Right and left-sided colon cancers - specificity of molecular mechanisms in tumorigenesis and progression

Integrative Analysis of Histone Acetylation Regulated CYP4F12 in Esophageal Cancer Development

Current therapeutic strategies for esophageal cancer (EC) patients have yielded limited improvements in survival rates. Recent research has highlighted the influence of drug metabolism enzymes on both drug response and EC development. Our study aims to identify specific drug metabolism enzymes regulated by histone acetylation and to elucidate its molecular and clinical features. CYP4F12 exhibited a notable upregulation subsequent to trichostatin A treatment as evidenced by RNA sequencing analysis conducted on the KYSE-150 cell line. The change in gene expression was associated with increased acetylation level of histone 3 K18 and K27 in the promoter. The regulation was dependent on p300. In silicon analysis of both The Cancer Genome Atlas esophageal carcinoma and GSE53624 dataset suggested a critical role of CYP4F12 in EC development, because CYP4F12 was downregulated in tumor tissues and predicted better disease-free survival. Gene ontology analysis has uncovered a robust correlation between CYP4F12 and processes related to cell migration, as well as its involvement in cytosine-mediated immune activities. Further investigation into the relationship between immune cells and CYP4F12 expression has indicated an increased level of B cell infiltration in samples with high CYP4F12 expression. CYP4F12 was also negatively correlated with the expression of inhibitory checkpoints. An accurate predictive nomogram model was established combining with clinical factors and CYP4F12 expression. In conclusion, CYP4F12 was crucial in EC development, and targeting CYP4F12 may improve the therapeutic efficacy of current treatment in EC patients. SIGNIFICANCE STATEMENT: CYP4F12 expression was downregulated in esophageal cancer (EC) patients and could be induced by trichostatin A. During EC development, CYP4F12 was linked to reduced cell migration and increased infiltration of B cells. CYP4F12 also is a biomarker as prognostic predictors and therapeutic guide in EC patients.

Predicting treatment failure in stage III colon cancer patients after radical surgery

Purpose

The aim to assess treatment failure in patients with stage III colon cancer who underwent radical surgery and was analyzed using the nomogram.

Methods

Clinical factors and survival outcomes for stage III colon cancer patients registered in the SEER database from 2018 to 2019 were analyzed, with patients split into training and testing cohorts (7:3 ratio). A total of 360 patients from the First Affiliated Hospital of Longyan served as an external validation cohort. Independent predictors of treatment failure were identified using logistic regression analyses. The nomograms was evaluated by concordance index (C-index), calibration curves, and the area under the curve (AUC), decision curve analysis (DCA) and clinical impact curves (CIC) assessed the clinical utility of nomograms versus TNM staging.

Results

The study included 4,115 patients with stage III colon cancer. Multivariate logistic analysis age, tumor site, pT stage, pN stage, chemotherapy, pretreatment CEA levels, number of harvested lymph nodes, perineural invasion and marital status were identified as independent risk factors for treatment failure. The C-indices for the training and testing sets were 0.853 and 0.841. Validation by ROC and calibration curves confirmed the stability and reliability of the model. DCA showed that the net clinical effect of the histogram was superior to that of the TNM staging system, while CIC highlighted the potentially large clinical impact of the model.

Conclusions

The developed Nomogram provides a powerful and accurate tool for clinicians to assess the risk of treatment failure after radical surgery in patients with stage III colon cancer.

Short- and long-term outcome differences between patients undergoing left and right colon cancer surgery: cohort study

PURPOSE

Since the literature currently provides controversial data on the postoperative outcomes following right and left hemicolectomies, we carried out this study to examine the short- and long-term treatment outcomes.

METHODS

This study included consecutive patients who underwent right or left-sided colonic resections from year 2014 to 2018 and then they were followed up. The short-term outcomes such as postoperative morbidity and mortality according to Clavien-Dindo score, duration of hospital stay, and 90-day readmission rate were evaluated as well as long-term outcomes of overall survival and disease-free survival. Multivariable Cox regression analysis was performed of overall and progression-free survival.

RESULTS

In total, 1107 patients with colon tumors were included in the study, 525 patients with right-sided tumors (RCC) and 582 cases with tumors in the left part of the colon (LCC). RCC group patients were older (P < 0.001), with a higher ASA score (P < 0.001), and with more cardiovascular comorbidities (P < 0.001). No differences were observed between groups in terms of postoperative outcomes such as morbidity and mortality, except 90-day readmission which was more frequent in the RCC group. Upon histopathological analysis, the RCC group's patients had more removed lymph nodes (29 ± 14 vs 20 ± 11, P = 0.001) and more locally progressed (pT3-4) tumors (85.4% versus 73.4%, P = 0.001). Significantly greater 5-year overall survival and disease-free survival (P = 0.001) were observed for patients in the LCC group, according to univariate Kaplan-Meier analysis.

CONCLUSIONS

Patients with right-sided colon cancer were older and had more advanced disease. Short-term surgical outcomes were similar, but patients in the LCC group resulted in better long-term outcomes.

Identification of unique rectal cancer-specific subtypes

BACKGROUND

Existing colorectal cancer subtyping methods were generated without much consideration of potential differences in expression profiles between colon and rectal tissues. Moreover, locally advanced rectal cancers at resection often have received neoadjuvant chemoradiotherapy which likely has a significant impact on gene expression.

METHODS

We collected mRNA expression profiles for rectal and colon cancer samples (n = 2121). We observed that (i) Consensus Molecular Subtyping (CMS) had a different prognosis in treatment-naïve rectal vs. colon cancers, and (ii) that neoadjuvant chemoradiotherapy exposure produced a strong shift in CMS subtypes in rectal cancers. We therefore clustered 182 untreated rectal cancers to find rectal cancer-specific subtypes (RSSs).

RESULTS

We identified three robust subtypes. We observed that RSS1 had better, and RSS2 had worse disease-free survival. RSS1 showed high expression of MYC target genes and low activity of angiogenesis genes. RSS2 exhibited low regulatory T cell abundance, strong EMT and angiogenesis signalling, and high activation of TGF-β, NF-κB, and TNF-α signalling. RSS3 was characterised by the deactivation of EGFR, MAPK and WNT pathways.

CONCLUSIONS

We conclude that RSS subtyping allows for more accurate prognosis predictions in rectal cancers than CMS subtyping and provides new insight into targetable disease pathways within these subtypes.

Comparison of left- and right-sided colorectal cancer to explore prognostic signatures related to pyroptosis

Background

Colorectal cancer (CRC) is one of the most common malignancies, and pyroptosis exerts an immunoregulatory role in CRC. Although the location of the primary tumor is a prognostic factor for patients with CRC, the mechanisms of pyroptosis in left- and right-sided CRC remain unclear.

Methods

Expression and clinical data were collected from The Cancer Genome Atlas and Gene Expression Omnibus databases. Differences in clinical characteristics, immune cell infiltration, and somatic mutations between left- and right-sided CRC were then compared. After screening for differentially expressed genes, Pearson correlation analysis was performed to select pyroptosis-related genes, followed by a gene set enrichment analysis. Univariate and multivariate Cox regression analyses were used to construct and validate the prognostic model and nomogram for predicting prognosis. Collected left- and right-sided CRC samples were subjected to reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to validate the expression of key pyroptosis-related genes.

Results

Left- and right-sided CRC exhibited significant differences in clinical features and immune cell infiltration. Five prognostic signatures were identified from among 134 pyroptosis-related differentially expressed genes to construct a risk score-based prognostic model, and adverse outcomes for high-risk patients were further verified using an external cohort. A nomogram was also generated based on three independent prognostic factors to predict survival probabilities, while calibration curves confirmed the consistency between the predicted and actual survival. Experiment data confirmed the significant differential expression of five genes between left- and right-sided CRC.

Conclusion

The five identified pyroptosis-related gene signatures may be potential biomarkers for predicting prognosis in left- and right-sided CRC and may help improve the clinical outcomes of patients with CRC.

q-Diffusion leverages the full dimensionality of gene coexpression in single-cell transcriptomics

Unlocking the full dimensionality of single-cell RNA sequencing data (scRNAseq) is the next frontier to a richer, fuller understanding of cell biology. We introduce q-diffusion, a framework for capturing the coexpression structure of an entire library of genes, improving on state-of-the-art analysis tools. The method is demonstrated via three case studies. In the first, q-diffusion helps gain statistical significance for differential effects on patient outcomes when analyzing the CALGB/SWOG 80405 randomized phase III clinical trial, suggesting precision guidance for the treatment of metastatic colorectal cancer. Secondly, q-diffusion is benchmarked against existing scRNAseq classification methods using an in vitro PBMC dataset, in which the proposed method discriminates IFN-γ stimulation more accurately. The same case study demonstrates improvements in unsupervised cell clustering with the recent Tabula Sapiens human atlas. Finally, a local distributional segmentation approach for spatial scRNAseq, driven by q-diffusion, yields interpretable structures of human cortical tissue.

Pathological and pharmacological functions of the metabolites of polyunsaturated fatty acids mediated by cyclooxygenases, lipoxygenases, and cytochrome P450s in cancers

Oxylipins have garnered increasing attention because they were consistently shown to play pathological and/or pharmacological roles in the development of multiple cancers. Oxylipins are the metabolites of polyunsaturated fatty acids via both enzymatic and nonenzymatic pathways. The enzymes mediating the metabolism of PUFAs include but not limited to lipoxygenases (LOXs), cyclooxygenases (COXs), and cytochrome P450s (CYPs) pathways, as well as the down-stream enzymes. Here, we systematically summarized the pleiotropic effects of oxylipins in different cancers through pathological and pharmacological aspects, with specific reference to the enzyme-mediated oxylipins. We discussed the specific roles of oxylipins on cancer onset, growth, invasion, and metastasis, as well as the expression changes in the associated metabolic enzymes and the associated underlying mechanisms. In addition, we also discussed the clinical application and potential of oxylipins and related metabolic enzymes as the targets for cancer prevention and treatment. We found the specific function of most oxylipins in cancers, especially the underlying mechanisms and clinic applications, deserves and needs further investigation. We believe that research on oxylipins will provide not only more therapeutic targets for various cancers but also dietary guidance for both cancer patients and healthy humans.

Assessment of postoperative circulating tumour DNA to predict early recurrence in patients with stage I-III right-sided colon cancer: prospective observational study

BACKGROUND

Right-sided colon cancer (RCC) differs in mutation profile and risk of recurrence compared to distal colon cancer. Circulating tumour DNA (ctDNA) present after surgery can identify patients with residual disease after curative surgery and predict risk of early recurrence.

METHODS

This is a prospective observational biomarker trial with exploration of ctDNA in 50 non-metastatic RCC patients for which oncological right-sided colectomy was performed. Blood samples were collected preoperatively, within 1 month post surgery, 3 months (not mandatory), 6 months and every 6 months thereafter. Plasma cell free DNA and/or tumour was investigated for cancer-related mutations by the next-generation sequencing (NGS) panel AVENIO surveillance specifically designed for ctDNA analysis. Detected mutations were quantified using digital droplet PCR (ddPCR) for follow-up. Recurrence-free survival was explored.

RESULTS

50 patients were recruited. Somatic cancer-related mutations were detected in 47/50 patients. ddPCR validated results from NGS for 27/34 (plasma) and 72/72 samples (tumour). Preoperative ctDNA was detected in 31/47 of the stage I/III patients and the majority of ctDNA positive patients showed reduction of ctDNA after surgery (27/31). ctDNA-positive patients at first postoperative sample had high recurrence risk compared to patients without measurable ctDNA (adjusted hazard ratio: 172.91; 95% c.i.: 8.70 to 3437.24; P: 0.001).

CONCLUSION

ctDNA was detectable in most patients with non-metastatic RCC before surgery. Positive postoperative ctDNA was strongly associated with early recurrence. Detectable postoperative ctDNA is a prognostic factor with high (100%) positive predictive value for recurrence in this cohort of non-metastatic RCC.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03776591.

The colibactin-producing Escherichia coli alters the tumor microenvironment to immunosuppressive lipid overload facilitating colorectal cancer progression and chemoresistance

Intratumoral bacteria flexibly contribute to cellular and molecular tumor heterogeneity for supporting cancer recurrence through poorly understood mechanisms. Using spatial metabolomic profiling technologies and 16SrRNA sequencing, we herein report that right-sided colorectal tumors are predominantly populated with Colibactin-producing Escherichia coli (CoPEC) that are locally establishing a high-glycerophospholipid microenvironment with lowered immunogenicity. It coincided with a reduced infiltration of CD8+ T lymphocytes that produce the cytotoxic cytokines IFN-γ where invading bacteria have been geolocated. Mechanistically, the accumulation of lipid droplets in infected cancer cells relied on the production of colibactin as a measure to limit genotoxic stress to some extent. Such heightened phosphatidylcholine remodeling by the enzyme of the Land's cycle supplied CoPEC-infected cancer cells with sufficient energy for sustaining cell survival in response to chemotherapies. This accords with the lowered overall survival of colorectal patients at stage III-IV who were colonized by CoPEC when compared to patients at stage I-II. Accordingly, the sensitivity of CoPEC-infected cancer cells to chemotherapies was restored upon treatment with an acyl-CoA synthetase inhibitor. By contrast, such metabolic dysregulation leading to chemoresistance was not observed in human colon cancer cells that were infected with the mutant strain that did not produce colibactin (11G5∆ClbQ). This work revealed that CoPEC locally supports an energy trade-off lipid overload within tumors for lowering tumor immunogenicity. This may pave the way for improving chemoresistance and subsequently outcome of CRC patients who are colonized by CoPEC.

Serrated colorectal cancer: preclinical models and molecular pathways

Serrated lesions are histologically heterogeneous, and detection can be challenging as these lesions have subtle features that may be missed by endoscopy. Furthermore, while approximately 30% of colorectal cancers (CRCs) arise from serrated lesions, only 8-10% of invasive serrated CRCs exhibit serrated morphology at presentation, suggesting potential loss of apparent characteristics with increased malignancy. Thus, understanding the genetic basis driving serrated CRC initiation and progression is critical to improve diagnosis and identify therapeutic biomarkers and targets to guide disease management. This review discusses the preclinical models of serrated CRCs reported to date and how these systems have been used to provide mechanistic insights into tumor initiation, progression, and novel treatment targets.

Comprehensive analysis of alternative splicing across multiple transcriptomic cohorts reveals prognostic signatures in prostate cancer

BACKGROUND

Alternative splicing (AS) plays a crucial role in transcriptomic diversity and is a hallmark of cancer that profoundly influences the development and progression of prostate cancer (PCa), a prevalent and potentially life-limiting cancer among men. Accumulating evidence has highlighted the association between AS dysregulation and the onset and progression of PCa. However, a comprehensive and integrative analysis of AS profiles at the event level, utilising data from multiple high-throughput cohorts and evaluating the prognosis of PCa progression, remains lacking and calls for thorough exploration.

RESULTS

We identified a differentially expressed retained intron event in ZWINT across three distinct cohorts, encompassing an original array-based dataset profiled by us previously and two RNA sequencing (RNA-seq) datasets. Subsequent in-depth analyses of these RNA-seq datasets revealed  141 altered events, of which 21 demonstrated a significant association with patients' biochemical recurrence-free survival (BCRFS). We formulated an AS event-based prognostic signature, capturing six pivotal events in genes CYP4F12, NFATC4, PIGO, CYP3A5, ALS2CL, and FXYD3. This signature effectively differentiated  high-risk patients diagnosed with PCa, who experienced shorter BCRFS, from their low-risk counterparts. Notably, the signature's predictive power surpassed traditional clinicopathological markers in forecasting 5-year BCRFS, demonstrating robust performance in both internal and external validation sets. Lastly, we constructed a novel nomogram that integrates patients' Gleason scores with pathological tumour stages, demonstrating improved prognostication of BCRFS.

CONCLUSIONS

Prediction of clinical progression remains elusive in PCa. This research uncovers novel splicing events associated with BCRFS, augmenting existing prognostic tools, thus potentially refining clinical decision-making.

Multi-omic analysis reveals metabolic pathways that characterize right-sided colon cancer liver metastasis

There are well demonstrated differences in tumor cell metabolism between right sided (RCC) and left sided (LCC) colon cancer, which could underlie the robust differences observed in their clinical behavior, particularly in metastatic disease. As such, we utilized liquid chromatography-mass spectrometry to perform an untargeted metabolomics analysis comparing frozen liver metastasis (LM) biobank samples derived from patients with RCC (N = 32) and LCC (N = 58) to further elucidate the unique biology of each. We also performed an untargeted RNA-seq and subsequent network analysis on samples derived from an overlapping subset of patients (RCC: N = 10; LCC: N = 18). Our biobank redemonstrates the inferior survival of patients with RCC-derived LM (P = 0.04), a well-established finding. Our metabolomic results demonstrate increased reactive oxygen species associated metabolites and bile acids in RCC. Conversely, carnitines, indicators of fatty acid oxidation, are relatively increased in LCC. The transcriptomic analysis implicates increased MEK-ERK, PI3K-AKT and Transcription Growth Factor Beta signaling in RCC LM. Our multi-omic analysis reveals several key differences in cellular physiology which taken together may be relevant to clinical differences in tumor behavior between RCC and LCC liver metastasis.

[Clinical and histopathological characteristics of malignant colon tumors by location]

Background

The colon has two different embryological origins, which is why it can be divided into right and left with different characteristics each one; therefore, neoplastic lesions have a different clinical picture and are also associated with different pathologies.

Objective

To describe the clinical and histopathological characteristics of malignant colon tumors acording to their location.

Material and methods

Descriptive, retrospective study with 94 patients diagnosed with colon cancer. Descriptive statistics were performed with the calculation of frequencies and percentages, and chi-squared tests were calculated.

Results

Mean age was 61.3 years, 49 (52.1%) were women; 53 (56.4%) were left-sided and 41 (43.6%) right-sided. The main symptom was hematochezia in 32 (60.4%), in patients with left cancer; and diarrhea in 20 (48.8%), in patients with right-sided colon cancer. The presentation of stage I tumors and polyps, p = 0.044 and p = 0.043, respectively, was more frequent on the right side compared to the left side; in the left, hematochezia (p = 0.001), narrow stools(p = 0.05), and a history of type 2 diabetes mellitus (T2DM) (p= 0.036) were more frequent compared to the opposite site.

Conclusions

Stage I and the presence of polyps were more frequent in right-sided cancer compared to left-sided cancer; T2DM, as well as hematochezia and narrow stools were more associated with the left side compared to the right side.

Dichotomous colorectal cancer behaviour

Colorectal cancer (CRC) is the third most common malignant tumor and one of the deadliest cancers. At molecular level, CRC is a heterogeneous disease that could be divided in four Consensus Molecular Subtypes. Given the differences in the disease due to its anatomical location (proximal and distal colon), another classification should be considered. Here, we review the current knowledge on CRC dichotomic´s behaviour based on two different entities; right and left-sided tumors, their impact on clinical trial data, microbiota spatial composition and the interaction with the nervous system. We discuss recent advances in understanding how the spatial tumor heterogeneity influences the tumor growth, progression, and responses to current therapies.

Proteomic Profiling and Tumor Microenvironment Characterization Reveal Molecular and Immunological Hallmarks of Left-Sided and Right-Sided Colon Cancer Tumorigenesis

Left-sided and right-sided colon cancer (LSCC and RSCC) display different biological and clinical characteristics. However, the differences in their tumorigenesis and tumor microenvironment remain unclear. In this study, we profiled the proteomic landscapes of LSCC and RSCC with data-independent acquisition mass spectrometry (DIA-MS) using fresh tumor and adjacent normal tissues from 24 patients. A total of 7403 proteingroups were primarily identified with DIA-MS. After quality control, 7212 proteingroups were used for further analysis. Through comparing the difference in proteomic profiles between LSCC and RSCC samples, 2556 commonly and 1982 region-type-specific regulated proteingroups were characterized. During the development of LSCC and RSCC, metabolic, growth, cell division, cell adhesion, and migration pathways were found to be significantly dysregulated (P < 0.05), which was further confirmed by transcriptome data from TCGA. Compared to RSCC, most parts of the immune-related signatures, immune cell infiltration scores, and overall immune scores of LSCC were higher. The systematic elucidation of proteomic and transcriptomic profiles in this work improves our understanding of tumorigenesis and immune microenvironment characteristics of LSCC and RSCC.

Identification of LncPVT1 and CircPVT1 as prognostic biomarkers in human colorectal polyps

LncPVT1 and CircPVT1 are isoforms for the PVT1 gene and are associated with cancer progression and carcinogenesis. Our study investigated the expression of LncPVT1 and CircPVT1 in colon adenoma polyps. 40 tissues of colorectal polyps and 40 normal-adjacent tissues (NATs) were taken. The expression of LncPVT1 and CircPVT1 was evaluated through qRael-Time PCR. The relation between expression and features of clinicopathological was explored. The ceRNA network was constructed by LncPVT1 and CircPVT1 and predicted miRNAs and miRNAs targets. Further, hub nodes in this network were determined using the cytoHubba package. Over-expressed LncPVT1 and CircPVT1 were differentiated in polyp and NATs. The expression level of LncPVT1 and CircPVT1 were significantly higher in adenoma polyps than in hyperplastic polyps. The area under the curve of the ROC estimate for the LncPVT1 and CircPVT1 was 0.74 and 0.77, respectively. A positive correlation was observed between the LncPVT1 expression and CircPVT1. Three miRNAs, including hsa-miR-484, hsa-miR-24-3p, hsa-miR-423-5p, and CircPVT1, were detected as ceRNA hub nodes. In this study, expression profiles of LncPVT1 and CircPVT1 were significantly higher in precancerous polyps. In addition, based on our in silico analysis, LncPVT1, CircPVT1/miR-484, miR-24-3p, miR-423-5p/PLAGL2 axis might be involved in colon cancer development. LncPVT1 and CircPVT1 can be prescribed as warning problems as potential prognostic biomarkers in patients with pre-CRC colon polyps.

A nomogram model for predicting distant metastasis of newly diagnosed colorectal cancer based on clinical features

Objective

Colorectal cancer is one of the most common primary malignancies and the third most common cause of cancer death in both men and women in the United States. Among people diagnosed with initial colorectal cancer, 22% had metastatic colorectal cancer, while the 5-year survival rate was less than 20%. The purpose of this study is to develop a nomogram for predicting distant metastasis in newly diagnosed colorectal cancer patients and to identify high-risk groups.

Methods

We retrospectively reviewed the data of patients who were diagnosed with colorectal cancer at Zhong nan Hospital of Wuhan University and People's Hospital of Gansu Province between January 2016 and December 2021. Risk predictors for distant metastasis from colorectal patients were determined by the univariate and multivariate logistic regression analyses. Nomograms were developed to predict the probabilities of distant metastatic sites of colorectal cancer patients and evaluated by calibration curves, receiver operating characteristic curves, and decision curve analysis (DCA).

Results

A total of 327 cases were included in this study: 224 colorectal cancer patients from Zhong nan Hospital of Wuhan University were incorporated into the training set, and 103 colorectal cancer patients from Gansu Provincial People's Hospital were incorporated into the testing set. By univariate logistic regression analysis, platelet (PLT) level (p = 0.009), carcinoembryonic antigen (CEA) level (p = 0.032), histological grade (p < 0.001), colorectal cancer tumor markers (p < 0.001), N stage (p < 0.001), and tumor site (p = 0.005) were associated with distant metastasis in colorectal cancer patients. Multivariate logistic regression analysis showed that N stage (p < 0.001), histological grade (p = 0.026), and colorectal cancer markers (p < 0.001) were independent predictors of distant metastasis in patients initially diagnosed with colorectal cancer. The above six risk factors were used to predict distant metastasis of newly diagnosed colorectal cancer. The C-indexes for the prediction of the nomogram were 0.902 (95% confidence interval (CI), 0.857-0.948).

Conclusion

The nomogram showed excellent accuracy in predicting distant metastatic sites, and clinical utility may facilitate clinical decision-making.

Exploring the prognostic function of TMB-related prognostic signature in patients with colon cancer

Tumor mutation burden (TMB) level is identified as a useful predictor in multiple tumors including colon adenocarcinoma (COAD). However, the function of TMB related genes has not been explored previously. In this study, we obtained patients' expression and clinical data from The Cancer Genome Atlas (TCGA) and the National Center for Biotechnology Information (NCBI). TMB genes were screened and subjected to differential expression analysis. Univariate Cox and LASSO analyses were utilized to construct the prognostic signature. The efficiency of the signature was tested by using a receiver operating characteristic (ROC) curve. A nomogram was further plotted to assess the overall survival (OS) time of patients with COAD. In addition, we compared the predictive performance of our signature with other four published signatures. Functional analyses indicated that patients in the low-risk group have obviously different enrichment of tumor related pathways and tumor infiltrating immune cells from that of high-risk patients. Our findings suggested that the ten genes' prognostic signature could exert undeniable prognostic functions in patients with COAD, which might provide significant clues for the development of personalized management of these patients.

Activated tissue resident memory T-cells (CD8+CD103+CD39+) uniquely predict survival in left sided "immune-hot" colorectal cancers

Introduction

Characterization of the tumour immune infiltrate (notably CD8+ T-cells) has strong predictive survival value for cancer patients. Quantification of CD8 T-cells alone cannot determine antigenic experience, as not all infiltrating T-cells recognize tumour antigens. Activated tumour-specific tissue resident memory CD8 T-cells (T_RM) can be defined by the co-express of CD103, CD39 and CD8. We investigated the hypothesis that the abundance and localization of T_RM provides a higher-resolution route to patient stratification.

Methods

A comprehensive series of 1000 colorectal cancer (CRC) were arrayed on a tissue microarray, with representative cores from three tumour locations and the adjacent normal mucosa. Using multiplex immunohistochemistry we quantified and determined the localization of T_RM.

Results

Across all patients, activated T_RM were an independent predictor of survival, and superior to CD8 alone. Patients with the best survival had immune-hot tumours heavily infiltrated throughout with activated T_RM. Interestingly, differences between right- and left-sided tumours were apparent. In left-sided CRC, only the presence of activated T_RM (and not CD8 alone) was prognostically significant. Patients with low numbers of activated T_RM cells had a poor prognosis even with high CD8 T-cell infiltration. In contrast, in right-sided CRC, high CD8 T-cell infiltration with low numbers of activated T_RM was a good prognosis.

Conclusion

The presence of high intra-tumoural CD8 T-cells alone is not a predictor of survival in left-sided CRC and potentially risks under treatment of patients. Measuring both high tumour-associated T_RM and total CD8 T-cells in left-sided disease has the potential to minimize current under-treatment of patients. The challenge will be to design immunotherapies, for left-sided CRC patients with high CD8 T-cells and low activate T_RM,that result in effective immune responses and thereby improve patient survival.

Development and validation of a clinical survival model for young-onset colorectal cancer with synchronous liver-only metastases: a SEER population-based study and external validation

Background

The morbidity and mortality of young-onset colorectal cancer (YO-CRC) patients have been increasing in recent years. Moreover, YO-CRC patients with synchronous liver-only metastases (YO-CRCSLM) have various survival outcomes. Therefore, the purpose of this study was to construct and validate a prognostic nomogram for patients with YO-CRCSLM.

Methods

The YO-CRCSLM patients were rigorously screened from the Surveillance, Epidemiology, and End Results (SEER) database in January 2010 and December 2018 and then assigned to a training and validation cohort randomly (1488 and 639 patients, respectively). Moreover, the 122 YO-CRCSLM patients who were enrolled in The First Affiliated Hospital of Nanchang University were served as a testing cohort. The variables were selected using the multivariable Cox model based on the training cohort and then developed a nomogram. The validation and testing cohort were used to validate the model's predictive accuracy. The calibration plots were used to determine the Nomogram's discriminative capabilities and precision, and the decision analysis (DCA) was performed to evaluate the Nomogram's net benefit. Finally, the Kaplan-Meier survival analyses were performed for the stratified patients based on total nomogram scores classified by the X-tile software.

Results

The Nomogram was constructed including ten variables: marital status, primary site, grade, metastatic lymph nodes ratio (LNR), T stage, N stage, carcinoembryonic antigen (CEA), Surgery, and chemotherapy. The Nomogram performed admirably in the validation and testing group according to the calibration curves. The DCA analyses showed good clinical utility values. Low-risk patients (score<234) had significantly better survival outcomes than middle-risk (234-318) and high-risk (>318) patients (P < 0.001).

Conclusion

A nomogram predicting the survival outcomes for patients with YO-CRCSLM was developed. In addition to facilitating personalized survival prediction, this nomogram may assist in developing clinical treatment strategies for patients with YO-CRCSLM who are undergoing treatment.

Systemic treatment for metastatic colorectal cancer

Significant progress has been achieved in the treatment of metastatic colorectal cancer (mCRC) patients during the last 20 years. There are currently numerous treatments available for the first-line treatment of mCRC. Sophisticated molecular technologies have been developed to reveal novel prognostic and predictive biomarkers for CRC. The development of next-generation sequencing and whole-exome sequencing, which are strong new tools for the discovery of predictive molecular biomarkers to facilitate the delivery of customized treatment, has resulted in tremendous breakthroughs in DNA sequencing technology in recent years. The appropriate adjuvant treatments for mCRC patients are determined by the tumor stage, presence of high-risk pathologic characteristics, microsatellite instability status, patient age, and performance status. Chemotherapy, targeted therapy, and immunotherapy are the main systemic treatments for patients with mCRC. Despite the fact that these novel treatment choices have increased overall survival for mCRC, survival remains optimal for individuals with non-metastatic disease. The molecular technologies currently being used to support our ability to practice personalized medicine; the practical aspects of applying molecular biomarkers to regular clinical practice; and the evolution of chemotherapy, targeted therapy, and immunotherapy strategies for the treatment of mCRC in the front-line setting are all reviewed here.

Systemic treatment for metastatic colorectal cancer

Significant progress has been achieved in the treatment of metastatic colorectal cancer (mCRC) patients during the last 20 years. There are currently numerous treatments available for the first-line treatment of mCRC. Sophisticated molecular technologies have been developed to reveal novel prognostic and predictive biomarkers for CRC. The development of next-generation sequencing and whole-exome sequencing, which are strong new tools for the discovery of predictive molecular biomarkers to facilitate the delivery of customized treatment, has resulted in tremendous breakthroughs in DNA sequencing technology in recent years. The appropriate adjuvant treatments for mCRC patients are determined by the tumor stage, presence of high-risk pathologic characteristics, microsatellite instability status, patient age, and performance status. Chemotherapy, targeted therapy, and immunotherapy are the main systemic treatments for patients with mCRC. Despite the fact that these novel treatment choices have increased overall survival for mCRC, survival remains optimal for individuals with non-metastatic disease. The molecular technologies currently being used to support our ability to practice personalized medicine; the practical aspects of applying molecular biomarkers to regular clinical practice; and the evolution of chemotherapy, targeted therapy, and immunotherapy strategies for the treatment of mCRC in the front-line setting are all reviewed here.

KRAS Mutational Profiles among Colorectal Cancer Patients in the East Coast of Peninsular Malaysia

BACKGROUND

KRAS is a key driver gene in colorectal carcinogenesis. Despite this, there are still limited data on the mutational status of KRAS amongst colorectal cancer (CRC) patients in Malaysia. In the present study, we aimed to analyze the KRAS mutational profiles on codons 12 and 13 amongst CRC patients in Hospital Universiti Sains Malaysia, Kelantan, located on the East Coast of Peninsular Malaysia.

METHODS

DNA were extracted from formalin-fixed, paraffin-embedded tissues obtained from 33 CRC patients diagnosed between 2018 and 2019. Amplifications of codons 12 and 13 of KRAS were conducted using conventional polymerase chain reaction (PCR) followed by Sanger sequencing.

RESULTS

Mutations were identified in 36.4% (12/33) of patients, with G12D (50%) being the most frequent single-point mutation observed, followed by G12V (25%), G13D (16.7%), and G12S (8.3%). No correlation was found between mutant KRAS and location of the tumor, staging, and initial carcinoembryonic antigen (CEA) level.

CONCLUSION

Current analyses revealed that a significant proportion of CRC patients in the East Coast of Peninsular Malaysia have KRAS mutations, where this frequency is higher compared to those in the West Coast. The findings of this study would serve as a precursor for further research that explores KRAS mutational status and the profiling of other candidate genes among Malaysian CRC patients.

Circulating Tumor DNA Methylation Biomarkers for Characterization and Determination of the Cancer Origin in Malignant Liver Tumors

Malignant liver tumors include primary malignant liver tumors and liver metastases. They are among the most common malignancies worldwide. The disease has a poor prognosis and poor overall survival, especially with liver metastases. Therefore, early detection and differentiation between malignant liver tumors are critical for patient treatment selection. The detection of cancer and the prediction of its origin is possible with a DNA methylation profile of the tumor DNA compared to that of normal cells, which reflects tissue differentiation and malignant transformation. New technologies enable the characterization of the tumor methylome in circulating tumor DNA (ctDNA), providing a variety of new ctDNA methylation biomarkers, which can provide additional information to clinical decision-making. Our review of the literature provides insight into methylation changes in ctDNA from patients with common malignant liver tumors and can serve as a starting point for further research.

Anatomical Distribution of Colon Cancer: A Retrospective 10-year Study to Evaluate Rightward Shift in Two Referral Hospitals in Iran

Background: In Iran, the incidence of colorectal cancer has been increasing over the last 25 years. Although left-sided colon cancers are still more common, several studies in recent years have shown a shift toward right colon. This rightward shift could have important clinical and healthcare consequences, as right-sided tumors generally have poorer prognoses compared to left-sided tumors and besides, are more likely to be missed in screening colonoscopy. Objectives: This retrospective study aimed at describing the demographic and clinicopathologic characteristics of patients with colon cancer based on tumor sidedness in two referral hospitals in Tehran. Methods: Data of the patients with colon cancer who had been treated from 2010 to 2020 in two referral hospitals in Tehran, Iran were retrospectively reviewed. Collected data included patients’ demographics, tumor histology and differentiation, tumor location, stage, and disease-free survival (DFS). Results: A total of 1535 cases entered the study including 849 (55.3%) males and 686 (44.7%) females with a mean age of 58.22 years (range: 22 - 89). Regarding the sidedness, 800 (52.1%) had left-sided and 735 (47.9%) had right-sided tumors. Although there were more cases of left-sided tumors compared to right-sided ones on total, there existed a trend toward shifting to the right side, which was statistically significant. There existed more cases of poorly differentiated tumors in the right side and besides, right-sided tumors had poorer DFS compared to the left-sided tumors (68.3% vs 78.3%). Conclusions: Left and right colon tumors differ in molecular mechanisms involved in tumorigenesis. These differences in epidemiological, molecular and histological parameters can have clinical implications. Tumor-sidedness should be acknowledged as an important epidemiological parameter with significant impacts on screening, tumorgenesis, response to treatment, and prognosis.

Assessment of Pre-existing Type 2 Diabetes Mellitus Prevalence and Risk Factors Among Colorectal Cancer Patients in King Abdulaziz Medical City, Jeddah

BACKGROUND

Diabetes mellitus (DM) and cancer are recognized as non-communicable chronic disorders which are among the top ten causes of death globally. In Saudi Arabia, the prevalence of type 2 DM (T2DM) and colorectal cancer (CRC) is alarmingly high. Both T2DM and CRC share common risk factors. In this study, we aim to assess the prevalence of pre-existing T2DM among CRC Saudi patients.

METHODS

In this cross-sectional study, data were collected from the medical records of 275 Saudi adult patients with CRC from 2009 to 2018 at King Abdulaziz Medical City, Jeddah (KAMC-J).

RESULTS

Participants had a mean age of 57.0 years, standard deviation (SD) of 13.0, and were mostly males (60.00%) and Saudi (100.0%). Participants had a mean BMI of 26.42 (7.35) kg/m². The prevalence of pre-existing T2DM in this study was 40.80%. 15.8% of participants were overweight and obese (BMI>30), respectively. The average age of diabetics and non-diabetics was 63.6 (10.64) and 52.73 (12.43), respectively. Diabetic patients are significantly older than non-diabetic patients (p<0.001). The average BMI for diabetics was 26.96 (7.26) kg/m², whereas the average BMI for non-diabetics was 25.93 (7.48) kg/m². No significant differences were found between the two groups.

CONCLUSION

This study provides new insight into the high prevalence of pre-existing T2DM in CRC patients in Saudi Arabia. In particular, the age of diagnosis of CRC in diabetic patients was significantly higher than in non-diabetics.

Chemoprevention for Colorectal Cancers: Are Chemopreventive Effects Different Between Left and Right Sided Colorectal Cancers?

BACKGROUND AND AIMS

Recent studies have suggested that right- and left-sided colorectal cancers (CRCs) are molecularly distinct. In this study, we examined the association between the risk of right- and left-sided CRC and drug use to estimate their chemopreventive effects METHODS: This multicenter retrospective cohort study was conducted using the data of hospitalized patients between 2014 and 2019 from nine hospital databases. The primary outcomes were right- and left-sided CRC. We evaluated the association of CRCs with drug use and clinical factors. Odds ratios adjusted for age, sex, Charlson Comorbidity Index scores, and smoking status were calculated. We also compared the transcriptional profiling in precancerous lesions, including sessile serrated lesions (SSLs) RESULTS: A total of 307,938 patients, including 2745 with right-sided CRC and 4819 with left-sided CRC, were analyzed. The use of nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, cyclooxygenase-2 inhibitors, and steroids was associated with a lower risk of both right- and left-sided CRCs. In contrast, statins, other lipid-lowering agents, and metformin were associated with a lower risk of left-sided CRC. Transcriptomic analysis showed that SSL, which predominantly develops in the right colon, was associated with a lower expression of lipid metabolism-related genes.

CONCLUSIONS

Targeting lipid metabolism may be useful for chemoprevention of left-sided CRCs, while development of right-sided CRCs may be independent of this pathway.

A population-based predictive model identifying optimal candidates for primary and metastasis resection in patients with colorectal cancer with liver metastatic

BACKGROUND

The survival benefit of primary and metastatic resection for patients with colorectal cancer with liver metastasis (CRLM) has been observed, but methods for discriminating which individuals would benefit from surgery have been poorly defined. Herein, a predictive model was developed to stratify patients into sub-population based on their response to surgery.

METHODS

We assessed the survival benefits for adults diagnosed with colorectal liver metastasis by comparing patients with curative surgery vs. those without surgery. CRLM patients enrolled in the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015 were identified for model construction. Other data including CRLM patients from our center were obtained for external validation. Calibration plots, the area under the curve (AUC), and decision curve analysis (DCA) were used to evaluate the performance of the nomogram compared with the tumor-node-metastasis (TNM) classification. The Kaplan-Meier analysis was performed to examine whether this model would distinguish patients who could benefit from surgery.

RESULTS

A total of 1,220 eligible patients were identified, and 881 (72.2%) underwent colorectal and liver resection. Cancer-specific survival (CSS) for the surgery group was significantly better than that for the no-surgery group (41 vs. 14 months, p < 0.001). Five factors were found associated with CSS and adopted to build the nomograms, i.e., age, T stage, N stage, neoadjuvant chemotherapy, and primary tumor position. The AUC of the CRLM nomogram showed a better performance in identifying patients who could obtain benefits in the surgical treatment, compared with TNM classification (training set, 0.826 [95% CI, 0.786-0.866] vs. 0.649 [95% CI, 0.598-0.701]; internal validation set, 0.820 [95% CI, 0.741-0.899] vs. 0.635 [95% CI, 0.539-0.731]; external validation set, 0.763 [95% CI, 0.691-0.836] vs. 0.626 [95% CI, 0.542-0.710]). The calibration curves revealed excellent agreement between the predicted and actual survival outcomes. The DCA showed that the nomogram exhibited more clinical benefits than the TNM staging system. The beneficial and surgery group survived longer significantly than the non-beneficial and surgery group (HR = 0.21, 95% CI, 0.17-0.27, p < 0.001), but no difference was observed between the non-beneficial and surgery and non-surgery groups (HR = 0.89, 95% CI, 0.71-1.13, p = 0.344).

CONCLUSIONS

An accurate and easy-to-use CRLM nomogram has been developed and can be applied to identify optimal candidates for the resection of primary and metastatic lesions among CRLM patients.

Tumor-infiltrated activated B cells suppress liver metastasis of colorectal cancers

More than 40% of patients with late-stage colorectal cancer (CRC) develop liver metastasis (LM). Which immune cells play important roles in CRC-LM and contribute to the difference between left-sided CRC (LCC) and right-sided CRC (RCC) remain unclear. By single-cell RNA sequencing (scRNA-seq), we not only find that activated B cells are significantly depleted in CRC with LM, but also find a subtype of B cells developed from activated B cells, namely immature plasma cell population alpha (iMPA), highly correlated with metastasis. Mechanistically, inhibition of the Wnt and transforming growth factor β (TGF-β) pathways in cancer cell promotes activated B cell migration via the SDF-1-CXCR4 axis. This study reveals that B cell subpopulations in the tumor immune microenvironment (TIME) play a key role in CRC-LM as well as in LCC and RCC. The preventive effects of modulating B cell subpopulations in CRC may provide a rationale for subsequent drug development and CRC-LM management.

Mechanical signatures of human colon cancers

Besides the standard parameters used for colorectal cancer (CRC) management, new features are needed in clinical practice to improve progression-free and overall survival. In some cancers, the microenvironment mechanical properties can contribute to cancer progression and metastasis formation, or constitute a physical barrier for drug penetration or immune cell infiltration. These mechanical properties remain poorly known for colon tissues. Using a multidisciplinary approach including clinical data, physics and geostatistics, we characterized the stiffness of healthy and malignant colon specimens. For this purpose, we analyzed a prospective cohort of 18 patients with untreated colon adenocarcinoma using atomic force microscopy to generate micrometer-scale mechanical maps. We characterized the stiffness of normal epithelium samples taken far away or close to the tumor area and selected tumor tissue areas. These data showed that normal epithelium was softer than tumors. In tumors, stroma areas were stiffer than malignant epithelial cell areas. Among the clinical parameters, tumor left location, higher stage, and RAS mutations were associated with increased tissue stiffness. Thus, in patients with CRC, measuring tumor tissue rigidity may have a translational value and an impact on patient care.

The Role of Inflammatory Cytokines in the Pathogenesis of Colorectal Carcinoma—Recent Findings and Review

The inflammatory process plays a significant role in the development of colon cancer (CRC). Intestinal cytokine networks are critical mediators of tissue homeostasis and inflammation but also impact carcinogenesis at all stages of the disease. Recent studies suggest that inflammation is of greater importance in the serrated pathway than in the adenoma-carcinoma pathway. Interleukins have gained the most attention due to their potential role in CRC pathogenesis and promising results of clinical trials. Malignant transformation is associated with the pro-tumorigenic and anti-tumorigenic cytokines. The harmony between proinflammatory and anti-inflammatory factors is crucial to maintaining homeostasis. Immune cells in the tumor microenvironment modulate immune sensitivity and facilitate cancer escape from immune surveillance. Therefore, clarifying the role of underlying cytokine pathways and the effects of their modulation may be an important step to improve the effectiveness of cancer immunotherapy.

Dynamic Co-Evolution of Cancer Cells and Cancer-Associated Fibroblasts: Role in Right- and Left-Sided Colon Cancer Progression and Its Clinical Relevance

Simple Summary

The versatile crosstalk between cancer cells and cancer-associated fibroblasts (CAFs) of the tumour microenvironment (TME) drives colorectal carcinogenesis and heterogeneity. Colorectal cancer (CRC) can be classified by the anatomical sites from which the cancer arises, either from the right or left colon. Although the cancer cell–CAF interaction is being widely studied, its role in the progression of cancer in the right and left colon and cancer heterogeneity are still yet to be elucidated. Further insight into the complex interaction between different cellular components in the cancer niche, their evolutionary process and their influence on cancer progression would propel the discovery of effective targeted CRC therapy.

Abstract

Cancer is a result of a dynamic evolutionary process. It is composed of cancer cells and the tumour microenvironment (TME). One of the major cellular constituents of TME, cancer-associated fibroblasts (CAFs) are known to interact with cancer cells and promote colorectal carcinogenesis. The accumulation of these activated fibroblasts is linked to poor diagnosis in colorectal cancer (CRC) patients and recurrence of the disease. However, the interplay between cancer cells and CAFs is yet to be described, especially in relation to the sidedness of colorectal carcinogenesis. CRC, which is the third most commonly diagnosed cancer globally, can be classified according to the anatomical region from which they originate: left-sided (LCRC) and right-sided CRC (RCR). Both cancers differ in many aspects, including in histology, evolution, and molecular signatures. Despite occurring at lower frequency, RCRC is often associated with worse diagnosis compared to LCRC. The differences in molecular profiles between RCRC and LCRC also influence the mode of treatment that can be used to specifically target these cancer entities. A better understanding of the cancer cell–CAF interplay and its association with RCRC and LRCR progression will provide better insight into potential translational aspects of targeted treatment for CRC.

Modular and mechanistic changes across stages of colorectal cancer

BACKGROUND

While mechanisms contributing to the progression and metastasis of colorectal cancer (CRC) are well studied, cancer stage-specific mechanisms have been less comprehensively explored. This is the focus of this manuscript.

METHODS

Using previously published data for CRC (Gene Expression Omnibus ID GSE21510), we identified differentially expressed genes (DEGs) across four stages of the disease. We then generated unweighted and weighted correlation networks for each of the stages. Communities within these networks were detected using the Louvain algorithm and topologically and functionally compared across stages using the normalized mutual information (NMI) metric and pathway enrichment analysis, respectively. We also used Short Time-series Expression Miner (STEM) algorithm to detect potential biomarkers having a role in CRC.

RESULTS

Sixteen Thousand Sixty Two DEGs were identified between various stages (p-value ≤ 0.05). Comparing communities of different stages revealed that neighboring stages were more similar to each other than non-neighboring stages, at both topological and functional levels. A functional analysis of 24 cancer-related pathways indicated that several signaling pathways were enriched across all stages. However, the stage-unique networks were distinctly enriched only for a subset of these 24 pathways (e.g., MAPK signaling pathway in stages I-III and Notch signaling pathway in stages III and IV). We identified potential biomarkers, including HOXB8 and WNT2 with increasing, and MTUS1 and SFRP2 with decreasing trends from stages I to IV. Extracting subnetworks of 10 cancer-relevant genes and their interacting first neighbors (162 genes in total) revealed that the connectivity patterns for these genes were different across stages. For example, BRAF and CDK4, members of the Ser/Thr kinase, up-regulated in cancer, displayed changing connectivity patterns from stages I to IV.

CONCLUSIONS

Here, we report molecular and modular networks for various stages of CRC, providing a pseudo-temporal view of the mechanistic changes associated with the disease. Our analysis highlighted similarities at both functional and topological levels, across stages. We further identified stage-specific mechanisms and biomarkers potentially contributing to the progression of CRC.

Prognostic Factors in Stage IV Colorectal Cancer Patients With Resection of Liver and/or Pulmonary Metastases: A Population-Based Cohort Study

Importance

Currently, surgical resection of distant metastatic lesions has become the preferred treatment for select colorectal cancer (CRC) patients with liver metastasis (LM) and/or pulmonary metastasis (PM). Metastasectomy is the most common curative method. However, evidence of the factors affecting the prognosis of CRC patients after resection of LM and/or PM is still insufficient.

Objective

To explore the prognostic factors of CRC patients with LM and/or PM who have undergone resection of metastatic tumors and to provide reliable selection factors for surgical treatment in patients affected by LM and/or PM from CRC.

Methods

The SEER database was used to identify eligible CRC LM and/or PM patients who underwent resection of the primary tumor and distant metastases from January 1, 2010, to December 31, 2018. The Kaplan-Meier method was used to calculate survival, and comparisons were performed using the log-rank test for univariate analysis. A Cox proportional hazards regression model was used to identify prognostic factors for the multivariate analysis. The outcomes included overall survival (OS) and cancer-specific survival (CSS).

Results

A total of 3,003 eligible colorectal cancer patients with LM and/or PM were included in this study. The 3-year and 5-year OS rates were 53% and 33.6%, respectively, and the 3-year and 5-year CSS rates were 54.2% and 35.3%, respectively. In the adjusted multivariate analysis, age < 65 years (OS: p=0.002, CSS: p=0.002) was associated with better long-term outcomes, and primary tumors located on the left side of the colon (OS: p=0.004, CSS: p=0.006) or rectum (OS: p=0.004, CSS: p=0.006), T3 stage (OS: p<0.001, CSS: p<0.001), number of regional lymph nodes examined ≥ 12 (OS: p<0.001, CSS: p=0.001), and CRC LM (OS: p<0.001, CSS: p<0.001) were positive prognostic factors for survival after resection of metastatic tumors.

Conclusion

Age < 65 years is associated with better long-term outcomes in colorectal cancer patients with LM and/or PM, analogously to the left sided primary tumor, T3 stage, number of regional lymph nodes examined ≥ 12 and liver metastases.

Right colon, left colon, and rectal cancer have different oncologic and quality of life outcomes

PURPOSE

Colorectal cancer patients are commonly considered a single entity in outcomes studies. This is particularly true for quality of life (QOL) studies. This study aims to compare oncologic and QOL outcomes between right colon, left colon, and rectal cancer in patients operated on in a single high-volume institution.

METHODS

A prospectively maintained database was queried to identify patients with pathological stages I-III colorectal adenocarcinoma electively operated on with curative intent between 2000 and 2010. Patient characteristics, perioperative and oncologic outcomes, and QOL were compared according to cancer location.

RESULTS

Two-thousand sixty-five (606 right colon cancer [RCC], 366 left colon cancer [LCC], and 1093 rectal cancer [RC]) patients met the inclusion criteria. LCC had better overall survival (OS) and disease-free survival (DFS) in the non-adjusted analysis (p < 0.001) and better OS in multivariate analysis adjusted by age, gender, ASA, chemotherapy, and pathological stage (p = 0.024). Although RCC had worse OS and DFS in non-adjusted survival analysis than LCC and RC, when adjusted for the factors above, RCC had better survival outcomes than RC, but not LCC. COX regression analysis showed age (p < 0.001), gender (p = 0.016), ASA (p < 0.001), pathological stage (p < 0.001), adjuvant chemotherapy (p = 0.043), and cancer location (p = 0.024) were independently associated with OS. Age (p < 0.001), gender (p = 0.030), ASA (p = 0.004), and pathological stage (p < 0.001) were independently associated with DFS. Patients with RC reported more sexual dysfunction and work restrictions than colon cancers (p = 0.015 and p < 0.001, respectively).

CONCLUSION

In an adjusted multivariate analysis, colon cancers demonstrated better survival outcomes when compared to rectal cancers.

Perineural invasion is a prognostic factor in stage II colorectal cancer but not a treatment indicator for traditional chemotherapy: a retrospective cohort study

BACKGROUND

Perineural invasion (PNI) is considered a risk factor of survival but does not yet inform treatment decisions, and has not been studied separately in stage II colorectal cancer (CRC) patients whose postoperative traditional chemotherapy is controversial. This cohort study aimed to assess the association of PNI with basic clinicopathological features and patient outcomes after curative resection and the effects of PNI on responses to adjuvant chemotherapy in stage II CRC.

METHODS

The clinical data of 371 stage II CRC patients who underwent curative-intent surgery at the National Cancer Center/Cancer Hospital in 2014 were retrospectively reviewed. The adjuvant chemotherapy data were acquired from follow-up information. PNI status was examined, and the overall survival (OS) and disease-free survival (DFS) rates were analyzed.

RESULTS

PNI was detected in 82 of the 371 patients (22.1%) and was closely correlated with preoperative serum carcinoembryonic antigen (CEA) levels (P=0.030), gross tumor type (P=0.010), tumor differentiation (P=0.010), p stage (P<0.001), and extramural vascular invasion (EMVI) (P<0.001). The median follow-up time was 71 months. The 5-year OS was 84.1% and 96.5% (P<0.001), and the 5-year DFS was 75.6% and 91.3% (P<0.001) for PNI-positive (+) and PNI-negative (-) patients, respectively. The multivariate regression analyses identified PNI as an independent negative prognostic factor for DFS [hazard ratio (HR): 2.95; 95% confidence interval (CI), 1.546-5.626; P=0.001] and OS (HR: 3.966; 95% CI, 1.642-9.575; P=0.002). Among PNI (+) patients, DFS and OS were positively correlated with CEA levels (P=0.005 and P=0.004, respectively). Postoperative chemotherapy failed to improve DFS (P=0.480 and P=0.267, respectively) and OS (P=0.940 and P=0.077, respectively) regardless of whether the patients were PNI positive or not.

CONCLUSIONS

In stage II CRC patients, PNI was a poor independent predictor for DFS and OS. Among PNI (+) patients, CEA levels were positively correlated with DFS and OS. Traditional postoperative adjuvant chemotherapy does not improve outcomes of PNI (+) patients. Therefore, as to the active role of PNI and vacancy for treatment in allusion to PNI, follow-up of PNI (+) patients with elevated CEA level should be strengthened and further research on drug conducted on PNI deserve to be carried on.

Liquid Biopsy and Artificial Intelligence as Tools to Detect Signatures of Colorectal Malignancies: A Modern Approach in Patient's Stratification

Colorectal cancer (CRC) is the second most frequently diagnosed type of cancer and a major worldwide public health concern. Despite the global efforts in the development of modern therapeutic strategies, CRC prognosis is strongly correlated with the stage of the disease at diagnosis. Early detection of CRC has a huge impact in decreasing mortality while pre-lesion detection significantly reduces the incidence of the pathology. Even though the management of CRC patients is based on robust diagnostic methods such as serum tumor markers analysis, colonoscopy, histopathological analysis of tumor tissue, and imaging methods (computer tomography or magnetic resonance), these strategies still have many limitations and do not fully satisfy clinical needs due to their lack of sensitivity and/or specificity. Therefore, improvements of the current practice would substantially impact the management of CRC patients. In this view, liquid biopsy is a promising approach that could help clinicians screen for disease, stratify patients to the best treatment, and monitor treatment response and resistance mechanisms in the tumor in a regular and minimally invasive manner. Liquid biopsies allow the detection and analysis of different tumor-derived circulating markers such as cell-free nucleic acids (cfNA), circulating tumor cells (CTCs), and extracellular vesicles (EVs) in the bloodstream. The major advantage of this approach is its ability to trace and monitor the molecular profile of the patient's tumor and to predict personalized treatment in real-time. On the other hand, the prospective use of artificial intelligence (AI) in medicine holds great promise in oncology, for the diagnosis, treatment, and prognosis prediction of disease. AI has two main branches in the medical field: (i) a virtual branch that includes medical imaging, clinical assisted diagnosis, and treatment, as well as drug research, and (ii) a physical branch that includes surgical robots. This review summarizes findings relevant to liquid biopsy and AI in CRC for better management and stratification of CRC patients.

HOXD8 hypermethylation as a fully sensitive and specific biomarker for biliary tract cancer detectable in tissue and bile samples

Background

Biliary tract cancers (BTC) are rare but highly aggressive tumours with poor prognosis, usually detected at advanced stages. Herein, we aimed at identifying BTC-specific DNA methylation alterations.

Methods

Study design included statistical power and sample size estimation. A genome-wide methylation study of an explorative cohort (50 BTC and ten matched non-tumoral tissue samples) has been performed. BTC-specific altered CpG islands were validated in over 180 samples (174 BTCs and 13 non-tumoral controls). The final biomarkers, selected by a machine-learning approach, were validated in independent tissue (18 BTCs, 14 matched non-tumoral samples) and bile (24 BTCs, five non-tumoral samples) replication series, using droplet digital PCR.

Results

We identified and successfully validated BTC-specific DNA methylation alterations in over 200 BTC samples. The two-biomarker panel, selected by an in-house algorithm, showed an AUC > 0.97. The best-performing biomarker (chr2:176993479-176995557), associated with HOXD8, a pivotal gene in cancer-related pathways, achieved 100% sensitivity and specificity in a new series of tissue and bile samples.

Conclusions

We identified a novel fully efficient BTC biomarker, associated with HOXD8 gene, detectable both in tissue and bile by a standardised assay ready-to-use in clinical trials also including samples from non-invasive matrices.

The significance of subdivisions of microscopically positive (R1) margins in colorectal cancer: A retrospective study of a national cancer registry

AIM

Microscopically positive (R1) margins are associated with poorer outcomes in patients with colorectal cancer. However, little is known of the differential impact of subdivisions of R1 margins, be they to the primary tumour (R1tumour) or to lymph node metastases/tumour deposits (R1LNM).

METHODS

Patients treated for Stage III colorectal cancer from 1 January 2016 to 31 December 2019 were identified from the Danish national cancer registry. Patients were stratified into three groups according to margin status (R0 vs. R1tumour vs. R1LNM). The primary outcome was overall survival.

RESULTS

In all, 4186 patients were included, comprising 3012 patients with colon cancer and 1174 patients with rectal cancer. The R1 resection rates were 16.5% and 18.2% in patients with colon and rectum cancer, respectively. In colon cancers, 3-year overall survival was reduced in patients with R1LNM (65.7%, 95% CI 62.8-68.6) or R1tumour margins (51.8%, 95% CI 47.3-56.3) compared with R0 resections (80.8%, 95% CI 79.9-81.6, P < 0.001). A similar impact on survival was seen in rectal cancers (R0, 84.2%, 95% CI 82.9-85.5; R1LNM, 72.2%, 95% CI 67.8-76.6; R1tumour, 56.6%, 95% CI 50.0-63.2, P < 0.001). Margin status was independently prognostic of survival in both colon (R1tumour, hazard ratio 2.08, 95% CI 1.50-2.89, P < 0.001; R1LNM, hazard ratio 1.48, 95% CI 1.11-1.97, P = 0.008) and rectal cancers (R1tumour, hazard ratio 2.35, 95% CI 1.42-3.90, P < 0.001; R1LNM, hazard ratio 1.54, 95% CI 0.95-2.48, P = 0.077).

CONCLUSION

R1 subdivisions have distinct impacts on survival in Stage III colorectal cancer. Further focused research in these patient subgroups is warranted.

The Association of Metformin, Other Antidiabetic Medications, and Statins With the Prognosis of Colon Cancer in Patients With Type 2 Diabetes: A Retrospective Cohort Study

BACKGROUND

Use of metformin and statins have been associated with improved prognosis of colon cancer (CC) in patients with type 2 diabetes (T2D). We examined the survival from CC in relation to the use of metformin, other oral antidiabetic medications (ADM), insulin, and statins in T2D patients.

MATERIALS AND METHODS

A cohort (n = 2252) of persons with pre-existing T2D diagnosed with incident CC between 1998 and 2011 was identified from several Finnish registers. Cox models were fitted for cause-specific mortality rates to obtain adjusted estimates of the hazard ratios (HR) with 95% confidence intervals (CI) in relation to use of ADM and statins before the CC diagnosis. Cox models were also fitted for mortality in relation to post-diagnostic use of the medications treating these as time-dependent exposures, and starting follow-up 1 year after the CC diagnosis.

RESULTS

Pre- and post-diagnostic metformin use was weakly associated with the risk of CC-related death (HR .75; 95% CI .58-.99, and HR .78; 95% CI .54-1.14, respectively) compared to the use of other oral ADMs. Pre- and post-diagnostic statin use predicted a reduced risk of CC-related death (HR .83; 95% CI .71- .98, and HR .69; 95% CI .54-.89, respectively).

CONCLUSION

Additional evidence was found for use of statins being associated with an improved survival from CC in patients with pre-existing T2D, but for metformin use the evidence was weaker.

Cholangiocarcinoma: new perspectives for new horizons

INTRODUCTION

Biliary tract cancer represents a heterogeneous group of malignancies characterized by dismal prognosis and scarce therapeutic options.

AREA COVERED

In the last years, a growing interest in BTC pathology has emerged, thus highlighting a significant heterogeneity of the pathways underlying the carcinogenesis process, from both a molecular and genomic point of view. A better understanding of these differences is mandatory to deepen the behavior of this complex disease, as well as to identify new targetable target mutations, with the aim to improve the survival outcomes. The authors decided to provide a comprehensive overview of the recent highlights on BTCs, with a special focus on the genetic, epigenetic and molecular alterations, which may have an interesting clinical application in the next future.

EXPERT OPINION

In the last years, the efforts resulted from international collaborations have led to the identification of new promising targets for precision medicine approaches in the BTC setting. Further investigations and prospective trials are needed, but the hope is that these new knowledge in cooperation with the new technologies and procedures, including bio-molecular and genomic analysis as well radiomic studies, will enrich the therapeutic armamentarium thus improving the survival outcomes in a such lethal and complex disease.

Development and Validation of the Individualized Prognostic Nomograms in Patients With Right- and Left-Sided Colon Cancer

Background

The overall survival (OS) of patients diagnosed with colon cancer (CC) varied greatly, so did the patients with the same tumor stage. We aimed to design a nomogram that is capable of predicting OS in resected left-sided colon cancers (LSCC) and right-sided colon cancers (RSCC), and thus to stratify patients into different risk groups, respectively.

Methods

Records from a retrospective cohort of 577 patients with complete information were used to construct the nomogram. Univariate and multivariate analyses screened risk factors associated with overall survival. The performance of the nomogram was evaluated with concordance index (c-index), calibration plots, and decision curve analyses for discrimination, accuracy, calibration ability, and clinical net benefits, respectively, which was further compared with the American Joint Committee on Cancer (AJCC) 8th tumor-node-metastasis (TNM) classification. Risk stratification based on nomogram scores was performed with recursive partitioning analysis.

Results

The LSCC nomogram incorporated carbohydrate antigen 12-5 (CA12-5), age and log odds of positive lymph nodes (LODDS), and RSCC nomogram enrolled tumor stroma percentage (TSP), age and LODDS. Compared with the TNM classification, the LSCC and RSCC nomograms both had a statistically higher C-index (0.837, 95% CI: 0.827-0.846 and 0.780, 95% CI 0.773-0.787, respectively) and more clinical net benefits, respectively. Calibration plots revealed no deviations from reference lines. All results were reproducible in the validation cohort.

Conclusions

An original predictive nomogram was constructed and validated for OS in patients with CC after surgery, which had facilitated physicians to appraise the individual survival of postoperative patients accurately and to identify high-risk patients who were in need of more aggressive treatment and follow-up strategies.

The Impact of Patient Characteristics and Tumor Biology on the Accuracy of Preoperative Staging of Colon Cancer in Denmark. A Nationwide Cohort Study

Simple Summary

The roles of mismatch repair and other colon tumor characteristics were investigated in a nationwide registry study with data extracted from the Danish Colorectal Cancer Group. Mismatch repair can arise during DNA replication. In this study, 6102 patients were included with a median age of 72 (range 23–97 years). The mismatch repair was deficient in 24% and proficient in 76%. Mismatch repair deficiency impacted the accuracy of the preoperative staging of colon cancer. In the future, mismatch repair status should be taken into consideration in the clinical staging of colon cancer.

Abstract

Background: Colon cancer is a common disease in western populations. The aim of this study was to assess the impact of mismatch repair (MMR) deficiency and other patient and tumor characteristics on the accuracy of preoperative staging by comparing histopathological T- and N-categories of the resected specimen with the preoperative clinical stage in a nationwide cohort of patients treated for colon cancer by elective bowel resection with curative intent. Methods: A register study of a cohort extracted from the Danish Colorectal Cancer Group (DCCG) database, which holds prospective data on all new cases of colon and rectum cancer in Denmark. Patients diagnosed with colon cancer and treated with an elective bowel resection with curative intent in the years 2016–2019 were analyzed. Results: A total of 6102 patients were included (n = 3161 (52%) men and n = 2941 (48%) women) with a median age of 72 years (range 23–97 years). MMR was deficient in 24% of the patients and proficient in 76%. MMR deficiency, tumor sidedness and histopathological type were significant predictors of the accuracy of preoperative staging of colon cancer in univariate and multivariate analysis. MMR status in particular showed a strong impact on the risk of overstaging. Conclusions: MMR deficiency, but also tumor sidedness and to some degree histopathological type, impacted the accuracy of preoperative staging of colon cancer. MMR status should be taken into consideration in everyday clinical staging.

An investigation on the c-MYC, AXIN1, and COL11A1 gene expression in colorectal cancer

The high incidence rate of CRC demands early diagnosis of the disease and readiness of diagnostic biomarker. In present study, we have investigated c-MYC, AXIN1, and COL11A1 expression levels in course of CRC progression and their correlation with demographics and clinical risk factors. Fifty-five tumors and 41 normal tissues were obtained from Tumor Bank of Iran, total RNA was extracted, cDNA was synthesized, and RT-qPCR was performed. Results were analyzed using Rest 2009 and SPSS software. Analysis at mRNA level showed upregulation of the two genes; c-MYC with a p-value of 0.001 and COL11A1 with an observed p-value of 0.02, while a p-value of 0.04 indicated AXIN1 downregulation. The observed overexpression of COL11A1 in stage 0 compared to other stages of CRC asserts importance of this gene in CRC prognosis. Moreover, statistical analysis confirms a significant correlation between expression of these genes and several clinical risk factors of CRC. Our study supports the importance of the studied genes and provides further information regarding the molecular mechanism of CRC. Further studies on these genes could elucidate their pivotal role for both early detection and/or diagnosis of CRC in addition to have important biomarkers for CRC management available.

Regulatory Network Analysis of Mutated Genes Based on Multi-Omics Data Reveals the Exclusive Features in Tumor Immune Microenvironment Between Left-Sided and Right-Sided Colon Cancer

Left-sided colon cancer (LCC) and right-sided colon cancer (RCC) have distinct characteristics in tumor immune microenvironment (TIME). Although existing studies have shown a strong association between gene mutations and TIME, whether the regulatory mechanisms between gene mutations and TIME are different between RCC and LCC is still unclear. In this study, we showed the fractions of CD8+ T cells were higher while those of regulatory T cells were lower in RCC. Besides, a stronger association between gene mutations and TIME was observed in RCC. Specifically, using multi-omics data, we demonstrated the mutations of most top mutated genes (TMGs) including BRAF, PCLO, MUC16, LRP2, ANK3, KMT2D, RYR2 made great contributions to elevated fraction of immune cells by up-regulating immune-related genes directly or indirectly through miRNA and DNA methylation, whereas the effects of APC, TP53 and KRAS mutations on TIME were reversed in RCC. Remarkably, we found the expression levels of several immune checkpoint molecules such as PD-1 and LAG3 were correlated with corresponding DNA methylation levels, which were associated with the mutations of TMGs in RCC. In contrast, the associations between gene mutations and TIME were less significant in LCC. Besides, survival analyses showed APC mutation had adverse impact on immunotherapy while patients with BRAF mutation were more suitable for immunotherapy in colon cancer. We hope that our results will provide a deeper insight into the sophisticated mechanism underlying the regulation between mutations and TIME, and thus boost the discovery of differential immunotherapeutic strategies for RCC and LCC.

Differences in the On- and Off-Tumor Microbiota between Right- and Left-Sided Colorectal Cancer

This study aims to determine differences in the on- and off-tumor microbiota between patients with right- and left-sided colorectal cancer. Microbiome profiling of tumor and tumor-adjacent biopsies from patients with right-sided (n = 17) and left-sided (n = 7) colorectal adenocarcinoma was performed using 16S ribosomal RNA sequencing. Off-tumor alpha and beta diversity were significantly different between right- and left-sided colorectal cancer patients. However, no differences in on-tumor diversity were observed between tumor locations. Comparing the off-tumor microbiota showed the right colon to be enriched with species of the Lachnoclostridium, Selenomonas, and Ruminococcus genera. Whereas the left colon is enriched with Epsilonbacteraeota phylum, Campylobacteria class, and Pasteurellales and Campylobacterales orders, in contrast, the on-tumor microbiota showed relatively fewer differences in bacterial taxonomy between tumor sites, with left tumors being enriched with Methylophilaceae and Vadin BE97 families and Alloprevotella, Intestinibacter, Romboutsia, and Ruminococcus 2 genera. Patients with left-sided colorectal cancer had large taxonomic differences between their paired on- and off-tumor microbiota, while patients with right-sided colorectal cancer showed relatively fewer taxonomic differences. Collectively, this suggests that the right and left colon show distinctive bacterial populations; however, the presence of a colonic tumor leads to a more consistent microbiota between locations.

Colorectal cancer demographics in Barbados

Barbados is an island in the Eastern Caribbean that is reported to have the 8th highest incidence of colorectal cancer (CRC) worldwide. However, these figures are based only on estimates, and there is little available epidemiological data collected from Barbadians with CRC. The present study sought to collect epidemiologic data from patients in Barbados diagnosed with CRC. This information is considered important to shape national public health policies. For this purpose, hospital admission registers at all tertiary care facilities in Barbados were retrospectively audited over a four-year period from January 1, 2014 to December 31, 2018 to identify patients who underwent operative treatment for CRC. The following data were extracted: Age, sex, ethnicity, the location of the primary tumour and tumour stage. Descriptive statistical analyses were generated using SPSS version 21.0. The results revealed that there were 97 patients with CRC at a mean age of 64.9 years (SD ±12.2) and a male preponderance (1.3:1). The majority (93.8%) were from the African diaspora. Only 18.5% of diagnoses were made at (opportunistic) screening. Consequently, two thirds of the patients had advanced-stage disease at diagnosis. The disease staging of the patients was as follows: Stage 0 (1%), stage I (10.3%), stage II (23.7%), stage III (38.1%) and stage IV (26.8%). Right-sided primary tumours were most common (44.3%), followed by left-sided (41.2%) and rectal lesions (14.4%). Women were significantly more likely to have right-sided lesions (55 vs. 45%) and males were more likely to have rectal lesions (77 vs. 23%). On the whole, the present study highlights the need to implement a national screening programme in this high-risk population of African origin with a predominantly right-sided distribution of CRC primary tumours. This is reinforced by the fact that 10% of patients will be diagnosed before the age of 50 years with more aggressive disease.

Prognostic nomograms for predicting overall survival and cause-specific survival of signet ring cell carcinoma in colorectal cancer patients

BACKGROUND

Signet ring cell carcinoma (SRCC) is an uncommon subtype in colorectal cancer (CRC), with a short survival time. Therefore, it is imperative to establish a useful prognostic model. As a simple visual predictive tool, nomograms combining a quantification of all proven prognostic factors have been widely used for predicting the outcomes of patients with different cancers in recent years. Until now, there has been no nomogram to predict the outcome of CRC patients with SRCC.

AIM

To build effective nomograms for predicting overall survival (OS) and cause-specific survival (CSS) of CRC patients with SRCC.

METHODS

Data were extracted from the Surveillance, Epidemiology, and End Results database between 2004 and 2015. Multivariate Cox regression analyses were used to identify independent variables for both OS and CSS to construct the nomograms. Performance of the nomograms was assessed by concordance index, calibration curves, and receiver operating characteristic (ROC) curves. ROC curves were also utilized to compare benefits between the nomograms and the tumor-node-metastasis (TNM) staging system. Patients were classified as high-risk, moderate-risk, and low-risk groups using the novel nomograms. Kaplan-Meier curves were plotted to compare survival differences.

RESULTS

In total, 1230 patients were included. The concordance index of the nomograms for OS and CSS were 0.737 (95% confidence interval: 0.728-0.747) and 0.758 (95% confidence interval: 0.738-0.778), respectively. The calibration curves and ROC curves demonstrated good predictive accuracy. The 1-, 3-, and 5-year area under the curve values of the nomogram for predicting OS were 0.796, 0.825 and 0.819, in comparison to 0.743, 0.798, and 0.803 for the TNM staging system. In addition, the 1-, 3-, and 5-year area under the curve values of the nomogram for predicting CSS were 0.805, 0.847 and 0.863, in comparison to 0.740, 0.794, and 0.800 for the TNM staging system. Based on the novel nomograms, stratified analysis showed that the 5-year probability of survival in the high-risk, moderate-risk, and low-risk groups was 6.8%, 37.7%, and 67.0% for OS (P < 0.001), as well as 9.6%, 38.5%, and 67.6% for CSS (P < 0.001), respectively.

CONCLUSION

Convenient and visual nomograms were built and validated to accurately predict the OS and CSS rates for CRC patients with SRCC, which are superior to the conventional TNM staging system.