Histological and molecular classification of gastrointestinal polyps

Prevalence and risk factors of colon polyps and other colonic lesions in acromegaly: Insights from colonoscopy screening

PURPOSE

The existing data on colon lesions in acromegaly is notably heterogeneous. This study aimed to analyze the endoscopic and histopathological characteristics of colon polyps and other colonic lesions in acromegaly patients.

METHODS

This case-control study included 192 acromegaly patients and 256 controls. Colon polyps were categorized based on their size and histopathological classification. Colon malignancies and other colonic lesions, such as anal fissures, hemorrhoids, and diverticulosis, were also documented.

RESULTS

The prevalence of colon polyps was higher in the acromegaly group than in controls (p = 0.003), however, no differences were observed in the number, size, or histopathological subtypes of the polyps. Polyps in acromegaly patients were predominantly located in the distal colon and rectum. Multiple polyp locations and histopathological subtypes were more frequent in the control group (p = 0.042 and p = 0.018). Rates of low-grade dysplasia, high-grade dysplasia, and malignancy were similar between groups. Anal fissures were more common in the acromegaly group, whereas diverticulosis was less frequent (p = 0.001 and p < 0.001; respectively). Logistic regression analysis identified no significant clinical or laboratory predictors for colon polyps in acromegaly.

CONCLUSION

Patients with acromegaly exhibited a higher prevalence of colon polyps, predominantly located in the distal colon, which typically displayed a single histopathological subtype. No increased rates of colonic dysplasia, colon cancer, or other colonic lesions were observed in patients with acromegaly, except for an elevated prevalence of anal fissures.

Gastric Epithelial Polyps: Current Diagnosis, Management, and Endoscopic Frontiers

Polyps are defined as luminal lesions that project into the mucosal surface of the gastrointestinal tract and are characterized according to their morphological and histological features [...].

A non-aligned translation with a neoplastic classifier regularization to include vascular NBI patterns in standard colonoscopies

Polyp vascular patterns are key to categorizing colorectal cancer malignancy. These patterns are typically observed in situ from specialized narrow-band images (NBI). Nonetheless, such vascular characterization is lost from standard colonoscopies (the primary attention mechanism). Besides, even for NBI observations, the categorization remains biased for expert observations, reporting errors in classification from 59.5% to 84.2%. This work introduces an end-to-end computational strategy to enhance in situ standard colonoscopy observations, including vascular patterns typically observed from NBI mechanisms. These retrieved synthetic images are achieved by adjusting a deep representation under a non-aligned translation task from optical colonoscopy (OC) to NBI. The introduced scheme includes an architecture to discriminate enhanced neoplastic patterns achieving a remarkable separation into the embedding representation. The proposed approach was validated in a public dataset with a total of 76 sequences, including standard optical sequences and the respective NBI observations. The enhanced optical sequences were automatically classified among adenomas and hyperplastic samples achieving an F1-score of 0.86%. To measure the sensibility capability of the proposed approach, serrated samples were projected to the trained architecture. In this experiment, statistical differences from three classes with a ρ-value <0.05 were reported, following a Mann-Whitney U test. This work showed remarkable polyp discrimination results in enhancing OC sequences regarding typical NBI patterns. This method also learns polyp class distributions under the unpaired criteria (close to real practice), with the capability to separate serrated samples from adenomas and hyperplastic ones.

Using of endoscopic polypectomy in patients with diagnosed malignant colorectal polyp - The cross-sectional clinical study

The aim of this study was to evaluate the efficacy of endoscopic polypectomy as a therapeutic treatment for malignant alteration of colorectal polyps. In a 5-year research, 89 patients were included, who were tested and treated at the University Clinical Center Kragujevac, Kragujevac, Serbia, with the confirmed presence of malignant alteration polyps of the colon by colonoscopy, which were removed using the method of endoscopic polypectomy and confirmed by the histopathological examination of the entire polyp. After that, the same group of patients was monitored endoscopically within a certain period, controlling polypectomy locations and the occurrence of a possible remnant of the polyp, in the period of up to 2 years of polypectomy. We observed that, with an increasing size of polyps, there is also an increase in the percentage of the complexity of endoscopic resection and the appearance of remnant with histological characteristics of the invasive cancer. The highest percentage of incomplete endoscopic resection and the appearance of remnant with histological characteristics of the invasive cancer were shown at malignant altered polyps in the field of tubulovillous adenoma. Eighteen patients in total underwent the surgical intervention. In conclusion, our data support the high efficacy of endoscopic polypectomy for the removal of the altered malignant polyp.

Atrophic gastritis rather than Helicobacter pylori infection can be an independent risk factor of colorectal polyps: a retrospective study in China

BACKGROUND

Colonoscopy is considered the most effective screening method for colorectal polyps. However, the longevity and complexity of the procedure makes it less desirable to screen for colorectal polyps in the general population. Therefore, it is essential to identify other independent risk factors. In this study, we explored the link between Hp infection, atrophic gastritis, and colorectal polyps to identify a new potential risk factors of colorectal polyps.

METHODS

In this study, atrophic gastritis and intestinal polyps were diagnosed by endoscopy and pathology. All the 792 patients in this retrospective study were divided into sub-groups based on the presence of colorectal polyps. The correlation between polyps and atrophic gastritis was analyzed using the chi-square test and Kruskal-Wallis test. The receiver operating characteristic (ROC) curve was used to compare the predictive value for colorectal polyps between Hp infection and atrophic gastritis. Binary logistic regression was utilized to identify independent risk factors for colorectal polyps.

RESULTS

Patients with colorectal polyps were primarily male with advanced age, and the number of patients with colorectal polyps had a higher association with smoking, alcohol drinking, and Hp infection than the control group. A positive correlation between the number of colorectal polyps and the severity of atrophic gastritis was observed. ROC analysis showed that atrophic gastritis was a better risk factors for colorectal polyps. Multivariate analysis identified atrophic gastritis as an independent risk factor for colorectal polyps (OR 2.294; 95% CI 1.597-3.296).

CONCLUSIONS

Atrophic gastritis confirmed could be an independent risk factors for colorectal polyps.

A Non-Aligned Deep Representation to Enhance Standard Colonoscopy Observations from Vascular Narrow Band Polyp Patterns

Colorectal cancer (CRC) was responsible during 2020 for about one million deaths worldwide. Polyps are protuberance masses, observed in routine colonoscopies, that constitute the main CRC biomarker. Nonetheless, one of the best alternatives to the polyp malignancy classification is the vascular pattern analysis, typically observed from specialized narrow-band images (NBI). Even worst, these patterns are only characterized from gastroenterologist observations, introducing subjectivity and being prone to diagnostic errors, with misclassi-fications ranging from 59.5 % to 84.2 %. This work introduces a non-aligned and bi-directional deep projection between optical colonoscopy (OC) and NBI sequences, to recover enhanced OC sequences, integrating vascular patterns, that allow better dis-crimination among adenomas, hyperplastic and serrated polyps. This self-supervised representation help with misclassification in standard OC observations. The validation was performed on a total of 76 OC and 76 NBI sequences, achieving a gain of 22.34% w.r.t descriptors computed from raw OC. Clinical relevance- A deep representation that enhances standard OC observations associating vascularity to the polyps to discriminate among adenomas hyperplastic and serrated polyps.

Hyperplastic polyp or sessile serrated lesion? The contribution of serial sections to reclassification

BACKGROUND

The histological discrimination of hyperplastic polyps from sessile serrated lesions can be difficult. Sessile serrated lesions and hyperplastic polyps are types of serrated polyps which confer different malignancy risks, and surveillance intervals, and are sometimes difficult to discriminate. Our aim was to reclassify previously diagnosed hyperplastic polyps as sessile serrated lesions or confirmed hyperplastic polyps, using additional serial sections.

METHODS

Clinicopathological data for all colorectal hyperplastic polyps diagnosed in 2016 and 2017 was collected. The slides were reviewed and classified as hyperplastic polyps, sessile serrated lesion, or other, using current World Health Organization criteria. Eight additional serial sections were performed for the confirmed hyperplastic polyp group and reviewed.

RESULTS

Of an initial 147 hyperplastic polyps from 93 patients, 9 (6.1%) were classified as sessile serrated lesions, 103 as hyperplastic polyps, and 35 as other. Of the 103 confirmed hyperplastic polyps, 7 (6.8%) were proximal, and 8 (7.8%) had a largest fragment size of ≥5 mm and < 10 mm. After 8 additional serial sections, 11 (10.7%) were reclassified as sessile serrated lesions. They were all less than 5 mm and represented 14.3% of proximal polyps and 10.4% of distal polyps. An average of 3.6 serial sections were required for a change in diagnosis.

CONCLUSION

Histopathological distinction between hyperplastic polyps and sessile serrated lesions remains a challenge. This study has uncovered a potential role for the use of additional serial sections in the morphological reappraisal of small hyperplastic polyps, especially when proximally located.

Integrative analysis of exogenous, endogenous, tumour and immune factors for precision medicine

Immunotherapy strategies targeting immune checkpoints such as the CTLA4 and CD274 (programmed cell death 1 ligand 1, PD-L1)/PDCD1 (programmed cell death 1, PD-1) T-cell coreceptor pathways are revolutionising oncology. The approval of pembrolizumab use for solid tumours with high-level microsatellite instability or mismatch repair deficiency by the US Food and Drug Administration highlights promise of precision immuno-oncology. However, despite evidence indicating influences of exogenous and endogenous factors such as diet, nutrients, alcohol, smoking, obesity, lifestyle, environmental exposures and microbiome on tumour-immune interactions, integrative analyses of those factors and immunity lag behind. Immune cell analyses in the tumour microenvironment have not adequately been integrated into large-scale studies. Addressing this gap, the transdisciplinary field of molecular pathological epidemiology (MPE) offers research frameworks to integrate tumour immunology into population health sciences, and link the exposures and germline genetics (eg, HLA genotypes) to tumour and immune characteristics. Multilevel research using bioinformatics, in vivo pathology and omics (genomics, epigenomics, transcriptomics, proteomics and metabolomics) technologies is possible with use of tissue, peripheral blood circulating cells, cell-free plasma, stool, sputum, urine and other body fluids. This immunology-MPE model can synergise with experimental immunology, microbiology and systems biology. GI neoplasms represent exemplary diseases for the immunology-MPE model, given rich microbiota and immune tissues of intestines, and the well-established carcinogenic role of intestinal inflammation. Proof-of-principle studies on colorectal cancer provided insights into immunomodulating effects of aspirin, vitamin D, inflammatory diets and omega-3 polyunsaturated fatty acids. The integrated immunology-MPE model can contribute to better understanding of environment-tumour-immune interactions, and effective immunoprevention and immunotherapy strategies for precision medicine.