Expression of programmed cell death protein 1 (PD-1) and its ligand PD-L1 in colorectal cancer: Relationship with sidedness and prognosis

Expressions of CXCR3 and PD-1 on T cells and their clinical relevance in colorectal cancer

PURPOSE

Clinical application of immunotherapy represented by Programmed Death-1 (PD-1) monoclonal antibody has changed the treatment paradigm for colorectal cancer (CRC), and tumor-infiltrating T lymphocytes are critical for anti-PD-1 therapy in CRC. However, there are few studies on the relationship between the expression CXCR3 on T lymphocytes and the clinical aspects of CRC. In this study, we analyzed the expression levels of CXCR3 and PD-1 in CD8+ and CD4+ T lymphocytes in healthy donors (HDs) and patients with CRC.

METHODS

We detected the expressions of CXCR3 and PD-1 on T lymphocytes in peripheral blood of healthy donors as well as peripheral blood, tumor tissue and para-cancerous tissues of patients with CRC using flow cytometry. We also analyzed the relationship between the expressions of CXCR3 and PD-1 on T lymphocytes and the pathological characteristics of CRC using t test.

RESULTS

Expression of CXCR3 on tumor-infiltrating T lymphocytes was lower, whereas the expression of PD-1 was higher than that on para-cancerous tissues and PB in patients with CRC. In patients with lymph node metastasis of CRC, the expressions levels of CXCR3+ PD-1+ on tumor-infiltrating CD8+ and CD4+ T lymphocytes were higher than those in patients without lymph node metastasis. The levels of CXCR3+ PD-1+ expressions differed depending on the primary tumor site.

CONCLUSION

Expressions of CXCR3 and PD-1 on tumor-infiltrating T lymphocytes are related to the development of CRC and metastasis, providing clues for exploring the pathogenesis of CRC and developing new strategies for tumor immunotherapy.

Immunotherapy and radiotherapy for older patients with locally advanced rectal cancer unfit for surgery or decline surgery: a practical proposal by the International Geriatric Radiotherapy Group

The standard of care for locally advanced rectal cancer is total neoadjuvant therapy followed by surgical resection. Current evidence suggests that selected patients may be able to delay or avoid surgery without affecting survival rates if they achieve a complete clinical response (CCR). However, for older cancer patients who are too frail for surgery or decline the surgical procedure, local recurrence may lead to a deterioration of patient quality of life. Thus, for clinicians, a treatment algorithm which is well tolerated and may improve CCR in older and frail patients with rectal cancer may improve the potential for prolonged remission and potential cure. Recently, immunotherapy with check point inhibitors (CPI) is a promising treatment in selected patients with high expression of program death ligands receptor 1 (PD- L1). Radiotherapy may enhance PD-L1 expression in rectal cancer and may improve response rate to immunotherapy. We propose an algorithm combining immunotherapy and radiotherapy for older patients with locally advanced rectal cancer who are too frail for surgery or who decline surgery.

Exploring the Expression and Prognosis of Mismatch Repair Proteins and PD-L1 in Colorectal Cancer in a Chinese Cohort

Purpose

Exploring the expression and prognosis of mismatch repair proteins and PD-L1 in colorectal cancer.

Patients and Methods

A total of 272 patients with surgically resected CRC were enrolled in the study from January 2018 to May 2022 at Nanjing Drum Tower Hospital (The Affiliated Hospital of Nanjing University Medical School). Surgically resected samples were collected from patients along with general, clinicopathological, and imaging data for each patient. Immunohistochemistry (IHC) was used to detect expression of MSH2, MSH6, MLH1, and PMS2 proteins in tumor tissue. X-squared (X2) testing was performed to investigate the correlation between expression of MMR proteins and PD-L1 in CRC tumor tissues and clinicopathological characteristics. Correlation analysis was also used to compare the deletion of four MMR proteins in CRC tumor tissues. A survival curve and Log rank test were used to investigate the relationship between the expression of MMR proteins and PD-L1 with regard to CRC patient prognosis and survival.

Results

MMR protein expression deletion was correlated with tumor location, the degree of tissue differentiation, and TNM stage (P<0.05). PD-L1 expression was correlated with TNM stage (P<0.05). Correlation analysis of deletion of MMR protein isoform expression found that PMS2 deletion was significantly correlated with MLH1 deletion (P<0.05). Similarly, MSH2 deletion was significantly correlated with MSH6 deletion (P<0.05). PMS2 deletion was also found to be correlated with PD-L1 expression (P<0.05). Progression-free survival was found to be significantly longer in mismatch repair-proficient (pMMR) patients compared with mismatch repair-deficient (dMMR) patients.

Conclusion

Deletion of MMR proteins and expression of PD-L1 are closely related to clinicopathological characteristics and overall prognosis of CRC patients. This suggests the relevance of MMR and PD-L1 as potential biomarkers for treatment of CRC patients.

The significance of the microlymphangiogenesis, microangiogenesis, and combined detection of programmed cell death-1 protein (PD-1)/ki67 in gastric cancer tissues

PURPOSE

To investigate the relationship between the microlymphangiogenesis, microangiogenesis, and combined detection of the programmed cell death-1 protein (PD-1)/ki67 in patients with gastric cancer as well as the disease prognosis.

METHODS

Immunohistochemistry was used to detect the microlymphatic density (MLD) and microvessel density (MVD) in the central and peripheral zones in 92 cases of gastric cancer, along with the number of PD-1- and ki67-positive tumor cells.

RESULTS

The central zone of the gastric cancer tissue contained fewer atretic cord-like lymphatic vessels than the peripheral zone, while the peripheral zone contained an increased number of lymphatic vessels compared with the central zone. In most cases, the lumen was also dilated. Compared with the MLD in the peripheral zone, the MLD in central zone was significantly decreased. Compared with the number of PD-1-positive cells in the peripheral zone, the number of PD-1-positive cells in the central zone was significantly decreased, and compared with the number of ki67-positive cells in the peripheral zone. The differences in the microlymphangiogenesis, microangiogenesis, and the number of PD-1- and ki67-positive cells among the different histological types were not statistically significant. The microlymphangiogenesis, microangiogenesis, and PD-1- and ki67-positive cells were significantly decreased in the gastric cancer tissues from the patients in stages T1 and T2 compared with the gastric cancer tissues from the patients in stages T3 and T4.

CONCLUSIONS

The detection of the MLD and MVD as well as the positive expression of PD-1 and ki67 in gastric cancer tissue are important reference indicators for judging the prognosis of gastric cancer.

Diatom-Based Nanomedicine for Colorectal Cancer Treatment: New Approaches for Old Challenges

Colorectal cancer is among the most prevalent and lethal cancers globally. To address this emergency, countries have developed diffuse screening programs and innovative surgical techniques with a consequent decrease in mortality rates in non-metastatic patients. However, five years after diagnosis, metastatic CRC is still characterized by less than 20% survival. Most patients with metastatic CRC cannot be surgically treated. For them, the only option is treatment with conventional chemotherapies, which cause harmful side effects in normal tissues. In this context, nanomedicine can help traditional medicine overcome its limits. Diatomite nanoparticles (DNPs) are innovative nano-based drug delivery systems derived from the powder of diatom shells. Diatomite is a porous biosilica largely found in many areas of the world and approved by the Food and Drug Administration (FDA) for pharmaceutical and animal feed formulations. Diatomite nanoparticles with a size between 300 and 400 nm were shown to be biocompatible nanocarriers capable of delivering chemotherapeutic agents against specific targets while reducing off-target effects. This review discusses the treatment of colorectal cancer with conventional methods, highlighting the drawbacks of standard medicine and exploring innovative options based on the use of diatomite-based drug delivery systems. Three targeted treatments are considered: anti-angiogenetic drugs, antimetastatic drugs, and immune checkpoint inhibitors.

Roles and mechanisms of tumour-infiltrating B cells in human cancer: a new force in immunotherapy

Immune checkpoint inhibitors (ICIs) targeting PD-1 or PD-L1 have emerged as a revolutionary treatment strategy for human cancer patients. However, as the response rate to ICI therapy varies widely among different types of tumours, we are beginning to gain insight into the mechanisms as well as biomarkers of therapeutic response and resistance. Numerous studies have highlighted the dominant role of cytotoxic T cells in determining the treatment response to ICIs. Empowered by recent technical advances, such as single-cell sequencing, tumour-infiltrating B cells have been identified as a key regulator in several solid tumours by affecting tumour progression and the response to ICIs. In the current review, we summarized recent advances regarding the role and underlying mechanisms of B cells in human cancer and therapy. Some studies have shown that B-cell abundance in cancer is positively associated with favourable clinical outcomes, while others have indicated that they are tumour-promoting, implying that the biological function of B cells is a complex landscape. The molecular mechanisms involved multiple aspects of the functions of B cells, including the activation of CD8+ T cells, the secretion of antibodies and cytokines, and the facilitation of the antigen presentation process. In addition, other crucial mechanisms, such as the functions of regulatory B cells (Bregs) and plasma cells, are discussed. Here, by summarizing the advances and dilemmas of recent studies, we depicted the current landscape of B cells in cancers and paved the way for future research in this field.

IMMUNOREACT 5: female patients with rectal cancer have better immune editing mechanisms than male patients – a cohort study

BACKGROUND

Studies evaluating sex differences in colorectal cancer (CRC) tumor microenvironment are limited, and no previous study has focused on rectal cancer patients' constitutive immune surveillance mechanisms. The authors aimed to assess gender-related differences in the immune microenvironment of rectal cancer patients.

METHODS

A systematic review and meta-analysis were conducted up to 31 May 2021, including studies focusing on gender-related differences in the CRC tumor microenvironment. Data on the mutational profile of rectal cancer were extracted from the Cancer Genome Atlas (TCGA). A subanalysis of the two IMMUNOREACT trials (NCT04915326 and NCT04917263) was performed, aiming to detect gender-related differences in the immune microenvironment of the healthy mucosa in patients with early (IMMUNOREACT 1 cohort) and locally advanced rectal cancer following neoadjuvant therapy (IMMUNOREACT 2 cohort). In the retrospective IMMUNOREACT 1 cohort (therapy naive), the authors enrolled 442 patients (177 female and 265 male), while in the retrospective IMMUNOREACT 2 cohort (patients who had neoadjuvant therapy), we enrolled 264 patients (80 female and 184 male). In the prospective IMMUNOREACT 1 cohort (therapy naive), the authors enrolled 72 patients (26 female and 46 male), while in the prospective IMMUNOREACT 2 cohort (patients who had neoadjuvant therapy), the authors enrolled 105 patients (42 female and 63 male).

RESULTS

Seven studies reported PD-L1 expression in the CRC microenvironment, but no significant difference could be identified between the sexes. In the TGCA series, mutations of SYNE1 and RYR2 were significantly more frequent in male patients with rectal cancer. In the IMMUNOREACT 1 cohort, male patients had a higher expression of epithelial cells expressing HLA class I, while female patients had a higher number of activated CD4+Th1 cells. Female patients in the IMMUNOREACT 2 cohort showed a higher infiltration of epithelial cells expressing CD86 and activated cytotoxic T cells (P=0.01).

CONCLUSIONS

Male patients have more frequent oncogene mutations associated with a lower expression of T-cell activation genes. In the healthy mucosa of female patients, more Th1 cells and cytotoxic T cells suggest a potentially better immune response to the tumor. Sex should be considered when defining the treatment strategy for rectal cancer patients or designing prognostic scores.

Prognostic Value of BRAF, Programmed Cell Death 1 (PD1), and PD Ligand 1 (PDL1) Protein Expression in Colon Adenocarcinoma

Patients with colorectal cancer in different stages show variable outcomes/therapeutic responses due to their distinct tumoral biomarkers and biological features. In this sense, this study aimed to explore the prognostic utility of BRAF, programmed death-1 (PD1), and its ligand (PDL1) protein signatures in colon adenocarcinoma. The selected protein markers were explored in 64 archived primary colon adenocarcinomas in relation to clinicopathological features. BRAF overexpression was found in 39% of the cases and was significantly associated with grade 3, N1, advanced Dukes stage, presence of relapse, and shorter overall survival (OS). PD1 expression in the infiltrating immune cells (IICs) exhibited significant association with T2/T3, N0/M0, early Dukes stage, and absence of relapse. PDL1 expression in IICs is significantly associated with advanced nodal stage/distant metastasis, advanced Dukes stage, and shorter OS. Meanwhile, PDL1 expression in neoplastic cells (NC) was associated with the advanced lymph node/Dukes stage. A positive combined expression pattern of PDL1 in NC/IICs was associated with poor prognostic indices. Tumor PDL1 expression can be an independent predictor of OS and DFS. The multivariate analyses revealed that short OS was independently associated with the RT side location of the tumor, PD1 expression in stromal IICs, and PDL1 expression in NC. In conclusion, overexpression of BRAF in colon adenocarcinoma is considered a poor prognostic pathological marker. In addition, PDL1 expression in NC is considered an independent prognostic factor for DFS/OS. Combined immunohistochemical assessment for BRAF and PD1/PDL1 protein expressions in colon adenocarcinoma might be beneficial for selecting patients for future targeted therapy.

B-cells Drive Response to PD-1 Blockade in Glioblastoma Upon Neutralization of TGFβ-mediated Immunosuppression

Immunotherapy has revolutionized cancer treatment but has yet to be translated into brain tumors. Studies in other solid tumors suggest a central role of B-cell immunity in driving immune-checkpoint-blockade efficacy. Using single-cell and single-nuclei transcriptomics of human glioblastoma and melanoma brain metastasis, we found that tumor-associated B-cells have high expression of checkpoint molecules, known to block B-cell-receptor downstream effector function such as plasmablast differentiation and antigen-presentation. We also identified TGFβ-1/TGFβ receptor-2 interaction as a crucial modulator of B-cell suppression. Treatment of glioblastoma patients with pembrolizumab induced expression of B-cell checkpoint molecules and TGFβ-receptor-2. Abrogation of TGFβ using different conditional knockouts expanded germinal-center-like intratumoral B-cells, enhancing immune-checkpoint-blockade efficacy. Finally, blocking αVβ8 integrin (which controls the release of active TGFβ) and PD-1 significantly increased B-cell-dependent animal survival and immunological memory. Our study highlights the importance of intratumoral B-cell immunity and a remodeled approach to boost the effects of immunotherapy against brain tumors.

Tim3 and PD-1 as a therapeutic and prognostic targets in colorectal cancer: Relationship with sidedness, clinicopathological parameters, and survival

Background

Colorectal cancer (CRC) is a heterogeneous disease that complicates predicting patients' prognosis and their response to treatment. CRC prognosis is influenced by the tumor microenvironment (TME). The immune system is a critical component of the TME. Programmed cell death receptor 1 (PD-1) and T-cell immunoglobulin and mucin-domain containing-3 (Tim3) are inhibitory immune checkpoints that regulate immune response and may provide prognostic power. However, the effect of their expressions and co-expressions on the CRC prognosis remains unclear. Accordingly, this study aimed to investigate the prognostic value of the CD8, CD3, PD-1, Tim3 expression, and PD-1/Tim3 co-expression in patients with CRC.

Materials and Methods

One hundred and thirty six patients with CRC who underwent curative surgery were enrolled in the study. Immunohistochemical staining was performed for PD-1, Tim3, CD8, and CD3, and the expression of each marker was evaluated in the center of the tumor (CT), invasive margin (IM), and adjacent normal-like tissue.

Result

Our results indicated that high expression of PD-1 in IM was significantly associated with lower TNM stage, T-stage, M-stage, lack of metastasis, the presence of tertiary lymphoid structure (TLS), lack of recurrence (in the left-sided tumors), and larger tumor size (in right-sided tumors) (P<0.05). High expression of PD-1 in IM was also associated with improved overall survival (OS) in a subgroup of patients with high CD8 expression. High Tim3 expression in CT was associated with higher M-stage (M1) (in left-sided CRCs) (P<0.05). It was also associated with decreased OS in total cohort and left-sided CRCs and represented an independent prognostic factor for CRC patients in multivariate analysis. PD-1 and Tim3 co-expression had no synergistic effects on predicting OS.

Conclusion

Our findings suggest that the clinicopathological and prognostic significance of immune system-related markers such as CD8, PD-1, and Tim3 depends on the primary tumor sides. We also showed that Tim3 could act as a prognostic factor and therapeutic target in CRC. This marker is probably a more preferred target for immunotherapy than PD-1, especially in left-sided CRCs.

Expression of Cartilage Oligomeric Matrix Protein in colorectal cancer is an adverse prognostic factor and correlates negatively with infiltrating immune cells and PD-L1 expression

Introduction

Cartilage Oligomeric Matrix Protein (COMP) is an oncogenic protein that has been associated with a decrease in infiltrating T-cells in periampullary adenocarcinoma. This study aimed to investigate whether this is also the case for colorectal cancer (CRC) and to evaluate the relationship between COMP expression and clinopathological features.

Methods

Immunohistochemistry was used to determine the expression levels of COMP in tumor cells and stroma in primary tumors from a cohort of 537 CRC patients. The expression of immune cell markers, including CD3+, CD8+, FoxP3+, CD68+, CD56+, CD163+, and PD-L1, was evaluated previously. Tumor fibrosis was assessed by Sirius Red staining and evaluation of collagen fiber organization.

Results

COMP expression correlated positively with TNM-stage and grade of differentiation. Patients with CRC expressing high levels of COMP had significantly shorter OS than those with low COMP expression (p<0.0001), and fewer infiltrating T-cells were detected in tumors with high COMP expression. Additionally, a negative correlation was identified between the expression of COMP and PD-L1 on both tumor cells and immune cells. Cox regression analysis showed that tumors expressing high levels of COMP had significantly shorter OS, independent of all evaluated immune cell markers. Tumor fibrosis was correlated with high expression of COMP in the stroma (p<0.0001), and tumors with high levels of COMP expression and denser fibrosis displayed more sparse immune cell infiltration.

Discussion

The results suggest that COMP expression in CRC may exert an immune regulatory effect by increasing dense fibrosis and decreasing immune cell infiltration. These findings support the notion that COMP is an important factor in the development and progression of CRC.

Case report: Complete pathologic response with first-line immunotherapy combination in a young adult with massive liver dissemination of mismatch repair-deficient metastatic colorectal cancer: Immunological and molecular profiling

The current level of evidence for immunotherapy in previously untreated microsatellite unstable metastatic colorectal cancer is based on recent pieces of evidence of few studies that demonstrated durable response and clinical benefit, in terms of objective response rate, disease control rate, and progression-free survival in this subgroup of patients. On the basis of combinatorial immunotherapy with nivolumab plus ipilimumab, we report the exceptional case of a complete pathological response in a 21-year-old woman presenting a clinically aggressive stage IV colorectal cancer with massive nodal and liver involvement. Extensive molecular analyses based on whole genome next-generation DNA sequencing, RNA sequencing, fluorescent multiplex immunohistochemistry, and flow cytometry provided a detailed description of tumoral and immunological characteristics of this noteworthy clinical case.

Comprehensive analysis of the differences between left- and right-side colorectal cancer and respective prognostic prediction

Background

Previous studies have reported that the tumor heterogeneity and complex oncogenic mechanisms of proximal and distal colon cancer (CRC) are divergent. Therefore, we aim to analyze the differences between left-sided CRC (L_cancer) and right-sided CRC (R_cancer), as well as constructing respective nomograms.

Methods

We enrolled 335 colon cancer patients (146 L_cancer patients and 189 R_cancer patients) from The Cancer Genome Atlas (TCGA) data sets, and 102 pairs of color cancer tissue and adjacent normal tissue (51 L_cancer patients and 51 R_cancer patients) from our hospital. Firstly, we analyzed the differences between the L_cancer patients and R_cancer patients, and then established the L_cancer and R_cancer prognostic models using LASSO Cox.

Results

R_cancer patients had lower survival than L_cancer patients. R_cancer patients had higher ESTIMATE and immune scores and lower tumor purity. These patterns of expression of immune checkpoint-related genes and TMB level were higher in R_cancer than in L_cancer patients. Finally, we using Lasso Cox regression analyses established a prognostic model for L_cancer patients and a prognostic model for R_cancer patients. The AUC values of the risk score for OS in L_cancer were 0.862 in the training set and 0.914 in the testing set, while those in R_cancer were 0.835 in the training set and 0.857 in the testing set. The AUC values in fivefold cross-validation were between 0.727 and 0.978, proving that the two prognostic models have great stability. The nomogram of L_cancer included prognostic genes, age, pathological M, pathological stage, and gender, the AUC values of which were 0.800 in the training set and 0.905 in the testing set. Meanwhile, the nomogram of R_cancer comprised prognostic genes, pathological N, pathological T, and age, the AUC values of which were 0.836 in the training set and 0.850 in the testing set. In the R_cancer patients, high-risk patients had a lower proportion of ‘B cells memory’, ‘Dendritic cells resting’, immune score, ESTIMATE score, immune checkpoint-related genes, and HLA-family genes, and a higher proportion of ‘T cells follicular helper’, ‘Dendritic cells activated’, and ‘Mast cells activated’.

Conclusions

We found significant differences between L_cancer and R_cancer patients and established a clinical predictive nomogram for L_cancer patients and a nomogram for R_cancer patients. Additionally, R_cancer patients in low-risk groups may be more beneficial from immunotherapy.

Loss of SATB2 expression correlates with cytokeratin 7 and PD-L1 tumor cell positivity and aggressiveness in colorectal cancer

Colorectal carcinoma (CRC) is a disease that causes significant morbidity and mortality worldwide. To improve treatment, new biomarkers are needed to allow better patient risk stratification in terms of prognosis. This study aimed to clarify the prognostic significance of colonic-specific transcription factor special AT-rich sequence-binding protein 2 (SATB2), cytoskeletal protein cytokeratin 7 (CK7), and immune checkpoint molecule programmed death-ligand 1 (PD-L1). We analyzed a cohort of 285 patients with surgically treated CRC for quantitative associations among the three markers and five traditional prognostic indicators (i.e., tumor stage, histological grade, variant morphology, laterality, and mismatch-repair/MMR status). The results showed that loss of SATB2 expression had significant negative prognostic implications relative to overall survival (OS) and cancer-specific survival (CSS), significantly shortened 5 years OS and CSS and 10 years CSS in patients with CRC expressing CK7, and borderline insignificantly shortened OS in patients with PD-L1 + CRC. PD-L1 showed a significant negative impact in cases with strong expression (membranous staining in 50-100% of tumor cells). Loss of SATB2 was associated with CK7 expression, advanced tumor stage, mucinous or signet ring cell morphology, high grade, right-sided localization but was borderline insignificant relative to PD-L1 expression. CK7 expression was associated with high grade and SATB2 loss. Additionally, a separate analysis of 248 neoadjuvant therapy-naïve cases was performed with mostly similar results. The loss of SATB2 and CK7 expression were significant negative predictors in the multivariate analysis adjusted for associated parameters and patient age. In summary, loss of SATB2 expression and gain of CK7 and strong PD-L1 expression characterize an aggressive phenotype of CRC.

The Role of Tumor Microenvironment and Immune Response in Colorectal Cancer Development and Prognosis

Colorectal cancer (CRC) is one of the most common cancers worldwide. The patient’s prognosis largely depends on the tumor stage at diagnosis. The pathological TNM Classification of Malignant Tumors (pTNM) staging of surgically resected cancers represents the main prognostic factor and guidance for decision-making in CRC patients. However, this approach alone is insufficient as a prognostic predictor because clinical outcomes in patients at the same histological tumor stage can still differ. Recently, significant progress in the treatment of CRC has been made due to improvements in both chemotherapy and surgical management. Immunotherapy-based approaches are one of the most rapidly developing areas of tumor therapy. This review summarizes the current knowledge about the tumor microenvironment (TME), immune response and its interactions with CRC development, immunotherapy and prognosis.

A Genetic Variant in CD274 Is Associated With Prognosis in Metastatic Colorectal Cancer Patients Treated With Bevacizumab-Based Chemotherapy

Bevacizumab plus chemotherapy is a well-established first-line treatment for metastatic colorectal cancer (mCRC). We investigated whether polymorphisms of genes involved in immune regulation signaling are related to the clinical outcome of mCRC patients treated with bevacizumab-based chemotherapy. In this study, we genotyped 14 single-nucleotide polymorphisms (SNP) in IFN-γ/IFNGRs/JAKs/STATs/PD-L1 pathway by using DNA from blood samples of 141 mCRC patients treated with first-line bevacizumab-based chemotherapy. In the univariate and multivariate analysis, patients with AA genotype of CD274:rs2297136 had a significantly better PFS and OS than patients with AG or GG genotype (10.8 versus 9.8, log-rank P=0.0031; 31.4 versus 20.9, log-rank P=0.0233). Patients with AG/GG genotype of IFNGR1:rs2234711, CT/TT genotype of IFNGR1:rs9376267 also showed longer OS than patients with AA or CC genotype, however, the statistic did not reach significant after adjusted by clinical factors in the multivariate analysis. A nomogram based on the genetic variants and clinic characteristics was developed with a good accuracy to predict patients’ survival. Our result indicates that CD274:rs2297136 is one of the most important predictors for the prognosis of mCRC patients treated with bevacizumab-based chemotherapy, if further validated in larger population.

A combination of stromal PD-L1 and tumoral nuclear β-catenin expression as an indicator of colorectal carcinoma progression and resistance to chemoradiotherapy in locally advanced rectal carcinoma

Programmed cell death-1 (PD-1) and its ligand (PD-L1) are significant mediators of immune suppression in the tumor microenvironment. We focused on the immunological impact of PD-1/PD-L1 signaling during tumor progression in colorectal carcinoma (CRC) and its association with resistance to neoadjuvant chemoradiotherapy (NCRT) in locally advanced rectal carcinoma (LAd-RC). Histopathological and immunohistochemical analyses of 100 CRC cases (including 34 RC) without NCRT and 109 NCRT-treated LAd-RC cases were performed. Membranous tumoral PD-L1 expression was identified in 9 of 100 (9%) CRC cases, including 1 of 34 (2.9%) RC cases, but PD-L1 immunopositivity was not associated with any clinicopathological factors, with the exception of deficient mismatch repair (dMMR) status. In contrast, stromal PD-L1+ immune cells, which frequently exhibited coexpression of PD-1 and CD8 markers, were significantly correlated with tumor vessel invasion, nuclear β-catenin+ tumor budding cancer stem cell (CSC)-like features, and unfavorable prognosis. In the LAd-RC cases, stromal CD8+ (but not PD-L1+) immune cell infiltration in pretreatment-biopsied samples was significantly and positively associated with therapeutic efficacy. After NCRT, tumoral PD-L1 expression was observed in only 2 of 83 (2.4%) tumors, independent of dMMR status, whereas high stromal PD-L1+ and tumoral nuclear β-catenin positivity were significantly linked to a poor response to NCRT and high tumor budding features. In addition, high stromal PD-L1 immunoreactivity was significantly associated with poorer overall survival. In conclusion, a combination of stromal PD-L1+ immune cells and nuclear β-catenin+ tumor budding may contribute to tumor progression in CRC and resistance to NCRT in LAd-RC, through formation of niche-like lesions that exhibit immune resistance and CSC properties.

Analysis of anti-apoptotic PVT1 oncogene and apoptosis-related proteins (p53, Bcl2, PD-1, and PD-L1) expression in thyroid carcinoma

Background

An aberrant expression of long non‐coding RNA PVT1 has been associated with apoptosis in various cancer types. We aimed to explore the PVT1 and four apoptosis‐related proteins (p53, Bcl2, and PD‐1/PD‐L1) signature in thyroid cancer (TC).

Methods

The PVT1 expression level was measured in 64 FFPE TC paired samples by real‐time quantitative PCR. Overall and stratified analyses by different clinicopathological features were done. The apoptotic proteins were evaluated by immunohistochemistry staining.

Results

Overall analysis showed significant PVT1upregulation in TC tissues (p < 0.001). Similarly, subgroup analysis by BRAF^V600E mutation showed consistent results. Lower expression of p53 was associated with mortality (p = 0.001). Bcl2 overexpression was associated with greater tumor size (p = 0.005). At the same time, HCV‐positive cases were associated with repressed Bcl2 expression levels (54.3% in HCV‐negative vs. 6.9% in HCV‐positive cases, p = 0.011). PD‐1 expression was associated with lymph node metastasis (p = 0.004). Enhanced PD‐L1 expression in the tumor was associated with a higher tumor stage, lymphovascular invasion, and mortality risk. Kaplan–Meier curves for overall survival showed that low p53 and high PD‐L1 expressions were associated with lower survival time. The p53‐positive staining is associated with a 90% decreased mortality risk (HR = 0.10, 95%CI = 0.02–0.47, p = 0.001), while patients with high PD‐L1 were five times more likely to die (HR = 4.74, 95%CI = 1.2–18.7, p = 0.027).

Conclusion

Our results confirm the upregulation of PVT1 in TC. The apoptosis‐related proteins (p53, Bcl2, and PD‐1/PD‐L1) showed different prognostic utility in TC patients; in particular, low p53 and high PD‐L1 expressions associated with low survival times. Further large‐scale and mechanistic studies are warranted.

Cytokine-Induced Senescence in the Tumor Microenvironment and Its Effects on Anti-Tumor Immune Responses

In contrast to surgical excision, chemotherapy or radiation therapy, immune checkpoint blockade therapies primarily influence cells in the tumor microenvironment, especially the tumor-associated lymphocytes and antigen-presenting cells. Besides complete remission of tumor lesions, in some patients, early tumor regression is followed by a consolidation phase where residing tumors remain dormant. Whereas the cytotoxic mechanisms of the regression phase (i.e., apoptosis, necrosis, necroptosis, and immune cell-mediated cell death) have been extensively described, the mechanisms underlying the dormant state are still a matter of debate. Here, we propose immune-mediated induction of senescence in cancers as one important player. Senescence can be achieved by tumor-associated antigen-specific T helper 1 cells, cytokines or antibodies targeting immune checkpoints. This concept differs from cytotoxic treatment, which often targets the genetic makeup of cancer cells. The immune system's ability to establish "defensive walls" around tumors also places the tumor microenvironment into the fight against cancer. Those "defensive walls" isolate the tumor cells instead of increasing the selective pressure. They also keep the tumor cells in a non-proliferating state, thereby correcting the derailed tissue homeostasis. In conclusion, strengthening the senescence surveillance of tumors by the immune cells of the microenvironment is a future goal to dampen this life-threatening disease.

Association of PD-1 and PDL-1 gene polymorphisms with colorectal cancer risk and prognosis

BACKGROUND

Programmed Cell Death-1 (PD-1) together with Programmed Death Ligand 1 (PDL-1) have crucial roles in anti-tumor immune response, cancer susceptibility and prognosis. Since PD-1 and PDL-1 have been considered as important genetic risk factors in cancer development and their functions can be affected by polymorphic sites, we investigated the effects of PD-1 rs2227981, rs2227982, rs36084323 and PDL-1 rs2282055, rs822336 gene polymorphisms on colorectal cancer (CRC) risk and prognosis in Turkish subjects.

METHODS AND RESULTS

Our study group consisted of 5-FU or Capacitabine prescribed CRC diagnosed patients and healthy controls. Genotype analyses of PD1 and PDL-1 polymorphisms were performed with Agena MassARRAY platform. rs36084323 CT genotype frequency was found to be higher in controls compared to cases (p < 0.001). rs36084323 CT genotype was highly associated with reduced CRC risk compared to CC genotype (OR 0.068, 95% CI 0.022-0.211, p < 0.001). In adjusted analysis, rs2282055 GG genotype was found to be associated with reduced CRC risk (OR 0.271, 95% CI 0.078-0.940, p = 0.040). rs2282055 TT genotype was found to be related to longer progression-free (Bonferroni corrected Log rank p = 0.013) and overall survival (Bonferroni corrected Log rank p = 0.009) to that of GG genotypes. Patients with rs822336 GC+CC genotypes showed longer overall survival times compared to GG (Log rank p = 0.044).

CONCLUSIONS

According to our results, PD-1 rs822336 G > C polymorphism might be useful in predicting CRC prognosis. PDL-1 rs2282055 T > G polymorphism might be useful in predicting both CRC risk and prognosis. Further studies should be conducted in larger and different populations to clear the roles of PD-1 and PDL-1 polymorphisms in CRC risk and prognosis.

The role and relationship between programmed death ligand 1 and cytotoxic T lymphocyte-associated antigen-4 immunohistochemical expression in colorectal carcinoma patients: an impact on outcome

Background

Globally, colorectal carcinoma (CRC) is the third most common cancer diagnosed in both men and women. Programmed death ligand 1 (PD-L1) and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4) are immune checkpoints that induce tumour immune escape.

Aim

This study aimed to evaluate the immunohistochemical expression of PD-L1 and CTLA-4 in CRC and their relationship with clinicopathological parameters and survival data.

Result

This study included 103 CRC, 22 adenoma and 21 non-neoplastic specimens. High PD-L1 epithelial expression was in favour of CRC and high-grade dysplastic adenoma compared to normal specimens. High PD-L1 epithelial expression was associated with larger sized tumours, perforation, advanced T stage, infiltrative tumour border configuration (TBC), high tumour budding (TB) score, low tumour-stroma ratio (TSR) and absence of peritumoural lymphocytes. High PD-L1+ tumour infiltrating lymphocytes (TILs) showed an association with absence of perforation, early T stage, pushing TBC, lower TB score, high TSR and presence of peritumoural lymphocytes. High epithelial CTLA-4 expression was in favour of adenocarcinoma, high-grade dysplastic adenoma and low-grade dysplastic adenoma compared to normal specimens. High CTLA-4 epithelial score showed an association with positive lymph nodes (LNs), presence of an infiltrative TBC and absence of peritumoural lymphocytes. Low CTLA-4+ TILs showed a significant association with advanced tumour stage and increased number of positive LNs. Prolonged survival was associated with low epithelial PD-L1 and CTLA-4, high PD-L1+ TILs and high CTLA-4+ TILs. By multivariate Cox regression analysis, PD-L1+ TILs immunoreactivity score (p = 0.020) and CTLA-4+ TILs H. score (p = 0.036) were independent prognostic factors affecting overall survival among the other prognostic factors.

Conclusion

PD-L1 and CTLA-4 expression by tumour cells could cooperate with each other in enhancing progression of CRC leading to poor patient outcome, while their expression by TILs could stand against tumour progression.

The immune microenvironment in patients with mismatch‐repair‐proficient oligometastatic colorectal cancer exposed to chemotherapy: the randomized MIROX GERCOR cohort study

In the era of immune checkpoint inhibitors, understanding the metastatic microenvironment of proficient mismatch repair/microsatellite stable (pMMR/MSS) colorectal cancer (CRC) is of paramount importance to both prognostication and the development of more effective novel therapies. In this study, primary and paired metastasis tissue samples were collected from patients with resectable metastatic CRC treated with adjuvant FOLFOX or peri‐operative chemotherapy in the MIROX phase III prospective study. In total, 74 cancer tissues were stained for CD3, CD8, Forkhead box protein 3 (FOXP3), programmed cell death protein‐1 (PD‐1, invasive front, stromal, intra‐epithelial compartments), and programmed death‐ligand 1 (PD‐L1, tumor, immune cells). The immune profiling of primary CRC had a limited value to predict the immune context of paired metastases for all markers but CD3+. The expression of CD8 and PD‐L1 was higher in metastases after neoadjuvant FOLFOX. In metastases, both CD3 T cells at the invasive front and PD‐L1 expressions on immune cells were predictive of better disease‐free survival. These results show that the effect of FOLFOX on modifying the immune microenvironment in resected CRC metastases and measurement of PD‐L1 expression and tumor‐infiltrating CD8 T cells in pMMR/MSS metastatic tissue samples could improve treatment strategies of metastatic CRC patients.

B cells and cancer: To B or not to B?

Whereas T cells have been considered the major immune cells of the tumor microenvironment able to induce tumor regression and control cancer clinical outcome, a burst of recent publications pointed to the fact that B cells may also play a prominent role. Activated in germinal centers of tertiary lymphoid structures, B cells can directly present tumor-associated antigens to T cells or produce antibodies that increase antigen presentation to T cells or kill tumor cells, resulting in a beneficial clinical impact. Immune complexes can also increase inflammation, angiogenesis, and immunosuppression via macrophage and complement activation, resulting in deleterious impact.

Association of PIK3CA mutation and PTEN loss with expression of CD274 (PD-L1) in colorectal carcinoma

Immunotherapy targeting the CD274 (PD-L1)/PDCD1 (PD-1) immune checkpoint axis has emerged as a promising treatment strategy for various cancers. Experimental evidence suggests that phosphatidylinositol-4,5-bisphosphonate 3-kinase (PI3K) signaling may upregulate CD274 expression. Thus, we hypothesized that PIK3CA mutation, PTEN loss, or their combined status might be associated with CD274 overexpression in colorectal carcinoma. We assessed tumor CD274 and PTEN expression by immunohistochemistry and assessed PIK3CA mutation by pyrosequencing in 753 patients among 4,465 incident rectal and colon cancer cases that had occurred in two U.S.-wide prospective cohort studies. To adjust for potential confounders and selection bias due to tissue availability, inverse probability weighted multivariable ordinal logistic regression analyses used the 4,465 cases and tumoral data including microsatellite instability, CpG island methylator phenotype, KRAS and BRAF mutations. PIK3CA mutation and loss of PTEN expression were detected in 111 of 753 cases (15%) and 342 of 585 cases (58%), respectively. Tumor CD274 expression was negative in 306 (41%), low in 195 (26%), and high in 252 (33%) of 753 cases. PTEN loss was associated with CD274 overexpression [multivariable odds ratio (OR) 1.83; 95% confidence interval (CI), 1.22–2.75; P = .004]. PIK3CA mutation was statistically-insignificantly (P = .036 with the stringent alpha level of 0.005) associated with CD274 overexpression (multivariable OR, 1.54; 95% CI, 1.03–2.31). PIK3CA-mutated PTEN-lost tumors (n = 33) showed higher prevalence of CD274-positivity (82%) than PIK3CA-wild-type PTEN-lost tumors (n = 204; 70% CD274-positivity) and PTEN-expressed tumors (n = 147; 50% CD274-positivity) (P = .003). Our findings support the role of PI3K signaling in the CD274/PDCD1 pathway.

Association Between PDL1 Genetic Variation and Efficacy of Apatinib Monotherapy in Patients with Previously Treated Advanced NSCLC: A Real-World Retrospective Study

Background

This study aimed to explore associations between PDL1 polymorphisms and efficacy of apatinib for patients with previously treated advanced non-small cell lung cancer (NSCLC) in a real-world setting.

Methods

We retrospectively recruited 148 patients with previously treated advanced NSCLC from January 2015 to December 2019 continuously. Clinical efficacy in patients receiving apatinib treatment was evaluated. Adverse reactions were documented during treatment. Biological specimens of peripheral blood and cancer tissue biopsies were obtained for the genotyping of genetic variations in PDL1 and corresponding gene-mRNA expression, respectively. Univariate association analysis between the status of PDL1 genetic variations and survival was performed with Kaplan-Meier survival analysis.

Results

The objective response rate of the 148 patients was 17.6% and disease-control rate 68.9%. Prognostic data suggested that median progression-free survival (PFS) was 3.8 (95% CI 3.13-4.47) months and median overall survival (OS) 10.5 (95% CI 9.06-11.95) months. Regarding PDL1 genetic variation, only rs2297136 was of clinical significance. Prognosis analysis revealed that PFS and OS for the rs2297136 genotype were significantly different. Median PFS of patients with TC/CC and TT genotypes was 3 and 4.5 months, respectively (P=0.006). Median OS of the two genotypes was 9 and 11.6 months, respectively (P=0.04). Furthermore, the safety profile suggested that the most common adverse reactions were hypertension, dermal toxicity, fatigue, and oral toxicity. This study failed to find any significant association between adverse reactions and rs2297136. Interestingly, mRNA-expression analysis demonstrated that mRNA expression of PDL1 in biopsy cancer-tissue specimens was significantly different based on rs2297136-genotype status (P<0.001).

Conclusion

The PDL1 polymorphism rs2297136 could be used as a potential biomarker for the prognosis of patients with NSCLC receiving apatinib monotherapy.

Clinical retrospective study on the expression of the PD-L1 molecule in sporadic colorectal cancer and its correlation with K-ras gene mutations in Chinese patients

OBJECTIVE

To detect the expression of PD-L1 and K-ras gene status in colorectal cancer tissues and analyze the relationship between PD-L1 expression and the clinicopathological features and K-ras gene status in colorectal cancer.

METHODS

Two hundred fifty colorectal cancer tissues were collected from the First Affiliated Hospital of Nanchang University. The normal intestinal mucosal tissues of 20 patients were randomly selected for inclusion in the control group. PD-L1 expression was detected by immunohistochemistry. K-ras gene mutation in colorectal cancer tissues was detected by sequencing. The clinical significance of PD-L1 expression and relationship between PD-L1 expression and K-ras gene mutation were analyzed.

RESULTS

The immunohistochemistry assay showed that PD-L1 was highly expressed in colorectal cancer. The positive expression of PD-L1 was increased with lymph node metastasis and high TNM stage. The 5-year survival rate of PD-L1-positive patients was significantly lower than that of PD-L1-negative patients. The K-ras gene mutation rate was 35.6%, and the main mutation site was in codon 12. The positive PD-L1 expression rate in patients with K-ras gene mutations was significantly higher than that in patients with wild-type K-ras gene mutations.

CONCLUSION

PD-L1 is highly expressed in colorectal cancer, and its expression is related to metastasis and tumor stage. PD-L1 expression is closely related to K-ras gene mutation, and the K-ras gene status may affect PD-L1 expression.

TRIAL REGISTRATION

retrospectively registered.

Comparative Analysis and in vitro Experiments of Signatures and Prognostic Value of Immune Checkpoint Genes in Colorectal Cancer

Purpose

Immune checkpoints, as pivotal regulators of immune escape in cancer, can motivate the emergence of immune checkpoint inhibitors (ICIs). The aim of this study is to identify the expression of the immune checkpoint genes (ICGs) in colorectal cancer (CRC) and to relate their individual as well as combined expression to prognosis and therapeutic effectiveness in CRC.

Methods

RNA expression of 47 ICGs and clinical information of CRC patients were collected from two public databases to elucidate the expression levels and prognostic values of these ICGs in CRC. Then, the Shapiro–Wilk normality test was used to determine the normality of variables. Overall survival (OS) rates of each subset were found by Kaplan–Meier method, and the statistical significance was determined by the Log rank test (p < 0.05).

Results

The expression of 13 and 9 ICGs was significantly associated with CRC prognosis in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) cohorts. A series of ICGs was found to be significantly associated with TMB, neoantigens and MMR in CRC indicating that the combination of immunotherapy treatment biomarkers and ICGs may achieve accurate prognostic stratification of CRC, and potentially identify CRC cases that might respond to checkpoint inhibitors (CPIs). The subsets of high or low PD1/PD-L1/IDO1 expression stratified by CD48 were accurately associated with prognosis in CRC. In addition, in vitro experiments confirmed that VTCN1(B7-H4)-KD increases anti-PD-L1-mediated NK cell cytotoxicity on CRC tumor cells.

Conclusion

Although the expression of a single immune-checkpoint molecule does not predict the efficacy of immunotherapy in CRC, our findings infer that subsets defined by ICGs are associated with prognosis and imply the possibility that VTCN1 and CD48 serve as new immunotherapeutic targets.

Tumor morphology and location associate with immune cell composition in pleomorphic sarcoma

Background

Soft-tissue sarcomas (STS) are a rare group of mesenchymal malignancies that account for approximately 1% of adult human cancer. Undifferentiated pleomorphic sarcoma (UPS) is one of the most common subtypes of adult STS. Clinical stratification of UPS patients has not evolved for decades and continues to rely on tumor-centric metrics including tumor size and depth. Our understanding of how the tumor microenvironment correlates to these clinicopathologic parameters remains limited.

Methods

Here, we performed single-cell flow cytometric immune-based profiling of 15 freshly resected UPS tumors and integrated this analysis with clinical, histopathologic, and outcomes data using both a prospective and retrospective cohort of UPS patients.

Results

We uncovered a correlation between physiologic and anatomic properties of UPS tumors and the composition of immune cells in the tumor microenvironment. Specifically, we identified an inverse correlation between tumor-infiltrating CD8 + T cells and UPS tumor size; and a positive correlation between tumor-infiltrating CD8 + T cells and overall survival. Moreover, we demonstrate an association between anatomical location (deep or superficial) and frequency of CD4 + PD1^hi infiltrating T cells in UPS tumors.

Conclusions

Our study provides an immune-based analysis of the tumor microenvironment in UPS patients and describes the different composition of tumor infiltrating lymphocytes based on size and tumor depth.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00262-021-02935-2.

PD-L1+ dendritic cells in the tumor microenvironment correlate with good prognosis and CD8+ T cell infiltration in colon cancer

Background

The prognostic value of tumor‐associated dendritic cells (DC) in colon cancer remains poorly understood. This may be in part due to the interchangeable expression of immunostimulatory and immunoinhibitory molecules on DC. Here we investigated the prognostic impact of CD11c⁺ DC co–expressing the immunoinhibitory molecule PD‐L1 and their spatial relationship with CD8⁺ T‐cells in patients treated for stage III colon cancer.

Methods

Tissue microarrays containing representative cores of central tumor, leading edge, and adjacent normal tissue from 221 patients with stage III colon cancer were immunostained for CD8, CD11c, PD‐L1, and cytokeratin using immunofluorescent probes. Cells were quantified using StrataQuest digital image analysis software, with intratumoral and stromal regions analyzed separately. Kaplan‐Meier estimates and Cox regression were used to assess survival.

Results

Intratumoral CD8⁺ cell density (HR = .52, 95% confidence interval [CI] .33‐.83, P = .007), stromal CD11c⁺ cell density (HR = .52, 95% CI .33‐.83, P = .006), intratumoral CD11c⁺PD‐L1⁺ cell density (HR = .57, 95% CI .35‐.92, P = .021), and stromal CD11c⁺PD‐L1⁺ cell density (HR = .48, 95% CI .30‐.77, P = .003) on leading‐edge cores were all significantly associated with good survival. CD8⁺ cell density was positively correlated with both CD11c⁺ cell density and CD11c⁺PD‐L1⁺ cell density in tumor epithelium and stromal compartments.

Conclusion

Here we showed that PD‐L1‐expressing DC in the tumor microenvironment are associated with improved survival in stage III colon cancer and likely reflect an immunologically “hot” tumor microenvironment. Further investigation into the expression of immunomodulatory molecules by tumor‐associated DC may help to further elucidate their prognostic value.

Clinicopathological and prognostic significance of PD-L1 expression in colorectal cancer: a meta-analysis

PURPOSE

To systematically evaluate the correlation between PD-L1 expression and clinicopathological features and prognosis of colorectal cancer (CRC).

METHODS

Seven databases (PubMed, Cochrane Library, EMBASE, Web of Science, CBM, Wanfang, and CNKI) were searched through May 2020. Risk of bias and quality of evidence were assessed by using the Newcastle-Ottawa scale (NOS), and meta-analysis was carried out by using the Review Manager 5.3 software on the studies with the quality evaluation scores ≥ 6. Meta-regression analysis was used to determine the independent role of PD-L1 expression on CRC prognosis after adjusting clinicopathological features and treatment methods.

RESULTS

A total of 8823 CRC patients in 32 eligible studies. PD-L1 expression was correlated with lymphatic metastasis (yes/no; OR = 1.24, 95% CI (1.11, 1.38)), diameter of tumor (≥ 5 cm/< 5 cm; OR = 1.34, 95% CI (1.06, 1.70)), differentiation (high-middle/low; OR = 0.68, 95% CI (0.53, 0.87)), and vascular invasion (yes/no; OR = 0.80, 95% CI (0.69, 0.92)). PD-L1 expression shortened the overall survival (hazard ratio (HR) = 1.93, 95% CI (1.66, 2.25)), disease-free survival (HR = 1.76, 95% CI (1.50, 2.07)), and progression-free survival (HR = 1.93, 95% CI (1.55, 2.41)). Meta-regression showed that PD-L1 expression played a significant role on poor CRC OS (HR = 1.95, 95% CI (1.92, 3.98)) and disease-free survival (HR = 2.14, 95% CI (0.73, 4.52)).

CONCLUSION

PD-L1 expression independently predicted a poor prognosis of CRC.

Impact of sidedness of colorectal cancer on tumor immunity

Background

Clinical and molecular characteristics differ between right-sided and left-sided colorectal cancer (CRC). This study aimed to clarify the correlation between CRC sidedness and tumor immunity.

Methods

A total of 102 patients who underwent curative colectomy for stage II/III CRC were included in this study. The expression of programmed cell death (PD)-1, PD1-ligand 1 (PD-L1), forkhead box P3 (Foxp3), transforming growth factor (TGF)-β, and indoleamine-pyrrole 2,3-dioxygenase (IDO) were examined using immunohistochemistry and the relationships between sidedness and several prognostic factors were examined.

Results

Clinicopathological factors were not significantly different between right- and left-sided CRC. The tumor immunity-related molecule PD-L1 was more highly expressed in right-sided than in left-sided CRC (62.9% vs. 30.6%, p<0.01). No significant difference was found in overall survival (OS) and disease-free survival (DFS) by sidedness. PD-1 and Foxp3 expression were significant prognostic factors for OS. Lymph node metastasis (N), lymphatic invasion (ly), and PD-L1 expression were significant prognostic factors for DFS. In right-sided CRC, IDO-positive patients had a poor OS (p<0.05), and IDO was the only independent prognostic indicator for OS. N and venous invasion were identified as independent prognostic indicators for DFS. In left-sided CRC, univariate analysis identified PD-1, PD-L1, and Foxp3 expression as significant predictors of poor OS. Multivariate analysis confirmed PD-L1 expression as an independent prognostic indicator. N, ly, and PD-L1 expression levels were identified as significant predictors of poor DFS.

Conclusions

The prognostic factors were IDO in right-sided CRC and PD-L1 and Foxp3 in left-sided CRC. These findings indicated that tumor immunity might play different roles depending upon sidedness. Tumor location may be an important factor to consider when assessing immune response and therapeutic decisions in CRC patients.

Radiotherapy Scheme Effect on PD-L1 Expression for Locally Advanced Rectal Cancer

In locally advanced rectal cancer, radiotherapy (RT) followed by surgery have improved locoregional control, but distant recurrences remain frequent. Although checkpoint inhibitors have demonstrated objective response in several cancers, the clinical benefit of PD-1/PD-L1 blockade remains uncertain in rectal cancer. We collected data from biopsies and surgical specimens in 74 patients. The main objective was to evaluate the impact of neoadjuvant RT and fractionation on PD-L1 expression. Secondary objectives were to study the relation between PD-L1 expression and tumor regression grade (TRG), progression-free survival (PFS), overall survival (OS), and CD8 TILs infiltration. Median rates of cells expressing PD-L1 pre- and post-RT were 0.15 (range, 0-17) and 0.5 (range, 0-27.5), respectively (p = 0.0005). There was no effect of RT fractionation on PD-L1+ cell rates. We found no relation between CD8+ TILs infiltration and PD-L1 expression and no difference between high-PD-L1 or low-PD-L1 expression and TRG. High-to-high PD-L1 expression profile had none significant higher OS and PFS compared to all other groups (p = 0.06). Median OS and PFS were higher in biopsies with >0.08 PD-L1+ cells. High-to-high PD-L1 profile and ypT0-2 were significantly associated with higher OS and PFS. This study did not show the differential induction of PD-L1 expression according to fractionation.

Clinical Impact of PD-L1 Expression for Survival in Curatively Resected Colon Cancer

BACKGROUND

Programmed death 1 (PD-1) and its ligand PD-L1 play a key dysfunction of T lymphocytes. The purpose of this study was to assess and compare the prognostic role of tumor- TILs and its relationship with PD-L1 expression in stage II and III colon cancer.

METHODS

Immunohistochemisty was used to assess the densities of CD8⁺, CD4⁺, and FOXP3⁺ cells, and PD-L1 expression in intraepithelial tumor site from 58 stage II and III colon cancers. These were evaluated for association with histopathologic features and overall survival.

RESULTS

PD-L1-positive tumors contained a higher number of CD8⁺ TILs with statistical significance (p = 0.001). CD4⁺ TILs showed positive correlation with PD-L1 expression (p = 0.034). There were no associations between PD-L1 expression and FOXP3⁺ TILs. Microsatellite instability (MSI)-high status (p = 0.001; Odd ration 18.0; 95% CI = 4.3-74.8) was the strongest prognostic factor along with mucinous/poor cell differentiation, CD8 and right tumor location was associated with PD-L1 expression (p = 0.024, 0.035 and 0.033, respectively).

CONCLUSION

This study demonstrated that PD-L1 expression was associated with MSI-high, increased CD8⁺ TILs, mucinous and poor cell differentiation, and right-sided tumor location.

Influence of Programmed Death Ligand-1-Gene Polymorphism rs822336 on the Prognosis and Safety of Postoperative Patients with NSCLC Who Received Platinum-Based Adjuvant Chemotherapy

Purpose

This study was done to investigate the influence of PDL1-gene polymorphism on the prognosis and safety of postoperative patients with non–small cell lung cancer (NSCLC) who had received platinum-based adjuvant chemotherapy.

Methods

A total of 289 postoperative patients with NSCLC who had received platinum-based adjuvant chemotherapy from January 2012 to June 2019 participated in this study. Recurrence status and adverse reactions were documented during adjuvant chemotherapy. Overall survival (OS) data were obtained through telephone follow-up. DNA extracted from hematologic specimens was genotyped for PDL1-gene polymorphism. Associations between genotype status and prognosis were assessed using Kaplan–Meier survival analysis, and multivariate adjustment was performed using Cox regression analysis.

Results

Median disease-free survival of the 289 patients with NSCLC was 3.3 years and median OS 4.9 years. With regard to the PDL1 gene polymorphism, only rs822336 was of clinical significance in the subsequent analysis. The minor-allele frequency of rs822336 was 0.21, and distribution of the three genotypes was in accordance with the Hardy–Weinberg equilibrium (P=0.807). Survival analysis according to genotype status suggested that median disease-free survival of patients with GG and GC/CC genotypes was 2.8 and 4.1 years, respectively (P=0.01). Median OS of patients with GG and GC/CC genotypes was 4.1 and 5.4 years, respectively (P=0.008). However, the safety analysis failed to find a significant association between the polymorphism and adverse reactions. Interestingly, expression analysis of RNA extracted from peripheral blood mononuclear cells indicated that PDL1-mRNA expression of patients with the GG genotype was significantly higher than for the GC/CC genotype (P<0.001).

Conclusion

The prognosis of postoperative patients with NSCLC who have received platinum-based adjuvant chemotherapy may be influenced by the rs822336 polymorphism through mediation of the mRNA expression of PDL1.

Differences in the immunosurveillance pattern associated with DNA mismatch repair status between right-sided and left-sided colorectal cancer

Tumor location and immunity play important roles in the progression of colorectal cancer (CRC). This study aimed to investigate the differences in the immunosurveillance pattern between right‐ and left‐sided CRC and analyze their association with clinicopathologic features, including mismatch repair (MMR) status. We included surgically resected stage II/III CRC cases and evaluated the immunohistochemical findings of HLA class I, HLA class II, programmed cell death‐ligand 1 (PD‐L1), PD‐1, CTLA‐4, CD3, CD4, CD8, TIA‐1, T‐bet, GATA3, RORγT, Foxp3, and CD163. A total of 117 patients were included in the analyses; of these, 30 and 87 had right‐ and left‐sided cancer, respectively. Tumor immunity varied according to the tumor location in the overall cohort. Analysis of the tumors excluding those with DNA mismatch repair (MMR) deficiency also revealed that tumor immunity differed according to the tumor location. In right‐sided colon cancer (CC), high expression of Foxp3 (P = .0055) and TIA‐1 (P = .0396) were associated with significantly better disease‐free survival (DFS). High CD8 (P = .0808) and CD3 (P = .0863) expression tended to have better DFS. Furthermore, in left‐sided CRC, only high PD‐L1 expression in the stroma (P = .0426) was associated with better DFS. In multivariate analysis, high Foxp3 expression in right‐sided CC was an independent prognostic factor for DFS (hazard ratio, 7.6445; 95% confidence interval, 1.2091‐150.35; P = .0284). In conclusion, the immunosurveillance pattern differs between right‐ and left‐sided CRC, even after adjusting for MMR deficiency.

Prognostic Impact of PD-1 and Tim-3 Expression in Tumor Tissue in Stage I-III Colorectal Cancer

Background

Programmed cell death receptor 1 (PD-1) and T cell immunoglobulin mucin-3 (Tim-3) are considered as important immunosuppressive molecules and play an important role in tumor immune escape and cancer progression. However, it remains unclear whether PD-1 and Tim-3 are coexpressed in stage I-III colorectal cancer (CRC) and how they impact on the prognosis of the disease.

Materials and Methods

A total of two cohorts with 451 patients who underwent surgery for stage I-III CRC treatment were enrolled in the study. Among which, 378 cases were from The Cancer Genome Atlas (TCGA) database and 73 cases were from the Fourth Hospital of Hebei Medical University (FHHMU) cohort. The mRNA expressions of PD-1 and Tim-3 in tumor tissue in stage I-III CRC were obtained from TCGA database. Immunohistochemistry was used to assess the expressions of PD-1 and Tim-3 in tumor tissue in stage I-III CRC in the FHHMU cohort. Interactive relationships between PD-1 and Tim-3 were retrieved through the online STRING database, which was used to study the interactions between proteins. DAVID, consisting of comprehensive biological function annotation information, was applied for the GO and KEGG pathway enrichment analysis of the interactive genes.

Results

In the FHHMU cohort, the high expressions of PD-1 and Tim-3 were, respectively, found in 42.47% and 84.93% of stage I-III CRC tissue. PD-1 was significantly associated with age, primary site, and lymphatic metastasis. Tim-3 was closely related to the primary site. Correlation analysis showed that PD-1 and Tim-3 were positively correlated (r = 0.5682, P < 0.001). In TCGA cohort, PD-1 and Tim-3 were associated with the prognosis of CRC patients in terms of 5-year survival (P < 0.05). In the FHHMU cohort, the 5-year survival of patients with high levels of PD-1 and Tim-3 was 54.84% and 65.85%, respectively. Among which, the high expression of PD-1 was associated with poor prognosis (5-year OS: 54.84% vs. 88.10%, P = 0.003). The 5-year survival rate of CRC patients with coexpression of PD-1 and Tim-3 was 45.00%, which was significantly worse than non-coexpression (72.73%, 85.71%, and 90.48% separately). The functional network of PD-1 and Tim-3 primarily participates in the regulation of immune cell activation and proliferation, immune cell receptor complex, cell adhesion molecules, and T cell receptor signaling pathway.

Conclusion

In summary, upregulation of PD-1 and Tim-3 in stage I-III CRC tumor tissue could be associated with the poor prognosis of patients. Those patients with coexpression of PD-1 and Tim-3 may have a significantly worse prognosis.

Overcoming resistance to anti-PD1 and anti-PD-L1 treatment in gastrointestinal malignancies

In the last few years, the unprecedented results of immune checkpoint inhibitors have led to a paradigm shift in clinical practice for the treatment of several cancer types. However, the vast majority of patients with gastrointestinal cancer do not benefit from immunotherapy. To date, microsatellite instability high and DNA mismatch repair deficiency are the only robust predictive biomarkers of response to immune checkpoint inhibitors. Unfortunately, these patients comprise only 5%-10% of all gastrointestinal cancers. Several mechanisms of both innate and adaptive resistance to immunotherapy have been recognized that may be at least in part responsible for the failure of immune checkpoint inhibitors in this population of patients. In the first part of this review article, we provide an overview of the main clinical trials with immune checkpoint inhibitors in patients with gastrointestinal cancer and the role of predictive biomarkers. In the second part, we discuss the actual body of knowledge in terms of mechanisms of resistance to immunotherapy and the most promising approach that are currently under investigation in order to expand the population of patients with gastrointestinal cancer who could benefit from immune checkpoint inhibitors.

The influence of PD-L1 genetic variation on the prognosis of R0 resection colorectal cancer patients received capecitabine-based adjuvant chemotherapy: a long-term follow-up, real-world retrospective study

PURPOSE

This study investigated the influence of PD-L1 genetic variation on the prognosis of R0 resection colorectal cancer (CRC) patients who received capecitabine-based adjuvant chemotherapy in real world.

METHODS

A total of 315 CRC patients underwent R0 surgical resection and received capecitabine-based adjuvant chemotherapy were included. Clinical characteristics were collected from the hospital record system, prognosis was obtained by telephone follow-up. Peripheral blood and peripheral blood mononuclear cell (PBMC) specimen of CRC patients were performed for the genotyping of polymorphism and mRNA expression of PD-L1, respectively. Analysis on the association between genotypes and prognosis was conducted.

RESULTS

The median disease-free survival (DFS) of the 315 CRC patients was 5.1 years, the median overall survival (OS) was 6.0 years. Regarding the PD-L1 gene polymorphism analysis, the prevalence of 901T>C among the CRC patients was as follows: TT genotype 221 cases (70.16%), TC genotype 86 cases (27.30%), CC genotype 8 cases (2.54%), the minor allele frequency was 0.16, the distribution of three genotypes was in accordance with Hardy-Weinberg equilibrium (P = 0.915). Moreover, the prognosis analysis indicated that the median DFS of patients with TT and TC/CC genotype was 5.4 and 4.0 years, respectively (P = 0.008). The median OS of patients with the two genotypes was 6.4 and 5.0 years (P = 0.007). The multivariate Cox regression analysis showed that the TC/CC genotypes were an independent factor for DFS (odds ratio = 1.56, P = 0.018). Furthermore, the mRNA expression results indicated that the mRNA expression of PD-L1 in PBMC of the patients with TC/CC genotype was significantly higher than patients with TT genotype (P < 0.001).

CONCLUSION

The prognosis of R0 resection CRC patients received capecitabine-based adjuvant chemotherapy in real world may be influenced by PD-L1 901T>C polymorphism through mediation of the mRNA expression of PD-L1.

Prevalence of PD-L1 expression is associated with EMAST, density of peritumoral T-cells and recurrence-free survival in operable non-metastatic colorectal cancer

INTRODUCTION

Microsatellite instability (MSI) predict response to anti-PD1 immunotherapy in colorectal cancer (CRC). CRCs with MSI have higher infiltration of immune cells related to a better survival. Elevated Microsatellite Alterations at Tetranucleotides (EMAST) is a form of MSI but its association with PD-L1 expression and immune-cell infiltration is not known.

METHODS

A consecutive, observational cohort of patients undergoing surgery for CRC. EMAST and clinicopathological characteristics were investigated against PD-L1, as well as CD3 and CD8 expression in the invasive margin or tumour centre (Immunoscore). Difference in survival between groups was assessed by log rank test.

RESULTS

A total of 149 stage I-III CRCs patients, with a median follow up of 60.1 months. Patients with PD-L1+ tumours (7%) were older (median 79 vs 71 years, p = 0.045) and had EMAST+ cancers (OR 10.7, 95% CI 2.2-51.4, p = 0.001). Recurrence-free survival was longer in cancers with PD-L1+ immune cells (HR 0.35, 95% CI 0.16-0.76, p = 0.008, independent of EMAST) and high Immunoscore (HR 0.10, 95% CI 0.01-0.72, p = 0.022). Patients expressing PD-L1 in immune cells had longer disease-specific survival (HR 0.28, 95% CI 0.10-0.77, p = 0.014).

CONCLUSIONS

Higher Immunoscore (CD3/CD8 cells) and expression of tumour PD-L1 is found in CRCs with EMAST. Lymphocytic infiltrate and peritumoral PD-L1 expression have prognostic value in CRC.

Immune Profiling of Deficient Mismatch Repair Colorectal Cancer Tumor Microenvironment Reveals Different Levels of Immune System Activation

To understand the immune landscape of deficient mismatch repair colorectal cancer (dMMR CRC) tumor microenvironment, gene expression profiling was performed by the nCounter PanCancer Immune Profiling Panel. This study was conducted retrospectively on 89 dMMR-CRC samples. The expression of CD3, CD8, programmed death-1, and programmed death ligand-1 protein was evaluated on a subset of samples by immunohistochemistry, and lymphocyte density was calculated. A subset of deregulated genes was identified. Functional clustering analysis performed on these genes generated four main factors: antigen processing and presentation, with its major histocompatibility complex-II-related genes; genes correlated with the cytotoxic activity of immune system; T-cell chemotaxis/cell adhesion genes; and T-CD4⁺ regulator cell-related genes. A deregulation score (DS) was calculated for each sample. On the basis of their DS, tumors were then classified as COLD (DS ≤ -3) to select the samples with a strong down-regulation of the immune system and NOT COLD (DS ≥ -2). The COLD group of patients showed a worse prognosis in terms of survival considering all patients (P = 0.0172) and patients with metastatic disease (P = 0.0031). These results confirm that dMMR-CRCs do not constitute a homogeneous group as concerns the immune system activity of tumor microenvironment. In particular, the distinction between COLD and NOT COLD tumors may improve the management of these two subsets of patients.

Targeted Nano-Drug Delivery of Colchicine against Colon Cancer Cells by Means of Mesoporous Silica Nanoparticles

Antimitotics are important anticancer agents and include the natural alkaloid prodrug colchicine (COL). However, a major challenge of using COL as an anticancer drug is its cytotoxicity. We developed a novel drug delivery system (DDS) for COL using mesoporous silica nanoparticles (MSNs). The MSNs were functionalized with phosphonate groups, loaded with COL, and coated with folic acid chitosan-glycine complex. The resulting nanoformulation, called MSNsPCOL/CG-FA, was tested for action against cancer and normal cell lines. The anticancer effect was highly enhanced for MSNsPCOL/CG-FA compared to COL. In the case of HCT116 cells, 100% inhibition was achieved. The efficiency of MSNsPCOL/CG-FA ranked in this order: HCT116 (colon cancer) > HepG2 (liver cancer) > PC3 (prostate cancer). MSNsPCOL/CG-FA exhibited low cytotoxicity (4%) compared to COL (~60%) in BJ1 normal cells. The mechanism of action was studied in detail for HCT116 cells and found to be primarily intrinsic apoptosis caused by an enhanced antimitotic effect. Furthermore, a contribution of genetic regulation (metastasis-associated lung adenocarcinoma transcript 1 (MALAT 1), and microRNA (mir-205)) and immunotherapy effects (angiopoietin-2 (Ang-2 protein) and programmed cell death protein 1 (PD-1) was found. Therefore, this study shows enhanced anticancer effects and reduced cytotoxicity of COL with targeted delivery compared to free COL and is a novel method of developing cancer immunotherapy using a low-cost small-molecule natural prodrug.

Pre-diagnostic anthropometry, sex, and risk of colorectal cancer according to tumor immune cell composition

Obesity is a well-established risk factor for colorectal cancer (CRC), but the association with the tumor microenvironment has been sparsely described. Herein, we examined the relationship between pre-diagnostic anthropometry and CRC risk according to tumor immune cell composition, with particular reference to potential sex differences.

The density of different immune cell subsets was assessed by immunohistochemistry in tissue microarrays with tumors from 584 incident CRC cases in a prospective, population-based cohort (n = 28098). Multivariable Cox regression models, adjusted for age, smoking, alcohol intake, and educational level, were applied to calculate risk of immune marker-defined CRC in relation to quartiles of pre-diagnostic height, weight, body mass index (BMI), waist and hip circumferences, waist-hip ratio (WHR), and body fat percentage (BFP).

Obesity was all over significantly associated with risk of CRC with low density of FoxP3⁺ T cells and low programmed cell-death protein 1 (PD-L1) expression on tumor cells, but with high density of CD8⁺ T cells and CD20⁺ B cells. In women, obesity was significantly associated with risk of PD-L1 high tumors (p= 0.009 for weight, p= 0.039 for BMI). Contrastingly, in men, obesity defined by all anthropometric factors was significantly associated with PD-L1 low tumors (p= 0.005 for weight, p = 0.002 for BMI, p<0.001 for waist, p= 0.011 for hip, p<0.001 for WHR, and p= 0.004 for BFP).

In summary, obesity appears to influence the immune landscape of CRC, possibly in a sex-dependent manner. Thus, anthropometry and sex may be important factors to take into account when assessing the prognostic or predictive value of relevant complementary immune biomarkers.

Association between PD-1 and PD-L1 Polymorphisms and the Risk of Cancer: A Meta-Analysis of Case-Control Studies

A number of case-control studies regarding the association of the polymorphisms in the programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) genes with the risk of cancer have yielded inconsistent findings. Therefore, we have conducted a comprehensive, updated meta-analysis study to identify the impact of PD-1 and PD-L1 polymorphisms on overall cancer susceptibility. The findings revealed that PD-1 rs2227981 and rs11568821 polymorphisms significantly decreased the overall cancer risk (Odds Ratio (OR) = 0.82, 95% CI = 0.68–0.99, p = 0.04, TT vs. CT+CC; OR = 0.79, 95% CI = 0.67–0.94, p = 0.006, AG vs. GG, and OR = 0.82, 95% CI = 0.70–0.96, p = 0.020, AG+AA vs. GG, respectively), while PD-1 rs7421861 polymorphism significantly increased the risk of developing cancer (OR = 1.16, 95% CI = 1.02–1.33, p = 0.03, CT vs. TT). The PD-L1 rs4143815 variant significantly decreased the risk of cancer in homozygous (OR = 0.62, 95% CI = 0.41–0.94, p = 0.02), dominant (OR = 0.70, 95% CI = 0.50–0.97, p = 0.03), recessive (OR = 0.76, 95% CI = 0.60–0.96, p = 0.02), and allele (OR = 0.78, 95% CI = 0.63–0.96, p = 0.02) genetic models. No significant association between rs2227982, rs36084323, rs10204525, and rs2890658 polymorphisms and overall cancer risk has been found. In conclusions, the results of this meta-analysis have revealed an association between PD-1 rs2227981, rs11568821, rs7421861, as well as PD-L1 rs4143815 polymorphisms and overall cancer susceptibility.

M2 macrophage infiltration into tumor islets leads to poor prognosis in non-small-cell lung cancer

Background: Lung cancer is the leading cause of cancer-related death worldwide. Although the macrophages can affect the development of tumor, the contribution of macrophages to the prognosis of non-small-cell lung cancer (NSCLC) is still controversial. Moreover, anti-PD-1 therapy can redirect macrophages from an M2 to an M1 phenotype, suggesting that tumor PD-L1 may affect the prognostic role of macrophages. Therefore, in this study, we aimed to display a macrophage landscape to clarify the function of macrophages, considering the localization and polarization of the macrophages, and evaluate the effect of M2 macrophages and tumor PD-L1 in combination on the prognosis of NSCLC. Methods: We performed multiplex quantitative immunofluorescence staining of pan-cytokeratin (CK), CD68, CD163, PD-L1, and DAPI on one tissue specimen simultaneously from 137 NSCLC patients. Results: M2 macrophages, involved marginM2 (M2 macrophages in tumor stroma), and centralM2 (M2 macrophages infiltrating into tumor islets) increased as the tumor stage increased. More macrophages were found in lung squamous cell carcinoma (LUSC) patients, patients with wild-type EGFR, and smokers than in patients with lung adenocarcinoma (LUAD), patients with EGFR mutations, and non-smokers. Infiltration of centralM2 was an independent prognostic factor of poor overall survival (OS) and disease-free survival (DFS) for NSCLC patients (P<0.05), which was superior to total macrophages and total M2 macrophages. Moreover, patients with centralM2^lessPD-L1^- tumors showed the best OS and DFS, while the patients with centralM2^morePD-L1⁺ tumors showed the worst OS and DFS, and the two groups with centralM2^lessPD-L1⁺ and centralM2^morePD-L1^- were in the middle (P=0.002, 0.034, respectively). Conclusion: Tumor islet-infiltrating M2 macrophages influence the prognosis of NSCLC patients. The analysis of M2 macrophages and tumor PD-L1 in combination may enhance the accuracy of prognostic prediction. This study provides a new understanding of macrophages in the development of NSCLC through the analysis of macrophage landscape.

Expression of PD-L1 and PD-1 in Chemoradiotherapy-Naïve Esophageal and Gastric Adenocarcinoma: Relationship With Mismatch Repair Status and Survival

Background: The outlook for patients with esophageal and gastric (EG) cancer remains poor. Hence, there is a compelling need to identify novel treatment strategies and complementary biomarkers. Programmed death ligand 1 (PD-L1) and mismatch repair deficiency (dMMR) are putative biomarkers of response to immune-checkpoint blockade, but their prognostic value and interrelationship in EG cancer have been sparsely investigated.

Methods: Immunohistochemical expression of PD-L1 on tumour cells (TC) and tumour-infiltrating immune cells (TIC), and of PD-1 (programmed death receptor 1) on TIC was assessed using tissue microarrays with primary tumours and a subset of paired lymph node metastases from a consecutive, retrospective cohort of 174 patients with chemoradiotherapy-naïve EG adenocarcinoma. MMR proteins MLH1, PMS2, MSH2, and MSH6 were assessed by immunohistochemistry. The total number (intratumoural, tumour-adjacent, and stromal) of CD8⁺ T cells in each core was calculated by automated analysis.

Results: High PD-L1 expression on both TC and TIC, but not PD-1 expression, was significantly associated with dMMR. PD-L1 expression on TIC was significantly higher in lymph node metastases than in primary tumours. High expression of PD-L1 or PD-1 on TIC was significantly associated with a prolonged survival, the former independently of established prognostic factors. A significant stepwise positive association was found between CD8⁺ T cells and categories of PD-L1 expression on TIC.

Conclusion: PD-L1 expression on TIC is higher in lymph node metastases compared to primary tumours, correlates with dMMR, and is an independent factor of prolonged survival in patients with chemoradiotherapy-naïve EG adenocarcinoma. These findings suggest that PD-L1 expression on TIC may be a useful biomarker for identifying patients who may not need additional chemo- or chemoradiotherapy, and who may benefit from PD-1/PD-L1 immune-checkpoint blockade.

First-in-class ruthenium anticancer drug (KP1339/IT-139) induces an immunogenic cell death signature in colorectal spheroids in vitro

ICD enhances antigenicity from dying cancer cells, which leads to antitumor immunity. We show for the first time that a ruthenium-complex induces the ICD signature in a 3D model.

The clinicopathological and prognostic value of programmed death-ligand 1 in colorectal cancer: a meta-analysis

INTRODUCTION

Programmed death-ligand 1 (PD-L1) is reportedly expressed in colorectal tumors. However, the prognostic role of PD-L1 in colorectal cancer (CRC) remains controversial. Therefore, we performed a meta-analysis to investigate the clinicopathological and prognostic impact of PD-L1 in CRC.

METHODS

A comprehensive search in PubMed, Embase, the Cochrane Library, Web of Science and the ClinicalTrials.gov for publications about PD-L1 expression in colorectal cancer was done. The correlation between PD-L1 expression and clinicopathological features or survival outcomes was analyzed by odds ratios (OR) or hazard ratios (HR), at 95% confidence intervals (CI).

RESULTS

The results show that the pooled HR of (1.34, 95% CI 1.02-1.65, p = 0.01) indicated the association of PD-L1 expression with overall survival (OS) in CRC patients. Meanwhile, the expression of PD-L1 was positively correlated with the lymph node metastasis (OR: 0.70, 95% CI 0.51-0.95, p = 0.00), gender (OR: 0.86, 95% CI 0.76-0.98, p = 0.05) and tumor location (OR: 1.39, 95% CI 1.14-1.71, p = 0.12).

CONCLUSIONS

These results suggest that high expression of PD-L1 is associated with low OS in CRC. High PD-L1 expression may act as a negative factor for patients with CRC and help to identify patients suitable for anticancer therapy.