Detailed deletion mapping of loss of heterozygosity on 22q13 in sporadic colorectal cancer

AIM: Both development and progression of malignancies occur as a multistep process, requiring the activation of oncogenes and the inactivation of several tumor suppressor genes. The loss of heterozygosity (LOH) of tumor suppressor genes is believed to play a key role in carcinogenesis of colorectal cancer (CRC). In this study, we analyzed the LOH of seven loci on chromosome 22q13 in an effort to identify candidate tumor suppressor genes involved in colorectal carcinogenesis. METHODS: Matched tumor and normal tissue DNA were analyzed by PCR using fluorescence-labeled polymorphic microsatellite markers in 83 CRC patients. PCR products were eletrophoresed and LOH was determined by calculating the peak height acquired through computer software. Comparisons between LOH frequency and clinicopathological features were performed by x2 test. P<0.05 was considered as statistical significance. RESULTS: The average LOH frequency of chromosome 22q13 was 28.38%. The highest LOH frequency was 64.71% on D22S1160 locus, and the lowest was 21.43% on D22S1141 locus. We detected two obvious minimal deletion regions: one between markers D22S1171 and D22S274, the other flanked by markers D22S1160 and D22S1149, each about 2.7 and 1.8 cm, respectively. None had lost in all informative loci. LOH frequency on D22S1171 is 50% on distal colon, which was higher than that on proximal one (P= 0.020); on D22S114 locus, none LOH event occurred in patients with liver metastasis, whilst 46.94% occurred in patients without liver metastasis (P= 0.008); on D22S1160 locus, LOH frequency in lymph nodes metastasis patients was 83.33%, which was much higher than 43.75% without lymph nodes metastasis ones (P= 0.016). There was no statistical significance between clinicopathological features and other loci. CONCLUSION: This study provides evidence of two minimal deletion regions, which may harbor putative tumor suppressor genes related to progression and metastasis in sporadic colorectal carcinoma on chromosome 22q13.

Colorectal cancer cell dormancy:An insight into pathways

Cancer cell dormancy(CCD)in colorectal cancer(CRC)poses a significant challenge to effective treatment.In CRC,CCD contributes to tumour recurrence,drug resistance,and amplifying the disease's burden.The molecular mechanisms governing CCD and strategies for eliminating dormant cancer cells remain largely unexplored.Therefore,understanding the molecular mechanisms governing dormancy is crucial for improving patient outcomes and developing targeted therapies.This editorial highlights the complex interplay of signalling pathways and factors involved in colorectal CCD,emphasizing the roles of Hippo/YAP,pluripotent transcription factors such as NANOG,HIF-1αsignalling,and Notch signalling pathways.Additionally,ERK/p38α/β/MAPK pathways,AKT signalling pathway,and Extracellular Matrix Metalloproteinase Inducer,along with some potential less explored pathways such as STAT/p53 switch and canonical and non-canonical Wnt and SMAD signalling,are also involved in promoting colorectal CCD.Highlighting their clinical significance,these findings may offer the potential for identifying key dormancy regulator pathways,improving treatment strategies,surmounting drug resistance,and advancing personalized medicine approaches.Moreover,insights into dormancy mechanisms could lead to the development of predictive biomarkers for identifying patients at risk of recurrence and the tailoring of targeted therapies based on individual dormancy profiles.It is essential to conduct further research into these pathways and their modulation to fully comprehend CRC dormancy mechanisms and enhance patient outcomes.

Molecular pathogenesis of sporadiccolorectal cancers

Colorectal cancer(CRC)results from the progressive accumulation of genetic and epigenetic alterations that lead to the transformation of normal colonic mucosa to adenocarcinoma.Approximately 75%of CRCs are sporadic and occur in people without genetic predisposition or family history of CRC.During the past two decades,sporadic CRCs were classified into three major groups according to frequently altered/mutated genes.These genes have been identified by linkage analyses of cancer-prone families and by individual mutation analyses of candidate genes selected on the basis of functional data.In the first half of this review,we describe the genetic pathways of sporadic CRCs and their clinicopathologic features.Recently,large-scale genome analyses have detected many infrequently mutated genes as well as a small number of frequently mutated genes.These infrequently mutated genes are likely described in a limited number of pathways.Gene-oriented models of CRC progression are being replaced by pathway-oriented models.In the second half of this review,we summarize the present knowledge of this research field and discuss its prospects.

Gene expression profiling:Canonical molecular changes and clinicopathological features in sporadic colorectal cancers

AIM： To investigate alternative or subordinate pathways involved in colorectal tumorigenesis and tumor growth, possibly determining at-risk populations and predicting responses to treatment. METHODS： Using microarray gene-expression analysis, we analyzed patterns of gene expression relative to canonical molecular changes and clinicopathological features in 84 sporadic colorectal cancer patients, standardized by tumor location. Subsets of differentially expressed genes were confirmed by real-time reverse-transcript polymerase chain reaction （RT-PCR）. RESULTS： The largest number of genes identified as being differentially expressed was by tumor location, and the next largest number by lymphovascular or neural invasion of tumor cells and by mismatch repair （NMR） defects. Amongst biological processes, the immune response was significantly implicated in entire molecular changes observed during colorectal tumorigenesis （P 〈 0.001）. Amongst 47 differentially expressed genes, seven （PISD, NIBP, BAI2, STOML1, MRPL21, MRPL16, and MKKS） were newly found to correlate with tumorigenesis and tumor growth. Most location-associated molecular changes had distinct effects on gene expression, but the effects of the latter were sometimes contradictory. CONCLUSION： We show that several differentially expressed genes were associated with canonical molecular changes in sporadic colorectal cancers, possibly constituting alternative or subordinate pathways of tumorigenesis. As tumor location was the dominant factor influencing differential gene expression, location-specific analysis may identify location-associated pathways and enhance the accuracy of class prediction.

Deficient DNA mismatch repair is associated with favorable prognosis in Thai patients with sporadic colorectal cancer

AIM:To determine the prognostic significance of deficient mismatch repair(d MMR) and BRAF V600 E in Thai sporadic colorectal cancer(CRC) patients.METHODS:We studied a total of 211 out of 405 specimens obtained from newly diagnosed CRC patients between October 1,2006 and December 31,2007 at Siriraj Hospital,Mahidol University.Formalinfixed paraffin-embedded blocks of CRC tissue samples w e re a n a l y ze d fo r d M M R b y d e t e c t i o n o f M M R protein expression loss by immunohistochemistry or microsatellite instability using polymerase chain reaction(PCR)-DHPLC.BRAF V600 E mutational analysis was performed in DNA extracted from the same archival tissues by two-round allele-specific PCR and analyzed by high sensitivity DHPLC.Associations between patient characteristics,MMR and BRAF status with diseasefree survival(DFS) and overall survival(OS) were determined by Kaplan-Meier survival plots and log-rank test together with Cox's proportional hazard regression.RESULTS:d MMR and BRAF V600 E mutations were identified in 31 of 208(14.9%) and 23 of 211(10.9%) tumors,respectively.d MMR was more commonly found in patients with primary colon tumors rather than rectal cancer(20.4% vs 7.6%,P =0.01),but there was no difference in MMR status between the right-sided and left-sided colon tumors(20.8% vs 34.6%,P = 0.24).d MMR was associated with early-stage rather than metastatic disease(17.3% vs 0%,P = 0.015).No clinicopathological features such primary site or tumor differentiation were associated with the BRAF mutation.Six of 31(19.3%) samples with d MMR carried the BRAFmutation,while 17 of 177(9.6%) with proficient MMR(p MMR) harbored the mutation(P = 0.11).Notably,patients with d MMR tumors had significantly superior DFS(HR = 0.30,95%CI:0.15-0.77; P = 0.01) and OS(HR = 0.29,95%CI:0.10-0.84; P = 0.02) compared with patients with p MMR tumors.By contrast,the BRAF V600 E mutation had no prognostic impact on DFS and OS.CONCLUSION:The prevalence of d MMR and BRAF V600 E in Thai sporadic CRC patients was 15% and 11%,respectively.The d MMR phenotype was associated with a favorable outcome.

Early-onset colorectal cancer:A sporadic or inherited disease?

Colorectal cancer is the third most common cancer diagnosed worldwide. Although epidemiology data show a marked variability around the world, its overall incidence rate shows a slow but steady decrease, mainly in developed countries. Conversely, early-onset colorectal cancer appears to display an opposite trend with an overall prevalence in United States and European Union ranging from 3.0% and 8.6%. Colorectal cancer has a substantial proportion of familial cases. In particular, early age at onset is especially suggestive of hereditary predisposition. The clinicopathological and molecular features of colorectal cancer cases show a marked heterogeneity not only between early- and late-onset cases but also within the early-onset group. Two distinct subtypes of early-onset colorectal cancers can be identified: a &#x0201c;sporadic&#x0201d; subtype, usually without family history, and an inherited subtype arising in the context of well defined hereditary syndromes. The pathogenesis of the early-onset disease is substantially well characterized in the inherited subtype, which is mainly associated to the Lynch syndrome and occasionally to other rare mendelian diseases, whereas in the &#x0201c;sporadic&#x0201d; subtype the origin of the disease may be attributed to the presence of various common/rare genetic variants, so far largely unidentified, displaying variable penetrance. These variants are thought to act cumulatively to increase the risk of colorectal cancer, and presumably to also anticipate its onset. Efforts are ongoing in the attempt to unravel the intricate genetic basis of this &#x0201c;sporadic&#x0201d; early-onset disease. A better knowledge of molecular entities and pathways may impact on family-tailored prevention and clinical management strategies.

Utility of the Asia-Pacific colorectal screening scoring system and the presence of metabolic syndrome components in screening for sporadic colorectal cancer

AIM: To determine the utility of the Asia-Pacific colorectal screening (APCS) scoring system and metabolic syndrome components in individual screening for sporadic colorectal cancer.

Risk factors for sporadic colorectal cancer in southern Chinese

AIM:To investigate the role of smoking, alcohol drinking, family history of cancer, and body mass index(BMI) in sporadic colorectal cancer in southern Chinese.METHODS:A hospital-based case-control study was conducted from July 2002 to December 2008.There were 706 cases and 723 controls with their sex and age(within 5 years) matched.An unconditional logistic regression model was used to analyze the association between smoking, alcohol drinking, family history of cancer, BMI and sporadic colorectal cancer.RESULTS:No positive association was observed between smoking status and sporadic colorectal cancer risk.Compared with the non alcohol drinkers, the current and former alcohol drinkers had an increased risk of developing sporadic colorectal cancer(CRC)(adjusted OR = 8.61 and 95% CI = 6.15-12.05;adjusted OR = 2.30, 95% CI = 1.27-4.17).Moreover, the increased risk of developing sporadic CRC was significant in those with a positive family history of cancer(adjusted OR = 1.62, 95% CI = 1.12-3.34) and in those with their BMI ≥ 24.0 kg/m2(adjusted OR = 1.39, 95% CI = 1.10-1.75).Stratification analysis showed that the risk of developing both colon and rectal cancers was increased in current alcohol drinkers(adjusted OR = 7.60 and 95% CI = 5.13-11.25;adjusted OR = 7.52 and 95% CI = 5.13-11.01) and in those with their BMI ≥ 24.0 kg/m2(adjusted OR = 1.38 and 95% CI = 1.04-1.83;adjusted OR = 1.35 and 95% CI = 1.02-1.79).The risk of developing colon cancer, but not rectal cancer, was found in former alcohol drinkers and in those with a positive family history of cancer(adjusted OR = 2.51 and 95% CI = 1.24-5.07;adjusted OR = 1.82 and 95% CI = 1.17-2.82).CONCLUSION:Alcohol drinking, high BMI(≥ 24.0 kg/m2) and positive family history of cancer are the independent risk factors for colorectal cancer in southern Chinese.

Genetic alterations and expression of inhibitor of growth 1 in human sporadic colorectal cancer

AIM： To explore the effect and significance of inhibitor of growth 1 （ING1） gene in carcinogenesis and progression of human sporadic colorectal cancer. METHODS： mRNA expression, mutation, and loss of heterozygosity （LOH） of ING1 gene in 35 specimens of sporadic colorectal cancer tissues and the matched normal mucous membrane tissues were detected by semi-quantitative reverse transcriptase-polymerase chain reaction （RT-PCR）, PCR-single strain conformation polymorphism （PCR-SSCP） and PCR-simple sequence length polymorphism （PCR-SSLP） using microsatellite markers, respectively. RESULTS： The average ratios of light intensities of p33^ING1b and p47^ING1a mRNA expression in the cancerous tissues were significantly lower than those in normal tissues. The difference between the two mRNA splices was not significant in the matched tissues. In addition, the ratios of light intensities of p33^ING1b and p47^ING1a mRNA expression in the cancerous tissues of Dukes＇ stages C and D were significantly lower than those in cancerous tissues of Dukes＇ stages A and B. However, no mutation of ING1 gene was detected in all 35 cases; only 4 cases of LOH （11.4%） were found. CONCLUSION： p33^ING1b and p47^ING1a mRNA expressions are closely related with the carcinogenesis and progression of human sporadic colorectal cancer. No mutation of ING1 gene is found, and there are only few LOH in sporadic colorectal cancers. These might not be the main reasons for the down regulation of ING1 expression. Its low expression may happen in transcription or post-transcription.

Methylenetetrahydrofolate reductase C677T genotype affects promoter methylation of tumor-specific genes in sporadic colorectal cancer through an interaction with folate/vitamin B_(12) status

AIM:To evaluate joint effects of Methylentetra-hydrofolate reductase(MTHFR) C677T genotypes,and serum folate/vitamin B12 concentrations on promoter methylation of tumor-associated genes among Iranian colorectal cancer patients. METHODS:We examined the associations between MTHFR C677T genotype,and promoter methylation of P16,hMLH1,and hMSH2 tumor-related genes among151 sporadic colorectal cancer patients. The promoter methylation of tumor-related genes was determined by methylation-specific PCR. Eighty six patients from whom fresh tumor samples were obtained and 81 controls were also examined for serum folate and vitamin B12 concentrations by a commercial radioimmunoassay kit. RESULTS:We found 29.1% of cases had tumors with at least one methylated gene promoter. In case-case comparison,we did not find a significant association between methylation in tumors and any single genotype. However,in comparison to controls with the CC genotype,an increased risk of tumor methylation was associated with the CT genotype(OR = 2.5;95% CI,1.1-5.6) . In case-case comparisons,folate/vitamin B12 levels were positively associated with tumor methylation. Adjusted odds ratios for tumor methylation in cases with high(above median) versus low(below median) serum folate/vitamin B12 levels were 4.9(95% CI,1.4-17.7) ,and 3.9(95% CI,1.1-13.9) ,respectively. The frequency of methylated tumors was significantly higher in high methyl donor than low methyl donor group,especially in those with MTHFR CT(P = 0.01) ,and CT/TT(P = 0.002) genotypes,but not in those with the CC genotype(P = 1.0) . CONCLUSION:We conclude that high concentrations of serum folate/vitamin B12 levels are associated with the risk of promoter methylation in tumor-specific genes,and this relationship is modified by MTHFR C677T genotypes.

CDH1 promoter polymorphism(-347G→GA) is a possible prognostic factor in sporadic colorectal cancer

AIM:To investigate the role of the-347G→GA polymorphism in the progression of colorectal cancer(CRC) .METHODS:We designed a case-control study based on a population of CRC patients in China and normal healthy controls with no history of tumors or inherited diseases.Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) analyses were used to genotype the variants,and immunohistochemical staining was performed to measure the expression of E-cadherin in different allele cases among the CRC patients and normal controls.RESULTS:The GA-allele(G/GA heterozygous and GA/GA homozygous) did not increase the risk of CRC compared with the G-allele(OR = 1.232,95% CI = 0.898-1.691) .However,the frequencies of the GAallele were higher in poorly differentiated(P = 0.002) and proximal(P = 0.019) CRC patients than in normal controls.We also observed that E-cadherin expression was lower in poorly differentiated CRC patients than in well differentiated CRC patients(P = 0.001) .Furthermore,E-cadherin expression was lower for the GA-allele than for the G-allele(G/G heterozygous) in CRC patients(P = 0.018) .In contrast,there was no significant difference in E-cadherin expression for the G-allele and GA-allele in normal controls(P = 0.292) .CONCLUSION:The-347G→GA promoter polymorphism in E-cadherin gene is associated with specific CRC features,and may be a prognostic factor rather than a susceptibility factor during the progression of CRC.

SATB1 Protein Is Associated with a More Aggressive Phenotype of Sporadic Colorectal Cancer

Background: Experimental studies have shown that cyclo-oxygenase-2 (Cox2) is related to the development and progression of tumors, since this enzyme is induced and expressed by cells such as macrophages, osteoblasts, “activated” endothelial cells, and tumor cells. The activity in tumors includes proliferation, cell transformation, tumor growth, invasion and metastasis and may play an important role in carcinogenesis of the canine osteosarcoma, since it has high expression in tissue fragments. The combination of selective Cox2 inhibitors and other treatment modalities is the basis for a new anti-cancer therapy strategy. This in vitro study exposed primary cells of five different canine osteosarcoma cultures to selective Cox2 inhibitor at increasing concentrations and times. Results: For Cox2 negative cultures, despite the absence of differences, greater sensitivity of cells to treatment was observed. For Cox2 positive cultures, a higher number of necrotic cells were observed (P ≤ 0.05), when compared with negative cultures. For exposure times with Celecoxib doses, no difference (P > 0.05) was found between the three times analyzed for living, apoptotic and apop- totic/necrotic cells. There are similarities in the values of 24 h and 48 h, with slight reduction of living cells, increasing those undergoing apoptosis and apoptosis/necrosis. There was significance for necrosis (P ≤ 0.05). In 72 hours, a significant difference was observed between the other two previous values (P ≤ 0.05). It was found for the group of 100 μM?L?1, that there was a numerically greater signaling for apoptosis and lower (P = 0.08) for necrosis, and this point was the onset of the pharmacodynamic phenomenon, with drop in the values for living cells and increased number of necrotic cells, with a tendency (P = 0.08) for reducing the percentage of necrotic cells for the group of 100 μM?L?1 when compared to that of 10 μM?L?1. Conclusions: For Cox2 positive and negative cultures, there was difference for necrotic cells and there was no difference between Cox2 positive and Cox2 negative groups in relation to the percentage of living cells and apoptotic and apoptotic/necrotic cells. At time of 72 hours, higher percentage of living cells, lower percentage of apoptotic cells and increased percentage of necrotic cells in relation to groups of 24 and 48 hours were observed. A tendency for reducing the percentage of necrotic cells for the group of 100 μM?L?1 when compared to that of the group of 10 μM?L?1 was observed.

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.

Efficacy of chemotherapy containing bevacizumab in patients with metastatic colorectal cancer according to programmed cell death ligand 1

BACKGROUND Bevacizumab,an anti-vascular endothelial growth factor(VEGF)monoclonal antibody,inhibits angiogenesis and reduces tumor growth.Serum VEGF-C,lactate dehydrogenase,and inflammatory markers have been reported as predictive markers related to bevacizumab treatment.Programmed cell death ligand 1(PD-L1)could act upon VEGF receptor 2 to induce cancer cell angiogenesis and metastasis.AIM To investigate the efficacy of bevacizumab-containing chemotherapy in patients with metastatic colorectal cancer(CRC)according to the expression of PD-L1.METHODS This analysis included CRC patients who received bevacizumab plus FOLFOX or FOLFIRI as first-line therapy between June 24,2014 and February 28,2022,at Samsung Medical Center(Seoul,South Korea).Analysis of patient data included evaluation of PD-L1 expression by the combined positive score(CPS).We analyzed the efficacy of bevacizumab according to PD-L1 expression status in patients with CRC.RESULTS A total of 124 patients was included in this analysis.Almost all patients were treated with bevacizumab plus FOLFIRI or FOLFOX as the first-line chemotherapy.While 77%of patients received FOLFOX,23%received FOLFIRI as backbone first-line chemotherapy.The numbers of patients with a PD-L1 CPS of 1 or more,5 or more,or 10 or more were 105(85%),64(52%),and 32(26%),respectively.The results showed no significant difference in progression-free survival(PFS)and overall survival(OS)with bevacizumab treatment between patients with PDL1 CPS less than 1 and those with PD-L1 CPS of 1 or more(PD-L1<1%vs PD-L1≥1%;PFS:P=0.93,OS:P=0.33),between patients with PD-L1 CPS less than 5 and of 5 or more(PD-L1<5%vs PD-L1≥5%;PFS:P=0.409,OS:P=0.746),and between patients with PD-L1 CPS less than 10 and of 10 or more(PD-L1<10%vs PD-L1≥10%;PFS:P=0.529,OS:P=0.568).CONCLUSION Chemotherapy containing bevacizumab can be considered as first-line therapy in metastatic CRC irrespective of PD-L1 expression.

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.

Clinical Efficacy of Laparoscopic Radical Colorectal Cancer Treatment for Colorectal Cancer and Its Effect on Immune Function

Objective:To explore the therapeutic effect of laparoscopic radical colorectal cancer treatment in colorectal cancer patients.Methods:A total of 50 colorectal cancer patients treated between August 2018 and August 2023 were randomly divided into two groups:Group A underwent laparoscopic radical colorectal cancer surgery,while Group B received open surgery.Clinical indicators,inflammatory factors,immune function indicators,and complications were compared between the two groups.Results:Group A showed significantly shorter operation times,faster recovery times,and reduced hospital stays compared to Group B.Additionally,Group A had less abdominal drainage and intraoperative bleeding(P<0.05).Levels of interleukin(IL)-4,IL-6,ultrasensitive C-reactive protein(hs-CRP),and tumor necrosis factor-alpha(TNF-α)were lower in Group A compared to Group B(P<0.05).Furthermore,immune function indicators,including CD3+,CD4+,CD8+,and CD4+/CD8+ratios,were better in Group A(P<0.05).The complication rate in Group A was also lower than in Group B(P<0.05).Conclusion:Laparoscopic radical treatment for colorectal cancer is efficient and feasible,causing minimal immune function impairment and inflammatory response.It also shortens postoperative recovery time.

Clinical significance of MLH1/MSH2 for stage Ⅱ/Ⅲ sporadic colorectal cancer

BACKGROUND The development of colorectal cancer(CRC) is a complicated multistep process that involves an accumulation of mutations in tumor suppressor genes and oncogenes.In the process of DNA replication, base mismatch often occurs due to various factors leading to abnormal expression of mismatch repair genes(MMR),among which MLH1 and MSH2 are the most important.Recently, numerous studies indicated that MLH1/MSH2 phenotype is associated with CRC.We wanted to elucidate the role of MLH1/MSH2 in the prediction and prognosis of CRC through long-term clinical observation.AIM To evaluate the prognostic and predictive significance of MLH1/MSH2 in patients with stage Ⅱ-Ⅲ CRC using immunohistochemical analysis and GeneScan.METHODS Specimens from 681 patients with CRC(395 stage Ⅱ and 286 stage Ⅲ, 387 males and 294 females) who underwent curative surgical resection from 2013 to 2016 were tested.Immunohistochemistry was used to analyze MMR status and the microsatellite status of 133 patients was determined by GeneScan analysis.RESULTS Five hundred and fifty(80.76%) patients were MLH1/MSH2 positive and 131(19.24%) were negative by immunohistochemistry.MLH1/MSH2-positive tumors were significantly more frequent in the colon than in the rectum, and had poor differentiation and less mucin production(P < 0.05).Patients of different groups did not differ in terms of age, gender, tumor size, tumor stage, lymphocytic infiltration, or circumscribed margin.MLH1/MSH2-negative patients had a more favorable OS than MLH1/MSH2-positive patients(P < 0.001).Univariate and multivariate analyses demonstrated MLH1/MSH2 expression as an independent prognostic and predictive factor for stage Ⅱ/Ⅲ CRC.MLH1/MSH2 expression was a strong prognostic factor in all patients [P < 0.001, hazard ratio(HR) = 4.064,95%CI: 2.241–7.369].Adjuvant chemotherapy had a greater correlation with survival advantage in MLH1/MSH2-negative patients with stage Ⅲ disease(P <0.001, HR = 7.660, 95%CI: 2.974–15.883).However, patients with stage Ⅱ disease or MLH1/MSH2-positive patients with stage Ⅲ disease did not benefit from adjuvant chemotherapy.GeneScan analysis demonstrated that among 133 patients, 105(78.95%) were microsatellite stable, and 28(21.05%) had microsatellite instability(MSI), including 18(13.53%) with high MSI and 10(7.52%) with low MSI.This is consistent with the immunohistochemical results.CONCLUSION MLH1/MSH2 phenotype constitutes a pathologically and clinically distinct subtype of sporadic CRC.MLH1/MSH2 is an independent prognostic and predictive factor for outcome of stage Ⅱ-Ⅲ CRC.

IL-6 Plays Crucial Roles in Sporadic Colorectal Cancer through the Cytokine Networks including CXCL7

IL-6 is a multifunctional cytokine and involved in variety of carcinogenesis. However, the association between IL-6 and sporadic colorectal cancer has not been fully explained. Here, we investigated the role of IL-6 signaling and the cytokine network in sporadic colorectal cancer. We investigated the serum IL-6 levels in patients with sporadic colorectal adenoma, cancer patients, and normal controls. In addition, the expressions of IL-6, gp130, and the IL-6 receptor subunit were investigated in biopsy specimens collected from these subjects. Furthermore, the expressions of CXCL7 and CXCR2, a chemokine and its receptor involved in IL-6 production, were also investigated. We observed an elevated level of serum IL-6 in colorectal cancer patients and an increased expression of IL-6 in colorectal cancer tissues, compared with the levels in a control group and in patients with adenoma. The phosphorylation of gp130 was also increased in the colorectal cancer tissues, compared with that in control and adenoma tissues. The expressions of CXCL7 and CXCR2 in the colorectal cancer tissues were also higher than those in control and adenoma tissues. IL-6 signaling is involved in sporadic colorectal cancer. In addition, the increased expressions of CXCL7 and CXCR2 might, in turn, increase the expression of IL-6 in colorectal cancer. Further studies are required to elucidate the function of the IL-6 signaling and the cytokine network in sporadic colorectal cancer.

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.

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.