Can fish oil reduce the risk of colorectal adenomas?

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01 Chinese scholars revealed the pathogenesis of familial adenomatous polyposis. Professor Fu Wei of Peking University Third Hospital and Professor Tang Fuxuan of Peking University Frontier Innovation Center for Biotechnology published the latest research results in Gut [1].They used familial adenomatous polyposis (FAP) as a research model to deeply analyze the occurrence and development of colorectal cancer (CRC), especially the characteristics of important gene mutations and transcriptome changes in the process of adenoma and carcinogenesis.Prevention, early screening and treatment provide new clues and ideas.The study found that although the para-cancerous epithelial cells of FAP patients’ specimens have not yet accumulated potential driver mutations, they have been carcinogenic at the transcriptome level, showing enhanced metabolic processes and proliferative activity.This further confirms that it is of great significance to closely follow the population carrying APC germline mutations.The study also found that during the carcinogenesis of FAP patients, significant changes in carbohydrate metabolism have occurred in the early stages.This suggests that carbohydrate metabolism may be a potential target for early prevention of adenomas.■ Research details FAP is an autosomal dominant genetic syndrome caused by a germline mutation of the tumor suppressor gene APC. It is characterized by adenoma-like polyps of varying sizes in the colorectal cavity, numbering hundreds or thousands.If left untreated, it will almost always progress to adenocarcinoma.The characteristics of FAP make it a natural model for studying the adenoma-cancer transition process.The study cohort included 6 patients with FAP, 1 patient with MUTYH-associated polyposis (MAP), and 2 patients with sporadic CRC.This study performed whole exome sequencing, whole genome sequencing, and single-cell RNA sequencing (56 exomes, 56 genomes, 8757 single cells) on patients’ surgically resected specimens.Genomic variations (including copy number changes and somatic mutations) and dynamics of the transcriptome have been comprehensively studied.The results showed that analysis of the mutation load of adenomas and adenocarcinoma tissues at different stages of the same individual found that low-grade adenomas showed more somatic gene mutations than adjacent tissues.Interestingly, there were more somatic mutations in high-grade adenomas than in adenocarcinomas.However, due to the relatively limited sample size of high-grade adenomas (n = 9), the difference in mutational load between them and adenocarcinoma was not statistically significant.The findings suggest that grossly visible adenomas are already in the late stages of the cancerous process.The researchers found in two FAP specimens that multiple tumorous lesions adjacent to the physical location have a common origin, that is, the progeny cells of the cancerous initiating cells spread in the corresponding intestinal epithelium and accumulate other mutations to produce independent differences in location.Tumor, the phenomenon of regional canceration.Single cell transcriptome sequencing analysis of the paracancerous epithelium of 6 specimens of FAP patients and 2 specimens of sporadic CRC patients revealed that compared with sporadic CRC, the proliferation-related and metabolic function-related genes of FAP paracancerous epithelial cells were significantly expressed.Enhanced.Analysis of the dynamic changes of the transcriptome during canceration revealed that the expression of genes related to the tricarboxylic acid cycle (TCA) pathway was down-regulated during the transition from adjacent tissues to adenomas, while the transition from adenomas to adenocarcinomas was slightly up-regulated.This suggests that the TCA pathway is strongly inhibited in precancerous adenomas and is slightly relieved in adenocarcinomas.02 Low-dose fish oil does not reduce the risk of colorectal adenomas. Can omega-3 fatty acid supplements (fish oil) reduce the risk of colorectal precancerous lesions in the general population?A recent study published in “JAMA Oncology” showed that for the general risk American population, daily supplementation with 1 g of omega-3 does not reduce the risk of developing colorectal precancerous lesions (adenomas or jagged polyps) [2-3].■ Study Details This study is a placebo-controlled, randomized clinical trial VITAL pre-designated adjuvant study, which included a total of 25,871 adults (including 5,106 African Americans) who were 50 years of age and older and did not have cancer or cardiovascular disease..The study used a 2 × 2 factorial design, and participants were randomly assigned to receive omega-3 fatty acids (1 g daily, including 460 mg eicosapentaenoic acid and 380 mg docosahexaenoic acid) or placebo, vitamin D3 (each2000 IU) or placebo (Figure 3), designed to assess the impact of daily omega-3 fatty acid supplementation on the risk of colorectal precancerous lesions.The primary end point was common adenomas (including tubular adenomas, tubular villous adenomas, villous adenomas, and adenomas with highly atypical hyperplasia) or serrated polyps (including hyperplastic polyps, traditional serrated adenoma-like polyps, andPedicled serrated polyps).The results showed that 12938 people were included in the placebo group and 12933 people were included in the omega-3 treatment group. The overall average age was about 67 years, and the ratio of men to women was balanced.With a median follow-up of 5.3 years, multivariate analysis showed that 294 cases of common adenomas occurred in the omega-3 group and 301 cases in the placebo group (OR 0.98, 95% CI 0.83-1.15); 174 cases in the omega-3 groupThere were 167 cases of polyps in the placebo group (OR 1.05, 95% CI 0.84-1.29, Table 1).This suggests that omega-3 treatment is not associated with a reduced risk of common adenomas or jagged polyps.According to lesion size, location, diversity, or histological stratification analysis, there was no association between omega-3 treatment and the risk of precancerous lesions in advanced adenomas, high-risk serrated polyps, or other polyp subgroups.Secondary analyses found that omega-3 treatment appears to be associated with a lower risk of common adenomas in individuals with low levels of baseline omega-3 plasma (OR 0.76, 95% CI 0.57-1.02, P = 0.03).In addition, the African American population benefited from omega-3 treatment (OR 0.59, 95% CI 0.35-1.00), but other ethnic / ethnic populations did not benefit (P = 0.11).03 Machine vs. Human, better performance in detecting cancer in Barrett’s esophagus?Studies by Jacques Bergman and others at the University of Amsterdam Medical Center in the Netherlands show that in Barrett’s esophagus, deep learning computer-aided detection (CAD) systems have high accuracy in identifying tumor formation, and can almost perfectly identify the location and extent of the tumor, and its primary detection is accurateSex is higher than non-professional endoscope physicians [4-5].The findings were recently published in Gastroenterology.Researchers point out that the study may open the door to early detection of high-risk lesions without the need for biopsies.The CAD system has higher accuracy than non-professional endoscopic physicians, which strongly suggests that CAD can help improve the accuracy of the detection of early Barrett’s esophageal tumor formation by ordinary endoscopic physicians.Research details The researchers developed a hybrid ResNet-UNet model system using five independent endoscopic datasets.Machine pre-training was performed using 494,364 labeled endoscopic images, and then 1,704 esophageal high-resolution image learning of early tumors from patients with Barrett’s esophagus and atypically proliferative Barrett’s esophagus were learned.The study used datasets 4 and 5 to evaluate the performance of the CAD system.In data set 5, 53 general endoscopic physicians with extensive experience from 4 countries were scored to benchmark the performance of the CAD system.Combined with histopathological findings, multiple endoscopy experts described the location and extent of the tumor in detail, scored the images of early tumors in datasets 2-5, and used their evaluation as a reference standard.The results show that in a data set (data set 4) containing images of 80 patients, the CAD system can classify the images as tumor-containing or non-proliferative Barrett’s esophagus images with an accuracy of 89%, a sensitivity of 90%, and specificity.Sex is 88%.In another dataset (data set 5) containing images of 80 patients, the accuracy, sensitivity, and specificity of the CAD system compared to 53 general endoscopy physicians were: accuracy 88% vs 73%Sensitivity is 93% vs 72%.
Specificity 83% vs 74% In addition, the system identified the best location to detect a lesion for biopsy in 97% and 92% of cases (data sets 4 and 5), respectively.The above content is only authorized by for exclusive use, please do not reprint without authorization of the copyright party.


The author ouyangshaoxia