Screening colonoscopy: what is the most reliable modality for the detection and characterization of colorectal lesions?

Endoscopic Diagnosis of Superficial Gastrointestinal Cancer

White light image (WLI) findings are important for detection and characterization in the GI tract. However, magnified endoscopic examination with image enhanced endoscopy (IEE-NE) is becoming increasingly important for qualitative diagnosis of GI neoplastic lesions. IEE-ME is extremely useful for diagnosis of invasion depth in esophageal squamous cell cancer (ESCC) and colorectal cancer, whereas macroscopic findings of WLI are still useful in Barrett's adenocarcinoma (BAC) and gastric cancer. IEE-ME is also useful for diagnosis of tumor extent in BAC and gastric cancer, whereas chromoendoscopy with indigo carmine is useful in colorectal cancer and iodine staining is indispensable in ESCC.

Risk factors for inadequate bowel preparation before colonoscopy: a retrospective cohort study

BACKGROUND

Colonoscopy is the standard and most effective screening tool for colonic diseases and the accuracy of colonoscopy depends on the quality of bowel preparation. The aim of this study was to analyze the risk factors for inadequate bowel preparation before colonoscopy.

METHODS

In this retrospective study, patients who underwent colonoscopy in 2018 and received 3 L of Polyethylene Glycol Electrolytes powder were included. They were instructed to drink 1.5 L the night before the colonoscopy and 1.5 L 4-6 h before the procedure given in doses of 250 ml every 10 min with 30 ml of simethicone given 4-6 h before the colonoscopy. Patient- and procedure-related parameters were recorded. An adequate bowel preparation was defined as all 3 segments rated 2 or 3 on the Boston Bowel Preparation scale. Risk factors for inadequate bowel preparation were identified using multivariate logistic regression analysis.

RESULTS

A total of 6720 patients were included in the present study. The mean age of these patients was 49.7 ± 13.0 years old. Inadequate bowel preparation was found in 233 (12.4%), 139 (6.4%), 131 (7%), 68 (8.6%) patients in spring, summer, autumn and winter respectively. On the multivariate analysis, male gender (OR: 1.295; 95% CI: 1.088-1.542; P = 0.005), inpatient status (OR: 1.377; 95% CI: 1.040-1.822; P = 0.025) and season (spring vs. winter, OR: 1.514; 95% CI: 1.139-2.012; P = 0.004) were the independent risk factors for inadequate bowel preparation.

CONCLUSIONS

Male gender, inpatient status and spring season were the independent risk factors for inadequate bowel preparation. For patients with risk factors for inadequate bowel preparation, enhanced bowel preparation and instructions may help to optimize the quality of bowel preparation.

Modeling the survival of colorectal cancer patients based on colonoscopic features in a feature ensemble vision transformer

The prognosis of patients with colorectal cancer (CRC) mostly relies on the classic tumor node metastasis (TNM) staging classification. A more accurate and convenient prediction model would provide a better prognosis and assist in treatment. From May 2014 to December 2017, patients who underwent an operation for CRC were enrolled. The proposed feature ensemble vision transformer (FEViT) used ensemble classifiers to benefit the combinations of relevant colonoscopy features from the pretrained vision transformer and clinical features, including sex, age, family history of CRC, and tumor location, to establish the prognostic model. A total of 1729 colonoscopy images were enrolled in the current retrospective study. For the prediction of patient survival, FEViT achieved an accuracy of 94 % with an area under the receiver operating characteristic curve of 0.93, which was better than the TNM staging classification (90 %, 0.83) in the experiment. FEViT reduced the limited receptive field and gradient disappearance in the conventional convolutional neural network and was a relatively effective and efficient procedure. The promising accuracy of FEViT in modeling survival makes the prognosis of CRC patients more predictable and practical.

Impact of colorectal cancer screening on incidence, mortality and surgery rates: Evidences from programs based on the fecal immunochemical test in Italy

Fecal immunochemical tests (FIT) are among the most commonly used tests for colorectal cancer (CRC) screening programs worldwide. However, no randomised controlled trials have been carried out evaluating the impact of FIT-based screening programs (FIT-progr) on CRC incidence and mortality rates. Italian FIT-progr represent one of the most widespread and established experience worldwide. This paper reviews the evidence on the impact of FIT-progr on CRC incidence, tumor stage at diagnosis, mortality and surgery rates, deriving from Italian routine programs, i.e., outside the research setting. Unfortunately, the application of FIT-progr in Italy can be considered as an unplanned experimental model, due to the differences between Regions, both in health system management and adherence of the target population to the screening programs. The analysis of the manuscripts considered in the review, confirms that FIT-progr are effective in reducing CRC incidence and mortality rates and in improving the rate of endoscopic treatment of early invasive lesions. The review also highlights that FIT-progr are less performing for proximal colon than for distal colon and rectum.

Forceps Biopsies Are Not Reliable in the Workup of Large Colorectal Lesions Referred for Endoscopic Resection: Should They Be Abandoned?

BACKGROUND

Biopsies are routinely obtained in the workup of large colorectal polyps before endoscopic resection.

OBJECTIVE

This study aimed to examine how reliable biopsies are in terms of reflecting the true histopathology of large colorectal polyps, in the clinical routine.

DESIGN

This is a retrospective study.

SETTINGS

Data from patients undergoing polypectomy of large colorectal polyps at the endoscopy unit, Skåne University Hospital Malmö, between January 2014 and December 2016 were scrutinized.

PATIENTS

A total of 485 colorectal lesions were biopsied within 1 year before complete endoscopic removal. Biopsy-obtained specimens were compared with completely resected specimens in terms of concordance and discordance and if the final result was upgraded or downgraded.

MAIN OUTCOME MEASURES

The primary outcome measured was the concordance between biopsy-obtained specimens and completely resected specimens.

RESULTS

Median lesion size was 3 cm (range 1-11). In 189 cases (39%), biopsies did not provide a correct dysplastic grade compared with final pathology after complete resection. One hundred forty-three cases (29%) and 46 cases (9%) were upgraded and downgraded. The percentage of cases with discordant biopsy results was 40% in cases with 1 biopsy taken and 38% in cases where multiple biopsies had been sampled. Time from biopsy to complete resection did not influence the erroneous outcome of biopsies. Notably, the percentage of discordant biopsy results was 37% and 35% in lesions measuring 1 to 2 cm and 2 to 4 cm. However, this percentage increased to 48% in colorectal lesions larger than 4 cm.

LIMITATIONS

This study was designed to reflect the clinical routine, the number of biopsies obtained and forceps technique were hence not standardized, which constitutes a limitation.

CONCLUSIONS

This study demonstrates that cancer-negative forceps biopsies of large colorectal polyps, referred for endoscopic resection, are not reliable. Considering that endoscopic resection of lesions containing superficial cancer is plausible, the clinical value of forceps biopsies in lesions suitable for endoscopic resection is questionable. See Video Abstract at http://links.lww.com/DCR/A984. LAS BIOPSIAS CON FÓRCEPS NO SON CONFIABLES EN EL ESTUDIO DE LAS LESIONES COLORRECTALES GRANDES REFERIDAS PARA RESECCIÓN ENDOSCÓPICA: ¿DEBERÍAN ABANDONARSE?: Las biopsias se obtienen de forma rutinaria en el estudio de pólipos colorrectales grandes previo a resección endoscópica.

OBJETIVO

Analizar que tan confiables son las biopsias en cuanto a reflejar la verdadera histopatología de los pólipos colorrectales grandes, en la rutina clínica. DISEÑO:: Este es un estudio retrospectivo.

AJUSTES

Los datos de pacientes sometidos a polipectomía de pólipos colorrectales grandes en la unidad de endoscopia, en Skåne University Hospital Malmö, entre enero de 2014 y diciembre de 2016 fueron examinados.

PACIENTES

Un total de 485 lesiones colorrectales se biopsiaron dentro de un año antes de la resección endoscópica completa. Las muestras obtenidas mediante biopsia se compararon con las muestras completas resecadas en términos de concordancia y discordancia, y si el resultado final ascendió o disminuyó de categoría.

PRINCIPALES MEDIDAS DE RESULTADO

Concordancia entre muestras obtenidas mediante biopsia y muestras completamente resecadas.

RESULTADOS

La mediana de tamaño de lesiones fue de 3 cm (rango 1-11). En 189 casos (39%) las biopsias no proporcionaron un grado de displasia correcto en comparación con la patología final después de la resección completa. 143 casos (29%) y 46 casos (9%) ascendieron y descendieron de categoría, respectivamente. El porcentaje de casos con resultados de biopsia discordantes fue del 40% en los casos con una sola biopsia tomada y del 38% en los casos en los que se tomaron múltiples biopsias. El tiempo desde la biopsia hasta la resección completa no influyó en el resultado erróneo de las biopsias. Notablemente, el porcentaje de resultados de biopsia discordantes fue de 37% y 35% en lesiones que midieron 1-2 cm y 2-4 cm, respectivamente. Sin embargo, este porcentaje aumentó a 48% en lesiones colorrectales mayores de 4 cm.

LIMITACIONES

Este estudio se diseñó para reflejar la rutina clínica, el número de biopsias obtenidas y la técnica de fórceps no fueron estandarizadas, lo que constituye una limitación.

CONCLUSIONES

Este estudio demuestra que las biopsias con fórceps negativas a cáncer, de pólipos colorrectales grandes referidas para resección endoscópica, no son confiables. Teniendo en cuenta que la resección endoscópica de lesiones que contienen cáncer superficial es posible, el valor clínico de las biopsias con fórceps en lesiones aptas para la resección endoscópica es cuestionable. Vea el Resumen en video en http://links.lww.com/DCR/A984.

Risk factors associated with the detection and missed diagnosis of colorectal flat adenoma: a Chinese multicenter observational study

OBJECTIVES

Flat colorectal adenomas have a high risk of malignancy; however, their detection is often difficult due to their flat morphology. In this retrospective, large-scale study, we investigated the prevalence and characteristics of flat adenomas in a population in China.

METHODS

We analyzed the data collected for 16951 consecutive patients who underwent colonoscopy at four participating hospitals between September 2013 and September 2015. All colonoscopies were performed without magnification.

RESULTS

Among the 1,6951 patients, 2938 (17.3%) had adenoma and 796 (4.7%) had flat adenomas. The detection of flat adenoma showed a weak correlation with the detection of adenoma (r = 0.666). Multivariable logistic regression analysis revealed the following independent factors influencing the detection of flat adenomas: patient-related factors of age, presence of warning symptoms, history of adenomas and bowel preparation as well as endoscopist-related factors of endoscopist's level of proficiency, number of colonoscopy operators and withdrawal time.

CONCLUSIONS

The prevalence of flat adenomas in our study on Chinese patients was consistent with that reported from other countries. Factors conducive to the detection of flat adenomas were patient age of > 60 years, warning symptoms, history of adenoma, good bowel preparation, experienced endoscopist, single-operator colonoscopy and colonoscopy withdrawal time of >6 min.

Non-polypoid colorectal neoplasms: Classification, therapy and follow-up

In the last years, an increasing interest has been raised on non-polypoid colorectal tumors (NPT) and in particular on large flat neoplastic lesions beyond 10 mm tending to grow laterally, called laterally spreading tumors (LST). LSTs and large sessile polyps have a greater frequency of high-grade dysplasia and local invasiveness as compared to pedunculated lesions of the same size and usually represent a technical challenge for the endoscopist in terms of either diagnosis and resection. According to the Paris classification, NPTs are distinguished in slightly elevated (0-IIa, less than 2.5 mm), flat (0-IIb) or slightly depressed (0-IIc). NPTs are usually flat or slightly elevated and tend to spread laterally while in case of depressed lesions, cell proliferation growth progresses in depth in the colonic wall, thus leading to an increased risk of submucosal invasion (SMI) even for smaller neoplasms. NPTs may be frequently missed by inexperienced endoscopists, thus a careful training and precise assessment of all suspected mucosal areas should be performed. Chromoendoscopy or, if possible, narrow-band imaging technique should be considered for the estimation of SMI risk of NPTs, and the characterization of pit pattern and vascular pattern may be useful to predict the risk of SMI and, therefore, to guide the therapeutic decision. Lesions suitable to endoscopic resection are those confined to the mucosa (or superficial layer of submucosa in selected cases) whereas deeper invasion makes endoscopic therapy infeasible. Endoscopic mucosal resection (EMR, piecemeal for LSTs > 20 mm, en bloc for smaller neoplasms) remains the first-line therapy for NPTs, whereas endoscopic submucosal dissection in high-volume centers or surgery should be considered for large LSTs for which en bloc resection is mandatory and cannot be achieved by means of EMR. After piecemeal EMR, follow-up colonoscopy should be performed at 3 mo to assess resection completeness. In case of en bloc resection, surveillance colonoscopy should be scheduled at 3 years for adenomatous lesions ≥ 1 cm, or in presence of villous features or high-grade dysplasia patients (regardless of the size), while less intensive surveillance (colonoscopy at 5-10 years) is needed in case of single (or two) NPT < 1 cm presenting tubular features or low-grade dysplasia at histology.