Latest evidence on immune checkpoint inhibitors in metastatic colorectal cancer: A 2022 update

Immune checkpoint blocking in cancer therapy using thermosensitive hydrogels: a review

Cancer is a challenging issue requiring new strategies for management and control. Immune checkpoint blockades (ICBs) increase the body's immune response against cancer by targeting specific receptors on T-lymphocytes. The FDA approved different ICBs for cancer treatment: anti-PD-1, PDL-1, and CTLA-4 inhibitors. Many immune checkpoint inhibitors (ICIs) are in clinical trials, highlighting their significance. Challenges like resistance and side effects have led researchers to explore new delivery strategies for ICIs. Thermosensitive hydrogels can change from sol to gel and vice versa due to their structure. They interact with aqueous medium through groups like ethyl, methyl, and propyl, forming hydrogen bonds. These bonds of hydrogen are temperature-sensitive and cause the change of the polymer from sol to gel at a temperature named critical solution temperature (CST). The using temperature-responsive polymers and ICBs showed a promising approach to sustained localized cancer therapy with lowering side effects on normal tissues. In this paper, we first define new investigations on immune therapy in cancer via ICBs. Then, we present recent studies of thermosensitive polymers in cancer therapy and the most used thermosensitive polymers in studies. Eventually, we discuss studies that used thermosensitive polymers in the delivery of ICBs and discuss new investigations in this field.

Comprehensive cohort study: computer tomography-guided high-dose rate brachytherapy as metastasis-directed therapy for liver metastases from colorectal cancer in repeat oligoprogression

PURPOSE

The standard treatment for oligometastatic colorectal cancer includes systemic therapy, with surgery and metastasis-directed therapy as options. The optimal strategy, especially for repeat oligoprogression (rOP), remains unclear. We report outcomes of liver computer tomography-guided high-dose rate brachytherapy (CT-BRT) in this setting.

METHODS

This retrospective cohort study included colorectal cancer patients with liver-only oligoprogression during systemic therapy, meeting criteria of up to 5 liver metastases, CT-BRT eligibility, and ECOG status ≤ 2. Patients were followed for local response, progression-free survival (PFS), overall survival (OS), and toxicity. Response, according to RECIST 1.1, was initiated 6 months post-CT-BRT.

RESULTS

A total of 262 metastases were treated in 127 patients, with 67.7% receiving third-line or later systemic therapies. One to four liver metastases were found in 29.1%, 42.5%, 21.2%, and 7.1% of patients, respectively, with a median volume of 128 cm3. A median of 3 applicators was used, with CT-BRT doses of 15 Gy, 20 Gy, and 25 Gy given to 29.9%, 41.7%, and 28.3% of patients. At 6 months complete response occurred in 3.1%, progressive disease in 23.6%, partial response in 19.7%, and stable disease in 53.5%. Median PFS was 9 months, median OS was 16 months, with 1-year and 2-year OS rates of 65% and 16%, respectively. Liver-only metastases and objective response were associated with longer PFS. The G3 toxicity was 4.0%; no events > G3 were reported.

CONCLUSIONS

This largest study documents favorable outcomes of liver CT-BRT for rOP, establishing this method as a viable option in this indication.

Perspectives on photodynamic therapy combined with immunotherapy in treatment of colorectal cancer: An overview based on experimental studies

Colorectal cancer (CRC) is one of the major cancers threatening human health, with high mortality, tumor drug resistance and metastasis. Due to its advantages of non-invasive, strongly targeted and limited side effects, Photodynamic therapy (PDT) has become a promising treatment for CRC. Remarkably, PDT has been shown to activate T cell-adaptive immune response and induce immunogenic cell death (ICD). Used in combination with other treatment techniques, PDT has considerable promise in the management of colorectal cancer. In particular, the combination of PDT and tumor immunotherapy, the systemic anti-tumor immune response was enhanced more significantly. This strategy is expected to achieve a synergistic anti-tumor effect by inducing tumor cell apoptosis, regulating tumor immune microenvironment and effectively activating anti-tumor immunity during treatment process. This review focuses on the research of PDT combined with immunotherapy to improve the treatment of CRC. In most studies, a positive effect was observed for combination therapy, experimentally indicating new therapeutic opportunities for CRC.

Chromosome Missegregation Triggers Tumor Cell Pyroptosis and Enhances Anti-Tumor Immunotherapy in Colorectal Cancer

Immune checkpoint inhibitor (ICI) therapy is a promising anti-tumor therapeutic strategy; however, its efficacy in solid tumors is limited. Chromosome missegregation is common in various solid tumors; however, its role in tumor progression remains poorly understood, and its correlation with ICI is yet to be explored. Here, it is found that increased chromosome missegregation promotes tumor immune microenvironment, and eventually immunotherapeutic efficacy, by triggering pyroptosis. yin yang 2 (YY2) is identified as a mitotic checkpoint regulator, which promotes chromosome missegregation by upregulating BUB1B transcription. Increased chromosome missegregation promoted the formation of micronuclei and release of double-stranded DNA (dsDNA) into the cytosol, triggering an AIM2-mediated cytosolic dsDNA response. The subsequent pyroptosis strengthened the tumor immune microenvironment, thereby enhancing immunoinfiltration and cytotoxicity of CD8+ T cells, while preventing their exhaustion. Finally, through in vitro and in vivo experiments, it is demonstrated that combining YY2 overexpression-induced chromosome missegregation/cytosolic dsDNA response and PD-1 inhibitor significantly enhanced the efficacy of ICI immunotherapy in microsatellite instable and microsatellite stable colorectal cancer cells. Together, these findings provide new insights on the role of chromosome missegregation in triggering cytosolic dsDNA response-mediated pyroptosis and modulating the tumor immune microenvironment, suggesting a novel strategy for improving ICI therapeutic efficacy in colorectal cancer.

Enhancing Colorectal Cancer Treatment Through VEGF/VEGFR Inhibitors and Immunotherapy

OPINION STATEMENT

Colorectal cancer, ranking as the third most prevalent malignancy globally, substantially benefits from both immunotherapy and VEGF/VEGFR inhibitors. Nevertheless, the use of monotherapy proves inadequate in effectively tackling the heterogeneity of tumors and the intricacies of their microenvironment, frequently leading to drug resistance and immune evasion. This situation underscores the pressing need for innovative strategies aimed at augmenting the effectiveness and durability of treatments. Clinical research demonstrates that the combination of VEGF/VEGFR inhibitors (primarily including VEGF/VEGFR-targeted drugs and multi-kinase inhibitors) with immune checkpoint inhibitors creates a synergistic effect in the treatment of colorectal cancer. Our analysis explores how VEGF/VEGFR inhibitors recalibrate the tumor microenvironment, modulate immune cell functions, and influence the expression of immune checkpoints and cytokines. Furthermore, we critically evaluate the preclinical and clinical feasibility of these combined therapeutic approaches. Despite the potential for toxicity, the significant benefits and prospective applications of these strategies warrant thorough exploration. Exploring the synergistic mechanisms of these combined treatments has the potential to inaugurate a new paradigm in oncology, enabling more personalized and efficacious treatment modalities. Additionally, the synergy between VEGF/VEGFR inhibitors and nascent immunotherapies emerges as a promising field of inquiry.

Expert consensus on the optimal management of BRAFV600E-mutant metastatic colorectal cancer in the Asia-Pacific region

The burden of colorectal cancer (CRC) is high in the Asia-Pacific region, and several countries in this region have among the highest and/or fastest growing rates of CRC in the world. A significant proportion of patients will present with or develop metastatic CRC (mCRC), and BRAFV600E-mutant mCRC represents a particularly aggressive phenotype that is less responsive to standard chemotherapies. In light of recent therapeutic advances, an Asia-Pacific expert consensus panel was convened to develop evidence-based recommendations for the diagnosis, treatment, and management of patients with BRAFV600E-mutant mCRC. The expert panel comprised nine medical oncologists from Australia, Hong Kong, Singapore, and Taiwan (the authors), who met to review current literature and develop eight consensus statements that describe the optimal management of BRAFV600E-mutant mCRC in the Asia-Pacific region. As agreed by the expert panel, the consensus statements recommend molecular testing at diagnosis to guide individualized treatment decisions, propose optimal treatment pathways according to microsatellite stability status, advocate for more frequent monitoring of BRAFV600E-mutant mCRC, and discuss local treatment strategies for oligometastatic disease. Together, these expert consensus statements are intended to optimize treatment and improve outcomes for patients with BRAFV600E-mutant mCRC in the Asia-Pacific region.

Cancer immunotherapy response persists after lymph node resection

Lymphatic transport facilitates the presentation of cancer antigens in tumor-draining lymph nodes (tdLNs), leading to T cell activation and the generation of systemic antitumor immune surveillance. Surgical removal of LNs to control cancer progression is routine in clinical practice. However, whether removing tdLNs impairs immune checkpoint blockade (ICB) is still controversial. Our analysis demonstrates that melanoma patients remain responsive to PD-1 checkpoint blockade after LN dissection. We were able to recapitulate the persistent response to ICB after complete LN resection in murine melanoma and mammary carcinoma models. Mechanistically, soluble antigen and antigen-carrying migratory dendritic cells are diverted to non-directly tumor draining LNs (non-tdLNs) after tdLN dissection. Consistently, robust ICB responses in patients with head and neck cancer after primary tumor and tdLN resection correlated with the presence of reactive LNs in distant areas. These findings indicate that non-tdLNs sufficiently compensate for the removal of direct tdLNs and sustain the response to ICB.

Levels of serum lipids predict responses to PD-L1 inhibitors as first-line treatment in small cell lung cancer: an observational study

BACKGROUND

Immunotherapy provides new hope to individuals with small cell lung cancer (SCLC). Predicting biomarkers for clinical effects is crucial for SCLC patients receiving programed death-ligand 1 (PD-L1) inhibitor treatment.

AIM

The aim of this study was to clarify the value of serum lipids as predictors of immune related adverse events (irAEs) and the anti-tumour effects in SCLC patients who received PD-L1 inhibitors as first-line treatment.

METHOD

This study included patients with SCLC who received at least one cycle of PD-L1inhibitors at Shanghai Pulmonary Hospital from August 2020 to December 2023. We collected the clinical data of the SCLC patients, including basic information and serum lipid levels, before immunotherapy.

RESULTS

The irAEs rate was 16.1% of 124 enrolled patients. In multivariate analysis, the triglyceride (TG)/high-density lipoprotein cholesterol (HDL-C) ratio was an independent predictor of irAEs (p = 0.045). Tumour response analysis indicated that the objective response rate (ORR) was 43.4% and the disease control rate (DCR) was 79.5%. Seventy-seven patients experienced any progression-free survival (PFS) event. The median PFS was longer in the HDL-C-high group (10.03 months) than in the HDL-C-low group (6.67 months) (p = 0.043). In Cox regression analysis, the serum HDL-C level was an independent predictor of PFS (p = 0.002). For patients of the high TG/HDL-C ratio, the ORR significantly differed between patients who suffered from any irAEs and those who did not (p = 0.0139).

CONCLUSION

This study found that serum lipid levels might predict the responses to anti-PD-L1 as first-line treatment for SCLC.

Effect of colorectal cancer stem cells on the development and metastasis of colorectal cancer

The relevant mechanism of tumor-associated macrophages (TAMs) in the treatment of colorectal cancer patients with immune checkpoint inhibitors (ICIs) is discussed, and the application prospects of TAMs in reversing the treatment tolerance of ICIs are discussed to provide a reference for related studies. As a class of drugs widely used in clinical tumor immunotherapy, ICIs can act on regulatory molecules on cells that play an inhibitory role - immune checkpoints - and kill tumors in the form of an immune response by activating a variety of immune cells in the immune system. The sensitivity of patients with different types of colorectal cancer to ICI treatment varies greatly. The phenotype and function of TAMs in the colorectal cancer microenvironment are closely related to the efficacy of ICIs. ICIs can regulate the phenotypic function of TAMs, and TAMs can also affect the tolerance of colorectal cancer to ICI therapy. TAMs play an important role in ICI resistance, and making full use of this target as a therapeutic strategy is expected to improve the immunotherapy efficacy and prognosis of patients with colorectal cancer.

Targeting acid ceramidase enhances antitumor immune response in colorectal cancer

INTRODUCTION

Acid ceramidase (hereafter referred as ASAH1) is an enzyme in sphingolipid metabolism that converts pro-survival ceramide into sphingosine. ASAH1 has been shown to be overexpressed in certain cancers. However, the role of ASAH1 in colorectal cancer still remain elusive.

OBJECTIVE

The present study is aimed to understand how ASAH1 regulates colorectal cancer (CRC) progression and resistance to checkpoint inhibitor therapy.

METHODS

Both pharmacological and genetic silencing of ASAH1 was used in the study. In vitro experiments were done on human and mouse CRC cell lines. The in vivo studies were conducted in NOD-SCID and BALB/c mice models. The combination of ASAH1 inhibitor and checkpoint inhibitor was tested using a syngeneic tumor model of CRC. Transcriptomic and metabolomic analyses were done to understand the effect of ASAH1 silencing.

RESULTS

ASAH1 is overexpressed in human CRC cases, and silencing the expression resulted in the induction of immunological cell death (ICD) and mitochondrial stress. The ASAH1 inhibitor (LCL-521), either as monotherapy or in combination with an anti-PD-1 antibody, resulted in reduction of tumors and, through induction of type I and II interferon response, activation of M1 macrophages and T cells, leading to enhanced infiltration of cytotoxic T cells. Our findings supported that the combination of LCL-521 and ICIs, which enhances the antitumor responses, and ASAH1 can be a druggable target in CRC.

Copper and Colorectal Cancer

Minerals constitute only 5% of the typical human diet but are vital for health and functionality. Copper, a trace element, is absorbed by the human gut at 30-40% from diets typical of industrialized countries. The liver produces metallothioneins, which store copper. Copper is crucial for mitochondrial respiration, pigmentation, iron transport, antioxidant defense, hormone production, and extracellular matrix biosynthesis. Copper deficiency, often caused by mutations in the ATP7A gene, results in Menkes disease, an X-linked recessive disorder. On the contrary, Wilson disease is characterized by toxic copper accumulation. Cuproptosis, a unique form of cell death regulated by copper, is a subtype of necrosis induced by enhanced mitochondrial metabolism and intracellular copper accumulation. This process can reduce the malignant potential of tumor cells by inhibiting glucose metabolism. Therapeutically, copper and its complexes have shown efficacy in malignancy treatments. The disruption of copper homeostasis and excessive cuproplasia are significant in colorectal cancer development and metastasis. Therefore, manipulating copper status presents a potential therapeutic target for colorectal cancer, using copper chelators to inhibit copper formation or copper ion carriers to promote cuproptosis. This review highlights the role of copper in human physiology and pathology, emphasizing its impact on colorectal cancer and potential therapeutic strategies. Future AI-based approaches are anticipated to accelerate the development of new compounds targeting cuproptosis and copper disruption in colorectal cancer.

CAR-T and CAR-NK as cellular cancer immunotherapy for solid tumors

In the past decade, chimeric antigen receptor (CAR)-T cell therapy has emerged as a promising immunotherapeutic approach for combating cancers, demonstrating remarkable efficacy in relapsed/refractory hematological malignancies in both pediatric and adult patients. CAR-natural killer (CAR-NK) cell complements CAR-T cell therapy by offering several distinct advantages. CAR-NK cells do not require HLA compatibility and exhibit low safety concerns. Moreover, CAR-NK cells are conducive to "off-the-shelf" therapeutics, providing significant logistic advantages over CAR-T cells. Both CAR-T and CAR-NK cells have shown consistent and promising results in hematological malignancies. However, their efficacy against solid tumors remains limited due to various obstacles including limited tumor trafficking and infiltration, as well as an immuno-suppressive tumor microenvironment. In this review, we discuss the recent advances and current challenges of CAR-T and CAR-NK cell immunotherapies, with a specific focus on the obstacles to their application in solid tumors. We also analyze in depth the advantages and drawbacks of CAR-NK cells compared to CAR-T cells and highlight CAR-NK CAR optimization. Finally, we explore future perspectives of these adoptive immunotherapies, highlighting the increasing contribution of cutting-edge biotechnological tools in shaping the next generation of cellular immunotherapy.

Evaluation of the efficacy and safety of first- and second-line immunotherapy in patients with metastatic colorectal cancer: a systematic review and network meta-analysis based on randomized controlled trials

Background

A multitude of randomized controlled trials (RCTs) conducted in both the initial and subsequent treatment settings for patients diagnosed with metastatic colorectal cancer (mCRC) have provided clinical evidence supporting the efficacy of immunotherapy with the use of immune checkpoint inhibitors (ICIs). In light of these findings, the U.S. Food and Drug Administration (FDA) has authorized the use of several ICIs in specific subpopulations of mCRC patients. Nevertheless, there remains a dearth of direct comparative RCTs evaluating various treatment options. Consequently, the most effective ICI therapeutic strategy for microsatellite-stable (MSS) subgroup and microsatellite instability (MSI) subgroup in the first- and second-line therapies remains undefined. To address this gap, the present study employs a Bayesian network meta-analysis to ascertain the most effective first- and second-line ICI therapeutic strategies.

Methods

A comprehensive literature search was conducted across multiple databases, including PubMed, EMBASE, Cochrane Library, and Web of Science, with the retrieval date ranging from the databases' inception to August 20, 2024. A total of 875 studies were identified, and seven were ultimately included in the analysis after a screening process. A systematic review and network meta-analysis were conducted on the basis of the search results.

Results

This comprehensive analysis, comprising seven RCTs, evaluated first-line and second-line immunotherapy regimens in 1,358 patients diagnosed with mCRC. The treatments under investigation consisted of five initial treatments, including three focusing on MSS patients and two on MSI patients, as well as two secondary immunotherapy regimens, both focusing on MSS patients. A total of 1051 individuals underwent first-line treatment, while 307 received second-line treatment. The application of ICIs proved to offer varying degrees clinical benefits when compared to standard-of-care therapy alone, both in two subgroups of the first and the second treatment phases. Of particular note is the performance of Nivolumab combination with ipilimumab, which demonstrated superior efficacy in improving progression-free survival (PFS) (HR=0.21; 95% CI, 0.13-0.34),. Moreover, the treatment demonstrated an optimal safety profile, with a relatively low risk of adverse events (OR = 0.33; 95% CI, 0.19-0.56), compared to other first-line treatment modalities for MSI subgroup. Regarding MSS subgroup, the improvement of PFS by Nivolumab plus standard-of-care (SOC) was relatively significant (HR = 0.74; 95% CI, 0.53-1.02). In the realm of second-line therapies for MSS subgroup, the administration of Atezolizumab plus SOC has proven to be an effective approach for prolonging PFS, exhibiting an HR of 0.66 (95% CI, 0.44-0.99). These findings underscore the clinical benefits and safety profiles of ICIs in the treatment of mCRC across various treatment lines.

Conclusions

The clinical application of ICIs in both first- and second-line treatment strategies for patients with mCRC yields substantial therapeutic benefits. A detailed assessment in this study indicates that first-line treatment with Nivolumab combination with ipilimumab may represent an efficacious and well-tolerated therapeutic approach for MSI subgroup. In terms of MSS subgroup in first-line therapy, Nivolumab plus SOC may be a relative superior choice. In the context of second-line therapy for MSS subgroup, it is evident that a combination of Atezolizumab and SOC represents a preferable option for enhancing PFS. Furthermore, it is noteworthy that other ICIs treatment regimens also exhibit great value in various aspects, with the potential to inform the development of future clinical treatment guidelines and provide a stronger rationale for the selection of ICIs in both first- and second-line therapeutic strategies for mCRC.

Systematic review registration

https://www.crd.york.ac.uk/prospero/#recordDetails, identifier CRD42024543400.

Bridging the Gap: Immune Checkpoint Inhibitor as an Option in the Management of Advanced and Recurrent Cervical Cancer in Sub-Saharan Africa

Cervical cancer remains a leading cause of cancer-related mortality in women in low and middle-income countries despite efforts to improve prevention and standard-of-care interventions. Sub-Saharan Africa (SSA) leads the numbers for global cervical cancer incidence and mortality, with the majority of the incidence diagnosed in the late stage of the malignancy. Although the global cervical cancer death rate has been on the decline for the last two decades owing to advancements in screening and treatment options, the mortality rate in SSA has not declined very much. Chemotherapy has been the treatment of choice for cervical cancer in SSA without meeting the expected survival outcomes in these patients, with the majority having advanced diseases at diagnosis. Immune checkpoint inhibitors have recently shown clinical promise in improving the survival of patients with advanced cervical cancer and have been integrated into the treatment guidelines in most high-income countries, which have helped further reduce the mortality rate of cervical cancer. However, many SSA countries are yet to fully benefit from using immune checkpoint inhibitors in cervical cancer. In this review, we discuss the challenges hindering the effective use of immune checkpoint inhibitors for advanced cervical cancer in Africa and possible solutions.

Durable response to pembrolizumab in hepatic metastasis from colonic carcinoma with Lynch syndrome: a case report

Pembrolizumab and other immunotherapies have become central in treating metastatic colon cancer, particularly effective in patients with mismatch repair deficiencies. We report a case involving a man who initially underwent radical surgery for sigmoid colon cancer on April 27, 2011, followed by hepatic tumor resection on September 21, 2017. Post-surgery, he received eight cycles of adjuvant chemotherapy with the CAPEOX regimen and was regularly monitored through CT and MRI scans. On August 24, 2022, liver metastases were detected, and he was diagnosed with Lynch syndrome (LS) due to germline mutation in the MSH2 and EPCAM genes. He commenced treatment with 200mg of pembrolizumab intravenously every three weeks on September 2, 2022, and demonstrated a sustained response. However, after 17 cycles, he developed a treatment related adverse event (TRAE) of pancreatic endocrine dysfunction, leading to type 1 diabetes, managed with subcutaneous insulin injections. After 30 cycles of treatment, no evidence of disease was observed. This case underscores the significant clinical benefits of first-line pembrolizumab in managing hepatic metastasis in colonic carcinoma associated with LS, despite the occurrence of TRAEs. It raises critical questions regarding the optimal duration of immunotherapy following a complete or partial response and whether treatment should be discontinued upon the emergency of TRAEs. Continued research and forthcoming clinical trials with checkpoint inhibitors are expected to refine treatment protocols for LS-associated carcinoma.

Immunotherapy for colorectal cancer

Colorectal cancer is the third most common cancer and the second most lethal cancer in the world. The main cause of the disease is due to dietary and behavioral factors. The treatment of this complex disease is mainly based on traditional treatments, including surgery, radiotherapy, and chemotherapy. Due to its high prevalence and high morbidity, more effective treatments with fewer side effects are urgently needed. In recent years, immunotherapy has become a potential therapeutic alternative and one of the fastest-developing treatments. Immunotherapy inhibits tumor growth by activating or enhancing the immune system to recognize and attack cancer cells. This review presents the latest immunotherapies for immune checkpoint inhibitors, cell therapy, tumor-infiltrating lymphocytes, and oncolytic viruses. Some of these have shown promising results in clinical trials and are used in clinical treatment.

Somatic pharmacogenomics in the treatment prognosis of locally advanced rectal cancer patients: a narrative review of the literature

INTRODUCTION

Standard treatment for patients with locally advanced rectal cancer (LARC) includes neoadjuvant chemoradiotherapy (nCRT) with fluoropyrimidines, followed by surgical excision. The newly introduced therapeutic strategies propose intensified regimens or more conservative approaches based on risk stratification algorithms that currently include clinicoradiological criteria but not molecular variables. How to better stratify patients is a burning clinical question, and pharmacogenomics may prove useful in identifying new genetic markers that could be incorporated into clinical algorithms to personalize nCRT. An emerging area could be the evaluation of somatic mutations as potential genetic markers that correlate with patient prognosis. Tumor mutations in the RAS/BRAF genes, as well as microsatellite instability (MSI) status, are currently used in treatment selection for colorectal cancer (CRC); however, their clinical value in LARC is still unclear.

AREA COVERED

This literature review discusses the relevant findings on the prognostic role of mutations in the key oncogenes RAS, KRAS, BRAF, PIK3CA, SMAD4 and TP53, including MSI status in LARC patients treated with nCRT.

EXPERT OPINION

KRAS proved to be the most promising marker, consistently associated with poorer disease-free survival and overall survival. Therefore, KRAS could be a good candidate for integration into the risk stratification algorithm to develop a personalized treatment.

Innovative Semi-Nested Realtime PCR Assay with Extendable Blocking Probe for Enhanced Analysis of SEPT9 Methylation in Colorectal Cancer

(1) Background: The detection of methylated SEPT9 (mSEPT9) in plasma is a promising approach to non-invasive colorectal cancer (CRC) screening. Traditional approaches have limitations in sensitivity and cost-effectiveness, particularly in resource-limited settings. (2) Methods: We developed a semi-nested realtime PCR assay utilizing extendable blocking probes (ExBP) to enhance the detection of low-level mSEPT9 based on DNA melting. This assay allows for the discrimination of mSEPT9 in the presence of high concentrations of non-methylated SEPT9 (up to 100,000 times higher). (3) Results: The assay demonstrated a sensitivity of 73.91% and specificity of 80%, showcasing its ability to detect very low levels of methylated DNA effectively. The innovative use of ExBP without costly modified probes simplifies the assay setup and reduces the overall costs, enhancing its applicability in diverse clinical settings. (4) Conclusions: This novel assay significantly improves the detection of mSEPT9, offering a potential advance in CRC screening and monitoring. Its cost-efficiency and high sensitivity make it particularly suitable for the early detection and management of CRC, especially in settings with limited resources. Future studies are encouraged to validate this assay in larger populations to establish its clinical benefits and practical utility.

Prognostic relevance of prognostic nutritional indices in gastric or gastro-esophageal junction cancer patients receiving immune checkpoint inhibitors: a systematic review and meta-analysis

Background

The Prognostic Nutritional Index (PNI) has become an important predictive tool for assessing patients' nutritional status and immune competence. It is widely used in prognostic evaluations for various cancer patients. However, the prognostic relevance of the Prognostic Nutritional Index (PNI) in gastric or gastro-esophageal junction cancer patients (GC/GEJC) undergoing immune checkpoint inhibitors (ICIs) treatment remains unclear. This meta-analysis aimed to determine the prognostic impact of PNI in this specific patient cohort.

Methods

We conducted a thorough literature search, covering prominent databases such as PubMed, Embase, Web of Science, SpringerLink, and the Cochrane Library. The search spanned from the inception of these databases up to December 5, 2023. Employing the 95% confidence interval and Hazard Ratio (HR), the study systematically evaluated the relationship between PNI and key prognostic indicators, including the objective remission rate (ORR), disease control rate (DCR), overall survival (OS) and progression-free survival (PFS) in GC/GEJC patients undergoing ICI treatment.

Results

Eight studies comprising 813 eligible patients were selected. With 7 studies consistently demonstrating superior Overall Survival (OS) in the high-Prognostic Nutritional Index (PNI) group compared to their low-PNI counterparts (HR 0.58, 95% CI: 0.47-0.71, P<0.001). Furthermore, the results derived from 6 studies pointed out that the significant correlation between he low-PNI and poorer progression-free survival (PFS) (HR 0.58, 95% CI: 0.47-0.71, P<0.001). Subgroup analyses were performed to validate the robustness of the results. In addition, we conducted a meta-analysis of three studies examining the correlation between PNI and objective response rate/disease control rate (ORR/DCR) and found that the ORR/DCR was significantly superior in the high PNI group (ORR: RR: 1.24, P=0.002; DCR: RR: 1.43, P=0.008).

Conclusion

This meta-analysis indicates that the low-PNI in GC/GEJC patients undergoing ICI treatment is significantly linked to worse OS and PFS. Therefore, PNI can serve as a prognostic indicator of post-treatment outcomes in patients with GC receiving ICIs. Further prospective studies are required to assess the reliability of these findings.

Systematic review registration

https://inplasy.com/, identifier INPLASY202450133.

Spatiotemporal heterogeneity of LMOD1 expression summarizes two modes of cell communication in colorectal cancer

Cellular communication (CC) influences tumor development by mediating intercellular junctions between cells. However, the role and underlying mechanisms of CC in malignant transformation remain unknown. Here, we investigated the spatiotemporal heterogeneity of CC molecular expression during malignant transformation. It was found that although both tight junctions (TJs) and gap junctions (GJs) were involved in maintaining the tumor microenvironment (TME), they exhibited opposite characteristics. Mechanistically, for epithelial cells (parenchymal component), the expression of TJ molecules consistently decreased during normal-cancer transformation and is a potential oncogenic factor. For fibroblasts (mesenchymal component), the expression of GJs consistently increased during normal-cancer transformation and is a potential oncogenic factor. In addition, the molecular profiles of TJs and GJs were used to stratify colorectal cancer (CRC) patients, where subtypes characterized by high GJ levels and low TJ levels exhibited enhanced mesenchymal signals. Importantly, we propose that leiomodin 1 (LMOD1) is biphasic, with features of both TJs and GJs. LMOD1 not only promotes the activation of cancer-associated fibroblasts (CAFs) but also inhibits the Epithelial-mesenchymal transition (EMT) program in cancer cells. In conclusion, these findings demonstrate the molecular heterogeneity of CC and provide new insights into further understanding of TME heterogeneity.

Prognostic relevance of platelet lymphocyte ratio (PLR) in gastric cancer patients receiving immune checkpoint inhibitors: a systematic review and meta-analysis

Objectives

The prognostic relevance of the platelet-to-lymphocyte ratio (PLR) in gastric cancer (GC) patients undergoing immune checkpoint inhibitor (ICI) treatment remains unclear. This meta-analysis aimed to determine the prognostic impact of PLR in this specific patient cohort.

Methods

We searched the PubMed, Cochrane Library, CNKI, and EMBASE databases, including literature published up to September 2023, to investigate the prognostic implications of PLR in patients with gastric cancer undergoing immune checkpoint inhibitor therapy. Outcome measures encompassed overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and disease control rates (DCR).

Results

Nine studies from seven articles comprising 948 eligible patients were selected. The results revealed a significant correlation between elevated PLR and poorer OS and progression-free survival (PFS) (OS: HR 1.67, 95% CI 1.39-2.00, p < 0.001; PFS: HR 1.51, 95% CI 1.29-1.76, p < 0.001). Subgroup analyses were performed to validate the robustness of the results. Moreover, a meta-analysis of four studies investigating the correlation between the PLR in gastric cancer (GC) patients and the objective response rate/disease control rate (ORR/DCR), showed no significant association between the PLR and ORR/DCR (ORR: RR = 1.01, p = 0.960; DCR: RR = 0.96, p = 0.319).

Conclusions

This meta-analysis indicates that elevated PLR in GC patients undergoing ICI treatment is significantly linked to worse OS and PFS. Therefore, PLR can serve as a prognostic indicator of post-treatment outcomes in patients with GC receiving ICIs. Further prospective studies are required to assess the reliability of these findings.

Systematic review registration

https://inplasy.com/, identifier INPLASY2023120103.

A retrospective cohort study of neoadjuvant chemoradiotherapy combined with immune checkpoint inhibitors in locally advanced rectal cancer

INTRODUCTION

This study aimed to investigate the safety and efficacy of neoadjuvant chemoradiotherapy combined with immune checkpoint inhibitors (ICIs) in patients with locally advanced rectal cancer (LARC). Patients diagnosed with LARC and treated with programmed cell death protein-1 (PD-1) inhibitors were recruited.

METHODS

Four different treatment strategies were employed in this study: plan A [long-course radiotherapy + PD-1 inhibitor/capecitabine + PD-1 inhibitor/XELOX+ total mesorectal excision (TME)], plan B (long-course radiotherapy + capecitabine + PD-1 inhibitor/XELOX + TME), plan C (short-course radiotherapy + PD-1 inhibitor/XELOX + TME), and plan D (PD-1 inhibitor/XELOX + short-course radiotherapy + TME). The basic information about patients, pathological indicators, adverse events, and efficacy indexes of treatment plans were analyzed.

RESULTS

96.8 % of patients were mismatch repair proficient (pMMR) and only 2 patients belonged to mismatch repair deficient (dMMR). The 2 patients with dMMR showed a pathological complete response (pCR) rate of 100 %, while the pCR rate of pMMR patients was 43.3 %. The overall tumor descending rate reached 79 %, and the anus-retained rate was 88.7 % in all LARC patients. Plan A exhibited the highest pCR rate of 60 %, and plan C had the highest tumor descending rate and anal preservation rate. Radiation enteritis was the most common adverse event in LARC patients after neoadjuvant therapy, and its incidence was the highest in Plan A.

CONCLUSION

Neoadjuvant chemoradiotherapy combined with ICIs demonstrated favorable efficacy and safety in treating LARC patients.

Resistance to immune checkpoint inhibitors in colorectal cancer with deficient mismatch repair/microsatellite instability: misdiagnosis, pseudoprogression and/or tumor heterogeneity?

Colorectal carcinoma (CRC) with deficiency of the deficient mismatch repair (dMMR) pathway/microsatellite instability (MSI) is characterized by a high mutation load and infiltration of immune cells in the tumor microenvironment. In agreement with these findings, clinical trials have demonstrated a significant activity of immune checkpoint inhibitors (ICIs) in dMMR/MSI metastatic CRC (mCRC) patients and, more recently, in CRC patients with early disease undergoing neoadjuvant therapy. However, despite high response rates and durable clinical benefits, a fraction of mCRC patients, up to 30%, showed progressive disease when treated with single agent anti-programmed cell death 1 (PD-1) antibody. This article discusses the three main causes that have been associated with early progression of dMMR/MSI mCRC patients while on treatment with ICIs, i.e., misdiagnosis, pseudoprogression and tumor heterogeneity. While pseudoprogression probably does not play a relevant role, data from clinical studies demonstrate that some dMMR/MSI CRC cases with rapid progression on ICIs may be misdiagnosed, underlining the importance of correct diagnostics. More importantly, evidence suggests that dMMR/MSI mCRC is a heterogeneous group of tumors with different sensitivity to ICIs. Therefore, we propose novel diagnostic and therapeutic strategies to improve the outcome of dMMR/MSI CRC patients.

The Expression Patterns of Immune Checkpoint Molecules in Colorectal Cancer: An Analysis Based on Microsatellite Status

Recently, immunotherapy has arisen as a novel treatment approach for patients with colorectal cancer (CRC), but the effectiveness of immunotherapy varies in these patients. We hypothesized that immune checkpoint molecules (ICMs), which are the targets of immunotherapy, are often exhibited concomitantly. Our objective was to investigate the patterns of ICM expression in patients with CRC and the differences in ICM expression based on microsatellite instability status. The immunohistochemical expression of programmed cell death protein 1 (PD-1), programmed cell death ligand 1 (PD-L1), T cell immunoglobulin and mucin-domain containing-3 (TIM-3), and lymphocyte-activation gene 3 (LAG-3) in the tumor center and periphery was assessed in patients with non-metastatic colorectal cancer. We enrolled 83 patients with CRC: a total of 40 microsatellite-stable (MSS) and 43 microsatellite-instability-high (MSI-H) cancer patients. PD-L1 was more frequently expressed in the tumor center in the MSI-H patients with than that in the MSS patients (18 [41.9%] vs. 3 [7.5%], respectively; p < 0.001), and the same trend was observed for TIM-3 expression (30 [69.8%] vs. 19 [47.5%], respectively; p = 0.047). The concomitant expression of two or more ICMs was more frequently observed than no expression or the expression of a single molecule in both the MSS and MSI-H groups; a total of 34 (79.7%) patients with MSI-H cancer and 23 (57.5%) with MSS cancer showed ICM expression at the tumor center, whereas 34 (79.7%) patients with MSI-H cancer and 22 (55%) with MSS cancer showed expression at the tumor periphery. Patients with the genetic characteristics of MSI-H cancer showed higher expression levels of ICMs than those in patients with MSS cancer, and predominantly, two or more ICMs were concurrently expressed. Our findings highlight the potential efficacy of the dual-blockade approach in immunotherapy, particularly in patients with MSI-H CRC.

Epigenetic Alteration in Colorectal Cancer: Potential Diagnostic and Prognostic Implications

Colorectal cancer (CRC), a prevalent malignant tumor of the digestive system, ranks as the third and second in global incidence and mortality, respectively, in 2020, with 1.93 million new cases (≈10% of all cancers). There are 940,000 deaths (≈9.4% of all cancers), and the incidence of CRC in younger patients (under 50 years of age) has become a new trend. The pathogenesis of CRC is primarily attributed to a series of genetic and epigenetic abnormalities within normal colonic epithelial cells, coupled with the reshaping of the tumor microenvironment in the surrounding stroma. This process leads to the transformation of colorectal adenomas into invasive adenocarcinomas. Although genetic changes are known to be the primary driving force in the occurrence and progression of CRC, recent research indicates that epigenetic regulation serves as a crucial molecular marker in cancer, playing a significant role in the pathological and physiological control of interactions between genetics and the environment. This review discusses the current global epidemiology of CRC, its risk factors, and preventive treatment strategies. The current study explores the latest advancements in the epigenetic regulation of CRC, including DNA methylation, histone modifications, and non-coding RNAs (ncRNAs). These developments hold potential as screening tools, prognostic biomarkers, and therapeutic targets for CRC.

Targeting of focal adhesion kinase enhances the immunogenic cell death of PEGylated liposome doxorubicin to optimize therapeutic responses of immune checkpoint blockade

BACKGROUNDS

Immune checkpoint blockade (ICB) is widely considered to exert long-term treatment benefits by activating antitumor immunity. However, many cancer patients show poor clinical responses to ICB due in part to the lack of an immunogenic niche. Focal adhesion kinase (FAK) is frequently amplified and acts as an immune modulator across cancer types. However, evidence illustrates that targeting FAK is most effective in combination therapy rather than in monotherapy.

METHODS

Here, we used drug screening, in vitro and in vivo assays to filter out that doxorubicin and its liposomal form pegylated liposome doxorubicin (PLD) showed synergistic anti-tumor effects in combination with FAK inhibitor IN10018. We hypothesized that anti-tumor immunity and immunogenic cell death (ICD) may be involved in the treatment outcomes through the data analysis of our clinical trial testing the combination of IN10018 and PLD. We then performed cell-based assays and animal studies to detect whether FAK inhibition by IN10018 can boost the ICD of PLD/doxorubicin and further established syngeneic models to test the antitumor effect of triplet combination of PLD, IN10018, and ICB.

RESULTS

We demonstrated that the combination of FAK inhibitor IN10018, and PLD/doxorubicin exerted effective antitumor activity. Notably, the doublet combination regimen exhibited response latency and long-lasting treatment effects clinically, outcomes frequently observed in immunotherapy. Our preclinical study confirmed that the 2-drug combination can maximize the ICD of cancer cells. This approach primed the tumor microenvironment, supplementing it with sufficient tumor-infiltrating lymphocytes (TILs) to activate antitumor immunity. Finally, different animal studies confirmed that the antitumor effects of ICB can be significantly enhanced by this doublet regimen.

CONCLUSIONS

We confirmed that targeting FAK by IN10018 can enhance the ICD of PLD/doxorubicin, further benefiting the anti-tumor effect of ICB. The animal tests of the triplet regimen warrant further discovery in the real world.

Efficacy and safety of trifluridine/tipiracil (TAS-102) in patients with metastatic colorectal cancer: a systematic review and meta-analysis

OBJECTIVES

The purpose of this meta-analysis is to evaluate the efficacy and safety of TAS-102 in treating metastatic colorectal cancer (mCRC) using the most recent data available.

METHODS

The literature on the efficacy and safety of TAS-102 versus placebo and/or best supportive care (BSC) in mCRC was obtained through a systematic search of PubMed, Embase, and Web of Science databases through January 2023. Identify the included literature and extract pertinent data, such as the overall survival (OS), progression-free survival (PFS), time to treatment failure (TTF), disease control rate (DCR), incidence of adverse events (AEs) and serious adverse events (SAEs).

RESULTS

There were eight eligible articles that included 2903 patients (1964 TAS-102 versus 939 Placebo and/or BSC). In this meta-analysis, TAS-102 treatment resulted in longer OS, PFS, TTF, and higher DCR in patients with mCRC versus placebo and/or BSC. TAS-102 improved OS and PFS in subgroup analyses of mCRC patients with KRAS wild-type and KRAS mutant-type. In addition, TAS-102 did not increase the incidence of serious adverse events.

CONCLUSION

TAS-102 can enhance the prognosis of mCRC patients whose standard therapy has failed, regardless of KRAS mutation status, and its safety is acceptable.

Expanded Alternatives of CRISPR-Cas9 Applications in Immunotherapy of Colorectal Cancer

Immunotherapy for colorectal cancer (CRC) is limited to patients with advanced disease who have already undergone first-line chemotherapy and whose tumors exhibit microsatellite instability. Novel technical strategies are required to enhance therapeutic options and achieve a more robust immunological response. Therefore, exploring gene analysis and manipulation at the molecular level can further accelerate the development of advanced technologies to address these challenges. The emergence of advanced genome editing technology, particularly of clustered, regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein (Cas) 9, holds promise in expanding the boundaries of cancer immunotherapy. In this manuscript, we provide a comprehensive review of the applications and perspectives of CRISPR technology in improving the design, generation, and efficiency of current immunotherapies, focusing on solid tumors such as colorectal cancer, where these approaches have not been as successful as in hematological conditions.

Rosmarinic acid in combination with ginsenoside Rg1 suppresses colon cancer metastasis via co-inhition of COX-2 and PD1/PD-L1 signaling axis

Metastasis of colorectal cancer (CRC) is a leading cause of mortality among CRC patients. Elevated COX-2 and PD-L1 expression in colon cancer tissue has been linked to distant metastasis of tumor cells. Although COX-2 inhibitors and immune checkpoint inhibitors demonstrate improved anti-tumor efficacy, their toxicity and variable therapeutic effects in individual patients raise concerns. To address this challenge, it is vital to identify traditional Chinese medicine components that modulate COX-2 and PD-1/PD-L1: rosmarinic acid (RA) exerts striking inhibitory effect on COX-2, while ginsenoside Rg1 (GR) possesses the potential to suppress the binding of PD-1/PD-L1. In this study we investigated whether the combination of RA and GR could exert anti-metastatic effects against CRC. MC38 tumor xenograft mouse model with lung metastasis was established. The mice were administered RA (100 mg·kg-1·d-1, i.g.) alone or in combination with GR (100 mg·kg-1·d-1, i.p.). We showed that RA (50, 100, 150 μM) or a COX-2 inhibitor Celecoxib (1, 3, 9 μM) concentration-dependently inhibited the migration and invasion of MC38 cells in vitro. We further demonstrated that RA and Celecoxib inhibited the metastasis of MC38 tumors in vitro and in vivo via interfering with the COX-2-MYO10 signaling axis and inhibiting the generation of filopodia. In the MC38 tumor xenograft mice, RA administration significantly decreased the number of metastatic foci in the lungs detected by Micro CT scanning; RA in combination with GR that had inhibitory effect on the binding of PD-1 and PD-L1 further suppressed the lung metastasis of colon cancer. Compared to COX-2 inhibitors and immune checkpoint inhibitors, RA and GR displayed better safety profiles without disrupting the tissue structures of the liver, stomach and colon, offering insights into the lower toxic effects of clinical traditional Chinese medicine against tumors while retaining its efficacy.

NAT10 mediated mRNA acetylation modification patterns associated with colon cancer progression and microsatellite status

N4-acetylcytidine (ac4C) is one type of RNA modification found in eukaryotes. RNA acetylation modifications are gradually expanding in oncology. However, the role of RNA acetylation modifications in colorectal cancer and its association with colorectal cancer microsatellite status remain unclear. Using public databases and in vitro experiments, we verified the expression and biological function of NAT10, as the key RNA acetylation modification enzyme, in colorectal cancer. The results showed that NAT10 was highly expressed in colorectal cancer, and significantly promoted colorectal cancer cell proliferation. NAT10 was also involved in several aspects of cell homoeostasis such as ion transport, calcium-dependent phospholipid binding, and RNA stability. NAT10 expression positively correlated with immune infiltration in colorectal cancer. We further constructed a risk regression model for mRNA acetylation in colorectal cancer using acetylation-related differential genes. We found that tumour immune infiltration, microsatellite instability (MSI) proportion, tumour immune mutation burden, and patient response to immunotherapy were positively correlated with risk scores. For the first time, our study showed that the level of mRNA acetylation modification level is elevated in colorectal cancer and positively correlates with immune infiltration and microsatellite status of patients. Based on our findings, NAT10 may be a new target for colorectal cancer treatment.

A disulfidptosis-related lncRNA index predicting prognosis and the tumor microenvironment in colorectal cancer

Colorectal cancer (CRC) is a common and deadly cancer worldwide with a high lethality rate. Disulfidptosis has been found to be an emerging mode of death in cancer, and the purpose of this study was to explore the relationship between disulfidptosis-related lncRNAs (DRLs) and CRC and to develop a prognostic model for CRC and DRLs. The gene expression data and clinicopathologic information of colorectal cancer patients were obtained from The Cancer Genome Atlas (TCGA) and screened for DRLs based on correlation analysis. The least absolute shrinkage and selection operator (LASSO) and Cox regression were used to construct the prognostic model, and its validation was carried out by PCA and receiver operating characteristic (ROC) curves. We constructed nomograms combined with the model. Finally, the possible mechanisms by which lncRNAs affect CRC were explored by functional enrichment analysis, immune infiltration and immune escape analysis. In summary, we developed a prognostic marker consisting of lncRNAs associated with disulfidptosis to help clinicians predict the survival of different CRC patients and use different targeted therapies and immunotherapies depending on the condition.

Deubiquitinase inhibitor PR-619 potentiates colon cancer immunotherapy by inducing ferroptosis

A substantial number of colon cancer patients do not benefit from immunotherapy using programmed cell death 1 (PD1) antibodies. Therefore, combination therapy drugs are required to improve the efficacy of colon cancer immunotherapy. Recent studies have shown that deubiquitinases are negative regulators of anti-tumour immunity. In the present study, we investigated the effect of the deubiquitinase inhibitor PR-619 in combination with anti-PD1 for the treatment of colorectal cancer. The results revealed that co-treatment with PR-619 and anti-PD1 significantly inhibited tumour growth in tumour-bearing BALB/c mice compared to monotherapy with a single drug. In addition, PR-619/anti-PD1 combined therapy inhibited cell proliferation, promoted cell apoptosis, induced intratumor infiltration of CD8+ T cells, and enhanced the release of anti-tumour cytokines. Moreover, PR-619 induced ferroptosis in colon cancer cells, thereby inducing the release of damage-associated molecular patterns that triggered anti-tumour immunity. Finally, we discovered that PR-619 could degrade the GPX4 protein, the high expression of which was associated with poor prognosis and blocked CD8+ T cells infiltration in colon cancer. In conclusion, PR-619 may potentiate immunotherapy by inducing ferroptosis, and thereby promoting CD8+ T cells-mediated anti-tumour immunity, providing a potential strategy for colon cancer treatment.

Current status and prospects of GREM1 research in cancer (Review)

GREM1 is a secreted protein that antagonizes bone morphogenetic proteins (BMPs) and participates in critical biological processes, including embryonic development, organogenesis and tissue differentiation. Gremlin 1 (GREM1) is also an inhibitor of TGF-β and a ligand for vascular endothelial growth factor receptor 2. In addition, GREM1 can induce cells, participate in the process of epithelial-mesenchymal transition, and then participate in tumor development. GREM1 has a variety of biological functions and can participate in the malignant progression of a variety of tumors through the BMP signaling pathway. GREM1 also can inhibit TGF-β in some tumors, thereby inhibiting tumors, and its involvement in tumor development varies in different types of cancer. The present review examines the role and function of GREM1 in tumors. GREM1 is expressed in a variety of tumor types. GREM1 expression can affect the epithelial-mesenchymal transformation of tumor cells. GREM1 has been studied in breast and colon cancer, and its potential role is to promote cancer. However, in pancreatic cancer, which was found to act differently from other cancer types, overexpression of GREM1 inhibits tumor metastasis. The present review suggests that GREM1 can be a diagnostic and prognostic indicator. In future studies, the study of GREM1 based on single-cell sequencing technology will further clarify its role and function in tumors.

Expression of Immune-Related and Inflammatory Markers and Their Prognostic Impact in Colorectal Cancer Patients

The tumor microenvironment of colorectal cancer (CRC) is heterogenous; thus, it is likely that multiple immune-related and inflammatory markers are simultaneously expressed in the tumor. The aim of this study was to identify immune-related and inflammatory markers expressed in freshly frozen CRC tissues and to investigate whether they are related to the clinicopathological features and prognosis of CRC. Seventy patients with CRC who underwent curative surgical resection between December 2014 and January 2017 were included in this study. Tissue samples were obtained from tumor and non-tumor areas in the patients' colons. The concentrations of immune-related markers (APRIL/TNFSF13, BAFF, LAG-3, PD-1, PD-L1, and CTLA-4) and inflammatory markers (CHIT, MMP-3, osteocalcin, pentraxin-3, sTNF-R1, and sTNF-R2) in the samples were measured using the Bio-plex Multiplex Immunoassay system. The concentrations of APRIL/TNFSF13, BAFF, and MMP-3 in the samples were significantly high; thus, we conducted analyses based on the cut-off values for these three markers. The high-APRIL/TNFSH13-expression group showed a significantly higher rate of metastatic lesions than the low-expression group, whereas the high-MMP-3-expression group had higher CEA levels, more lymph node metastases, and more advanced disease stages than the low-expression group. The five-year disease-free survival of the high-MMP-3-expression group was significantly shorter than that of the low-expression group (65.1% vs. 90.2%, p = 0.033). This study provides evidence that the APRIL/TNFSF13, BAFF, and MMP-3 pathway is overexpressed in CRC tissues and is associated with unfavorable clinicopathological features and poor prognosis in CRC patients. These markers could serve as diagnostic or prognostic biomarkers for CRC.

Immune-checkpoint inhibitor resistance in cancer treatment: Current progress and future directions

Cancer treatment has been advanced with the advent of immune checkpoint inhibitors (ICIs) exemplified by anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), anti-programmed cell death protein 1 (PD-1) and programmed cell death ligand 1 (PD-L1) drugs. Patients have reaped substantial benefit from ICIs in many cancer types. However, few patients benefit from ICIs whereas the vast majority undergoing these treatments do not obtain survival benefit. Even for patients with initial responses, they may encounter drug resistance in their subsequent treatments, which limits the efficacy of ICIs. Therefore, a deepening understanding of drug resistance is critically important for the explorations of approaches to reverse drug resistance and to boost ICI efficacy. In the present review, different mechanisms of ICI resistance have been summarized according to the tumor intrinsic, tumor microenvironment (TME) and host classifications. We further elaborated corresponding strategies to battle against such resistance accordingly, which include targeting defects in antigen presentation, dysregulated interferon-γ (IFN-γ) signaling, neoantigen depletion, upregulation of other T cell checkpoints as well as immunosuppression and exclusion mediated by TME. Moreover, regarding the host, several additional approaches that interfere with diet and gut microbiome have also been described in reversing ICI resistance. Additionally, we provide an overall glimpse into the ongoing clinical trials that utilize these mechanisms to overcome ICI resistance. Finally, we summarize the challenges and opportunities that needs to be addressed in the investigation of ICI resistance mechanisms, with the aim to benefit more patients with cancer.

Developments in Checkpoint Inhibitor Therapy for the Management of Deficient Mismatch Repair (dMMR) Rectal Cancer

Deficient mismatch repair (dMMR)/microsatellite instability-high (MSIH) colorectal cancer is resistant to conventional chemotherapy but responds to immune checkpoint inhibition (ICI). We review the standard of care in locally advanced dMMR rectal cancer with a focus on ICI. We also present a case report to highlight the treatment complexities and unique challenges of this novel treatment approach. ICI can lead to immune related adverse events (irAEs), resulting in early treatment discontinuation as well as new challenges to surveillance and surgical management. Overall, neoadjuvant ICI can lead to robust treatment responses, but its impact on durable response and organ preservation requires further study.

CDX-2 expression correlates with clinical outcomes in MSI-H metastatic colorectal cancer patients receiving immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) showed efficacy in metastatic colorectal cancer (mCRC) with mismatch-repair deficiency or high microsatellite instability (dMMR-MSI-H). Unfortunately, a patient's subgroup did not benefit from immunotherapy. Caudal-related homeobox transcription factor 2 (CDX-2) would seem to influence immunotherapy's sensitivity, promoting the chemokine (C-X-C motif) ligand 14 (CXCL14) expression. Therefore, we investigated CDX-2 role as a prognostic-predictive marker in patients with mCRC MSI-H. We retrospectively collected data from 14 MSI-H mCRC patients treated with ICIs between 2019 and 2021. The primary endpoint was the 12-month progression-free-survival (PFS) rate. The secondary endpoints were overall survival (OS), PFS, objective response rate (ORR), and disease control rate (DCR). The PFS rate at 12 months was 81% in CDX-2 positive patients vs 0% in CDX-2 negative patients (p = 0.0011). The median PFS was not reached (NR) in the CDX-2 positive group versus 2.07 months (95%CI 2.07-10.8) in CDX-2 negative patients (p = 0.0011). Median OS was NR in CDX-2-positive patients versus 2.17 months (95% Confidence Interval [CI] 2.17-18.7) in CDX2-negative patients (p = 0.026). All CDX-2-positive patients achieved a disease response, one of them a complete response. Among CDX-2-negative patients, one achieved stable disease, while the other progressed rapidly (ORR: 100% vs 0%, p = 0.0005; DCR: 100% vs 50%, p = 0.02). Twelve patients received 1st-line pembrolizumab (11 CDX-2 positive and 1 CDX-2 negative) not reaching median PFS, while two patients (1 CDX-2 positive and 1 CDX-2 negative) received 3rd-line pembrolizumab reaching a median PFS of 10.8 months (95% CI, 10.8-12.1; p = 0.036). Although our study reports results on a small population, the prognostic role of CDX-2 in CRC seems confirmed and could drive a promising predictive role in defining the population more sensitive to immunotherapy treatment. Modulating the CDX-2/CXCL14 axis in CDX-2-negative patients could help overcome primary resistance to immunotherapy.

Comprehensive analysis of cuproptosis-related long noncoding RNA for predicting prognostic and diagnostic value and immune landscape in colorectal adenocarcinoma

BACKGROUND

Cuproptosis, as a copper-induced mitochondrial cell death, has attracted extensive attention recently, especially in cancer. Although some key regulatory genes have been identified in cuproptosis, the related lncRNAs have not been further studied. Exploring the prognostic and diagnostic value of cuproptosis-related lncRNAs (CRLs) in colon adenocarcinoma and providing guidance for individualized immunotherapy for patients are of great significance.

RESULTS

A total of 2003 lncRNAs were correlated with cuproptosis genes and considered as CRLs. We screened 33 survival-associated CRLs and established a prognostic signature base on 7 CRLs in the training group. The patients in the low-risk group had better outcomes in both training group (P < 0.001) and test group (P = 0.016). More exciting, our model showed good prognosis prediction in both stage I-II (P = 0.020) and stage III-IV (P = 0.001). The nomogram model could further improve the accuracy of prognosis prediction. Interestingly, glucose-related metabolic pathways, which were closely related to cuproptosis, were enriched in the low-risk group. Meanwhile, the immune infiltration scores were lower in the high-risk group. The high-risk group was more sensitive to OSI.906 and ABT.888, while low-risk group was more sensitive to Sorafenib. Three lncRNAs, FALEC, AC083967.1 and AC010997.4, were highly expressed in serum of COAD patients, and the AUC was 0.772, 0.726 and 0.714, respectively, indicating their valuable diagnostic value.

CONCLUSIONS

Our research constructed a prognostic signature based on 7 CRLs and found three promising diagnostic markers for COAD patients. Our results provided a reference to the personalized immunotherapy strategies.

Molecular mechanisms targeting drug-resistance and metastasis in colorectal cancer: Updates and beyond

Colorectal cancer (CRC) is the third most diagnosed malignancy and a major leading cause of cancer-related deaths worldwide. Despite advances in therapeutic regimens, the number of patients presenting with metastatic CRC (mCRC) is increasing due to resistance to therapy, conferred by a small population of cancer cells, known as cancer stem cells. Targeted therapies have been highly successful in prolonging the overall survival of patients with mCRC. Agents are being developed to target key molecules involved in drug-resistance and metastasis of CRC, and these include vascular endothelial growth factor, epidermal growth factor receptor, human epidermal growth factor receptor-2, mitogen-activated extracellular signal-regulated kinase, in addition to immune checkpoints. Currently, there are several ongoing clinical trials of newly developed targeted agents, which have shown considerable clinical efficacy and have improved the prognosis of patients who do not benefit from conventional chemotherapy. In this review, we highlight recent developments in the use of existing and novel targeted agents against drug-resistant CRC and mCRC. Furthermore, we discuss limitations and challenges associated with targeted therapy and strategies to combat intrinsic and acquired resistance to these therapies, in addition to the importance of implementing better preclinical models and the application of personalized therapy based on predictive biomarkers for treatment selection.

Predictive and Prognostic Value of Oncogene Mutations and Microsatellite Instability in Locally-Advanced Rectal Cancer Treated with Neoadjuvant Radiation-Based Therapy: A Systematic Review and Meta-Analysis

Markers of pathological complete response (pCR) to preoperative radiation-based therapy in locally advanced rectal cancer (LARC) are strongly needed. This meta-analysis aimed at elucidating the predictive/prognostic role of tumor markers in LARC. We systematically reviewed the impact of RAS, TP53, BRAF, PIK3CA, and SMAD4 mutations and MSI status on response (pCR, downstaging) and prognosis (risk of recurrence, survival) in LARC according to PRISMA guidelines and the PICO model. PubMed, Cochrane Library, and Web of Science Core Collection were systematically searched to identify relevant studies published before October 2022. KRAS mutations were significantly associated with the risk of not achieving pCR after preoperative treatment (summary OR = 1.80, 95% CI: 1.23-2.64). This association was even more significant in patients not receiving cetuximab (summary OR = 2.17, 95% CI: 1.41-3.33) than in patients receiving cetuximab (summary OR = 0.89, 95% CI: 0.39-20.05). MSI status was not associated with pCR (summary OR = 0.80, 95% CI: 0.41-1.57). No effect of KRAS mutation or MSI status on downstaging was detected. Meta-analysis of survival outcomes was not possible due to the large heterogeneity among studies in endpoint assessment. The minimum number of eligible studies to assess the predictive/prognostic role of TP53, BRAF, PIK3CA, and SMAD4 mutations was not reached. KRAS mutation, but not MSI status, proved to be a detrimental marker for response to preoperative radiation-based therapy in LARC. Translating this finding into the clinic could improve the management of LARC patients. More data are needed to clarify the clinical impact of TP53, BRAF, PIK3CA, and SMAD4 mutations.

Overview of Chemotherapy for Gastric Cancer

Gastric cancer (GC) is one of the most clinically challenging cancers worldwide. Over the past few years, new molecular-targeted agents and immunotherapy have markedly improved GC prognosis. Human epidermal growth factor receptor 2 (HER2) expression is a key biomarker in first-line chemotherapy for unresectable advanced GC. Further, the addition of trastuzumab to cytotoxic chemotherapy has extended the overall survival of patients with HER2-positive advanced GC. In HER2-negative GC, the combination of nivolumab, an immune checkpoint inhibitor, and a cytotoxic agent has been demonstrated to prolong the overall survival of GC patients. Ramucirumab and trifluridine/tipiracil, which are second- and third-line treatments for GC, and trastuzumab deruxtecan, an antibody-drug conjugate for HER2-positive GC, have been introduced in clinics. New promising molecular-targeted agents are also being developed, and combination therapy comprising immunotherapy and molecular-targeted agents is expected. As the number of available drugs increases, it is important to understand the target biomarkers and drug characteristics and select the optimal therapy for each patient. For resectable disease, differences in the extent of standard lymphadenectomy between Eastern and Western countries have led to different standard treatments: perioperative (neoadjuvant) and adjuvant therapy. This review aimed to summarize recent advances in chemotherapy for advanced GC.

Does Elevated Pre-Treatment Plasma PD-L1 Level Indicate an Increased Tumor Burden and Worse Prognosis in Metastatic Colorectal Cancer?

BACKGROUND

Programmed death-ligand 1 (PD-L1) and programmed cell death protein 1 (PD-1) have been reported as possibly favorable prognostic factors in colorectal cancer (CRC). However, their longitudinal effect is unknown.

METHODS

A pilot study was performed to investigate whether baseline PD-1/PD-L1 levels are associated with further laboratory changes and/or shorter survival.

RESULTS

A total of 506 laboratory measurements from 37 metastatic CRC patients were analyzed. The baseline plasma PD-1 and PD-L1 levels were 27.73 ± 1.20 pg/mL and 16.01 ± 1.09 pg/mL, respectively. Disease progression (p = 0.0443) and baseline high-sensitivity C-reactive protein (p = 0.0011), aspartate transaminase (p = 0.0253), alanine transaminase (p = 0.0386), and gamma-glutamyl transferase (p = 0.0103) were associated with higher PD-L1 levels. Based on the baseline PD-1/PD-L1 levels, low and high PD-1/PD-L1 groups were created. Constant, pathological levels of complete blood count values, high-sensitivity C-reactive protein, serum albumin, high-density lipoprotein cholesterol, and lactate dehydrogenase were characteristic for patients with high baseline PD-L1. High PD-L1 levels were significantly associated with increased tumor burden. Disease-specific survival and progression-free survival were significantly shorter in patients with high PD-L1.

CONCLUSIONS

Abnormal levels of laboratory parameters and intensified tumor burden can be expected if elevated baseline plasma PD-1/PD-L1 levels are found.