Programmed cell death ligand-1 protein expression and CD274/PD-L1 gene amplification in colorectal cancer: Implications for prognosis

Immunohistochemical expression of PD-L1 in colorectal carcinoma among black patients and the clinicopathological correlates: a cross-sectional study

BACKGROUND

Colorectal cancer (CRC) incidence is rising in Nigeria, with majority of patients presenting with advanced disease. Despite promising results of PD-L1 antibody therapy in clinical trials, efficacy data exclusively derives from Caucasian populations, leaving a critical knowledge gap for African populations. This study investigated PD-L1 expression in CRC among blacks, correlating it with clinicopathologic parameters.

METHODS

The immunohistochemical expression of PD-L1 was evaluated in 96 cases of CRC diagnosed between February 2022 and January 2024, using formalin-fixed paraffin-embedded (FFPE) tissue blocks. Statistical analysis was performed using SPSS version 25. The relationships between the PD-L1 expression and the clinicopathological parameters of CRC patients were determined using the chi-square test and Spearman's rank correlation. p < 0.05 was considered to be statistically significant.

RESULTS

CRC showed a male: female ratio of 1:1.8, most occurred in the seventh decade and 54.17% were right-sided. Adenocarcinoma NOS accounted for 72.5%. The majority (n = 55, 57.3%) of the patients were diagnosed at an advanced stage. PD-L1 expression was observed in 86.46% of cases, significantly correlating with tumour Size (r = 0.263, p = 0.010*), histologic Grade (r = 0.446, p = 0.000*) and tumour Stage (r = 0.367, p = 0.000*).

CONCLUSION

This study highlighted the high frequency of PD-L1 expression in CRC among black patients, with significant associations to clinicopathologic parameters. The findings suggest the potential benefit of PD-1/PD-L1 targeted therapies and emphasize the need for enhanced early detection and screening in Nigeria.

A Comprehensive Study on the Prognostic Value and Clinicopathological Significance of Different Immune Checkpoints in Patients With Colorectal Cancer: A Systematic Review and Meta-Analysis

Background

The prognostic significance of immune checkpoint expression in the tumor microenvironment has been widely investigated in colorectal cancers. However, the results of these studies are inconsistent and limited to some immune checkpoints.

Objective

The study aimed to investigate the correlation between different immune checkpoint expression and clinicopathological features and prognostic parameters.

Methods

We conducted a systematic review and meta-analysis of the published literature in PubMed, Web of Science-Core Collection, Scopus, Embase, and Cochrane databases to summarize the association between various immune checkpoints expression on both tumor cells and immune cells with clinicopathological features and prognostic parameters in patients with colorectal cancer.

Results

One hundred four studies incorporating 22,939 patients were included in our meta-analysis. Our results showed that among the B7 family, the high expression of B7H3, B7H4, PD-1, and PD-L1 on tumor cells and tumor tissue was significantly associated with higher T stage, advanced tumor, node, metastasis (TNM) stage, presence of vascular invasion, and lymphatic invasion. In addition, patients with high expression of B7H3, B7H4, PD-1, PD-L1, and PD-L2 were associated with shorter overall survival. High expression of PD-1 and PD-L1 in immune cells correlated with the absence of lymph node metastasis, lower TNM stage, early T stage, poor overall survival, and disease-free survival, respectively. Moreover, we found significant positive correlations between CD70 and Galectin-3 expression with advanced T stage. HLA-II overexpression was correlated with the absence of lymph node metastasis (odds ratio = 0.21, 95% CI = 0.11-0.38, P < 0.001) and early TNM stage (odds ratio = 0.35, 95% CI = 0.26-0.47, P < 0.001).

Conclusions

Overexpression of B7H3, B7H4, PD-1, PD-L1, PD-L2, CD70, and Galectin-3 on tumors is significantly associated with unfavorable clinicopathological characteristics and poor prognostic factors. Hence, these immune checkpoints can serve as predictive biomarkers for prognosis and the clinicopathological features of colorectal cancer because this is essential to identify patients suitable for anticancer therapy with immune checkpoint inhibitors.

The prognostic value of programmed death-ligand 1 (PD-L1) expression in resected colorectal cancer without neoadjuvant therapy - differences between antibody clones and cell types

BACKGROUND

Programmed death-ligand 1 (PD-L1) expression on tumor cells is associated with poor prognosis in several malignancies, while partly contradictory and inconclusive results have been presented for colorectal cancer (CRC). This study aimed to evaluate PD-L1 as a prognostic biomarker in CRC by comparing three different antibody clones.

METHODS

Patients surgically treated for CRC between January 1st, 2007, and December 31st, 2015, in Kalmar County, Sweden, were retrospectively included. Tissue microarrays from 862 primary tumors without neoadjuvant treatment were assessed for immunohistochemical expression of PD-L1 in tumor cells (TC) and immune cells (IC) using clones 73-10, SP263, and 22C3. Cox regression proportional hazard models were used to estimate hazard ratios for overall survival (OS) and disease-free interval (DFI) in univariable and multivariable analyses, with 1% and 5% set as cut-offs for positive expression in TC and IC respectively.

RESULTS

PD-L1 expression in TC was found in 89 (10%) cases for clone 73-10, 76 (9%) for clone SP263, and 38 (4%) for clone 22C3, while the numbers for IC were 317 (37%) cases for clone 73-10, 264 (31%) for clone SP263, and 89 (10%) for clone 22C3. PD-L1 expression in IC was associated with prolonged OS and DFI in univariable analysis for all three clones. The link to prolonged DFI remained in multivariable analysis for 73-10 and SP263, but only for 73-10 regarding OS. PD-L1 expression in TC was not prognostic of OS in any analysis, while it was associated with prolonged DFI for SP263, and a trend was seen for 73-10. The link to prolonged DFI remained for SP263 and was strengthened for 73-10 in multivariable analysis.

CONCLUSIONS

The prognostic value of PD-L1 expression in both IC and TC differs between antibody clones, with 73-10 and SP263 being more reliable for prognostic information than 22C3 in resected CRC.

Immune checkpoint inhibitors in colorectal cancer: limitation and challenges

Colorectal cancer exhibits a notable prevalence and propensity for metastasis, but the current therapeutic interventions for metastatic colorectal cancer have yielded suboptimal results. ICIs can decrease tumor development by preventing the tumor's immune evasion, presenting cancer patients with a new treatment alternative. The increased use of immune checkpoint inhibitors (ICIs) in CRC has brought several issues. In particular, ICIs have demonstrated significant clinical effectiveness in patients with MSI-H CRC, whereas their efficacy is limited in MSS. Acquired resistance can still occur in patients with a positive response to ICIs. This paper describes the efficacy of ICIs currently in the clinical treatment of CRC, discusses the mechanisms by which acquired resistance occurs, primarily related to loss and impaired presentation of tumor antigens, reduced response of IFN-λ and cytokine or metabolic dysregulation, and summarizes the incidence of adverse effects. We posit that the future of ICIs hinges upon the advancement of precise prediction biomarkers and the implementation of combination therapies. This study aims to elucidate the constraints associated with ICIs in CRC and foster targeted problem-solving approaches, thereby enhancing the potential benefits for more 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.

Immunohistochemical Expression of Programmed Death Ligand- 1 (PD-L1) in Colorectal Carcinoma; A Cross-sectional Study

Background & Objective

Colorectal carcinoma (CRC) is one of the most common cancers worldwide. The interaction of programmed cell death receptor 1 (PD-1) and programmed death ligand 1 (PD-L1) plays an important role by inhibiting the immune mechanism by which cancer cells escape antitumor immunity. Immunotherapy using checkpoint inhibitors is a growing treatment modality in many cancers; one such is anti-PD1/PD-L1. The present study aimed to study the immunohistochemical (IHC) expression of PD-L1 in CRC and its association with various known clinicopathological parameters.

Methods

This study was a 2-year prospective study and included 34 colectomy specimens diagnosed as colorectal adenocarcinoma. The expression of PD-L1 was evaluated on tumoral cells and tumor-infiltrating immune cells (TIICs) and was correlated with various clinicopathological parameters.

Results

Immunohistochemical expression of PD-L1 on tumoral cells and tumor microenvironment in CRC revealed positivity in 17.65% of cases each. The PD-L1 expression on tumoral cells was associated with lymphovascular invasion (LVI) and perineural invasion (PNI) with P- values of 0.012 and 0.005, respectively, while PD-L1 expression on TIICs was associated with tumor budding with a P-value of 0.022.

Conclusion

IHC expression of PD-L1 on tumoral cells and immune cells may be associated with some known poor prognostic factors. Since anti-PD1/PD-L1 is used for targeted therapy, it may be beneficial and economically feasible to evaluate PD-L1 in CRC and establish its role as a prognostic factor.

Krüppel-like Factor-9 and Krüppel-like Factor-13: Highly Related, Multi-Functional, Transcriptional Repressors and Activators of Oncogenesis

Specificity Proteins/Krüppel-like Factors (SP/KLF family) are a conserved family of transcriptional regulators. These proteins share three highly conserved, contiguous zinc fingers in their carboxy-terminus, requisite for binding to cis elements in DNA. Each SP/KLF protein has unique primary sequence within its amino-terminal and carboxy-terminal regions, and it is these regions which interact with co-activators, co-repressors, and chromatin-modifying proteins to support the transcriptional activation and repression of target genes. Krüppel-like Factor 9 (KLF9) and Krüppel-like Factor 13 (KLF13) are two of the smallest members of the SP/KLF family, are paralogous, emerged early in metazoan evolution, and are highly conserved. Paradoxically, while most similar in primary sequence, KLF9 and KLF13 display many distinct roles in target cells. In this article, we summarize the work that has identified the roles of KLF9 (and to a lesser degree KLF13) in tumor suppression or promotion via unique effects on differentiation, pro- and anti-inflammatory pathways, oxidative stress, and tumor immune cell infiltration. We also highlight the great diversity of miRNAs, lncRNAs, and circular RNAs which provide mechanisms for the ubiquitous tumor-specific suppression of KLF9 mRNA and protein. Elucidation of KLF9 and KLF13 in cancer biology is likely to provide new inroads to the understanding of oncogenesis and its prevention and treatments.

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

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

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.

Exploring immunotherapy in colorectal cancer

Chemotherapy combined with or without targeted therapy is the fundamental treatment for metastatic colorectal cancer (mCRC). Due to the adverse effects of chemotherapeutic drugs and the biological characteristics of the tumor cells, it is difficult to make breakthroughs in traditional strategies. The immune checkpoint blockades (ICB) therapy has made significant progress in the treatment of advanced malignant tumors, and patients who benefit from this therapy may obtain a long-lasting response. Unfortunately, immunotherapy is only effective in a limited number of patients with microsatellite instability-high (MSI-H), and segment initial responders can subsequently develop acquired resistance. From September 4, 2014, the first anti-PD-1/PD-L1 drug Pembrolizumab was approved by the FDA for the second-line treatment of advanced malignant melanoma. Subsequently, it was approved for mCRC second-line treatment in 2017. Immunotherapy has rapidly developed in the past 7 years. The in-depth research of the ICB treatment indicated that the mechanism of colorectal cancer immune-resistance has become gradually clear, and new predictive biomarkers are constantly emerging. Clinical trials examining the effect of immune checkpoints are actively carried out, in order to produce long-lasting effects for mCRC patients. This review summarizes the treatment strategies for mCRC patients, discusses the mechanism and application of ICB in mCRC treatment, outlines the potential markers of the ICB efficacy, lists the key results of the clinical trials, and collects the recent basic research results, in order to provide a theoretical basis and practical direction for immunotherapy strategies.

The clinicopathological features of programmed death ligand-1 expression in colorectal carcinoma

Background

Few studies have addressed the clinicopathological features of colorectal cancer (CRC) that express programed death-ligand 1 (PD-L1). Various assays and scoring methodologies were used and thus inconsistent results were obtained. In this study, we aimed to investigate the relationship of PD-L1 expression in CRC with various clinicopathological variables using a standardized assay and scoring algorithm.

Design

Tissue microarrays were constructed from 91 random cases of CRC diagnosed at King Hussein Cancer Center (KHCC). Immunohistochemical (IHC) staining using the monoclonal antibody 22C3 was performed. Scoring using the standard “Combined Positive Score” (CPS) method was done. CPS of ≥1 was considered positive. Various clinicopathological features were collected from the medical records of the patients.

Results

Of the 91 cases, 49 (53.8%) were PD-L1 positive (CPS ≥1). PD-L1 expression was more frequent among moderately differentiated carcinomas (43 of 72 (59.7%) were positive compared to 6 of 19 (31.5%) poorly differentiated cases ( P = 0.029)); among node negative cases (21 of 24 (87.5%) N0 cases were PD-L1 positive in contrast to 28 of 67 (41.8%) N1/N2 cases ( P = <0.001)); among mucinous subtype (12 of 15 (80%) of cases ( P = 0.02)); and among mismatch repair deficient (dMMR) (16 of 16 (100%) versus 11 of 30 (36.6%) MMR proficient ( P = <0.001)). Age, gender, localization, and T or M stages were not significantly associated with PD-L1 expression.

Conclusion

PD-L1 expression in CRC is associated with favorable prognostic features; namely, lower grade, N0, mucinous variant, and dMMR tumors.

Immune Profile of BRAF-Mutated Metastatic Colorectal Tumors with Good Prognosis after Palliative Chemotherapy

Background: BRAF-mutated colorectal cancers (BRAF-MT CRCs) are known to have poor prognoses. BRAF-MT CRC was reported to be possibly related to the immune-activated phenotype. Objectives: This study aimed to investigate the association between the immune microenvironment and prognosis of BRAF-MT CRC. Methods: We evaluated clinical outcomes and investigated the immune profile of the BRAF-MT CRC tumors using the multiplex immunohistochemistry of immune-related markers: cytokeratin, programmed death ligand-1 (PD-L1), programmed cell death protein-1 (PD-1), and a cluster of differentiation 8 (CD8). Results: Out of 2313 tumors, 123 were BRAF-MT tumors. Among them, 86 tumors with available tissue were included. Out of 86 patients, 75 patients were non-good responders (GR), whereas 11 patients were GR. Median progression-free survival after first-line chemotherapy (4.6 vs. 12.4 months, p = 0.008) and overall survival (11.8 vs. 45.0 months) were longer in the GR group (p < 0.001). Median CD8+ T cell (254.29 vs. 656.0, p = 0.092), PD-L1+ tumor cell (0.95 vs.15.56, p = 0.050), PD-L1+ stromal cell (3.17 vs. 72.38, p = 0.025), PD-L1+ tumor and stromal cell (5.08 vs. 74.92, p = 0.032), and PD-1+ stromal cell (45.08 vs. 325.40, p = 0.046) counts were greater in the GR group. Conclusion: The clinical outcomes of unselected patients with BRAF-MT CRC were generally similar to those in previous studies. Based on the immune profile analysis, higher PD-L1 expression and CD8-positive cell infiltration were observed in BRAF-MT tumors with a good prognosis.

Programmed death-ligand 1 and mammalian target of rapamycin signaling pathway in locally advanced rectal cancer

PURPOSE

To evaluate the role of programmed death-ligand 1 (PD-L1) and mammalian target of rapamycin (mTOR) signaling pathway in locally advanced rectal cancer (LARC).

METHODS

Between February 2012 and February 2018, 103 patients with LARC treated by neoadjuvant chemoradiotherapy (neoCRT) and total mesorectal excision (TME) were included. PD-L1, mTOR and p-mTOR of pair-matched pre-neoCRT biopsies and post-neoCRT surgical tissue were evaluated by immunohistochemistry.

RESULTS

The mean combined positive score (CPS), tumor proportion score (TPS) and immune cell score (IC) of pre-neoCRT were 2.24 (0-70), 1.87 (0-70) and 0.67 (0-10), respectively. The mean CPS, TPS and IC of post-neoCRT were 2.19 (0-80), 1.38 (0-80) and 1.60 (0-20), respectively. Significant difference was observed in terms of IC between pre-neoCRT and post-neoCRT (p = 0.010). The 5-year disease-free survival (DFS) rate of the whole group was 62.4%. Multivariate analysis by Cox model indicated that pre-neoCRT TPS [hazard ratio (HR) 1.052, 95% confidence interval (CI) 1.020-1.086, p = 0.001] and post-neoCRT CPS (HR 0.733, 95% CI 0.555-0.967, p = 0.028) were associated with DFS. In the 89 patients without pathological complete response, p-mTOR and IC were upregulated after neoCRT.

CONCLUSIONS

For patients with LARC treated by neoCRT and TME, p-mTOR and IC were upregulated after neoCRT. Pre-neoCRT TPS and post-neoCRT CPS were independent prognostic predictors of DFS.

Glasgow prognostic score and combined positive score for locally advanced rectal cancer

Purpose

This study was performed to investigate the association of Glasgow prognostic score (GPS), combined positive score (CPS), and clinicopathological characteristics of locally advanced rectal cancer.

Methods

Between February 2012 and February 2018, 103 patients with locally advanced rectal cancer treated by neoadjuvant chemoradiotherapy and total mesorectal excision (TME) were retrospectively evaluated.

Results

According to the classification of the GPS, 85 (82.5%), 13 (12.6%), and 5 patients (4.9%) were classified as a score of 0, 1, and 2, respectively. Patients were classified into the GPS-low group (GPS of 0, n = 85) and GPS-high group (GPS of 1 or 2, n = 18) with an area under the curve of 0.582 for overall survival (OS). The mean programmed death-ligand 1 (PD-L1) CPS of the whole group was 2.24 (range, 0–70). The PD-L1 CPS of the GPS-high group was higher than the GPS-low group (P < 0.001). Multivariate analysis by Cox proportional hazards model indicated that GPS was associated with OS and disease-free survival (DFS). Furthermore, PD-L1 CPS was associated with DFS (hazard ratio, 1.050; 95% confidence interval, 1.017–1.083; P = 0.003).

Conclusion

Elevated GPS was related to the PD-L1 CPS. GPS and PD-L1 CPS were associated with the prognosis of locally advanced rectal cancer treated with neoadjuvant chemoradiotherapy followed by TME.

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.

PD-L1 Protein Expression and Gene Amplification Correlate with the Clinicopathological Characteristics and Prognosis of Lung Squamous Cell Carcinoma

Purpose

To investigate PD-L1 protein expression and gene amplification in lung squamous cell carcinoma (LUSC) and analyse their correlation with the clinicopathological characteristics and prognosis of LUSC patients.

Patients and Methods

Tissue samples from 164 LUSC patients were collected. PD-L1 protein was detected by immunochemistry (IHC), and PD-L1 gene amplification was investigated by fluorescence in situ hybridization in LUSC patients.

Results

The positive expression rate of PD-L1 in LUSC was 47.6% (78/164), and the amplification rate of PD-L1 was 6.7% (11/164); both rates were higher than those of paratumor tissue. Both PD-L1 positive expression and gene amplification were correlated with clinical stage and lymph node metastasis (P<0.05). PD-L1 protein expression, PD-L1 gene amplification, late stage, lymph node metastasis and distant metastasis were significantly correlated with the prognosis of patients. Among these factors, late stage, lymph node metastasis, PD-L1 protein expression and PD-L1 gene amplification were independent prognostic factors for LUSC.

Conclusion

Positive PD-L1 protein expression and gene amplification are involved in the malignant progression and metastasis of LUSC. Both PD-L1 protein expression and gene amplification are associated with poor prognosis.

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.

The mutational pattern of homologous recombination-related (HRR) genes in Chinese colon cancer and its relevance to immunotherapy responses

BACKGROUND

Microsatellite-stable (MSS) colon adenocarcinoma (COAD) patients are not sensitive to immune checkpoint inhibitors. Here, we focused on analyzing the relationship between homologous recombination repair (HRR)-related gene mutations and clinical immunotherapy responses in MSS COAD.

METHODS

The mutational landscape was profiled in a cohort of 406 Chinese COAD patients via next-generation sequencing (NGS). Correlations between HRR gene mutations and tumor immunity or clinical outcomes in two COAD genomic datasets were analyzed via bioinformatics.

RESULTS

In the Chinese cohort, seventy (17%) patients exhibited genomic alterations in HRR genes; ATM (9%), BRCA2 (4%), ATR (3%), RAD50 (3%) and BRIP1 (3%) were the most frequently mutated. In the MSK-IMPACT COAD cohort (immune checkpoint inhibitor-treated), HRR-mut patients (n=34) survived longer than HRR-wt patients (n=50) (log-rank P < 0.01). Based on the TCGA MSS COAD cohort, HRR gene mutations increased immune activities, such as infiltration of cytotoxic cells (P < 0.05) and exhausted CD8+ T cells (P < 0.01), and increased the IFN-γ scores (P < 0.05). The results differed in MSI-H COAD patients (all P > 0.05).

CONCLUSION

HRR gene mutations significantly increased immune activities in MSS COAD patients, implying the feasibility of the HRR-mut status as an immunotherapy response predictor in MSS COAD.

A meta-analysis of CD274 (PD-L1) assessment and prognosis in colorectal cancer and its role in predicting response to anti-PD-1 therapy

BACKGROUND

PD-1 checkpoint inhibitors are novel therapeutic agents in colorectal cancer (CRC). Immunohistochemical staining for CD274 assessment is standardised in upper GI cancer, but not in CRC.

METHODS

Methodologies of relevant studies were scrutinized and meta-analysis of survival and CD274/PDCD1 performed. Furthermore, anti-PD-1 therapy clinical trial results in CRC were assessed with particular emphasis on CD274 assessment.

RESULTS

24 studies were included. CD274 on immune cells was associated with good prognosis. CD274 on tumour cells has heterogenous outcomes and does not meet requirements of a prognostic marker. As a marker of response to anti-PD-1 therapy, CD274 assessment is not standardised in CRC.

CONCLUSION

CD274 does not appear useful as a prognostic marker. As a marker of response to anti-PD-1 therapy, assessment methodology requires standardisation. As the Combined Positive Score (CPS) is used in upper GI cancer, this seems a logical method to adopt. Thresholds for CRC remain to be determined.

NDAT Targets PI3K-Mediated PD-L1 Upregulation to Reduce Proliferation in Gefitinib-Resistant Colorectal Cancer

The property of drug-resistance may attenuate clinical therapy in cancer cells, such as chemoresistance to gefitinib in colon cancer cells. In previous studies, overexpression of PD-L1 causes proliferation and metastasis in cancer cells; therefore, the PD-L1 pathway allows tumor cells to exert an adaptive resistance mechanism in vivo. Nano-diamino-tetrac (NDAT) has been shown to enhance the anti-proliferative effect induced by first-line chemotherapy in various types of cancer, including colorectal cancer (CRC). In this work, we attempted to explore whether NDAT could enhance the anti-proliferative effect of gefitinib in CRC and clarified the mechanism of their interaction. The MTT assay was utilized to detect a reduction in cell proliferation in four primary culture tumor cells treated with gefitinib or NDAT. The gene expression of PD-L1 and other tumor growth-related molecules were quantified by quantitative polymerase chain reaction (qPCR). Furthermore, the identification of PI3K and PD-L1 in treated CRC cells were detected by western blotting analysis. PD-L1 presentation in HCT116 xenograft tumors was characterized by specialized immunohistochemistry (IHC) and the hematoxylin and eosin stain (H&E stain). The correlations between the change in PD-L1 expression and tumorigenic characteristics were also analyzed. (3) The PD-L1 was highly expressed in Colo_160224 rather than in the other three primary CRC cells and HCT-116 cells. Moreover, the PD-L1 expression was decreased by gefitinib (1 µM and 10 µM) in two cells (Colo_150624 and 160426), but 10 µM gefitinib stimulated PD-L1 expression in gefitinib-resistant primary CRC Colo_160224 cells. Inactivated PI3K reduced PD-L1 expression and proliferation in CRC Colo_160224 cells. Gefitinib didn’t inhibit PD-L1 expression and PI3K activation in gefitinib-resistant Colo_160224 cells. However, NDAT inhibited PI3K activation as well as PD-L1 accumulation in gefitinib-resistant Colo_160224 cells. The combined treatment of NDAT and gefitinib inhibited pPI3K and PD-L1 expression and cell proliferation. Additionally, NDAT reduced PD-L1 accumulation and tumor growth in the HCT116 (K-RAS mutant) xenograft experiment. (4) Gefitinib might suppress PD-L1 expression but did not inhibit proliferation through PI3K in gefitinib-resistant primary CRC cells. However, NDAT not only down-regulated PD-L1 expression via blocking PI3K activation but also inhibited cell proliferation in gefitinib-resistant CRCs.

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.

Immune classification for the PD-L1 expression and tumour-infiltrating lymphocytes in colorectal adenocarcinoma

Background

Colorectal adenocarcinoma is the third most common cancer worldwide and a leading cause of cancer-related death. The recent emergence of diverse immunotherapeutic agents has made it crucial to interpret a complex tumour microenvironment intermingled with tumour-infiltrating immune cells to predict the immunotherapeutic response rate. However, in colorectal adenocarcinoma, studies are lacking that provide detailed analyses of programmed death-ligand 1 (PD-L1) and tumour-infiltrating lymphocytes (TIL) to elucidate their prognostic values and to identify immunotherapy-targetable subgroups, preferably with multiple immune-related biomarkers. In the present study, we categorize colorectal adenocarcinomas into four types of tumour immune microenvironments according to PD-L1 expression and TIL, analyse their prognostic values, and propose an immunotherapy-targetable subgroup.

Methods

Formalin-fixed, paraffin-embedded tissue samples of surgically resected primary colorectal adenocarcinomas (n = 489) were obtained and arrayed on tissue microarray blocks. Immunohistochemical stains for PD-L1, programmed cell death protein 1 (PD-1), cluster of differentiation 8 (CD8), and deficient mismatch repair (dMMR) were performed and evaluated.

Results

Tumour microenvironment immune type (TMIT) I (PD-L1-positive tumour cells and CD8-high TIL) and type II (PD-L1-negative tumour cells and CD8-low TIL) showed the best and worst prognoses, respectively. PD-L1 overexpression was significantly associated with dMMR status. PD-L1 immunoreactivity was positively correlated with TIL having CD8 or PD-1 overexpression.

Conclusions

TMIT I subgroup showed stronger CD8/PD-L1/PD-1 signalling interaction compared to the other TMIT. Therefore, we propose that the TMIT I subgroup is a candidate TMIT to predict effective response rate for existing immune checkpoint inhibitors and determine targetable subgroups for emerging therapies.

Identification of Prognostic Dosage-Sensitive Genes in Colorectal Cancer Based on Multi-Omics

Several studies have already identified the prognostic markers in colorectal cancer (CRC) based on somatic copy number alteration (SCNA). However, very little information is available regarding their value as a prognostic marker. Gene dosage effect is one important mechanism of copy number and dosage-sensitive genes are more likely to behave like driver genes. In this work, we propose a new pipeline to identify the dosage-sensitive prognostic genes in CRC. The RNAseq data, the somatic copy number of CRC from TCGA were assayed to screen out the SCNAs. Wilcoxon rank-sum test was used to identify the differentially expressed genes in alteration samples with |SCNA| > 0.3. Cox-regression was used to find the candidate prognostic genes. An iterative algorithm was built to identify the stable prognostic genes. Finally, the Pearson correlation coefficient was calculated between gene expression and SCNA as the dosage effect score. The cell line data from CCLE was used to test the consistency of the dosage effect. The differential co-expression network was built to discover their function in CRC. A total of six amplified genes (NDUFB4, WDR5B, IQCB1, KPNA1, GTF2E1, and SEC22A) were found to be associated with poor prognosis. They demonstrate a stable prognostic classification in more than 50% threshold of SCNA. The average dosage effect score was 0.5918 ± 0.066, 0.5978 ± 0.082 in TCGA and CCLE, respectively. They also show great stability in different data sets. In the differential co-expression network, these six genes have the top degree and are connected to the driver and tumor suppressor genes. Function enrichment analysis revealed that gene NDUFB4 and GTF2E1 affect cancer-related functions such as transmembrane transport and transformation factors. In conclusion, the pipeline for identifying the prognostic dosage-sensitive genes in CRC was proved to be stable and reliable.

Clinicopathological significance and prognostic implication of programmed death-1 ligand 2 expression in colorectal cancer

PURPOSE

The aim of this study was to evaluate the clinicopathological significance and prognostic role of programmed death-1 ligand 2 (PD-L2) expression in colorectal cancer according to intratumoral components.

METHODS

We used immunohistochemical analysis to investigate the impact of PD-L2 expression on clinicopathological characteristics and survival in 264 human colorectal cancer tissues. We also evaluated the correlation between PD-L2 expression and PD-L1 expression.

RESULTS

PD-L2 was expressed in 17.4% of the tumors (T-PD-L2) and in 19.3% of the immune cells (I-PD-L2) of the 264 CRC tissues. I-PD-L2 expression was significantly correlated with favorable tumor behaviors, including lower pathologic tumor stage, less lymph node metastasis, less distant metastasis, and lower pathologic tumor node metastasis stage. There was no significant correlation between I-PD-L2 expression and T-PD-L2 expression (P = 0.091). However, I-PD-L2 expression was correlated with PD-L1 expression in the immune cells (P < 0.001). There was also a significant correlation between high Immunoscore and I-PD-L2, but not T-PD-L2 (P < 0.001 and P = 0.190, respectively). The prognosis was better for patients who expressed I-PD-L2 than for patients who did not. In patients who expressed I-PD-L2, there was a significant difference in the survival rate between subgroups according to the presence or absence of T-PD-L2 expression.

CONCLUSIONS

Our results suggest that I-PD-L2 expression is significantly correlated with favorable tumor behaviors and better survival rates. There is also a significant correlation between PD-L2 expression and PD-L1 expression in immune cells.

PD-L1 is a double-edged sword in colorectal cancer: the prognostic value of PD-L1 depends on the cell type expressing PD-L1

PURPOSE

To investigate the associations between programmed cell death ligand-1 (PD-L1) on tumor cells (TCs) or PD-L1 on tumor-infiltrating immune cells (TIICs) and the microsatellite instability (MSI) status in colorectal cancer (CRC).

METHODS

In total, 238 CRC patients were enrolled. PD-L1 expression and MSI status were studied by immunohistochemical staining and polymerase chain reaction. The χ2 test was used to compare characteristics. The Kaplan-Meier method was used for survival analysis. Cox proportional hazards models were used to determine the prognostic influence of clinicopathological factors.

RESULTS

Eighteen patients (7.6%) were had MSI-high (MSI-H) CRC. The number of patients with PD-L1 expression on TCs, stromal TIICs and intraepithelial TIICs was 13 (5.5%), 64 (26.9%) and 45 (18.9%), respectively. The MSI-H phenotype was significantly associated with younger age, right sidedness, mucinous component, high grade, stromal TIICs expressing PD-L1 (P = 0.042) and intraepithelial TIICs expressing PD-L1 (P < 0.001), but not TCs expressing PD-L1. PD-L1-expressing TCs were an independent marker of poor prognosis [hazard ratio (HR) = 3.387, P = 0.003], and PD-L1-expressing stromal TIICs were an independent marker of good prognosis (HR = 0.551, P < 0.001).

CONCLUSIONS

PD-L1-expressing TCs were a marker of poor prognosis; in contrast, PD-L1-expressing TIICs were a marker of good prognosis. The MSI-H phenotype was associated with the presence of PD-L1-expressing TIICs, but not of PD-L1-expressing TCs.

High PD-L1 Expression Predicts for Worse Outcome of Leukemia Patients with Concomitant NPM1 and FLT3 Mutations

Compared to solid tumors, the role of PD-L1 in hematological malignancies is less explored, and the knowledge in this area is mostly limited to lymphomas. However, several studies indicated that PD-L1 is also overexpressed in myeloid malignancies. Successful treatment of the acute myeloid leukemia (AML) is likely associated with elimination of the residual disease by the immune system, and possible involvement of PD-L1 in this process remains to be elucidated. We analyzed PD-L1 expression on AML primary cells by flow cytometry and, in parallel, transcript levels were determined for the transcription variants v1 and v2. The ratio of v1/v2 cDNA correlated with the surface protein amount, and high v1/v2 levels were associated with worse overall survival (p = 0.0045). The prognostic impact of PD-L1 was limited to AML with mutated nucleophosmin and concomitant internal tandem duplications in the FLT3 gene (p less than 0.0001 for this particular AML subgroup).

The Prognostic and Clinicopathological Roles of PD-L1 Expression in Colorectal Cancer: A Systematic Review and Meta-Analysis

Background: Studies evaluating the prognostic significance of programmed death-ligand 1 (PD-L1) expression in colorectal cancer (CRC) are limited and remain controversial. This meta-analysis was conducted in order to evaluate the clinicopathological and prognostic significance of PD-L1 expression in CRC patients.

Methods: A comprehensive search was performed against the Medline/PubMed, Embase, Cochrane Library, Web of Science (WoS) and Scopus databases. Data were extracted with name of the first author, year of publication, country of origin, tumor type, number of cases, staining method, cut-off values, PD-L1 positive expression, clinicopathological parameters, outcome, and quality assessment score, and statistical analysis was conducted using Review Manager Version 5.3 (Revman the Cochrane Collaboration; Oxford, England) and STATA version 14 (Stata Corporation; College Station, TX, USA).

Results: Ten studies were included in this meta-analysis, in which the pooled hazard ratio (HR) showed that PD-L1 expression in tumor cells was significantly associated with a poor overall survival (HR = 1.50, 95% CI 1.05–2.13, P = 0.03). The pooled HR for disease-free survival (DFS) indicated that PD-L1 expression was significantly associated with shorter DFS (HR = 2.57, 95% CI 1.40–4.75, P = 0.002). The pooled odds ratios (ORs) showed that PD-L1 expression was associated with poor differentiation (OR = 3.47, 95% CI 1.37–8.77, P = 0.008) and right colon cancer (OR = 2.38, 95% CI 1.57–3.60, P < 0.0001). However, the expression of PD-L1 was independent of gender, age, tumor size, tumor stage, lymph node metastasis, and tumor-node metastasis stage.

Conclusion: This meta-analysis indicated that a high level of PD-L1 expression might be a biomarker for a poor prognosis in CRC patients. This information may be helpful for clinicians to stratify CRC patients for anti-PD-1/PD-L1 therapy, particularly patients with microsatellite instability high (MSI-H).

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

OBJECTIVE

To analyze the prognostic value of programmed death factor ligand 1 (PD-L1) in colorectal cancer.

METHODS

Electronic databases, such as PubMed, Web of Science, Embase, and Cochrane library, were searched to identify studies evaluating the PD-L1 expression and overall survival (OS) in these patients. Afterwards, the relevant data were extracted to perform the meta-analysis.

RESULTS

A total of 3481 patients were included in 10 studies. The combined hazard ratio (HR) was 1.22 (95%CI = 1.01-1.48, P = 0.04), indicating that high expression of PD-L1 was significantly correlated with poor prognosis of colorectal cancer. Apropos of clinicopathological features, the merged odds ratio (OR) exhibited that highly expressed PD-L1 was firmly related to lymphatic invasion (OR = 3.49, 95%CI = 1.54-7.90, P = 0.003) and advanced stage (OR = 1.77, 95%CI = 1.41-2.23, P < 0.00001), but not correlative with patients' gender, microsatellite instability, or tumor location.

CONCLUSION

The expression of PD-L1 can be utilized as an independent factor in judging the prognosis of colorectal cancer, and patients with advanced cancer or lymphatic invasion are more likely to express PD-L1. This conclusion may lay a theoretical foundation for the application of PD-1/PD-L1 immunoassay point inhibitors but still needs verifying by sizeable well-designed cohort studies.

Programmed cell death ligand-1 protein expression and CD274/PD-L1 gene amplification in colorectal cancer: Implications for prognosis

Programmed cell death ligand-1 (PD-L1) detection assays have not been standardized for patients with colorectal cancer, and the prognostic value of PD-L1 expression is unclear. We compared the PD-L1 expression patterns in colorectal cancer samples using various immunohistochemical assays using 3 primary PD-L1 antibodies (assay 1, MIH1; assay 2, E1L3; and assay 3, 22C3) and investigated the prognostic implication of PD-L1 expression using each. Additionally, PD-L1 gene amplification was evaluated using FISH. The percentage scorings and positivity rates of the 3 assays differed; the degrees of correlation and concordance between assays 2 and 3 were relatively high, whereas assay 1 was an outlier. Multivariate analyses indicated that PD-L1 positivity in tumor cells and its negativity in tumor-infiltrating lymphocytes were independent predictors of poorer overall and disease-free survival in patients with colorectal cancer. PD-L1 gene amplification was found in 2 patients (PD-L1/CEP ratio, 5.60 and 5.84, respectively); both had strong PD-L1 expression according to immunohistochemistry. Overall, our study showed that PD-L1 expression status in tumor and immune cells is an independent prognostic factor in patients with colorectal cancer. Standardizations of both PD-L1 detection using immunohistochemistry and the cut-off for positivity are necessary. Finally, PD-L1 gene amplification was found in a small fraction of samples, suggesting the possibility of an ancillary test for PD-L1 evaluation.