Post-colonoscopy colorectal cancer rate in the era of highdefinition colonoscopy

AIM To investigate the post-colonoscopy colorectal cancer(PCCRC) rate for high-definition(HD) colonoscopy compared with that for standard-definition colonoscopy reported previously.METHODS Using medical records at Sano Hospital(SH) and Dokkyo Medical University Koshigaya Hospital(DMUKH), we retrospectively obtained data on consecutive patients diagnosed as having CRC between January 2010 andDecember 2015. The definition of PCCRC was diagnosis of CRC between 7 and 36 mo after initial high-definition colonoscopy that had detected no cancer, and patients were divided into a PCCRC group and a non-PCCRC group. The primary outcome was the rate of PCCRC for HD colonoscopy. The secondary outcomes were factors associated with PCCRC and possible reason for occurrence of early and advanced PCCRC.RESULTS Among 892 CRC patients, 11 were diagnosed as having PCCRC and 881 had non-PCCRC. The PCCRC rate was 1.7%(8/471) at SH and 0.7%(3/421) at DMUKH. In comparison with the non-PCCRC group, the PCCRC group had a significantly higher preponderance of smaller tumors(39 mm vs 19 mm, P = 0.002), a shallower invasion depth(T1 rate, 25.4% vs 63.6%, P = 0.01), a non-polypoid macroscopic appearance(39.0% vs 85.7%, P = 0.02) and an earlier stage(59.7% vs 90.9%, P = 0.03). Possible reasons for PCCRC were "missed or new" in 9 patients(82%), "incomplete resection" in 1(9%), and "inadequate examination'" in 1(9%). Among 9 "missed or new" PCCRC, the leading cause was non-polypoid shape for early PCCRC and blinded location for advanced PCCRC.CONCLUSION The PCCRC rate for HD colonoscopy was 0.7%-1.7%, being lower than that for standard-definition colonoscopy(1.8%-9.0%) reported previously employing the same methodology.

Liver transplantation as an alternative for the treatment of non-resectable liver colorectal cancer: Advancing the therapeutic algorithm

Colorectal cancer is a leading cause of cancerrelated mortality,with nearly half of the affected patients developing liver metastases.For three decades,liver resection(LR)has been the primary curative strategy,yet its applicability is limited to about 20%of cases.Liver transplantation(LT)for unresectable metastases was attempted unsuccessfully in the 1990s,with high rates of perioperative death and recurrence.There is now more interest in this strategy due to improvements in systemic therapies and surgical techniques.A significant study conducted by the Oslo group showed that patients receiving liver transplants had a 60%chance of survival after five years.Significantly better results have been achieved by using advanced imaging for risk stratification and further refining selection criteria,especially in the Norvegian SECA trials.This review carefully charts the development and history of LT as a treatment option for colorectal cancer liver metastases.The revolutionary path from the early days of exploratory surgery to the current situation of cautious optimism is traced,highlighting the critical clinical developments and improved patient selection standards that have made LT a potentially curative treatment for such challenging very well selected cases.

Improving the value of molecular testing:current status and opportunities in colorectal cancer precision medicine

Colorectal cancer(CRC)is the second leading cause of cancer-related deaths worldwide1.Surgical radical resection with adjuvant chemotherapy remains the primary treatment choice for CRC,but the 5-year postoperative survival rate is only approximately 60%,and approximately one-third of patients with CRC experience recurrence within 2 years of surgery2.Fortunately,the transformation of high-throughput sequencing has accelerated the development of precision medicine.For example,KRAS mutations indicate resistance to anti-epidermal growth factor receptor(EGFR)-targeted therapies in CRC3.Furthermore,molecular-guided individualized therapy has brought new promise in major clinical areas and challenges,such as novel biomarkers predicting sensitivity and resistance to immunotherapy for microsatellite stable(MSS)CRC.

Trends in colorectal cancer incidence according to an increase in the number of colonoscopy cases in Korea

BACKGROUND The incidence of colorectal cancer(CRC)and preinvasive CRC(e.g.,early colon cancer and advanced adenoma)is gradually increasing in several countries.AIM To evaluate the trend in incidence of CRC and preinvasive CRC according to the increase in the number of colonoscopies performed in Korea.METHODS This retrospective cohort study enrolled Korean patients from 2002 to 2020 to evaluate the incidence of CRC and preinvasive CRC,and assess the numbers of diagnostic colonoscopies and colonoscopic polypectomies.Colonoscopy-related complications by age group were also determined.RESULTS The incidence of CRC showed a rapid increase,then decreased after 2012 in the 50-75 year-age group.During the study period,the rate of incidence of preinvasive CRC increased at a similar level in patients under 50 and 50-75 years of age.Since 2009,the increase has been rapid,showing a pattern similar to the increase in colonoscopies.The rate of colonoscopic polypectomy in patients aged under 50 was similar to the rate in patients over 75 years of age after 2007.The rate of complications after colonoscopy and related deaths within 3 mo was high for those over 75 years of age.CONCLUSION The diagnosis of preinvasive CRC increased with the increase in the number of colonoscopies performed.As the risk of colonoscopy-related hospitalization and death is high in the elderly,if early lesions at risk of developing CRC are diagnosed and treated under or at the age of 75,colonoscopy-related complications can be reduced for those aged 76 years or over.

Recent clinical trials and optical control as a potential strategy to develop microtubule-targeting drugs in colorectal cancer management

Colorectal cancer(CRC)has remained the second and the third leading cause of cancer-related death worldwide and in the United States,respectively.Although significant improvement in overall survival has been achieved,death in adult populations under the age of 55 appears to have increased in the past decades.Although new classes of therapeutic strategies such as immunotherapy have emerged,their application is very limited in CRC so far.Microtubule(MT)inhibitors such as taxanes,are not generally successful in CRC.There may be some way to make MT inhibitors work effectively in CRC.One potential advantage that we can take to treat CRC may be the combination of optical techniques coupled to an endoscope or other fiber optics-based devices.A combination of optical devices and photo-activatable drugs may allow us to locally target advanced CRC cells with highly potent MT-targeting drugs.In this Editorial review,we would like to discuss the potential of optogenetic approaches in CRC management.

Application of exosomal miRNA mediated macrophage polarization in colorectal cancer:Current progress and challenges

Colorectal cancer(CRC)is a major global health problem with high morbidity and mortality rates.Surgical resection is the main treatment for early-stage CRC,but detecting it early is challenging.Therefore,effective therapeutic targets for advanced patients are still lacking.Exosomes,tiny vesicles in body fluids,play a crucial role in tumor metastasis,immune regulation,and drug resistance.Interestingly,they can even serve as a biomarker for cancer diagnosis and prognosis.Studies have shown that exosomes can carry miRNA,mediate the polarization of M1/M2 macrophages,promote the proliferation and metastasis of cancer cells,and affect the prognosis of CRC.Since the gastrointestinal tract has many macrophages,understanding the mechanism behind exosomal miRNA-mediated macrophage polarization in CRC treatment is crucial.This article summarizes recent advancements in the study of exosomal miRNAs in CRC and their potential as diagnostic and prognostic markers.

Non-participation of asymptomatic candidates in screening protocols reduces early diagnosis and worsens prognosis of colorectal cancer

The Agatsuma et al’s study shows that despite the evidence of the benefits of an early colorectal cancer(CRC)diagnosis,through screening in asymptomatic subjects,up to 50%of candidates reject this option and many of those affected are diagnosed later,in advanced stages.The efficacy of screening programs has been well-established for several years,which reduces the risk of CRC morbidity and mortality,without taking into account the test used for screening,or other tools.Nevertheless,a significant proportion of patients remain unscreened,so understanding the factors involved,as well as the barriers of the population to adherence is the first step to possibly modify the participation rate.These barriers could include a full range of social and political aspects,especially the type of financial provision of each health service.In Japan,health services are universal,and this advantageous situation makes it easier for citizens to access to these services,contributing to the detection of various diseases,including CRC.Interestingly,the symptomatic CRC group had a lower early-stage diagnosis rate than the patients detected during follow-up for other comorbidities,and symptomatic and cancer screening groups showed similar early-stage diagnosis.

Refining the targeted population and achieving better for colorectal cancer screening

This editorial comments on the article entitled“Stage at diagnosis of colorectal cancer through diagnostic route:Who should be screened?”by Agatsuma et al,who conducted a retrospective study aiming at clarifying the stage at colorectal cancer(CRC)diagnosis based on different diagnostic routes.We share our opinion about CRC screening programs.The current situation suggests the need for a more specific and targeted population for CRC screening.

Stage at diagnosis of colorectal cancer through diagnostic route:Who should be screened?

BACKGROUND Colorectal cancer(CRC)is a global health concern,with advanced-stage diagnoses contributing to poor prognoses.The efficacy of CRC screening has been well-established;nevertheless,a significant proportion of patients remain unscreened,with>70%of cases diagnosed outside screening.Although identifying specific subgroups for whom CRC screening should be particularly recommended is crucial owing to limited resources,the association between the diagnostic routes and identification of these subgroups has been less appreciated.In the Japanese cancer registry,the diagnostic routes for groups discovered outside of screening are primarily categorized into those with comorbidities found during hospital visits and those with CRC-related symptoms.AIM To clarify the stage at CRC diagnosis based on diagnostic routes.METHODS We conducted a retrospective observational study using a cancer registry of patients with CRC between January 2016 and December 2019 at two hospitals.The diagnostic routes were primarily classified into three groups:Cancer screening,follow-up,and symptomatic.The early-stage was defined as Stages 0 or I.Multivariate and univariate logistic regressions were exploited to determine the odds of early-stage diagnosis in the symptomatic and cancer screening groups,referencing the follow-up group.The adjusted covariates were age,sex,and tumor location.RESULTS Of the 2083 patients,715(34.4%),1064(51.1%),and 304(14.6%)belonged to the follow-up,symptomatic,and cancer screening groups,respectively.Among the 2083 patients,CRCs diagnosed at an early stage were 57.3%(410 of 715),23.9%(254 of 1064),and 59.5%(181 of 304)in the follow-up,symptomatic,and cancer screening groups,respectively.The symptomatic group exhibited a lower likelihood of early-stage diagnosis than the follow-up group[P<0.001,adjusted odds ratio(aOR),0.23;95%confidence interval(95%CI):0.19-0.29].The likelihood of diagnosis at an early stage was similar between the follow-up and cancer screening groups(P=0.493,aOR for early-stage diagnosis in the cancer screening group vs follow-up group=1.11;95%CI=0.82-1.49).CONCLUSION CRCs detected during hospital visits for comorbidities were diagnosed earlier,similar to cancer screening.CRC screening should be recommended,particularly for patients without periodical hospital visits for comorbidities.

Has the open surgical approach in colorectal cancer really become uncommon?

Colorectal cancer is the third most common cancer in the world.Surgery is man-datory to treat patients with colorectal cancer.Can colorectal cancer be treated in laparoscopy?Scientific literature has validated the oncological quality of laparo-scopic approach for the treatment of patients with colorectal cancer.Randomized non-inferiority trials with good remote control have answered positively to this long-debated question.Early as 1994,first publications demonstrated technical feasibility and compliance with oncological imperatives and,as far as short-term outcomes are concerned,there is no difference in terms of mortality and post-operative morbidity between open and minimally invasive surgical approaches,but only longer operating times at the beginning of the experience.Subsequently,from 2007 onwards,long-term results were published that demonstrated the ab-sence of a significant difference regarding overall survival,disease-free survival,quality of life,local and distant recurrence rates between open and minimally in-vasive surgery.In this editorial,we aim to summarize the clinical and technical aspects which,even today,make the use of open surgery relevant and necessary in the treatment of patients with colorectal cancer.

Small nucleolar RNA and its potential role in the oncogenesis and development of colorectal cancer

Small nucleolar RNAs(snoRNAs)represent a class of non-coding RNAs that play pivotal roles in post-transcriptional RNA processing and modification,thereby contributing significantly to the maintenance of cellular functions related to protein synthesis.SnoRNAs have been discovered to possess the ability to influence cell fate and alter disease progression,holding immense potential in controlling human diseases.It is suggested that the dysregulation of snoRNAs in cancer exhibits differential expression across various cancer types,stages,metastasis,treatment response and/or prognosis in patients.On the other hand,colorectal cancer(CRC),a prevalent malignancy of the digestive system,is characterized by high incidence and mortality rates,ranking as the third most common cancer type.Recent research indicates that snoRNA dysregulation is associated with CRC,as snoRNA expression significantly differs between normal and cancerous conditions.Consequently,assessing snoRNA expression level and function holds promise for the prognosis and diagnosis of CRC.Nevertheless,current comprehension of the potential roles of snoRNAs in CRC remains limited.This review offers a comprehensive survey of the aberrant regulation of snoRNAs in CRC,providing valuable insights into the discovery of novel biomarkers,therapeutic targets,and potential tools for the diagnosis and treatment of CRC and furnishing critical cues for advancing research into CRC and the judicious selection of therapeutic targets.

Prognostic and predictive role of immune microenvironment in colorectal cancer

Colorectal cancer(CRC)represents a molecularly heterogeneous disease and one of the most frequent causes of cancer-related death worldwide.The traditional classification of CRC is based on pathomorphological and molecular character-istics of tumor cells(mucinous,ring-cell carcinomas,etc.),analysis of mechanisms of carcinogenesis involved(chromosomal instability,microsatellite instability,CpG island methylator phenotype)and mutational statuses of commonly altered genes(KRAS,NRAS,BRAF,APC,etc.),as well as expression signatures(CMS 1-4).It is also suggested that the tumor microenvironment is a key player in tumor progression and metastasis in CRC.According to the latest data,the immune microenvironment can also be predictive of the response to immune checkpoint inhibitors.In this review,we highlight how the immune environment influences CRC prognosis and sensitivity to systemic therapy.

Overcoming geographical and socioeconomic limitations in colorectal cancer screening

Despite colorectal cancer’s(CRC)high global incidence,residents of low-and middle-income countries,as well as low-income minorities in advanced economies have low screening rates.Observational studies demonstrate that in these groups higher incidence of CRC is observed,yet screening rates remain low for consistent reasons.Low income,low educational background,and lack of awareness in combination with inadequate social security of certain population groups impede access and compliance rates to CRC screening.On the other hand,despite the global availability of multiple screening approaches(colonoscopy,sigmoidoscopy,faecal occult blood test,faecal immunochemical test,computed tomography-colonography,etc.)with proven diagnostic validity,many low-income countries still lack established screening programs.The absence of screening guidelines in these countries along with the heterogeneity of guidelines in the rest of the world,demonstrate the need for global measures to tackle this issue comprehensively.An essential step forward is to develop a global approach that will link specific elements of screening with the incidence and available resources in each country,to ensure the achievement of at least a minimum screening program in low-income countries.Utilizing cheaper,cost-effective techniques,which can be carried out by less specialized healthcare providers,might not be equivalent to endoscopy for CRC screening but seems more realistic for areas with fewer resources.Awareness has been highlighted as the most pivotal element for the effective implementation of any screening program concerning CRC.Moreover,multiple studies have demonstrated that outreach strategies and community-based educational programs are associated with encouraging outcomes,yet a centrally coordinated expansion of these programs could provide more consistent results.Additionally,patient navigator programs,wherever implemented,have increased CRC screening and improved follow-up.Therefore,global coordination and patient education seem to be the main areas on which policy making needs to focus.

Microbiota in colorectal cancer related to liver metastasis

The prevalence of colorectal cancer(CRC) is increasing annually and metastasis is the principal cause of death in patients with CRC, with the liver being the most frequently affected site. Many studies have shown a strong interplay between the gut flora, particularly Fusobacterium nucleatum(F. nucleatum), Escherichia coli, and Bacteroides fragilis, and the development of gut tumors. Some strains can induce gut inflammation and produce toxins that directly harm gut epithelial cells, ultimately accelerating the onset and progression of CRC. However,little clinical evidence exists on the specific interplay between the gut microflora and colorectal cancer liver metastasis(CRLM). Some research showed the existence of viable F. nucleatum in distant metastasis of CRC.Subsequently, gut microbiota products, such as lipopolysaccharides, sodium butyrate, and protein cathepsin K, were also found to affect the development of CRC. This article summarizes the mechanism and research status of the interplay between gut microflora and CRLM, discusses the importance of gut microflora in the treatment of CRLM, and proposes a new approach to understanding the mechanism of CRLM and potential treatments for the microbiome. It is anticipated that the gut microbiota will be a formidable therapeutic and prophylactic tool for treating and preventing CRLM.

Colorectal cancer screening:A review of current knowledge and progress in research

Colorectal cancer(CRC)is one of the most prevalent malignancies worldwide,being the third most commonly diagnosed malignancy and the second leading cause of cancer-related deaths globally.Despite the progress in screening,early diagnosis,and treatment,approximately 20%-25%of CRC patients still present with metastatic disease at the time of their initial diagnosis.Furthermore,the burden of disease is still expected to increase,especially in individuals younger than 50 years old,among whom early-onset CRC incidence has been increasing.Screening and early detection are pivotal to improve CRC-related outcomes.It is well established that CRC screening not only reduces incidence,but also decreases deaths from CRC.Diverse screening strategies have proven effective in decreasing both CRC incidence and mortality,though variations in efficacy have been reported across the literature.However,uncertainties persist regarding the optimal screening method,age intervals and periodicity.Moreover,adherence to CRC screening remains globally low.In recent years,emerging technologies,notably artificial intelligence,and non-invasive biomarkers,have been developed to overcome these barriers.However,controversy exists over the actual impact of some of the new discoveries on CRC-related outcomes and how to effectively integrate them into daily practice.In this review,we aim to cover the current evidence surrounding CRC screening.We will further critically assess novel approaches under investigation,in an effort to differentiate promising inno-vations from mere novelties.

Association of tumor budding with clinicopathological features and prognostic value in stage III-IV colorectal cancer

BACKGROUND Tumor budding(TB)has emerged as a promising independent prognostic biomarker in colorectal cancer(CRC).The prognostic role of TB has been extensively studied and currently affects clinical decision making in patients with stage I and II CRC.However,existing prognostic studies on TB in stage III CRC have been confined to small retrospective cohort studies.Consequently,this study investigated the correlation among TB categories,clinicopathological features,and prognosis in stage III-IV CRC to further enhance the precision and individualization of treatment through refined prognostic risk stratification.AIM To analyze the relationship between TB categories and clinicopathological characteristics and assess their prognostic value in stage III-IV CRC to further refine the prognostic risk stratification of stage III-IV CRC.METHODS The clinical data of 547 CRC patients were collected for this retrospective study.Infiltration at the front edge of the tumor buds was counted according to the 2016 International Tumor Budding Consensus Conference guidelines.RESULTS Multivariate Cox proportional hazards regression analysis demonstrated that chemotherapy(P=0.004),clinical stage IV(P<0.001),≥4 regional lymph node metastases(P=0.004),left-sided colonic cancer(P=0.040),and Bd 2-3(P=0.002)were independent prognostic factors in patients with stage III-IV CRC.Moreover,the density of tumor infiltrating lymphocytes was higher in Bd 1 than in Bd 2-3,both in the tumor stroma and its invasive margin.CONCLUSION TB has an independent predictive prognostic value in patients with stage III-IV CRC.It is recommended to complete the TB report of stage III-IV CRC cases in the standardized pathological report to further refine risk stratification.

Colorectal cancer screening: Modalities and adherence

In the last decade,several studies have explored various modalities and strategies for colorectal cancer(CRC)screening,taking into account epidemiological data,individual characteristics,and socioeconomic factors.In this editorial,we comment further on a retrospective study by Agatsuma et al published in the recent issue of the World Journal of Gastroenterology.Our focus is on screening trends,particularly in relation to efforts to improve the currently suboptimal uptake among the general population worldwide,aiming to enhance early diagnosis rates of CRC.There is a need to raise awareness through health edu-cation programs and to consider the use of readily available,non-invasive screening methods.These strategies are crucial for attracting screen-eligible populations to participate in first-line screening,especially those in high-or average-risk groups and in regions with limited resources.Liquid biopsies and biomarkers represent rapidly evolving trends in screening and diagnosis;however,their clinical relevance has yet to be standardized.

Identification and Validation of SLC9A2 as A Potential Tumor Suppressor in Colorectal Cancer:Integrating Bioinformatics Analysis with Experimental Confirmation

Objective To uncover the mechanisms underlying the development of colorectal cancer(CRC),we applied bioinformatic analyses to identify key genes and experimentally validated their possible roles in CRC onset and progression.Methods We performed Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis on differentially expressed genes(DEGs),constructed a protein-protein interaction(PPI)network to find the top 10 hub genes,and analyzed their expression in colon adenocarcinoma(COAD)and rectum adenocarcinoma(READ).We also studied the correlation between these genes and immune cell infiltration and prognosis and validated the expression of SLC9A2 in CRC tissues and cell lines using qRT-PCR and Western blotting.Functional experiments were conducted in vitro to investigate the effects of SLC9A2 on tumor growth and metastasis.Results We found 130 DEGs,with 45 up-regulated and 85 down-regulated in CRC.GO analysis indicated that these DEGs were primarily enriched in functions related to the regulation of cellular pH,zymogen granules,and transmembrane transporter activity.KEGG pathway analysis revealed that the DEGs played pivotal roles in pancreatic secretion,rheumatoid arthritis,and the IL-17 signaling pathway.We identified 10 hub genes:CXCL1,SLC26A3,CXCL2,MMP7,MMP1,SLC9A2,SLC4A4,CLCA1,CLCA4,and ZG16.GO enrichment analysis showed that these hub genes were predominantly involved in the positive regulation of transcription.Gene expression analysis revealed that CXCL1,CXCL2,MMP1,and MMP7 were highly expressed in CRC,whereas CLCA1,CLCA4,SLC4A4,SLC9A2,SLC26A3,and ZG16 were expressed at lower levels.Survival analysis revealed that 5 key genes were significantly associated with the prognosis of CRC.Both mRNA and protein expression levels of SLC9A2 were markedly reduced in CRC tissues and cell lines.Importantly,SLC9A2 overexpression in SW480 cells led to a notable inhibition of cell proliferation,migration,and invasion.Western blotting analysis revealed that the expression levels of phosphorylated ERK(p-ERK)and phosphorylated JNK(p-JNK)proteins were significantly increased,whereas there were no significant changes in the expression levels of ERK and JNK following SLC9A2 overexpression.Correlation analysis indicated a potential link between SLC9A2 expression and the MAPK signaling pathway.Conclusion Our study suggests that SLC9A2 acts as a tumor suppressor through the MAPK pathway and could be a potential target for CRC diagnosis and therapy.

Evaluating combined bevacizumab and XELOX in advanced colorectal cancer: Serum markers carcinoembryonic antigen, carbohydrate antigen 125, carbohydrate antigen 199 analysis

BACKGROUND Colorectal cancer ranks third and second among common and fatal cancers.The treatment of metastatic colorectal cancer(mCRC)is generally based on XELOX in clinical practice,which includes capecitabine(CAP)and oxaliplatin.Serum tumor markers carcinoembryonic antigen(CEA),carbohydrate antigen(CA)125 and CA199 are prognostic factors for various tumors.AIM To investigate evaluating combined bevacizumab(BEV)and XELOX in advanced colorectal cancer:Serum markers CEA,CA125,CA199 analysis.METHODS In this retrospective study,a total of 94 elderly patients diagnosed with mCRC were recruited and subsequently categorized into two groups based on the distinct treatment modalities they received.The control group was treated with XELOX plus CAP(n=47),while the observation group was treated with XELOX plus CAP and BEV(n=47).Several indexes were assessed in both groups,including disease control rate(DCR),incidence of adverse effects,serum marker levels(CEA,CA125,and CA19)and progression-free survival(PFS).RESULTS After 9 wk of treatment,the serum levels of CEA,CA199 and CA125 in the observation group were significantly lower than those in the control group(P<0.05).Moreover,the PFS of the observation group(9.12±0.90 mo)was significantly longer than that of the control group(6.49±0.64 mo).Meanwhile,there was no statistically significant difference in the incidence of adverse reactions and DCR between the two groups during maintenance therapy(P>0.05).CONCLUSION On the basis of XELOX treatment,the combination of BEV and CAP can reduce serum tumor marker levels and prolong PFS in patients with mCRC.

Expression and significance of pigment epithelium-derived factor and vascular endothelial growth factor in colorectal adenoma and cancer

BACKGROUND The incidence and mortality of colorectal cancer(CRC)are among the highest in the world,and its occurrence and development are closely related to tumor neovascularization.When the balance between pigment epithelium-derived factors(PEDF)that inhibit angiogenesis and vascular endothelial growth factors(VEGF)that stimulate angiogenesis is broken,angiogenesis is out of control,resulting in tumor development.Therefore,it is very necessary to find more therapeutic targets for CRC for early intervention and later treatment.AIM To investigate the expression and significance of PEDF,VEGF,and CD31-stained microvessel density values(CD31-MVD)in normal colorectal mucosa,adenoma,and CRC.METHODS In this case-control study,we collected archived wax blocks of specimens from the Digestive Endoscopy Center and the General Surgery Department of Chengdu Second People's Hospital from April 2022 to October 2022.Fifty cases of specimen wax blocks were selected as normal intestinal mucosa confirmed by electronic colonoscopy and concurrent biopsy(normal control group),50 cases of specimen wax blocks were selected as colorectal adenoma confirmed by electronic colonoscopy and pathological biopsy(adenoma group),and 50 cases of specimen wax blocks were selected as CRC confirmed by postoperative pathological biopsy after inpatient operation of general surgery(CRC group).An immunohistochemical staining experiment was carried out to detect PEDF and VEGF expression in three groups of specimens,analyze their differences,study the relationship between the two and clinicopathological factors in CRC group,record CD31-MVD in the three groups,and analyze the correlation of PEDF,VEGF,and CD31-MVD in the colorectal adenoma group and the CRC group.The F test or adjusted F test is used to analyze measurement data statistically.Kruskal-Wallis rank sum test was used between groups for ranked data.The chi-square test,adjusted chi-square test,or Fisher's exact test were used to compare the rates between groups.All differences between groups were compared using the Bonferroni method for multiple comparisons.Spearman correlation analysis was used to test the correlation of the data.The test level(α)was 0.05,and a two-sided P<0.05 was considered statistically significant.RESULTS The positive expression rate and expression intensity of PEDF were gradually decreased in the normal control group,adenoma group,and CRC group(100%vs 78%vs 50%,χ^(2)=34.430,P<0.001;++~++vs+~++vs-~+,H=94.059,P<0.001),while VEGF increased gradually(0%vs 68%vs 96%,χ^(2)=98.35,P<0.001;-vs-~+vs++~+++,H=107.734,P<0.001).In the CRC group,the positive expression rate of PEDF decreased with the increase of differen-tiation degree,invasion depth,lymph node metastasis,distant metastasis,and TNM stage(χ^(2)=20.513,4.160,5.128,6.349,5.128,P<0.05);the high expression rate of VEGF was the opposite(χ^(2)=10.317,13.134,17.643,21.844,17.643,P<0.05).In the colorectal adenoma group,the expression intensity of PEDF correlated negatively with CD31-MVD(r=-0.601,P<0.001),whereas VEGF was not significantly different(r=0.258,P=0.07).In the CRC group,the expression intensity of PEDF correlated negatively with the expression intensity of CD31-MVD and VEGF(r=-0.297,P<0.05;r=-0.548,P<0.05),while VEGF expression intensity was positively related to CD31-MVD(r=0.421,P=0.002).CONCLUSION It is possible that PEDF can be used as a new treatment and prevention target for CRC by upregulating the expression of PEDF while inhibiting the expression of VEGF.