Objective:To explore the value of MRI features in predicting the pathological grade of rectal neuroendocrine tumors and to develop a predicting model.Methods:A retrospective analysis was performed on 30 cases of rectal neuroendocrine tumors confirmed by surgery and pathology between 2013 and 2019. All of them underwent plain rectal MRI, DWI and dynamic contrast-enhanced MRI. The clinical features and MRI characteristics (ie. tumor location, maximum tumor diameter, boundary, growth pattern, enhancement of three-staged lesions, and the lymph node metastasis) were analyzed by statistical methods to evaluate the difference between different tumor pathologic grades (G1, G2 and G3). Characteristics with statistical significance were analyzed by collinearity diagnostics, and stepwise regression method was used to select independent predictors. Ordinal logistic regression analysis was then conducted to develop the predicting model.Results:Maximum tumor diameter, tumor boundary, growth pattern, mr-T, mr-N, EMVI, MRF, T2WI signal intensity, tumor enhancement degree in venous phase and distant metastasis were closely correlated with the pathological grade of rectal neuroendocrine tumors ( P<0.001, 0.001, 0.001, <0.001, 0.001, 0.004, 0.024, 0.015, 0.001, and <0.001, respectively). The mr-T and tumor enhancement degree in venous phase were identified as the independent predictors to construct the prediction model. The model got ideal performance in predicting the grades, with the areas under the receiver operating characteristic (ROC) curves (AUCs) of 0.945, 0.624 and 0.896, the sensitivities were 75.0%, 85.7%, and 90.9% and corresponding specificities were 88.9%, 52.6% and 93.3% for G1, G2 and G3 rectal neuroendocrine tumors, respectively. Conclusion:The model based on mr-T and tumor enhancement degree in venous phase can serve as a clinical tool for predicting the pathological grade of rectal neuroendocrine tumors.

Objective:To explore the value of MRI features in predicting the pathological grade of rectal neuroendocrine tumors and to develop a predicting model.Methods:A retrospective analysis was performed on 30 cases of rectal neuroendocrine tumors confirmed by surgery and pathology between 2013 and 2019. All of them underwent plain rectal MRI, DWI and dynamic contrast-enhanced MRI. The clinical features and MRI characteristics (ie. tumor location, maximum tumor diameter, boundary, growth pattern, enhancement of three-staged lesions, and the lymph node metastasis) were analyzed by statistical methods to evaluate the difference between different tumor pathologic grades (G1, G2 and G3). Characteristics with statistical significance were analyzed by collinearity diagnostics, and stepwise regression method was used to select independent predictors. Ordinal logistic regression analysis was then conducted to develop the predicting model.Results:Maximum tumor diameter, tumor boundary, growth pattern, mr-T, mr-N, EMVI, MRF, T2WI signal intensity, tumor enhancement degree in venous phase and distant metastasis were closely correlated with the pathological grade of rectal neuroendocrine tumors ( P<0.001, 0.001, 0.001, <0.001, 0.001, 0.004, 0.024, 0.015, 0.001, and <0.001, respectively). The mr-T and tumor enhancement degree in venous phase were identified as the independent predictors to construct the prediction model. The model got ideal performance in predicting the grades, with the areas under the receiver operating characteristic (ROC) curves (AUCs) of 0.945, 0.624 and 0.896, the sensitivities were 75.0%, 85.7%, and 90.9% and corresponding specificities were 88.9%, 52.6% and 93.3% for G1, G2 and G3 rectal neuroendocrine tumors, respectively. Conclusion:The model based on mr-T and tumor enhancement degree in venous phase can serve as a clinical tool for predicting the pathological grade of rectal neuroendocrine tumors.

Objective:To explore the diagnostic accuracy improved by magnetic resonance imaging (MRI) biomarkers for lymph node metastasis in T1-2 stage rectal cancer before treatment.Methods:Medical records of 327 patients with T1-2 rectal cancer who underwent pretreatment MRI and rectal tumor resection between January 2015 and November 2019 were retrospectively analyzed. Fifty-seven cases were divided into the lymph node metastasis group (N+ group) while other 270 cases in the non-lymph node metastasis group (N-group) according to the pathologic diagnosis. Two radiologist evaluated the tumor characteristics of MRI images. The relationship of the clinical and imaging characteristics of lymph node metastasis was assessed by using univariate analysis and multivariable logistic regression analysis. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic abilities for the differentiation of N- from N+ tumors.Results:Among the 327 patients, MR-N evaluation was positive in 67 cases, which was statistically different from the pathological diagnosis ( P<0.001). The sensitivity, specificity and accuracy of MRI for lymph node metastasis were 45.6%, 84.8% and 78.0%, respectively. Multivariate regression analysis showed that tumor morphology ( P=0.002), including mucus or not ( P<0.001), and MR-N evaluation ( P<0.001) were independent influencing factors for stage T1-2 rectal cancer with lymph node metastasis. The area under the ROC curve of rectal cancer with lymph node metastasis analyzed by the logistic regression model was 0.786 (95% CI: 0.720~0.852). Conclusions:Tumor morphology, including mucus or not, and MR-N evaluation can serve as independent biomarkers for differentiation of N- and N+ tumors. The model combined with these biomarkers facilitates to improve the diagnostic accuracy of lymph node metastasis in T1-2 rectal cancers by using MRI.

Objective:To explore the diagnostic accuracy improved by magnetic resonance imaging (MRI) biomarkers for lymph node metastasis in T1-2 stage rectal cancer before treatment.Methods:Medical records of 327 patients with T1-2 rectal cancer who underwent pretreatment MRI and rectal tumor resection between January 2015 and November 2019 were retrospectively analyzed. Fifty-seven cases were divided into the lymph node metastasis group (N+ group) while other 270 cases in the non-lymph node metastasis group (N-group) according to the pathologic diagnosis. Two radiologist evaluated the tumor characteristics of MRI images. The relationship of the clinical and imaging characteristics of lymph node metastasis was assessed by using univariate analysis and multivariable logistic regression analysis. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic abilities for the differentiation of N- from N+ tumors.Results:Among the 327 patients, MR-N evaluation was positive in 67 cases, which was statistically different from the pathological diagnosis ( P<0.001). The sensitivity, specificity and accuracy of MRI for lymph node metastasis were 45.6%, 84.8% and 78.0%, respectively. Multivariate regression analysis showed that tumor morphology ( P=0.002), including mucus or not ( P<0.001), and MR-N evaluation ( P<0.001) were independent influencing factors for stage T1-2 rectal cancer with lymph node metastasis. The area under the ROC curve of rectal cancer with lymph node metastasis analyzed by the logistic regression model was 0.786 (95% CI: 0.720~0.852). Conclusions:Tumor morphology, including mucus or not, and MR-N evaluation can serve as independent biomarkers for differentiation of N- and N+ tumors. The model combined with these biomarkers facilitates to improve the diagnostic accuracy of lymph node metastasis in T1-2 rectal cancers by using MRI.

Objective:This study was to systematically update the economic evaluation evidence of colorectal cancer screening in mainland China.Methods:Based on a systematic review published in 2015, we expanded the scope of retrieval database (PubMed, EMbase, The Cochrane Library, Web of Science, CNKI, Wanfang Data, VIP, CBM) and extended it to December 2018. Focusing on the evidence for nearly 10 years (2009-2018), basic characteristics and main results were extracted. Costs were discounted to 2017 using the consumer price index of medical and health care being provided to the residents, and the ratio of incremental cost-effectiveness ratio (ICER) to per capita GDP in corresponding years were calculated.Results:A total of 12 articles (8 new ones) were included, of which 9 were population-based (all cross-sectional studies) and 3 were model-based. Most of the initial screening age was 40 years (7 articles), and most of the frequency was once in a lifetime (11 articles). Technologies used for primary screening included: questionnaire assessment, immunological fecal occult blood test (iFOBT) and endoscopy. The most commonly used indicator was the cost per colorectal cancer detected, and the median (range) of the 20 screening schemes was 52 307 Chinese Yuan (12 967-3 769 801, n=20). The cost per adenoma detected was 9 220 Yuan (1 859-40 535, n=10). In 3 articles, the cost per life year saved (compared with noscreening) was mentioned and the ratio of ICER to GDP was 0.673 (-0.013-2.459, n=11), which was considered by WHO as "very cost-effective" ; The range of ratios overlapped greatly among different technologies and screening frequencies, but the initial age for screening seemed more cost-effective at the age of 50 years (0.002, -0.013-0.015, n=3), than at the 40 year-olds (0.781, 0.321-2.459, n=8). Conclusions:Results from the population-based studies showed that the cost per adenoma detected was only 1/6 of the cost per colorectal cancer detected, and limited ICER evidence suggested that screening for colorectal cancer was generally cost-effective in Chinese population. Despite the inconclusiveness of the optimal screening technology, the findings suggested that the initial screening might be more cost-effective at older age. No high-level evidence such as randomized controlled trial evaluation was found.

Objective:To compare the rates of acceptance of colonoscopy, fecal immunochemical test (FIT), or a novel risk-adapted screening approach in the colorectal cancer (CRC) screening program. Related risk factors were also studied.Methods:The study has been based on an ongoing randomized controlled trial on colorectal cancer screening programs in six centers of research since May 2018. The involved participants were those who presented at the baseline screening phase. All the participants were randomly allocated into one of the following three intervention arms in a 1∶2∶2 ratio: colonoscopy group, FIT group, and a novel risk-adapted screening group. All the participants underwent risk assessment on CRC by an established risk score system. The subjects with high-risk were recommended to undertake the colonoscopy while the low-risk ones were receiving the FIT. Detailed epidemiological data was collected through questionnaires and clinical examinations. Rates of participation and compliance in all three groups were calculated. Multivariate logistic regression models were used to explore the potential associated factors related to the acceptance of screening.Results:There were 19 546 eligible participants involved in the study, including 3 916 in the colonoscopy group, 7 854 in the FIT group, and 7 776 in the novel risk-adapted screening group, respectively. Among the 19 546 participants, the mean age was 60.5 years ( SD=6.5), and 8 154 (41.7 %) were males. The rates of participation in the colonoscopy, FIT and the novel risk-adapted screening groups were 42.5 %, 94.0 % and 85.2 %, respectively. In the novel risk-adapted screening group, the participation rate was 49.2 % for the high-risk participants who need to undertake colonoscopy and was 94.0 % for the low-risk ones who need to undertake FIT. Results from the multivariate logistic regression models demonstrated that there were several factors associated with the rates of participation in CRC screening, including age, background of education, history of smoking cigarettes, previous history of bowel examination, chronic inflammatory bowel disease and family history of CRC among the 1 st-degree relatives. Conclusions:FIT and the novel risk-adapted screening approach showed superior participation rates to the colonoscopy. Further efforts including health promotion campaign for specific target population are needed to improve the engagement which ensures the effectiveness of CRC screening programs.

Objective:To evaluate the diagnostic performance of quantitative fecal immunochemical testing (FIT) and to provide reference for designing effective colorectal cancer (CRC) screening strategy in China.Methods:Based on an ongoing randomized controlled trial comparing the colorectal cancer screening strategies, this current study involved 3 407 participants aged 50-74 years who had undergone colonoscopies. All the feces samples were collected from the participants prior to receiving the colonoscopy. Fecal hemoglobin (Hb) was tested by FIT following a standardized operation process. Diagnosis-related indicators of FIT were calculated using the colonoscopy results as the gold standard.Results:Among the 3 407 participants, the mean age (SD) as 60.5 (6.3) years and 1 753 (51.5%) were males. The participants involved 28 (0.8%) CRCs, 255 (7.5%) advanced adenomas, 677 (19.9%) nonadvanced adenomas, and 2 447 (71.8%) benign or negative findings. With an overall positivity rate of 2.8% (96/3 407) at the recommended cutoff value of 20 μg Hb/g, the sensitivities of FIT for both CRC and advanced adenoma were 57.1% (95 %CI: 37.2%-75.5%) and 11.0% (95 %CI: 7.4%-15.5%), respectively, with the corresponding specificity as 98.4% (95 %CI: 97.8%-98.8%). At a decreased cut-off value of 5 μg Hb/g, the sensitivities for detecting CRC and advanced adenoma increased to 64.3% (95 %CI: 44.1%-81.4%) and 16.5% (95 %CI: 12.1%-21.6%), respectively, but the specificity reduced to 95.2% (95 %CI: 94.4%-95.9%). The areas under the ROC curve for CRC and advanced adenoma were 0.908 (95 %CI: 0.842-0.973) and 0.657 (95 %CI: 0.621-0.692), respectively. Of the diagnostic performance, there were no significant differences noticed by different sex and age groups. Conclusions:In our study, the quantitative FIT showed modest sensitivity in detecting CRC but limited sensitivity in detecting advanced adenoma. In population-based CRC screening programs, the quantitative FIT had the advantage of adjusting the positive threshold based on the targeted detection rate and available resource load of colonoscopy.

Objective:To analysis the clinical and follow-up data of the early colorectal carcinoma (ECC) after endoscopic resection, and explore the long-term outcome of patients who underwent the endoscopic resection.Methods:During June 2008 to June 2016, data of endoscopic resection for 550 cases of ECC were collected, including general information and follow-up data. The influence factors of disease-free survival rate of ECC after endoscopic resection were analyzed and the risk factors on long-term outcomes such as submucosa invasion depth, poorly differentiated adenocarcinoma, vascular invasion and positive vertical margin were investigated.Results:The mean follow-up time of 550 patients treated with endoscopy was (60.7±36.8) months. Among them, 433 cases were high-level intra-mucosal neoplasia, 117 cases were submucosa invasion carcinoma (the invasion depth <1 000 μm were 33 cases, ≥1 000 μm were 84 cases), 461 cases were curative resection, while 89 cases were non-curative resection. During the follow-up, 6 patients occurred recurrence or metastasis, including 2 patients with local recurrence (1 patient accompanied by lymph node metastasis) and 4 patients with lymph node metastasis (2 patients accompanied by distant metastasis). The overall 5-years disease-free survival rate was 98.8%, the 5-years disease-free survival rate was 100.0% for patients with curative resection and 93.3% for patients with non-curative resection. A total of 89 cases underwent non-curative resection were accompanied with invasion depth ≥1 000 μm, vascular invasion, poorly differentiated adenocarcinoma and positive vertical margin. Among them, 62 cases were accompanied with 1 risk factor, 23 cases with 2 risk factors and 4 cases with 3 risk factors. The risks of lymph nodes and distant metastasis raised with the increase of risk factors.Conclusions:The incidence of lymph node metastasis in ECC is extremely low. Endoscopic treatment can achieve a good long-term outcome. Close follow-up should be conducted after endoscopic treatment, and additional treatment should be selected reasonably for the early colorectal carcinoma after endoscopic non-curative resection to improve the therapeutic efficacy of endoscopic resection.

Objective:To analysis the clinical and follow-up data of the early colorectal carcinoma (ECC) after endoscopic resection, and explore the long-term outcome of patients who underwent the endoscopic resection.Methods:During June 2008 to June 2016, data of endoscopic resection for 550 cases of ECC were collected, including general information and follow-up data. The influence factors of disease-free survival rate of ECC after endoscopic resection were analyzed and the risk factors on long-term outcomes such as submucosa invasion depth, poorly differentiated adenocarcinoma, vascular invasion and positive vertical margin were investigated.Results:The mean follow-up time of 550 patients treated with endoscopy was (60.7±36.8) months. Among them, 433 cases were high-level intra-mucosal neoplasia, 117 cases were submucosa invasion carcinoma (the invasion depth <1 000 μm were 33 cases, ≥1 000 μm were 84 cases), 461 cases were curative resection, while 89 cases were non-curative resection. During the follow-up, 6 patients occurred recurrence or metastasis, including 2 patients with local recurrence (1 patient accompanied by lymph node metastasis) and 4 patients with lymph node metastasis (2 patients accompanied by distant metastasis). The overall 5-years disease-free survival rate was 98.8%, the 5-years disease-free survival rate was 100.0% for patients with curative resection and 93.3% for patients with non-curative resection. A total of 89 cases underwent non-curative resection were accompanied with invasion depth ≥1 000 μm, vascular invasion, poorly differentiated adenocarcinoma and positive vertical margin. Among them, 62 cases were accompanied with 1 risk factor, 23 cases with 2 risk factors and 4 cases with 3 risk factors. The risks of lymph nodes and distant metastasis raised with the increase of risk factors.Conclusions:The incidence of lymph node metastasis in ECC is extremely low. Endoscopic treatment can achieve a good long-term outcome. Close follow-up should be conducted after endoscopic treatment, and additional treatment should be selected reasonably for the early colorectal carcinoma after endoscopic non-curative resection to improve the therapeutic efficacy of endoscopic resection.

Objective: To acknowledge the availability and rates of annual transition of outcomes during the progression and regression stages of colorectal cancer (CRC) and related diseases, by pooling global follow-up studies on the natural history of CRC. Methods: Till March, 2017, data was collected through systematic literature review over multiple databases, including PubMed, Embase, Cochrane and Chinese Biology Medicine (CBM) disc. Information regarding the characteristics, classification system of health states, related outcomes and incidence rates on CRC or high-risk adenoma for the surveillance cohorts of the studies, were extracted and summarized. Both Meta and sensitivity analyses were performed on those outcomes if they appeared in more than 3 studies, using the random effects model. Annual transition rate with 95%CI was used to estimate each of the outcomes, Quality of the studies was assessed, using the Newcastle-Ottawa Scale. Results: A total of 29 cohort studies were included, with the mean follow-up period as 5.7 years. All studies except one, focused on adenoma-carcinoma pathway and reported the outcome parameters of adenomas by different risk, and some reported the findings on different sizes (n=6) of adenomas. These cohorts were divided into three groups (normal status, with low-risk or high-risk adenoma) according to the status of baseline endoscopic pathologic findings. Their available outcome parameters, corresponding number of involved articles, aggregated sample size and pooled annual transition rates were presented. Six parameters were obtained in the normal cohorts, including those from normal to low-risk adenoma (16 articles, 58 235, 0.030: 0.024-0.037), to high-risk adenoma (17 articles, 62 089, 0.003: 0.002-0.004), to diminutive adenoma (<5 mm, 4 articles, 1 277, 0.021: 0.013-0.029), to small adenoma (6-9 mm, 4 articles, 1 277, 0.006: 0.001-0.010), to large adenoma (≥10 mm, 7 articles, 3 531, 0.002: 0.000-0.003) and to CRC (19 articles, 104 836, 0.000 3: 0.000 2-0.000 5). Three parameters were obtained in low-risk adenoma in cohorts with polypectomy findings, including recurrence (9 articles, 4 788, 0.109: 0.062-0.157) from low-risk adenoma after polypectomy to high-risk adenoma (10 articles, 5 736, 0.009: 0.004-0.013) and to CRC (12 articles, 11 347, 0.000 6: 0.000 4-0.000 8). Three parameters were obtained on high-risk adenoma from cohorts with polypectomy findings, including recurrence (12 articles, 7 030, 0.038: 0.028-0.048) from high-risk adenoma after polypectomy to low-risk adenoma (8 articles, 2 489, 0.133: 0.081-0.185) and CRC (14 articles, 14 899, 0.002: 0.001-0.003). Except for normal to low-risk adenomas, results from the sensitivity analysis for the other parameters showed stable. Of the included studies, two presented incidence rates of CRC in different clinical stages and the another two were focusing on the parameters related to serrated pathway. Conclusions Globally, follow-up studies reported data on natural history of colorectal cancer is of paucity. Compared to the "adenoma-carcinoma" pathway, transition parameters of the serrated lesion pathway are more limited. This Meta-analysis provided convincing evidence for optimizing the strategies regarding follow-up program on the disease, using the baseline endoscopic findings from global CRC Screening Program. These results also offered strong data-related support for Chinese population- specific interventional model on colorectal cancer.