prognostic studies are increasingly providing new tools to stratify colo-rectal liver metastasis patients into clinical subgroups, with remarkable implications in terms of clinical management and therapeutic choice. Here, the strengths and hurdles of current prognostic tools in colo-rectal liver metastasis are discussed. Alongside more classic histopathological parameters, which capture features related to the tumor component, such as tumor invasion, tumor growth pattern and regression score, we will discuss immune mediators, which are starting to be considered important features. Their objective quantification has shown significant results in prognostication studies, with most of the work focused on adaptive immune cells, namely T cells. As for macrophages, they are only starting to be appreciated and we will present recent advances in evaluation of macrophage morphological features. Deeper knowledge acquired by multiparametric analyses is rapidly uncovering the variety of immune players that should be assessed. The future projection is to implement deep-learning histopathological tools and to integrate histopathological and immune metrics in multiparametric scores, with the ultimate objective to achieve a deeper resolution of the tumor features and their relevance for colo-rectal liver metastasis.

Advances in Modeling the Immune Microenvironment of Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer and second leading cause of cancer-related death in the US. CRC frequently metastasizes to the liver and these patients have a particularly poor prognosis. The infiltration of immune cells into CRC tumors and liver metastases accurately predicts disease progression and patient survival. Despite the evident influence of immune cells in the CRC tumor microenvironment (TME), efforts to identify immunotherapies for CRC patients have been limited. Here, we argue that preclinical model systems that recapitulate key features of the tumor microenvironment-including tumor, stromal, and immune cells; the extracellular matrix; and the vasculature-are crucial for studies of immunity in the CRC TME and the utility of immunotherapies for CRC patients. We briefly review the discoveries, advantages, and disadvantages of current in vitro and in vivo model systems, including 2D cell culture models, 3D culture systems, murine models, and organ-on-a-chip technologies.

Immune Cell Infiltration of the Primary Tumor Microenvironment Predicted the Treatment Outcome of Chemotherapy With or Without Bevacizumab in Metastatic Colorectal Cancer Patients

BACKGROUND

With the interest in cancer immunotherapy, it may be possible to combine immunotherapy with bevacizumab and chemotherapy. We evaluated whether tumor-infiltrating immune cells are associated with the efficacy of chemotherapy with or without bevacizumab for the treatment of metastatic colorectal cancer (mCRC).

METHODS

This study enrolled mCRC patients on standard treatment with available detailed data and tumor tissue at Sun Yat-sen University Cancer Center between July 1, 2005, and October 1, 2017. CD3+ and CD8+ T cell densities examined by immunohistochemistry in both the tumor core (CT) and invasive margin (IM) were summed as the Immunoscore, and the CD8+/CD3+ T cell ratio was calculated. The predictive and prognostic efficacies of tumor-infiltrating immune cells for progression-free survival (PFS) and overall survival (OS) were analyzed with Kaplan-Meier and Cox analyses.

RESULTS

The CD8+/CD3+ T cell ratio in the microenvironment was an independent prognostic factor for OS (28.12 mo vs. 16.56 mo, P = 0.017) among the 108 studied patients. In the chemotherapy only group, patients with a high Immunoscore had a high overall response rate (ORR, 40.0% vs. 60.0%, P = 0.022), those with a low CD8+/CD3+ T cell ratio in the microenvironment had a significantly longer PFS (8.64 mo vs. 6.01 mo, P = 0.017), and those with a high CD3+ T cell density in the CT had a longer OS (16.56 mo vs. 25.66 mo, P = 0.029). In the chemotherapy combined with bevacizumab group, patients with a higher CD8+ T cell density in the IM had a longer PFS (7.62 mo vs. 11.66 mo, P = 0.034) and OS (14.55 mo vs. 23.72 mo, P = 0.033).

CONCLUSION

Immune cells in primary tumors play an important role in predicting mCRC treatment efficacy. CD8 predicts the effect of bevacizumab plus chemotherapy, while CD3 and CD8/CD3 predict chemotherapy efficacy.

Immune gene therapy of cancer

Cancer gene therapy emerged as a promising treatment modality 3 decades ago. However, the failure of the first gene therapy trials in cancer treatment has decreased its popularity. Likewise, immunotherapy has followed a similar course. While it was a popular and promising treatment with IL-2 and interferon and cancer vaccines in the 1980s, it later lost its popularity. Immunotherapy became one of the main options for cancer treatment with the successful use of immune checkpoint inhibitors in clinics approximately 10 years ago. The success of immunotherapy has increased even more with the introduction of cancer gene therapy methods in this area. With the identification of the oncolytic herpes simplex virus and Chimeric antigen receptor (CAR) T-cells, immune gene therapy has become an essential modality in cancer treatments such as surgery, radiotherapy, chemotherapy, and targeted therapies.

Immune scores in colorectal cancer: Where are we?

There is growing evidence that the immune system may prevent the occurrence, growth and metastatic diffusion of colorectal cancer (CRC). The role played by the adaptive immune response at the tumour site is critical in the balance between tumour invasion and defence against cancer. Recent data have shown that the evaluation of this immune response may help to define the prognosis and possibly the treatment of localised CRC as well as metastatic CRC. Tumour infiltrates with T cells (CD3+), cytotoxic T cells (CD8+) and memory T cells (CD45RO+) are the immune parameters most consistently and strongly associated with good clinical outcome in CRC. Several scoring systems have been developed, including the Immunoscore®, based on the immunohistochemical determination with a digital image analysis system of the density of CD3+ and CD8+ lymphocytes in the centre and the invasive margin of the tumour. This review will focus on the different immunoscoring systems developed in CRC, their performance, their limitations and their potential for improving patients' care in the future.

Colorectal Cancer Immune Infiltrates: Significance in Patient Prognosis and Immunotherapeutic Efficacy

Colorectal cancer occurrence and progression involve multiple aspects of host immune deficiencies. In these events, immune cells vary their phenotypes and functions over time, thus enabling the immune microenvironment to be “tumor-inhibiting” as well as “tumor-promoting” as a whole. Because of the association of tumoricidal T cell infiltration with favorable survival in cancer patients, the Immunoscore system was established. Critically, the tumoral Immunoscore serves as an indicator of CRC patient prognosis independent of patient TNM stage and suggests that patients with high Immunoscores in their tumors have prolonged survival in general. Accordingly, stratifications according to tumoral Immunoscores provide new insights into CRC in terms of comparing disease severity, forecasting disease progression, and making treatment decisions. An important application of this system will be to shed light on candidate selection in immunotherapy for CRC, because the T cells responsible for determining the Immunoscore serve as responders to immune checkpoint inhibitors. However, the Immunoscore system merely provides a standard procedure for identifying the tumoral infiltration of cytotoxic and memory T cells, while information concerning the survival and function of these cells is still absent. Moreover, other infiltrates, such as dendritic cells, macrophages, and B cells, can still influence CRC prognosis, implying that those might also influence the therapeutic efficacy of immune checkpoint inhibitors. On these bases, this review is designed to introduce the Immunoscore system by presenting its clinical significance and application in CRC.

Prognostic value of long non-coding RNA ATB in digestive system cancers: A meta-analysis

BACKGROUND

The present meta-analysis has evaluated the association between lncRNA ATB, prognosis and clinicopathological parameters in patients with digestive cancers.

METHODS

Eligible studies were gathered from Web of Science, PubMed, Embase, Cochrane Library, WanFang databases and China National Knowledge Infrastructure (up to October 15, 2019). Hazard ratios (HRs) and 95 % confidence intervals (CIs) were calculated to estimate the prognosis and clinicopathological parameters of lncRNA ATB in patients with digestive cancers.

RESULT

We divided this study into two groups, pancreatic cancer (PC, downregulation) and non-pancreatic cancer (non-PC, upregulation). In the non-PC group, high expression levels of lncRNA ATB were significantly related to poor OS (pooled HR = 2.19, 95 % CI 1.68-2.85, P＜0.00001). In contrast, increased levels of lncRNA ATB in pancreatic cancer tissue were favorable factors in OS (HR = 0.47, 95 % CI 0.32-0.69, P = 0.0001). The pooled data suggested that high expression levels of lncRNA ATB predicted a poor DFS in CRC and a poor RFS in HCC. Increased expression of lncRNA ATB was correlated with negative lymph node metastasis and TNM stage in the non-PC group. In contrast, lncRNA ATB were favorable factors for LNM and TNM stages in pancreatic cancer.

CONCLUSION

LncRNA ATBs, whether cancer promoters or suppressors, were potential biomarkers and therapeutic targets for digestive system cancers.

Histological tumor response assessment in colorectal liver metastases after neoadjuvant chemotherapy: impact of the variation in tumor regression grading and peritumoral lymphocytic infiltration

Background: The objective of this study was to evaluate the prognostic value of the variation in tumor regression grade (TRG) and peritumoral lymphocytic infiltration of colorectal liver metastases (CRLMs) after neoadjuvant chemotherapy (NACT). Methods: A retrospective review was performed in 98 patients with CRLMs who underwent NACT between 2010 and 2016. The TRG scores and counts of TILs at the tumor-normal interface were assessed in all 176 resected liver metastases to determine their association with prognosis. According to the variation in TRG scores, 40 patients with more than one liver metastasis were divided into a decreased TRG group and a stable TRG group. An additional independent cohort of 64 patients with 106 resected liver specimens was established to validate our main findings. Results: In the derivation cohort of 98 patients, 41.8% patients had a favourable pathological response to NACT (TRG 1-3), which were significantly associated with improved prognosis. Seventeen patients (42.5%) showed decreased TRG scores, and the remaining patients had stable scores. The multivariate analysis indicated that patients with decreased TRG scores had a better recurrence-free survival (RFS) compared with those with stable TRG scores (HR=0.42, P=0.034), and a similar trend was observed in the validation cohort (P=0.068). Dense TILs surrounding the metastases were present in 55.1% of the derivation cohort and associated with pathological response (P=0.008). Among patients with a pathological response to NACT, those with dense TILs had a superior RFS compared to those with weak TILs in both cohorts (derivation: HR=0.36, P=0.035; validation: HR=0.34, P=0.016). Conclusions: Variation in TRG scores and peritumoral lymphocytic infiltration may be proposed as secondary pathological parameters to evaluate the pathological response to NACT and predict the risk of recurrence after liver surgery.

Significance of Herpesvirus Entry Mediator Expression in Human Colorectal Liver Metastasis

BACKGROUND

Herpesvirus entry mediator (HVEM) has been suggested to play various roles in cancer biology. The authors report that HVEM expression in tumor cells is associated with a reduction in the number of tumor-infiltrating lymphocytes and a poor prognosis after surgical resection in various human gastrointestinal cancers. This study aimed to clarify the clinical significance of HVEM expression in human colorectal liver metastasis (CRLM).

METHODS

This study examined the cases of 104 patients with CRLM who underwent curative liver resection at Nara Medical University between 2000 and 2014. The median follow-up period was 50.2 months. Immunohistochemical staining was performed using antibodies against HVEM, CD4, CD8, and CD45RO.

RESULTS

High HVEM expression was observed in 49 patients (47.1%) with CRLM. Expression of HVEM was not associated with age, gender, administration of preoperative chemotherapy, tumor size, number of tumors, or histologic differentiation. The high-HVEM group exhibited significantly worse overall survival (OS) than the low-HVEM group (P = 0.002). Multivariate analysis showed that high HVEM expression in CRLM, age of 70 years or older, and having five or more tumors are independent poor prognostic factors for OS (hazard ratio [HR], 3.35; 95% confidence interval [CI], 1.41-7.93; P = 0.006). The number of tumor-infiltrating CD8+ and CD45RO+ T cells was significantly lower in the high-HVEM group than in the low-HVEM group. High HVEM expression in primary colorectal cancer was significantly associated with synchronous CRLM, but not with metachronous CRLM.

CONCLUSIONS

Tumor HVEM expression might play a critical role in CRLM.

The Interplay of Autophagy and Tumor Microenvironment in Colorectal Cancer-Ways of Enhancing Immunotherapy Action

Autophagy as a primary homeostatic and catabolic process is responsible for the degradation and recycling of proteins and cellular components. The mechanism of autophagy has a crucial role in several cellular functions and its dysregulation is associated with tumorigenesis, tumor-stroma interactions, and resistance to cancer therapy. A growing body of evidence suggests that autophagy is also a key regulator of the tumor microenvironment and cellular immune response in different types of cancer, including colorectal cancer (CRC). Furthermore, autophagy is responsible for initiating the immune response especially when it precedes cell death. However, the role of autophagy in CRC and the tumor microenvironment remains controversial. In this review, we identify the role of autophagy in tumor microenvironment regulation and the specific mechanism by which autophagy is implicated in immune responses during CRC tumorigenesis and the context of anticancer therapy.

Harnessing the innate immune system and local immunological microenvironment to treat colorectal cancer

Significant progress in the development of new immunotherapies has led to successful clinical trials for malignant melanoma and non-small cell lung cancer; however, for the majority of solid tumours of the gastrointestinal tract, little or no progress has been seen. The efficacy of immunotherapies is limited by the complexities of a diverse set of immune cells, and interactions between the tumour cells and all other cells in the local microenvironment of solid tumours. A large fraction of immune cells present in and around solid tumours derive from the innate arm of the immune system and using these cells against tumours offers an alternative immunotherapeutic option, especially as current strategies largely harness the adaptive arm of the immune system. This option is currently being investigated and attempts at using the innate immune system for gastrointestinal cancers are showing initial results. Several important factors, including cytokines, chemotherapeutics and the microbiome, influence the plasticity and functionality of innate (myeloid) cells in the microenvironment, and this complexity of regulation has limited translation into successful trials so far. In this review, current concepts of the immunobiology of the innate arm in the tumour microenvironment are presented in the context of clinical translation.

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.

Systematic Review of the Prognostic Role of the Immune System After Surgery of Colorectal Liver Metastases

Background: The current prognostication of patient survival after surgery for colorectal liver metastases is based on clinical characteristics, but low accuracy makes it difficult to guide treatment for the individual patient. Rapidly evolving technologies have led to the expectation that biomarkers will be able to outperform the current clinical scoring systems and provide more effective personalised treatment. Two main topics prevail in cancer treatment, namely the role of the immune system and the prediction and prognostication by application of high-throughput methodology. The aim of this review is to examine the evidence for prognostic immunological and molecular markers studied in tumour tissue obtained at surgical resection for colorectal liver metastases.

Methods: First we analysed immunophenotypical protein markers, that are mainly studied by immunohistochemistry. Second, we review molecular markers by analysing high-throughput studies on tumour mRNA and microRNA expression.

Results: CD3, CD4, and CD8 are the most frequently studied protein markers. High intra-tumoural CD3+ T cell infiltration and low CXCR4 expression have the best association with favourable patient survival. Studies that analysed microRNA or mRNA expression data showed very little overlap in prognostic genes.

Conclusions: Patient prognostication after surgery for colorectal liver metastases by analysing the immune system remains difficult. Current data are based on diverse and heterogeneous patient populations which prohibits drawing firm conclusions.

Emerging role of long non-coding RNA MALAT1 in predicting clinical outcomes of patients with digestive system malignancies: A meta-analysis

Digestive system malignancies are the most common cancer types worldwide and exhibit an extremely low overall 5-year survival rate. Therefore, clinically applicable biomarkers for predicting clinical outcome are urgently required. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is abnormally expressed in several cancer types. However, to the best of our knowledge, the association between MALAT1 expression and the prognosis of digestive system malignancies remains unknown. Therefore, the current study performed a meta-analysis to comprehensively summarize the association between MALAT1 expression and digestive system malignancies. A total of 1,157 Asian patients from 12 eligible studies [eight studies that investigated overall survival (OS), two studies that investigated disease-free survival and two studies that investigated both indicators] were analyzed. The present results identified a significant association between MALAT1 abundance and poor OS in patients with digestive system malignancies, with a pooled hazard ratio (HR) of 1.62 [95% confidence interval (CI), 1.35–1.88; P<0.001]. The tumor type, region, sample size and analysis type did not alter the predictive value of MALAT1 as an independent factor for survival. Furthermore, MALAT1 overexpression was an unfavorable prognostic factor for the overall survival of patients with esophageal carcinoma, pancreatic cancer, hepatocellular carcinoma and gastric cancer, with HRs of 1.89 (95% CI, 1.29–2.49), 1.76 (95% CI, 0.89–2.63), 1.46 (95% CI, 0.76–2.17) and 1.41 (95% CI, 1.04–1.78), respectively. In particular, increased MALAT1 expression levels were significantly associated with decreased OS in patients with colorectal cancer (HR, 3.04; 95% CI, 1.77–4.31). In conclusion, lncRNA MALAT1 may be a potential prognostic factor for digestive system malignancies in Asian populations.

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.

The Immunoscore system predicts prognosis after liver metastasectomy in colorectal cancer liver metastases

BACKGROUND

The Immunoscore was initially established to evaluate the prognosis of stage I/II/III colorectal cancer patients. However, the feasibility of the Immunoscore for the prognosis of colorectal cancer liver metastases (CRCLM) has not been reported.

METHODS

Liver metastases in 249 CRCLM patients were retrospectively analyzed. The Immunoscore was assessed according to the counts and densities of CD3+ and CD8+ T cells in the central- and peritumoral areas by immunohistochemistry. The prognostic role of the Immunoscore for relapse-free survival (RFS) and overall survival (OS) was analyzed with Kaplan-Meier curves and Cox multivariate models, and confirmed via an internal validation. Receiver operating characteristic (ROC) curves were plotted to compare the prognostic values of the Immunoscore and the clinical risk score (CRS) system.

RESULTS

CRCLM patients with high Immunoscores (> 2) had significantly longer RFS [median RFS (95% confidence interval; 95% CI) 21.4 (7.8-35.1) vs. 8.7 (6.8-10.5) months, P < 0.001] and OS [median OS (95% CI): not reached vs. 28.7 (23.2-34.2) months, P < 0.001] than those with low Immunoscores (≤ 2). After stratification by CRS, the Immunoscore retained a statistically significant prognostic value for OS. The areas under the ROC curves (AUROCs) of the Immunoscore and the CRS system for RFS were 0.711 [95% CI 0.642-0.781] and 0.675[95% CI 0.601-0.749] (P = 0.492), whereas the AUROC of the Immunoscore system for OS was larger than that of the CRS system [0.759 (95% CI 0.699-0.818) vs. 0.660 (95% CI 0.592-0.727); P = 0.029].

CONCLUSIONS

The Immunoscore of liver metastases can be applied to predict the prognosis of CRCLM patients following liver resection.

The synergistic antitumor effect of arsenic trioxide combined with cytotoxic T cells in pulmonary metastasis model of colon cancer

Adoptive T cell therapy, including cytotoxic T lymphocytes (CTLs), represents a promising non-toxic anticancer strategy. The effects of this therapy can be impaired by tumor-infiltrated regulatory T cells (Tregs). Autologous murine CTLs acquired using cryopreservation exhibited a cytotoxic effect equivalent to that of conventional CTLs. The killing activity of CTLs was enhanced significantly using arsenic trioxide (ATO), accompanied by reduction in Tregs in vitro. Results using a pulmonary metastasis model of colon cancer indicated that compared with the control group, ATO group, and CTLs group, metastatic node number decreased significantly (p<0.001, p<0.001, p<0.001, respectively) and survival time was prolonged (p<0.001, p=0.669, p=0.158, respectively) in the ATO plus CTLs group. The number of infiltrated Foxp3+ Tregs decreased in the tumor center, but increased in the peri-tumor tissue. Our results indicate that this approach represents a practical protocol for acquiring autologous CTLs and a feasible strategy that uses a synergistic combination of ATO plus CTLs to treat pulmonary metastases of colon cancer.

Biomarkers for immune therapy in colorectal cancer: mismatch-repair deficiency and others

Colorectal cancer (CRC) is a heterogeneous disease for which the treatment backbone has primarily been cytotoxic chemotherapy. With better understanding of the involved molecular mechanisms, it is now known that there are a number of epigenetic and genetic events, which are involved in CRC pathogenesis. Specific biomarkers have been identified which can be used to determine the clinical outcome of patients beyond tumor staging and predict for treatment efficacy. Molecular testing is now routinely performed to select for patients that will benefit the most from targeted agents and immunotherapy. In addition to KRAS, NRAS, and BRAF mutation (MT), analysis of DNA mismatch repair (MMR) status, tumor infiltrating lymphocytes, and checkpoint protein expression may be helpful to determine whether patients are eligible for certain therapies. The focus of this article is to discuss present and upcoming biomarkers for immunotherapy in CRC.

Negative prognostic impact of low absolute CD4+ T cell counts in peripheral blood in mantle cell lymphoma

Tumor microenvironment and host immunity are closely related to outcome in patients with mantle cell lymphoma (MCL). However, few researchers have focused on the prognostic value of peripheral blood lymphocyte subsets counts. The purpose of this study was to investigate the prognostic value of lymphocyte subsets and absolute monocyte counts. Sixty-eight patients were analyzed retrospectively. Absolute CD4⁺ T cell counts (ACD4C), CD8⁺ T cell counts, nature killer cell counts, and CD4/CD8 ratios were assessed by peripheral blood flow cytometry and correlated with clinical parameters and long-term outcomes. The median follow-up for all patients was 21 months and the median survival time was 44 months. The overall survival (OS) rate at 1, 3, and 5 years was 80%, 51%, and 41%, respectively. In our cohort, high absolute monocyte count, and low ACD4C and CD4/CD8 ratio were associated with unfavorable OS (P = 0.029, P = 0.027, and P = 0.045, respectively) by univariate analysis. Multivariate analysis indicated that low ACD4C was a significant predictor of unfavorable OS (P = 0.004) independent of the simplified MCL International Prognostic Index (P = 0.048) in patients treated with or without rituximab (P = 0.011). Low CD4⁺ T cell counts proved to be a significant predictor of unfavorable OS in patients with MCL.

High infiltration of mast cells positive to tryptase predicts worse outcome following resection of colorectal liver metastases

BACKGROUND

Accumulation of tumor-infiltrating mast cells (MCs) predicts poor survival in several cancers after resection. However, its effect on the prognosis of patients with colorectal liver metastases (CRLM) is not known.

METHODS

Our retrospective study included 135 patients who underwent potentially curative resection for CRLM between 2001 and 2010. Expression of tryptase, MAC387, CD83, and CD31, which are markers for MCs, macrophages, mature dendritic cells, and vascular endothelial cells, respectively, was determined via immunohistochemistry of resected tumor specimens. The relationship between immune cell infiltration and long-term outcome was investigated.

RESULTS

The median follow-up time was 48.4 months for all patients and 57.5 months for survivors. Overall survival (OS) rates at 1, 3, and 5 years were 91.0, 62.4, and 37.4 %, respectively. Five-year disease-free survival (DFS) and OS rates were 21.6 and 38.1 %, respectively, in patients with high MC infiltration, and 42.6 and 55.6 %, respectively, in patients with low MC infiltration (p < 0.01 for both DFS and OS). Infiltration of other types of immune cells did not correlate with survival. Multivariate analyses indicated that hypoalbuminemia and high peritumoral MC infiltration were significant predictors of unfavorable OS.

CONCLUSION

High peritumoral MC infiltration predicts poor prognosis in patients who underwent hepatectomy for CRLM. The number of MCs in metastatic lesions is important for predicting the prognosis of CRLM patients and as an indication of therapy.

Colorectal cancer immunotherapy: Current clinical studies and prospect of clinical application

Colorectal cancer is a type of malignant gastrointestinal cancer with a high incidence rate. Current treatments, mostly surgery and chemotherapy, have not improved the 5-year survival rate of the patients significantly. About one-third of patients died of metastatic colorectal cancer eventually. Cancer immunotherapy has received more and more attention in recent years and become a hot research topic. Immunotherapy includes a variety of methods with an aim at improving the patient's own immune system and anti-tumor ability to control and kill tumor cells by the use of modern bio-technology. It has become the fourth form of cancer treatment after surgery, radiotherapy and chemotherapy. This paper expounds the types of tumor immunotherapy, their applications in colorectal cancer, and the advantages and disadvantages of different methods of immunotherapy. In particular, we discuss the relationship between inflammation microenvironment and immunotherapy, and the relationship between chemotherapy, radiation and immunotherapy in colorectal cancer. Immunotherapy may become an important component of individualized treatment for colorectal cancer in the near future.

Increased regulatory T cells in acute lymphoblastic leukemia patients

INTRODUCTION

Regulation in adaptive immune response balances a fine line that prevents instigation of self-damage or fall into unresponsiveness permitting abnormal cell growth. Mechanisms that keep this balance in check include regulatory T cells (Tregs). Tregs consist of a small but heterogeneous population which may be identified by the phenotype, CD3+CD4+CD25+CD127-. Role of Tregs in pathogenesis of cancers is thus far supported by evidence of increased Tregs in various cancers and may contribute to poorer prognosis. Tregs may also be important in acute leukemias.

OBJECTIVE

A review of the literature on Tregs in acute leukemias was conducted and Tregs were determined in B-cell acute lymphoblastic leukemias (ALLs).

RESULTS

Studies on Tregs in B-cell ALL are few and controversial. We observed a significantly increased percentage of Tregs (mean ± SD, 9.72 ± 3.79% vs. 7.05 ± 1.74%; P = 0.047) in the bone marrow/peripheral blood of ALL (n = 17) compared to peripheral blood of normal controls (n = 35). A positive trend between Tregs and age (R = 0.474, P = 0.055, n = 17) implicates this factor of poor prognosis in B-cell ALL.

DISCUSSION

Tregs in cancer are particularly significant in immunotherapy. The manipulation of the immune system to treat cancer has for a long time ignored regulatory mechanisms inducible or in place. In lymphoma studies tumor-specific mechanisms that are unlike conventional methods in the induction of Tregs have been hypothesized. In addition, tumor-infiltrating Tregs may present different profiles from peripheral blood pictures. Tregs will continue to be dissected to reveal their mysteries and their impact on clinical significance.