Prognostic models based on postoperative circulating tumor cells can predict poor tumor recurrence-free survival in patients with stage II-III colorectal cancer

Prognostic value of creatine kinase (CK)-MB to total-CK ratio in colorectal cancer patients after curative resection

OBJECTIVES

This study aimed to evaluate the prognostic significance of postoperative Creatine Kinase type M and B (CK-MB) to total Creatine Kinase (CK) ratio (CK-MB/CK) in colorectal cancer (CRC) patients after radical resection.

METHODS

This was a single-center retrospective cohort analysis. Subjects were stage I-III CRC patients hospitalized in Sichuan Cancer Hospital from January 2017 to May 2021. Patients were divided into abnormal group and normal group according to whether the CK-MB/CK ratio was abnormal after surgery. Through a comparative analysis of clinical data, laboratory test results, and prognosis differences between the two groups, we aimed to uncover the potential relationship between abnormal CK-MB > CK results and CRC patients. To gauge the impact of CK-MB/CK on overall survival (OS) and disease-free survival (DFS), we employed the multivariable COX regression and LASSO regression analysis. Additionally, Spearman correlation analysis, logistic regression, and receiver-operating characteristic (ROC) curve analysis were conducted to assess the predictive value of the CK-MB/CK ratio for postoperative liver metastasis.

RESULTS

Cox regression analysis revealed that the CK-MB/CK ratio was a stable risk factors for OS (HR = 3.82, p < 0.001) and DFS (HR = 2.31, p < 0.001). To distinguish hepatic metastases after surgery, the ROC area under the curve of CK-MB/CK was 0.697 (p < 0.001), and the optimal cut-off value determined by the Youden index was 0.347.

CONCLUSIONS

Postoperative abnormal CK-MB/CK ratio predicts worse prognosis in CRC patients after radical resection and serves as a useful biomarker for detecting postoperative liver metastasis.

Liquid biopsy in colorectal cancer

Liquid biopsy refers to a set of pathological samples retrieved from non-solid sources, such as blood, cerebrospinal fluid, urine, and saliva through non-invasive or minimally invasive approaches. In the recent decades, an increasing number of studies have focused on clinical applications and improving technological investigation of liquid biopsy biosources for diagnostic goals particularly in cancer. Materials extracted from these sources and used for medical evaluations include cells like circulating tumor cells (CTCs), tumor-educated platelets (TEPs), cell-free nucleic acids released by cells, such as circulating tumor DNA (ctDNA), cell-free DNA (cfDNA), cell-free RNA (cfRNA), and exosomes. Playing significant roles in the pathogenesis of human malignancies, analysis of these sources can provide easier access to genetic and transcriptomic information of the cancer tissue even better than the conventional tissue biopsy. Notably, they can represent the inter- and intra-tumoral heterogeneity and accordingly, liquid biopsies demonstrate strengths for improving diagnosis in early detection and screening, monitoring and follow-up after therapies, and personalization of therapeutical strategies in various types of human malignancies. In this review, we aim to discuss the roles, functions, and analysis approaches of liquid biopsy sources and their clinical implications in human malignancies with a focus on colorectal cancer.

Prognostic value of circulating tumor cells in patients with recurrent and metastatic colorectal cancer: a systematic review and meta-analysis

BACKGROUND

The detection of circulating tumor cells (CTCs) has been employed in prognosticating the likelihood of recurrence and metastasis in colorectal cancer (CRC). Nonetheless, the findings remain enigmatic. This meta-analysis aims to systematically assess the predictive utility of CTCs detection in postoperative recurrence and metastasis among CRC patients.

METHODS

A comprehensive search of PubMed, Web of Science, China National Knowledge Infrastructure (CNKI), and Cochrane Library was conducted from inception to March 2023. Pooled estimates including sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratio, and summary receiver operating characteristic curve were computed to gauge the predictive value. The QUADAS-2 tool was employed to appraise bias risks in individual studies. The assessment of publication bias in the included literature was performed using Deek's funnel plot.

RESULTS

The study encompassed 16 articles and 2037 patients. After synthesizing the pertinent indices, CTCs monitoring demonstrated sensitivity and specificity of 0.71 (95% confidence interval [CI], 0.62-0.79) and 0.71 (95% CI, 0.55-0.83), respectively. The corresponding values for positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 2.4 (95% CI, 1.5-4.0), 0.41 (95% CI, 0.29-0.58), and 6 (95% CI, 3-13). The summary receiver operating characteristic curve yielded an area under the curve of 0.76 (95% CI, 0.72-0.80). Deek's funnel plot analysis revealed no significant evidence of publication bias (P = .42).

CONCLUSION

This investigation underscores the potential of CTCs detection as a noninvasive modality to efficaciously prognosticate postoperative recurrence and metastasis in CRC.

Circulating Tumor Cells: From Basic to Translational Research

BACKGROUND

Metastasis is the leading cause of cancer-related deaths. Most studies have focused on the primary tumor or on overt metastatic lesions, leaving a significant knowledge gap concerning blood-borne cancer cell dissemination, a major step in the metastatic cascade. Circulating tumor cells (CTCs) in the blood of patients with solid cancer can now be enumerated and investigated at the molecular level, giving unexpected information on the biology of the metastatic cascade.

CONTENT

Here, we reviewed recent advances in basic and translational/clinical research on CTCs as key elements in the metastatic cascade.

SUMMARY

Findings from translational studies on CTCs have elucidated the complexity of the metastatic process. Fully understanding this process will open new potential avenues for cancer therapeutic and diagnostic strategies to propose precision medicine to all cancer patients.

Circulating tumor cells in colorectal cancer - a review of detection methods and clinical relevance

Colorectal cancer (CRC) is the third most common cancer; it is one of the leading malignancies contributing to cancer mortality. Colorectal cancer is the third most diagnosed cancer in men and the second in women worldwide. Diagnosis of CRC depends on several clinical features such as age, primary site, tumor-node-metastasis stage, genetic parameters and the presence or absence of metastasis. The latter is a phenomenon that is induced by the shedding of tumor cells in the blood circulation by the primary tumor. Such cells are known as circulating tumor cells (CTCs). The detection of CTCs is quite challenging due to their scarceness; thus it requires their enrichment and characterization. Studying the utility of CTCs in the diagnosis of CRC has been the aim of several studies; they demonstrated that ≥ 3 CTCs in 7.5 ml of blood is correlated with a worse prognosis and short progression-free and overall survival. Circulating tumor cells have also been monitored to study treatment response and predict future relapses. The present review aims to bring to light the different techniques used to detect and characterize these malignant cells in the peripheral blood of cancer patients as well as the clinical relevance of CTCs in CRC patients.

Utilization of Circulating Tumor Cells in the Management of Solid Tumors

Circulating tumor cells (CTCs) are tumor cells shed from the primary tumor into circulation, with clusters of CTCs responsible for cancer metastases. CTC detection and isolation from the bloodstream are based on properties distinguishing CTCs from normal blood cells. Current CTC detection techniques can be divided into two main categories: label dependent, which depends upon antibodies that selectively bind cell surface antigens present on CTCs, or label-independent detection, which is detection based on the size, deformability, and biophysical properties of CTCs. CTCs may play significant roles in cancer screening, diagnosis, treatment navigation, including prognostication and precision medicine, and surveillance. In cancer screening, capturing and evaluating CTCs from peripheral blood could be a strategy to detect cancer at its earliest stage. Cancer diagnosis using liquid biopsy could also have tremendous benefits. Full utilization of CTCs in the clinical management of malignancies may be feasible in the near future; however, several challenges still exist. CTC assays currently lack adequate sensitivity, especially in early-stage solid malignancies, due to low numbers of detectable CTCs. As assays improve and more trials evaluate the clinical utility of CTC detection in guiding therapies, we anticipate increased use in cancer management.

Circulating tumour cells in gastrointestinal cancers: food for thought?

Gastrointestinal (GI) cancers account for 35% of cancer-related deaths, predominantly due to their ability to spread and generate drug-tolerant metastases. Arising from different locations in the GI system, the majority of metastatic GI malignancies colonise the liver and the lungs. In this context, circulating tumour cells (CTCs) are playing a critical role in the formation of new metastases, and their presence in the blood of patients has been correlated with a poor outcome. In addition to their prognostic utility, prospective targeting of CTCs may represent a novel, yet ambitious strategy in the fight against metastasis. A better understanding of CTC biology, mechanistic underpinnings and weaknesses may facilitate the development of previously underappreciated anti-metastasis approaches. Here, along with related clinical studies, we outline a selection of the literature describing biological features of CTCs with an impact on their metastasis forming ability in different GI cancers.

The diagnostic significance of CDH17-positive circulating tumor cells in patients with colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is the second leading cause of cancer deaths in Hong Kong. We tested the hypothesis that circulating tumor cell (CTC) analysis by ARB101 antibody could be used as a tool for CRC detection, progression, and therapy response.

RESEARCH METHODS

ARB101 antibody was used for investigation of CDH17 expression in formalin-fixed, paraffin-embedded (FFPE) tissue sections and circulating tumor cells (CTCs) of CRC patients.

RESULTS

Using ARB101, highest sensitivity was observed in 98/100 (98%) colorectal cancer tissue compared to 72/100 gastric cancer (72%) and 27/32 pancreatic cancer (84%). Immunoreactivity of CDH17 was significantly higher in distant metastatic (tumor-node-metastasis [TNM] stage IV) than non-distant metastatic (TNM stage I to III) CRC. ARB101 antibody also manifested the higher sensitivity than c-erbB2 (8%) and epidermal growth factor receptor (EGFR)-targeting antibodies (37%) with the significance (p < 0.0001). ARB101 positive CTCs were detected in 64/83 (77%) TNM stage I to IV CRC patients. Furthermore, ARB101 positive CTCs detected in TNM stage I to III CRC patients before and after surgical operation are statistically significant (p < 0.0001).

CONCLUSIONS

CTC detection by ARB101 antibody could serve as a potential non-invasive approach for CRC detection, progression, and monitoring of treatment response.

Identification of a Prognostic Colorectal Cancer Model Including LncRNA FOXP4-AS1 and LncRNA BBOX1-AS1 Based on Bioinformatics Analysis

Background: Knowledge about the prognostic role of long noncoding RNA (lncRNA) in colorectal cancer (CRC) is limited. Therefore, we constructed a lncRNA-related prognostic model based on data from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA). Materials and Methods: CRC transcriptome and clinical data were downloaded from the GSE20916 dataset and the TCGA database, respectively. R software was used for data processing and analysis. The differential lncRNA expression within the two datasets was first screened, and then intersections were measured. Cox regression and the Kaplan-Meier method were used to evaluate the effects of various factors on prognosis. The area under the curve (AUC) of the receiver operating characteristic curve and a nomogram based on multivariate Cox analysis were used to estimate the prognostic value of the lncRNA-related model. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were applied to elucidate the significantly involved biological functions and pathways. Results: A total of 11 lncRNAs were crossed. The univariate Cox analysis screened out two lncRNAs, which were analyzed in the multivariate Cox analysis. A nomogram based on the two lncRNAs and other clinicopathological risk factors was constructed. The AUC of the nomogram was 0.56 at 3 years and 0.71 at 5 years. The 3-year nomogram model was compared with the ideal model, which showed that some indices of the 3-year model were consistent with the ideal model, suggesting that our model was highly accurate. The GO and KEGG enrichment analyses showed that positive regulation of secretion by cells, positive regulation of secretion, positive regulation of exocytosis, endocytosis, and the calcium signaling pathway were differentially enriched in the two-lncRNA-associated phenotype. Conclusions: A two-lncRNA prognostic model of CRC was constructed by bioinformatics analysis. The model had moderate prediction accuracy. LncRNA BBOX1-AS1 and lncRNA FOXP4-AS1 were identified as prognostic biomarkers.

The Potential Role of MUC16 (CA125) Biomarker in Lung Cancer: A Magic Biomarker but with Adversity

Lung cancer is the second most commonly diagnosed cancer in the world. In terms of the diagnosis of lung cancer, combination carcinoembryonic antigen (CEA) and cancer antigen 125 (CA125) detection had higher sensitivity, specificity, and diagnostic odds ratios than CEA detection alone. Most individuals with elevated serum CA125 levels had lung cancer that was either in stage 3 or stage 4. Serum CA125 levels were similarly elevated in lung cancer patients who also had pleural effusions or ascites. Furthermore, there is strong evidence that human lung cancer produces CA125 in vitro, which suggests that other clinical illnesses outside of ovarian cancer could also be responsible for the rise of CA125. MUC16 (CA125) is a natural killer cell inhibitor. As a screening test for lung and ovarian cancer diagnosis and prognosis in the early stages, CA125 has been widely used as a marker in three different clinical settings. MUC16 mRNA levels in lung cancer are increased regardless of gender. As well, increased expression of mutated MUC16 enhances lung cancer cells proliferation and growth. Additionally, the CA125 serum level is thought to be a key indicator for lung cancer metastasis to the liver. Further, CA125 could be a useful biomarker in other cancer types diagnoses like ovarian, breast, and pancreatic cancers. One of the important limitations of CA125 as a first step in such a screening technique is that up to 20% of ovarian tumors lack antigen expression. Each of the 10 possible serum markers was expressed in 29-100% of ovarian tumors with minimal or no CA125 expression. Therefore, there is a controversy regarding CA125 in the diagnosis and prognosis of lung cancer and other cancer types. In this state, preclinical and clinical studies are warranted to elucidate the clinical benefit of CA125 in the diagnosis and prognosis of lung cancer.

Circulating Tumor Cells in Colorectal Cancer: Detection Systems and Clinical Utility

Colorectal cancer (CRC) is the third most common cancer worldwide. The high mortality from CRC is mainly related to metastasis affecting distant organs and their function. Dissemination of tumor cells from the primary tumor and hematogeneous spread are considered crucial in the formation of tumor metastases. The analysis of circulating tumor cells (CTCs) and CTC clusters in the blood can be used for the early detection of invasive cancer. Moreover, CTCs have a prognostic significance in the monitoring of a malignant disease or the response to chemotherapy. This work presents an overview of the research conducted on CTCs with the aim of finding suitable detection systems and assessing the possibility of clinical applications in patients with CRC.

A meta-analysis of the value of circulating tumor cells in monitoring postoperative recurrence and metastasis of colorectal cancer

Objective

Circulating tumor cells (CTCs) as novel biomarkers are widely investigated in various cancers, although most of the literature shows that CTCs have predictive value for recurrence, metastasis, and prognosis after CRC surgery, results remain controversial. We aimed to systematically evaluate the value of CTCs in monitoring of colorectal cancer (CRC) recurrence and metastasis after surgery.

Method

The PubMed, Cochrane Library, Embase, and other databases were searched from the establishment of the database to May 27, 2021. Relevant literature searches and data extraction were performed independently by two reviewers. The quality assessment was performed using the QUADAS2 scale developed by the Cochrane collaboration. The heterogeneity was checked using the Spearman correlation coefficient and the Cochran-Q test in the Meta-Disc1.4 software. Subgroup analysis was used to explore the source of heterogeneity. Considering that all the included papers were clinical studies with clinical heterogeneity, random effect model was adopted for analysis. And the sensitivity (Sen), specificity (Spe), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curves of CTCs, in monitoring recurrence and metastasis after CRC, were calculated. The publication bias of the included studies was assessed using Deek’s funnel figure.

Result

The literature included a total of 13 articles, comprising 1788 cases, and the overall quality of the literature was high. After summing up the indicators, the sensitivity pooled-value of the peripheral blood CTCs to monitor the recurrence and metastasis value of CRC after CRC was 0.67 [95%CI (0.62, 0.71)], specificity pooled-value was 0.71 [95%CI (0.67, 0.72)], PLR pooled-value was 2.37 [95%CI [1.52, 3.71]), NLR pooled into 0.53 [95%CI (0.36, 0.78)], DOR pooled into 4.97 [95%CI (2.11, 11.72)], AUC was 0.7395.

Conclusion

Peripheral blood CTCs have a moderate monitoring value for recurrence and metastasis after CRC; CTCs detected one week after surgery may be more correlated with recurrence and metastasis.

Efficacy of jianpi huatan granule in reducing colorectal cancer metastasis and recurrence after radical resection and adjuvant chemotherapy: Study protocol for a randomised, double-blind, placebo-controlled, multicentre trial

Background: The high incidence and mortality rates of colorectal cancer (CRC) are a severe challenge in China. In patients with stage III and high-risk stage II CRC after radical resection and postoperative adjuvant chemoradiotherapy, 40–60% experience recurrence and metastasis. Several years of clinical practice have shown that traditional Chinese medicine, including Jianpi Huatan granule (JHG), effectively prevents stage III and high-risk stage II CRC recurrence and metastasis after radical resection and postoperative standard adjuvant chemotherapy. However, high-level systematic plans and evidence-based medicine are lacking in this regard. Therefore, this randomised control trial aimes to determine the efficacy of JHG in reducing stage III and high-risk stage II CRC metastasis and recurrence after radical resection and postoperative standard adjuvant chemotherapy.

Methods: This is a multicentre, randomised, double-blind, placebo-controlled clinical trial. Three hundred and fifty patients with stage III or high-risk stage II CRC who completed adjuvant chemotherapy after radical resection will be recruited from eight medical centres in China and randomly assigned to test (n = 175) and control (n = 175) groups at a ratio of 1:1. The test group will receive oral JHG for 3 months, whereas the control group will receive oral placebo for 3 months. The primary outcomes will be the disease-free survival and 1-, 2-, and 3-years metastasis and recurrence rates, whereas the secondary outcomes will be quality of life and circulating tumour cells. The patients will be followed-up monthly during treatment and every 3–6 months thereafter until recurrence, metastasis, death, or the end of the study.

Trial registration: This trial was registered at ClinicalTrials.gov (NCT03716063).

Special issue "The advance of solid tumor research in China": Prognosis prediction for stage II colorectal cancer by fusing CT radiomics and deep-learning features of primary lesions and peripheral lymph nodes

Currently, the prognosis assessment of stage II colorectal cancer (CRC) remains a difficult clinical problem; therefore, more accurate prognostic predictors must be developed. In this study, we developed a prognostic prediction model for stage II CRC by fusing radiomics and deep-learning (DL) features of primary lesions and peripheral lymph nodes (LNs) in computed tomography (CT) scans. First, two CT radiomics models were built using primary lesion and LN image features. Subsequently, an information fusion method was used to build a fusion radiomics model by combining the tumor and LN image features. Furthermore, a transfer learning method was applied to build a deep convolutional neural network (CNN) model. Finally, the prediction scores generated by the radiomics and CNN models were fused to improve the prognosis prediction performance. The disease-free survival (DFS) and overall survival (OS) prediction areas under the curves (AUCs) generated by the fusion model improved to 0.76±0.08 and 0.91±0.05, respectively. These were significantly higher than the AUCs generated by the models using the individual CT radiomics and deep image features. Applying the survival analysis method, the DFS and OS fusion models yielded concordance index (C-index) values of 0.73 and 0.9, respectively. Hence, the combined model exhibited good predictive efficacy; therefore, it could be used for the accurate assessment of the prognosis of stage II CRC patients. Moreover, it could be used to screen out high-risk patients with poor prognoses, and assist in the formulation of clinical treatment decisions in a timely manner to achieve precision medicine. This article is protected by copyright. All rights reserved.

Circulating tumor cells: biology and clinical significance

Circulating tumor cells (CTCs) are tumor cells that have sloughed off the primary tumor and extravasate into and circulate in the blood. Understanding of the metastatic cascade of CTCs has tremendous potential for the identification of targets against cancer metastasis. Detecting these very rare CTCs among the massive blood cells is challenging. However, emerging technologies for CTCs detection have profoundly contributed to deepening investigation into the biology of CTCs and have facilitated their clinical application. Current technologies for the detection of CTCs are summarized herein, together with their advantages and disadvantages. The detection of CTCs is usually dependent on molecular markers, with the epithelial cell adhesion molecule being the most widely used, although molecular markers vary between different types of cancer. Properties associated with epithelial-to-mesenchymal transition and stemness have been identified in CTCs, indicating their increased metastatic capacity. Only a small proportion of CTCs can survive and eventually initiate metastases, suggesting that an interaction and modulation between CTCs and the hostile blood microenvironment is essential for CTC metastasis. Single-cell sequencing of CTCs has been extensively investigated, and has enabled researchers to reveal the genome and transcriptome of CTCs. Herein, we also review the clinical applications of CTCs, especially for monitoring response to cancer treatment and in evaluating prognosis. Hence, CTCs have and will continue to contribute to providing significant insights into metastatic processes and will open new avenues for useful clinical applications.

Detection and clinical significance of circulating tumor cells in colorectal cancer

Histopathological examination (biopsy) is the "gold standard" for the diagnosis of colorectal cancer (CRC). However, biopsy is an invasive method, and due to the temporal and spatial heterogeneity of the tumor, a single biopsy cannot reveal the comprehensive biological characteristics and dynamic changes of the tumor. Therefore, there is a need for new biomarkers to improve CRC diagnosis and to monitor and treat CRC patients. Numerous studies have shown that "liquid biopsy" is a promising minimally invasive method for early CRC detection. A liquid biopsy mainly samples circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), microRNA (miRNA) and extracellular vesicles (EVs). CTCs are malignant cells that are shed from the primary tumors and/or metastases into the peripheral circulation. CTCs carry information on both primary tumors and metastases that can reflect dynamic changes in tumors in a timely manner. As a promising biomarker, CTCs can be used for early disease detection, treatment response and disease progression evaluation, disease mechanism elucidation, and therapeutic target identification for drug development. This review will discuss currently available technologies for plasma CTC isolation and detection, their utility in the management of CRC patients and future research directions.

Evaluation of circulating tumor cells in colorectal cancer using flow cytometry

Objective

We aimed to evaluate the prognostic value of circulating tumor cells (CTCs) and the impact of intraoperative tumor manipulation on CTCs in colorectal cancer (CRC) patients.

Methods

We performed a prospective study on 40 patients with CRC stages I to IV who received curative surgery using the no-touch technique. Flow cytometry was used to identify CTCs in peripheral blood samples (4 mL/sample) collected at two surgical moments: skin incision (T1) and after surgical resection (T2). A threshold of ≥4 CTCs/4 mL blood was established for considering patients CTC positive.

Results

In the univariate analysis, CTC evaluation at T2 was correlated with female sex, vascular invasion, tumor localization in the colon and metastatic lymph nodes. In the multivariate analysis, only female sex and colon cancer maintained statistical significance. At a medium follow-up of 15 months (1–25 months), the mortality rate was 10% (n = 4), with no significant differences between the overall survival of T1 or T2 CTC-positive and CTC-negative patients.

Conclusions

Flow cytometry is a feasible CTC identification technique in CRC, and although surgical manipulation has no influence on CTC numbers, CTCs may serve as a prognostic and predictive factor.

Liquid biopsy in NSCLC: a new challenge in radiation therapy

Lung cancer is the most common cancer and the leading cause of cancer mortality worldwide. To date, tissue biopsy has been the gold standard for the diagnosis and the identification of specific molecular mutations, to guide choice of therapy. However, this procedure has several limitations. Liquid biopsy could represent a solution to the intrinsic limits of traditional biopsy. It can detect cancer markers such as circulating tumor DNA or RNA (ctDNA, ctRNA), and circulating tumor cells, in plasma, serum or other biological fluids. This procedure is minimally invasive, reproducible and can be used repeatedly. The main clinical applications of liquid biopsy in non-small cell lung cancer (NSCLC) patients are the early diagnosis, stratification of the risk of relapse, identification of mutations to guide application of targeted therapy and the evaluation of the minimum residual disease. In this review, the current role of liquid biopsy and associated markers in the management of NSCLC patients was analyzed, with emphasis on ctDNA and CTCs, and radiotherapy.

Defining early recurrence in patients with resected primary colorectal carcinoma and its respective risk factors

PURPOSE

There is no evidence-based definition of early recurrence following resection of colorectal cancer. The purpose of this study is to define a point that discriminates between early and late recurrence in patients who have undergone colorectal cancer resection with curative intent and to analyze associated risk factors.

METHODS

A retrospective single-center cohort study was performed at a university hospital recognized as a comprehensive cancer center, specializing in colorectal cancer surgery. Patient data were retrieved from a prospectively maintained institutional database. Included patients underwent resection for primary, non-metastatic colorectal carcinomas with curative intent between 1995 and 2010. Aims of the study were (1) to define the optimal cut-off point of recurrence-free survival based on overall survival using a minimum p value approach and (2) to identify patterns of initial recurrence and putative risk factors for early recurrence using regression models.

RESULTS

Recurrence was diagnosed in 412 of 1893 patients. Statistical analysis suggested that a recurrence-free survival of 16 months could be used to distinguish between early and late recurrence based on overall survival (p < 0.001). Independent risk factors for early recurrence included advanced pT categories (pT3,4/ypT3,4) and positive lymph node status (pN+/ypN+). Early recurrence was independent of site of recurrence and was associated with worse prognosis.

CONCLUSIONS

Recurrence of colorectal carcinoma within 16 months after primary treatment should be labeled as "early." Tumor categories pT3,4/ypT3,4 and positive lymph node status pN+/ypN+ are predictive of early recurrence.

The potential of liquid biopsies in gastrointestinal cancer

BACKGROUND

Liquid biopsy is a novel approach for cancer diagnosis, the value of which in human gastrointestinal (GI) cancer has been confirmed by the previous studies. This article summarized the recent advances in liquid biopsy with a focus on novel technologies and the use of it in the screening, monitoring, and treatment of human GI cancer.

CONTENT

The concept of liquid biopsy was first used to define the detection of circulating tumor cells (CTCs) in cancer patients, and has been expanded to other biomarkers in blood and body fluids, such as circulating tumor DNA (ctDNA), extracellular vesicles (EVs) and circulating tumor RNA. If analyzed with proper and advanced techniques like next generation sequencing (NGS) or proteomics, liquid biopsies can open an enormous array of potential biomarkers. The amount changes of target biomarkers and the mutation of genetic materials provide quantitative and qualitative information, which can be utilized clinically for cancer diagnosis and disease monitoring.

SUMMARY

As a highly efficient, minimally invasive, and cost-effective approach to diagnose and evaluate prognosis of GI cancer, liquid biopsy has lots of advantages over traditional biopsy and is promising in future clinical utility. If the challenges are overcome in the near future, liquid biopsy will become a widely available and dependable option.

Tumor circulome in the liquid biopsies for cancer diagnosis and prognosis

Liquid biopsy is a convenient, fast, non-invasive and reproducible sampling method that can dynamically reflect the changes in tumor gene expression profile, and provide a robust basis for individualized therapy and early diagnosis of cancer. Circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) are the currently approved diagnostic biomarkers for screening cancer patients. In addition, tumor-derived extracellular vesicles (tdEVs), circulating tumor-derived proteins, circulating tumor RNA (ctRNA) and tumor-bearing platelets (TEPs) are other components of liquid biopsies with diagnostic potential. In this review, we have discussed the clinical applications of these biomarkers, and the factors that limit their implementation in routine clinical practice. In addition, the most recent developments in the isolation and analysis of circulating tumor biomarkers have been summarized, and the potential of non-blood liquid biopsies in tumor diagnostics has also been discussed.

Expression Status And Prognostic Value Of M6A-associated Genes in Gastric Cancer

Purpose: Gastric cancer (GC) is a primary cause of cancer-associated mortality worldwide. N6-methyladenosine (m6A) is one of the most common RNA modifications that involves in the progression of numerous cancers. However, the expression status and function of m6A-related genes in gastric cancer is still not well understood. The current study is aimed to investigate the expression status and determinate prognostic value of m6A-related genes in gastric cancer.

Methods: m6A-asssociated gene expression was evaluated via analyzing the expression data of GC patients from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. The protein expression levels of m6A-associated molecules were further validated by immunohistochemical (IHC) staining data from GC tissue microarray (TMA) cohort and Human Protein Atlas (HPA) database. Kaplan-Meier analysis was performed to assess the prognostic value of m6A-associated genes in gastric cancer. Risk score model was established by lasso COX regression analysis and its prognostic predicted efficiency was assessed by the receiver-operator characteristic (ROC) curve. Cox regression analyses were used for exploring risk factors related to GC patient prognosis.

Results: Most of m6A-related genes were upregulated at both mRNA and protein levels in gastric cancer tissues compared with that in normal gastric tissues. The expression levels of m6A-related genes were associated with clinicopathological features including race, age and TNM stage. High expression of WTAP and FTO predicted poor prognosis of GC patients. Survival analysis demonstrated that patients with high-risk scores had worse overall survival (OS) and ROC curves suggested the prediction performance for gastric patients. Moreover, Cox regression analyses indicated that m6A risk model score was a prognostic factor for OS and FTO upregulation might be a potential independent prognostic factor for recurrence-free survival (RFS) in gastric cancer patients.

Conclusion: m6A-related genes were dysregulated in GC and were closely associated with prognosis of GC patients. FTO might serve as a novel prognostic biomarker for gastric cancer, while the m6A-related risk score might be informative for risk assessment and prognostic stratification.