BACKGROUND: Microsatellite instability (MSI) is a key biomarker for cancer immunotherapy and prognosis. Integration of MSI testing into a next-generation-sequencing (NGS) panel could save tissue sample, reduce turn-around time and cost, and provide MSI status and comprehensive genomic profiling in single test. We aimed to develop an MSI calling model to detect MSI status along with the NGS panel-based profiling test using tumor-only samples. METHODS: From January 2019 to December 2020, a total of 174 colorectal cancer (CRC) patients were enrolled, including 31 MSI-high (MSI-H) and 143 microsatellite stability (MSS) cases. Among them, 56 paired tumor and normal samples (10 MSI-H and 46 MSS) were used for modeling, and another 118 tumor-only samples were used for validation. MSI polymerase chain reaction (MSI-PCR) was performed as the gold standard. A baseline was built for the selected microsatellite loci using the NGS data of 56 normal blood samples. An MSI detection model was constructed by analyzing the NGS data of tissue samples. The performance of the model was compared with the results of MSI-PCR. RESULTS: We first intersected the target genomic regions of the NGS panels used in this study to select common microsatellite loci. A total of 42 loci including 23 mononucleotide repeat sites and 19 longer repeat sites were candidates for modeling. As mononucleotide repeat sites are more sensitive and specific for detecting MSI status than sites with longer length motif and the mononucleotide repeat sites performed even better than the total sites, a model containing 23 mononucleotide repeat sites was constructed and named Colorectal Cancer Microsatellite Instability test (CRC-MSI). The model achieved 100% sensitivity and 100% specificity when compared with MSI-PCR in both training and validation sets. Furthermore, the CRC-MSI model was robust with the tumor content as low as 6%. In addition, 8 out of 10 MSI-H samples showed alternations in the four mismatch repair genes ( MLH1 , MSH2 , MSH6 , and PMS2 ). CONCLUSION MSI status can be accurately determined along the targeted NGS panels using only tumor samples. The performance of mononucleotide repeat sites surpasses loci with longer repeat motif in MSI calling.
Humans ; Microsatellite Instability ; Colorectal Neoplasms/diagnosis* ; Microsatellite Repeats/genetics* ; DNA Mismatch Repair

Objective To study the pathological types,expression of mismatch repair protein,human epidermal growth factor receptor 2(HER2),and Pan-TRK,and Epstein-Barr virus(EBV)infection in patients with colorectal cancer resected in Tibet. Methods A total of 79 patients with colorectal cancer resected in Tibet Autonomous Region People's Hospital from December 2013 to July 2021 were enrolled in this study.The clinical and pathological data of the patients were collected.The expression of mismatch repair protein,HER2,and Pan-TRK was detected by immunohistochemical(IHC)staining,and detection of HER2 gene by fluorescence in situ hybridization(FISH)in the patients with HER2 IHC results of 2+ or above.EBV was detected by in situ hybridization with EBV-encoded small RNA. Results A total of 79 colorectal cancer patients were included in this study,with the male-to-female ratio of 1.26:1 and the mean age of(57.06±12.74)years(24-83 years).Among them,4 patients received preoperative neoadjuvant therapy.Colonic cancer and rectal cancer occurred in 57(57/79,72.15%,including 31 and 26 in the right colon and left colon,respectively)and 22(22/79,27.85%)patients,respectively.The maximum diameter of tumor varied within the range of 1-20 cm,with the mean of(6.61±3.33)cm.Among the 79 colorectal cancer patients,75(75/79,94.94%)patients showed adenocarcinoma.Lymph node metastasis occurred in 12(12/21,57.14%)out of the 21 patients with severe tumor budding,13(13/23,56.52%)out of the 23 patients with moderate tumor budding,and 2(2/31,6.45%)out of the 31 patients with mild tumor budding,respectively.The lymph node metastasis rate showed differences between the patients with severe/moderate tumor budding and the patients with mild tumor budding(all P<0.001).The IHC staining showed that mismatch repair protein was negative in 10(10/65,15.38%)patients,including 5 patients with both MSH2 and MSH6 negative,4 patients with both MLH1 and PMS2 negative,and 1 patient with MSH6 negative.Pan-TRK was negative in 65 patients.The IHC results of HER2 showed 0 or 1+ in 60 patients and 2+ in 5 patients.FISH showed no positive signal in the 5 patients with HER2 IHC results of 2+.The detection with EBV-encoded small RNA showed positive result in 1(1/65,1.54%)patient. Conclusions Non-specific adenocarcinoma of the right colon is the most common in the patients with colorectal cancer resected in Tibet,and 15% of the patients showed mismatch repair protein defects.EBV-associated colorectal carcer is rare,Pan-TRK expression and HER2 gene amplification are seldom.The colorectal cancer patients with moderate and severe tumor budding are more likely to have lymph node metastasis.
Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Adenocarcinoma ; Biomarkers, Tumor/genetics* ; Colorectal Neoplasms/pathology* ; DNA Mismatch Repair ; DNA-Binding Proteins/genetics* ; Epstein-Barr Virus Infections/diagnosis* ; Herpesvirus 4, Human/metabolism* ; In Situ Hybridization, Fluorescence ; Lymphatic Metastasis ; Tibet ; Young Adult ; Aged, 80 and over

Objective: To explore the utility of stool-based DNA test of methylated SDC2 (mSDC2) for colorectal cancer (CRC) screening in residents of Shipai Town, Dongguan City. Methods: This was a cross-sectional study. Using a cluster sampling method, residents of 18 villages in Shipai Town, Dongguan City were screened for CRC from May 2021 to February 2022. In this study, mSDC2 testing was employed as a preliminary screening method. Colonoscopy examination was recommended for individuals identified as high-risk based on the positive mSDC2 tests. The final screening results, including the rate of positive mSDC2 tests, the rate of colonoscopy compliance, the rate of lesions detection, and the cost-effectiveness of screening, were analyzed to explore the benefits of this screening strategy. Results: A total of 10 708 residents were enrolled and completed mSDC2 testing, giving a participation rate of 54.99% (10 708/19 474) and a pass rate of 97.87% (10 708/10 941). These individuals included 4 713 men (44.01%) and 5 995 women (55.99%) with a mean age of (54.52±9.64) years. The participants were allocated to four age groups (40-49, 50-59, 60-69, and 70-74 years), comprising 35.21%(3770/10 708), 36.25% (3882/10 708), 18.84% (2017/10 708), and 9.70% (1039/10 708) of all participants, respectively. mSDC2 testing was positive in 821/10 708 (7.67%) participants, 521 of whom underwent colonoscopy, resulting in a compliance rate of 63.46% (521/821). After eliminating of 8 individuals without pathology results, data from 513 individuals were finally analyzed. Colonoscopy detection rate differed significantly between age groups (χ²=23.155, P<0.001),ranging from a low of 60.74% in the 40-49 year age group to a high of 86.11% in the 70-74 year age group. Colonoscopies resulted in the diagnosis of 25 (4.87%) CRCs, 192 (37.43%) advanced adenomas, 67 (13.06%) early adenomas, 15 (2.92%) serrated polyps, and 86 (16.76%) non- adenomatous polyps. The 25 CRCs were Stage 0 in 14 (56.0%) individuals, stage I in 4 (16.0%), and Stage II in 7(28.0%). Thus, 18 of the detected CRCs were at an early stage. The early detection rate of CRCs and advanced adenomas was 96.77% (210/217). The rate of mSDC2 testing for all intestinal lesions was 75.05% (385/513). In particular, the financial benefit of this screening was 32.64 million yuan, and the benefit-cost ratio was 6.0. Conclusion: Screening for CRCs using stool-based mSDC2 testing combined with colonoscopy has a high lesion detection rate and a high cost-effectiveness ratio. This is a CRC screening strategy that deserves to be promoted in China.
Male ; Humans ; Female ; Adult ; Middle Aged ; Cross-Sectional Studies ; Early Detection of Cancer/methods* ; Colorectal Neoplasms/pathology* ; Colonoscopy/methods* ; Mass Screening/methods* ; Adenoma/diagnosis* ; DNA ; Syndecan-2/genetics*

Colorectal cancer (CRC) has become a major medical and public health threat to human life and health. At present, the clinical diagnosis and treatment of CRC mainly depends on the laboratory tests. With the increasing demand for treatment and prognosis, screening methods for CRC are emerging. In order to provide a reference for reasonable selection of laboratory diagnostic biomarkers, and further improve the accuracy and reliability of colorectal cancer screening, auxiliary diagnosis, efficacy monitoring, as well as prognostic evaluation, this article reviews the laboratory screening and diagnostic methods for CRC, and makes outlook for the future detection markers of CRC.
Humans ; Biomarkers, Tumor ; Reproducibility of Results ; Colorectal Neoplasms/diagnosis*

Objective: To explore the concordance and causes of different mismatch repair (MMR) and microsatellite instability (MSI) detection results in endometrial carcinoma (EC) molecular typing. Methods: A total of 214 EC patients diagnosed from January 2021 to April 2023 were selected at the Department of Pathology, Peking University Third Hospital. The immunohistochemistry (IHC) results of MMR protein were reviewed. Tumor specific somatic mutations, MMR germline mutations, microsatellite scores and tumor mutation burden (TMB) were detected by next-generation sequencing (NGS) with multi-gene panel. Methylation-specific PCR was used to detect the methylation status of MLH1 gene promoter in cases with deficient MLH1 protein expression. In cases with discrepant results between MMR-IHC and MSI-NGS, the MSI status was detected again by PCR (MSI-PCR), and the molecular typing was determined by combining the results of TMB and MLH1 gene promoter methylation. Results: (1) In this study, there were 22 cases of POLE gene mutation subtype, 55 cases of mismatch repair deficient (MMR-d) subtype, 29 cases of p53 abnormal subtype, and 108 cases of no specific molecular profile (NSMP). The median age at diagnosis of MMR-d subtype (54 years old) and the proportion of aggressive histological types (40.0%, 22/55) were higher than those of NSMP subtype [50 years old and 12.0% (13/108) respectively; all P<0.05]. (2) Among 214 patients, MMR-IHC test showed that 153 patients were mismatch repair proficient (MMR-p), 49 patients were MMR-d, and 12 patients were difficult to evaluate directly. MSI-NGS showed that 164 patients were microsatellite stable (MSS; equal to MMR-p), 48 patients were high microsatellite instability (MSI-H; equal to MMR-d), and 2 patients had no MSI-NGS results because the effective sequencing depth did not meet the quality control. The overall concordance between MMR-IHC and MSI-NGS was 94.3% (200/212). All the 12 discrepant cases were MMR-d or subclonal loss of MMR protein by IHC, but MSS by NGS. Among them, 10 cases were loss or subclonal loss of MLH1 and (or) PMS2 protein. Three discrepant cases were classified as POLE gene mutation subtype. In the remaining 9 cases, 5 cases and 3 cases were confirmed as MSI-H and low microsatellite instability (MSI-L) respectively by MSI-PCR, 6 cases were detected as MLH1 gene promoter methylation and 7 cases demonstrated high TMB (>10 mutations/Mb). These 9 cases were classified as MMR-d EC. (3) Lynch syndrome was diagnosed in 27.3% (15/55) of all 55 MMR-d EC cases, and the TMB of EC with MSH2 and (or) MSH6 protein loss or associated with Lynch syndrome [(71.0±26.2) and (71.5±20.1) mutations/Mb respectively] were significantly higher than those of EC with MLH1 and (or) PMS2 loss or sporadic MMR-d EC [(38.2±19.1) and (41.9±24.3) mutations/Mb respectively, all P<0.01]. The top 10 most frequently mutated genes in MMR-d EC were PTEN (85.5%, 47/55), ARID1A (80.0%, 44/55), PIK3CA (69.1%, 38/55), KMT2B (60.0%, 33/55), CTCF (45.5%, 25/55), RNF43 (40.0%, 22/55), KRAS (36.4%, 20/55), CREBBP (34.5%, 19/55), LRP1B (32.7%, 18/55) and BRCA2 (32.7%, 18/55). Concurrent PTEN, ARID1A and PIK3CA gene mutations were found in 50.9% (28/55) of MMR-d EC patients. Conclusions: The concordance of MMR-IHC and MSI-NGS in EC is relatively high.The discordance in a few MMR-d EC are mostly found in cases with MLH1 and (or) PMS2 protein loss or MMR protein subclonal staining caused by MLH1 gene promoter hypermethylation. In order to provide accurate molecular typing for EC patients, MLH1 gene methylation, MSI-PCR, MMR gene germline mutation and TMB should be combined to comprehensively evaluate MMR and MSI status.
Female ; Humans ; Middle Aged ; Class I Phosphatidylinositol 3-Kinases/metabolism* ; Colorectal Neoplasms, Hereditary Nonpolyposis/diagnosis* ; DNA Mismatch Repair/genetics* ; Endometrial Neoplasms/pathology* ; Microsatellite Instability ; Mismatch Repair Endonuclease PMS2/genetics* ; Molecular Typing

This study was to develop a new method for detecting circulating tumor cells (CTCs) with high sensitivity and specificity, therefore to detect the colorectal cancer as early as possible for improving the detection rate of the disease. To this end, we prepared some micro-column structure microchips modified with graphite oxide-streptavidin (GO-SA) on the surface of microchips, further coupled with a broad-spectrum primary antibody (antibody1, Ab₁), anti-epithelial cell adhesion molecule (anti-EpCAM) monoclonal antibody to capture CTCs. Besides, carboxylated multi-walled carbon nanotubes (MWCNTs-COOH) were coupled with colorectal cancer related antibody as specific antibody 2 (Ab₂) to prepare complex. The sandwich structure consisting of Ab₁-CTCs-Ab₂ was constructed by the microchip for capturing CTCs. And the electrochemical workstation was used to detect and verify its high sensitivity and specificity. Results showed that the combination of immunosensor and micro-nano technology has greatly improved the detection sensitivity and specificity of the immunosensor. And we also verified the feasibility of the immunosensor for clinical blood sample detection, and successfully recognitized detection and quantization of CTCs in peripheral blood of colorectal cancer patients by this immunosensor. In conclusion, the super sandwich immunosensor based on micro-nano technology provides a new way for the detection of CTCs, which has potential application value in clinical diagnosis and real-time monitoring of disease.
Humans ; Nanotubes, Carbon/chemistry* ; Neoplastic Cells, Circulating/pathology* ; Biosensing Techniques ; Immunoassay/methods* ; Antibodies ; Colorectal Neoplasms/diagnosis* ; Electrochemical Techniques/methods* ; Gold/chemistry*

Objective: To evaluate the participation rate and detection of colorectal neoplasms based on annual fecal immunochemical testing (FIT) for three consecutive years in a population-based colorectal cancer screening program in China. Methods: Based on a population-based colorectal cancer screening program conducted from May 2018 to May 2021 in 6 centers in China, 7 793 eligible participants aged 50-74 were included and offered free FIT and colonoscopy (for those who were FIT-positive on initial screening). At baseline, all participants were invited to receive FIT. In subsequent screening rounds, only FIT-positive participants who did not undergo colonoscopy or FIT-negative participants were invited to have repeated FIT screening. FIT-positive participants were recommended to undertake colonoscopy and pathological examination (if abnormalities were found during colonoscopy). An overall of three rounds of annual FIT screening were conducted. The primary outcomes of the study were the participation rate of FIT screening, the compliance rate of colonoscopy for FIT-positive participants, and the detection rate of colorectal neoplasms. Results: Among the 7 793 participants included in this study, 3 310 (42.5%) were male, with age of (60.50±6.49) years. The overall participation rates for the first, second and third round of FIT screening were 94.0%(7 327/7 793), 86.8% (6 048/6 968) and 91.3% (6 113/6 693), respectively. Overall, 7 742 out of 7 793 participants (99.3%) attended at least one round of screening, and 5 163 out of 7 793 participants (66.3%) attended all three rounds of screening. The positivity rate was significantly higher in the first (14.6%, 1 071/7 327) round compared with the second (5.6%, 3 41/6 048) and third (5.5%, 3 39/6 113) screening rounds (P<0.001). The overall compliance rates of colonoscopy examination among FIT-positive subjects were over 70% in three rounds, which were 76.3% (817/1 071), 75.7% (258/341) and 71.7% (243/339), respectively. In a multivariate logistic regression model considering factors including sex, education background, smoking, alcohol drinking, previous colonoscopy examination, colonic polyp history and family history of colorectal cancer among first-degree relatives, gender and smoking status were related factors affecting the participation rate of FIT screening, with higher rate in males and non-smokers. In addition, logistic regression analysis also found that age was negatively correlated with the compliance rate of colonoscopy in FIT positive patients. The detection rate of advanced tumors (colorectal cancer + advanced adenoma) declined from the first round to subsequent rounds [1st round: 1.15% (90/7 793); 2nd round: 0.57% (40/6 968); and 3rd round: 0.58% (39/6 693)], however, the positive predictive value for advanced neoplasms increased round by round, and was 11.02% in the first screening round, 15.50% in the second screening round, and 16.05 % in the third screening round. In each screening round, the detection rate for advanced neoplasms was higher in men than that in women, and increased with age. Conclusions: Annual repeated FIT screening has high acceptance and satisfying detection rates in the Chinese population. To optimize and improve the effectiveness of colorectal cancer screening, multi-round repeated FIT screening should be implemented while ensuring high participation rates.
Humans ; Male ; Female ; Early Detection of Cancer ; Predictive Value of Tests ; Colonoscopy ; Mass Screening ; Adenoma/diagnosis* ; Colorectal Neoplasms/pathology*

Objective: To evaluate the participation rate and detection of colorectal neoplasms based on annual fecal immunochemical testing (FIT) for three consecutive years in a population-based colorectal cancer screening program in China. Methods: Based on a population-based colorectal cancer screening program conducted from May 2018 to May 2021 in 6 centers in China, 7 793 eligible participants aged 50-74 were included and offered free FIT and colonoscopy (for those who were FIT-positive on initial screening). At baseline, all participants were invited to receive FIT. In subsequent screening rounds, only FIT-positive participants who did not undergo colonoscopy or FIT-negative participants were invited to have repeated FIT screening. FIT-positive participants were recommended to undertake colonoscopy and pathological examination (if abnormalities were found during colonoscopy). An overall of three rounds of annual FIT screening were conducted. The primary outcomes of the study were the participation rate of FIT screening, the compliance rate of colonoscopy for FIT-positive participants, and the detection rate of colorectal neoplasms. Results: Among the 7 793 participants included in this study, 3 310 (42.5%) were male, with age of (60.50±6.49) years. The overall participation rates for the first, second and third round of FIT screening were 94.0%(7 327/7 793), 86.8% (6 048/6 968) and 91.3% (6 113/6 693), respectively. Overall, 7 742 out of 7 793 participants (99.3%) attended at least one round of screening, and 5 163 out of 7 793 participants (66.3%) attended all three rounds of screening. The positivity rate was significantly higher in the first (14.6%, 1 071/7 327) round compared with the second (5.6%, 3 41/6 048) and third (5.5%, 3 39/6 113) screening rounds (P<0.001). The overall compliance rates of colonoscopy examination among FIT-positive subjects were over 70% in three rounds, which were 76.3% (817/1 071), 75.7% (258/341) and 71.7% (243/339), respectively. In a multivariate logistic regression model considering factors including sex, education background, smoking, alcohol drinking, previous colonoscopy examination, colonic polyp history and family history of colorectal cancer among first-degree relatives, gender and smoking status were related factors affecting the participation rate of FIT screening, with higher rate in males and non-smokers. In addition, logistic regression analysis also found that age was negatively correlated with the compliance rate of colonoscopy in FIT positive patients. The detection rate of advanced tumors (colorectal cancer + advanced adenoma) declined from the first round to subsequent rounds [1st round: 1.15% (90/7 793); 2nd round: 0.57% (40/6 968); and 3rd round: 0.58% (39/6 693)], however, the positive predictive value for advanced neoplasms increased round by round, and was 11.02% in the first screening round, 15.50% in the second screening round, and 16.05 % in the third screening round. In each screening round, the detection rate for advanced neoplasms was higher in men than that in women, and increased with age. Conclusions: Annual repeated FIT screening has high acceptance and satisfying detection rates in the Chinese population. To optimize and improve the effectiveness of colorectal cancer screening, multi-round repeated FIT screening should be implemented while ensuring high participation rates.
Humans ; Male ; Female ; Early Detection of Cancer ; Predictive Value of Tests ; Colonoscopy ; Mass Screening ; Adenoma/diagnosis* ; Colorectal Neoplasms/pathology*

Ulcerative colitis-colorectal cancer (UC-CRC) is one of the most serious complications in patients with ulcerative colitis (UC), with worse prognosis and higher mortality than sporadic colorectal cancer (CRC). Since most UC-CRC developed through the "inflammation-dysplasia-carcinoma" approach, early detection of dysplasia through identification of high-risk groups reasonable monitoring and active prevention are extremely important. However, there is no consensus on the risk factors of UC carcinogenesis and the drugs that can be used for chemoprevention currently. This article combined with relevant literature at home and abroad, reviewed the current risk factors and chemopreventive drugs for UC carcinogenesis, in order to provide reference for early prevention, early detection and early diagnosis of UC-CRC.
Humans ; Colitis, Ulcerative/diagnosis* ; Colorectal Neoplasms/diagnosis* ; Risk Factors ; Chemoprevention/adverse effects* ; Carcinogenesis

Objective: To investigate the value of stool-based methylated SDC2 test in physical examination population for the screening of colorectal neoplasms. Methods: Using the prospective cohort study method, from December 2020 to November 2021, 2 107 participants from the First People's Hospital of Xiushui County, Jiangxi Province were enrolled, consisted of 1 012 males and 1 094 females, aged 20-90 years with the median age of 49 years old. Fresh stool samples were collected and SDC2 DNA methylation tests were carried out as the primary screening method. The participants with positive results were recommended to undergo colonoscopy, and those who were negative were followed up by telephone. The positive rate of screening, the compliance of colonoscopy, and the detection of colorectal lesions were analyzed by chi-square test. Combined the follow-up results of negative subjects, the value of SDC2 DNA methylation test for the screening of colorectal neoplasms was evaluated. Results: Among the 2 107 participants, 2 106 completed the SDC2 methylation test. 113 participants (5.4%) were positive. The positive rate of primary screening increased with age significantly (χ²=32.135, P<0.001). Out of 113 cases, 72 (63.7%) underwent colonoscopy examinations. Finally, 3 (4.2%) cases of colorectal cancer, 12 (16.7%) cases of advanced adenoma, 31 (43.1%) cases of non-advanced adenoma, and 16 (22.2%) cases of non-adenomatous polyp were detected. The positive predictive value (PPV) of stool-based SDC2 DNA methylation test for intestinal lesions and colorectal neoplasms were 86.1% and 63.9%, respectively. Among the 1 374 follow-up participants, the negative predictive value (NPV) of this test for intestinal lesions and colorectal neoplasms were 97.7% and 99.4%, respectively. Conclusion: Primary stool-based SDC2 DNA methylation test and subsequent colonoscopy examination can effectively find colorectal neoplasms. This strategy may be a potential tool for the screening of colorectal neoplasms in general risk population.
Male ; Female ; Humans ; Middle Aged ; Sensitivity and Specificity ; Prospective Studies ; Early Detection of Cancer/methods* ; Colorectal Neoplasms/diagnosis* ; Mass Screening/methods* ; Feces ; DNA Methylation ; Colonoscopy ; Physical Examination ; Syndecan-2/genetics*