Is there a true "shift" to the right colon in the incidence of colorectal cancer?

Colorectal adenocarcinoma in Uganda: are right-sided and left-sided colon cancers two distinct disease entities?

INTRODUCTION

In Western countries, right-sided colon cancers (RSCC) present at an older age and advanced stage. Researchers believe that there is a difference between left-sided colon cancer (LSCC) and RSCC. In Uganda, however, it is unknown whether differences exist in the pathological profile between RSCC and LSCC. The aim of this study was to determine the differences in clinicopathological characteristics between RSCC and LSCC in Ugandan patients.

METHODOLOGY

A cross-sectional study was conducted in which colorectal adenocarcinoma formalin-fixed paraffin-embedded tissue (FFPE) blocks were obtained from 2008 to 2021. Colorectal specimens were obtained from prospectively recruited patients. In the retrospective study arm, FFPE blocks and data were obtained from the archives of pathology laboratory repositories. Parameters studied included age, sex, location of the tumour, grade, stage, lymphovascular (LVI) status, and histopathological subtype between LSCC and RSCC.

RESULTS

Patients with RSCC were not older than those with LSCC (mean age, 56.3 years vs 53.5 years; p = 0.170). There was no difference in the stage between RSCC and LSCC. Poorly differentiated tumours were more commonly found in RSCC than in LSCC (18.7% vs 10.1%; p = 0.038). Moderately and poorly differentiated colonic tumours were more common with RSCC (89.3%) than with LSCC (75.1%) (p = 0.007). Younger patients had more poorly differentiated tumours than older patients (19.6% versus 8.6%; p = 0.002). LVI was more common with RSCC than with LSCC (96.8% vs 85.3%; p = 0.014). Mucinous adenocarcinoma (MAC) was more common with RSCC (15.8%) compared with LSCC (8.5%) (p = 0.056) although statistical significance was borderline.

CONCLUSIONS

Clinicopathological features of RSCCs tend to be different from those of LSCCs. RSCCs tend to be associated with MAC, a higher grade and LVI status compared to LSCC. LSCC and RSCC present predominantly with an advanced stage; therefore, national screening programmes for the early detection of CRC are necessary to reduce mortality in our Ugandan population.

Unlocking quality in endoscopic mucosal resection

A review of the development of the key performance metrics of endoscopic mucosal resection (EMR), learning from the experience of the establishment of widespread colonoscopy quality measurements. Potential future performance markers for both colonoscopy and EMR are also evaluated to ensure continued high quality performance is maintained with a focus service framework and predictors of patient outcome.

Influence of COVID-19 Pandemic on Colorectal Cancer Presentation, Management and Outcome during the COVID-19 Pandemic

The aim of the study was to investigate whether the COVID-19 pandemic and related measures had an influence on colorectal cancer (CRC) presentation, management, and outcomes; it was a retrospective monocentric study. CRC patients undergoing surgery during the COVID-19 pandemic (1 March 2020-28 February 2022) (group B) were compared with patients operated on in the previous two years (1 March 2018-29 February 2020) in the same unit (group A). The primary outcome was to investigate whether there were differences in concern regarding the stage at presentation, as a whole and after dividing groups based on cancer location (right colon cancer, left colon cancer, rectal cancer). Secondary outcomes included differences in the number of patients admitted from emergency departments and emergency surgeries between periods, and differences in the postoperative outcomes. A subanalysis within the pandemic group was conducted on the same outcomes, dividing the aforementioned group based on pandemic trends. Two hundred and eighty (280) were operated on during the study period: 147 in group A and 133 in group B. Stage at presentation was similar between groups; however, the subgroups analysis showed that in the pandemic group, the number of early-stage left colon cancer occurrences almost halves, yet not significantly. Emergency department referral was more common in group B (p-value: 0.003); in group B, they also had longer operations and there was a more frequent use of ostomy. No differences in the number of postoperative complications nor in the postoperative outcomes were found. Patients with CRC were more frequently referred through the emergency department during the COVID-19 pandemic and left-sided cancers appear to be generally diagnosed at a more advanced stage. Postoperative outcomes showed that high specialized colorectal units can deliver standard high-level treatment under high-pressure external conditions.

Gut Microbiota in Colorectal Cancer: Biological Role and Therapeutic Opportunities

Colorectal cancer (CRC) is the second-leading cause of cancer-related deaths worldwide. While CRC is thought to be an interplay between genetic and environmental factors, several lines of evidence suggest the involvement of gut microbiota in promoting inflammation and tumor progression. Gut microbiota refer to the ~40 trillion microorganisms that inhabit the human gut. Advances in next-generation sequencing technologies and metagenomics have provided new insights into the gut microbial ecology and have helped in linking gut microbiota to CRC. Many studies carried out in humans and animal models have emphasized the role of certain gut bacteria, such as Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, and colibactin-producing Escherichia coli, in the onset and progression of CRC. Metagenomic studies have opened up new avenues for the application of gut microbiota in the diagnosis, prevention, and treatment of CRC. This review article summarizes the role of gut microbiota in CRC development and its use as a biomarker to predict the disease and its potential therapeutic applications.

Advancing human gut microbiota research by considering gut transit time

Accumulating evidence indicates that gut transit time is a key factor in shaping the gut microbiota composition and activity, which are linked to human health. Both population-wide and small-scale studies have identified transit time as a top covariate contributing to the large interindividual variation in the faecal microbiota composition. Despite this, transit time is still rarely being considered in the field of the human gut microbiome. Here, we review the latest research describing how and why whole gut and segmental transit times vary substantially between and within individuals, and how variations in gut transit time impact the gut microbiota composition, diversity and metabolism. Furthermore, we discuss the mechanisms by which the gut microbiota may causally affect gut motility. We argue that by taking into account the interindividual and intraindividual differences in gut transit time, we can advance our understanding of diet-microbiota interactions and disease-related microbiome signatures, since these may often be confounded by transient or persistent alterations in transit time. Altogether, a better understanding of the complex, bidirectional interactions between the gut microbiota and transit time is required to better understand gut microbiome variations in health and disease.

Development of an Endoscopy Training Partnership in a Developing Country

Gastrointestinal and pulmonary disease is prevalent in many developing countries. Establishing an endoscopy training partnership can transfer skills that can influence policy and stakeholder support to address disease morbidity and mortality. Any new program needs to consider the environmental services that will be delivered and give consideration to the sustainability of the program over time. This article outlines what we have learned from our training partnership in the Pacific Islands Region.

Colorectal Cancer Trends of 2018 in Romania-an Important Geographical Variation Between Northern and Southern Lands and High Mortality Versus European Averages

PURPOSE

In Romania, one of the highest rates for colorectal cancer (CRC) incidence and mortality in Europe was estimated based on data available in 2008. Ever since, consistent data are missing. In this article, we tried to estimate the general burden of CRC in our country.

METHODS

We collected data from all hospitalized recorded cases according to the ICD-10 revision (codes C18-C20), as both primary and secondary diagnoses, as reported by all the hospitals to the DRG National System, between 2016 and 2018.

RESULTS

There were 50,890 persons hospitalized with CRC. The prevalence of hospitalized colorectal cancer was 108.24/100,000 inhabitants in 2016, 113.09/100,000 inhabitants in 2017, and 116.83/100,000 inhabitants in 2018. Distal localization prevailed. We registered 34.13/100,000 deaths by CRC within the mentioned period of time, almost twofold higher than average European range. There are significant geographical differences regarding CRC prevalence and mortality, with higher rates in the Northern and Central Regions, and a very low prevalence and mortality in Bucharest and Southern provinces.

CONCLUSION

We note a high colorectal mortality rate in Romania, especially in the Northern and Central Regions, nearly double versus European ranges.

Molecular Oncology in Management of Colorectal Cancer

Colorectal cancers are the third most common cancers in the world. Management of both primary and metastatic colorectal cancers has evolved over the last couple of decades. Extensive research in molecular oncology has helped us understand and identify these complex intricacies in colorectal cancer biology and disease progression. These advances coupled with improved knowledge on various mutations have helped develop targeted chemotherapeutics and has allowed planning an effective treatment regimen in this era of immunotherapy with precision. The diverse chemotherapeutic and biological agents at our disposal can make decision making a very complex process. Molecular profile, including CIN, RAS, BRAF mutations, microsatellite instability, ctDNA, and consensus molecular subtypes, are some of the important factors which are to be considered while planning an individualized treatment regimen. This article summarizes the current status of molecular oncology in the management of colorectal cancer and should serve as a practical guide for the clinical team.

Reevaluation of a rightward shift in colorectal cancer: A single-center retrospective study in Tianjin

OBJECTIVES

Some Western reports have shown a proximal shift in colorectal cancer (CRC), but there are few studies in China. This study aimed to provide more information for the management and screening of CRC by investigating trends in the anatomic distribution of CRC among the Chinese population in recent years.

METHODS

A retrospective study was conducted on patients with CRC admitted to the Digestive Endoscopy Center of Tianjin Medical University General Hospital between January 2000 and December 2017. Patients were divided into a left-sided colorectal cancer (LSCRC) group and a right-sided colon cancer (RSCC) group. The detection rates of LSCRC and RSCC based on patients' age and sex, and on the time periods were analyzed.

RESULTS

A total of 2319 cases were diagnosed with CRC among 75 183 consecutive patients. The prevalence of CRC showed a significant reduction from 2000-2008 to 2009-2017 (3.8% vs 2.7%, P < .001). The proportion of RSCC presented a downtrend from 2000-2008 to 2009-2017 (40.6% vs 37.7%, P > .05). There were slightly more RSCCs in female patients than in male patients, with no significant difference (40.9% vs 36.5%, P > .05). The proportion of RSCC in patients aged ≥50 years was similar to that in younger patients. The alarming symptoms between LSCRC and RSCC showed a significant difference (P < .05).

CONCLUSIONS

In the present study, the prevalence of CRC declined significantly with time. However, there did not appear to be a rightward shift in CRC among the patients in Tianjin over the past 18 years.

Analysis of population-based colorectal cancer screening in Guangzhou, 2011-2015

Objective

To analyze the detection rates of colorectal cancer (CRC) and polyps by population‐based screening in Guangzhou.

Methods

From January 2011 to December 2015, the residents aged 30‐79 were selected for CRC screening. The residents were conducted Questionnaires and/or FOBT to assess high‐risk groups, the free colonoscopy examination was recommended, and the results were evaluated in detail.

Results

There were 98 927 residents involving screening, 5306 high‐risk residents identified (males 1859 and females 3447), and 4713 subjects underwent colonoscopy (males 1690 and females 3023). CRC was seen in 55 individuals (males 28 and females 27), and the detection rates in male were higher than in female (P = 0.019). And the detection rates increasing with age, for people over 60 years old, were obviously higher than those younger (x² = 18.64, P = 0.000924).

The polyps were seen in 1458 (30.94%) cases， and 1420 subjects received pathological examination (adenomas 971 and non‐adenomatous polyps 449). Advanced adenomas were seen in 462 cases (males 240 and females 222) and 509 cases of non‐advanced adenomas (males 255 and females 254). For advanced adenomas, the detection rates in male were higher than female (14.20% vs 7.34%, P = 2.64 × 10⁻¹⁴). For the detection rates of adenomas or advanced adenomas by age, the people over 40 years were higher than younger (20.91% vs 3.61% P = 7.87 × 10⁻⁶; 9.94% vs 2.41%, P = 0.009).

Conclusions

For Guangzhou residents, the detection rates of CRC and adenoma were 1.17% and 20.60%. The detection rates of CRC increasing with age, for people over 60 years old, were obviously higher than those younger. But for people over 40 years, the detection rate of adenoma and advanced adenoma was higher than younger. So for people over 40 years, the CRC screening is recommended.

Risk factors for advanced colorectal neoplasms in the proximal colon in 6218 subjects undergoing complete colonoscopy

BACKGROUND AND AIM

Proximal migration of colonic lesion has been observed; however, risk factors of lesions in the proximal colon remain uncertain. This study aimed to investigate risk factors of lesions in the proximal colon.

METHODS

Consecutive subjects with complete colonoscopy were included. The primary outcome was risk factors associated with advanced neoplasm (AN) and serrated lesion in the proximal colon. Age, gender, first-degree relative (FDR) with colorectal cancer (CRC), smoking, alcohol consumption, body mass index, hypertension, diabetes, ischemic heart disease, and the use of aspirin, non-steroidal anti-inflammatory drug, and anticoagulants were fitted into a regression model, with reference to subjects without colonic finding. Results were measured by odds ratio (OR) with 95% confidence interval (CI).

RESULTS

Among 6218 subjects (mean age 56.65 ± 6.15 years; 46.8% male), 352 (5.7%) had AN; 809 (13.0%) had serrated lesions, and 3648 (58.7%) had no colonic finding. There were 148 (2.4%) and 235 (3.8%) subjects having AN and serrated lesion in the proximal colon. Age ≥ 50 (OR: 13.30; 95% CI: 1.85-95.76), male gender (OR: 1.82; 95% CI: 1.26-2.62), FDR with CRC (OR: 2.12; 95% CI: 1.43-3.15), and hypertension (OR: 1.86; 95% CI: 1.30-2.68) were associated with AN in the proximal colon. Age ≥ 50 (OR: 5.72; 95% CI: 2.10-15.53), male gender (OR: 1.54; 95% CI: 1.15-2.05), and smoking (OR: 1.85; 95% CI: 1.23-2.79) increased risk of serrated lesions in the proximal colon.

CONCLUSION

Age ≥ 50 and male gender were associated with both proximally located AN and serrated lesion; FDR with CRC and hypertension increased the risk of proximal AN, while ever smoking increased the risk of proximal serrated lesion. FDR with CRC was not associated with serrated lesion.

Brain metastases in newly diagnosed colorectal cancer: a population-based study

Background

Population-based incidence evaluations and prognosis assessments of brain metastasis (BM) at diagnosis of colorectal cancer (CRC) are lacking. Our study sought to determine the incidence of BM in CRC patients, median survival of patients with BM, and the risk factors of BM in CRC.

Patients and methods

Patients diagnosed with CRC were identified using the Surveillance, Epidemiology, and End Results database. Multivariable logistic and Cox regression analyses were performed to identify predictors of the presence of BM at CRC diagnosis and the factors associated with poor survival. Kaplan–Meier analysis was used to estimate the survival difference between subgroups.

Results

We identified 170,793 adult patients diagnosed with CRC between 2010 and 2013. From these patients, we identified 401 patients with BM at the time of CRC diagnosis, which represents 0.23% of the entire patient CRC cohort and 1.3% of the patients with metastatic disease to any site. Median survival of patients with BM was 7.0 months, and the survival could increase to 15.59 months if there was no metastasis to other organs. We found that extracranial metastases number, tumor site, and pathology type were associated with BM at CRC diagnosis.

Conclusion

The findings of this study indicate the incidence and prognosis for patients with BM at the time of CRC diagnosis. Our findings lend support for positive treatment for BM without metastasis to other organs.

Rates of metachronous adenoma after curative resection for left-sided or right-sided colon cancer

Background/Aims

We determined the rates of metachronous colorectal neoplasm in colorectal cancer (CRC) patients after resection for right (R)-sided or left (L)-sided cancer.

Methods

Consecutive CRC patients who had undergone surgical resection for curative intent in our hospital between 2001 and 2004 were identified. R-sided colonic cancers refer to cancer proximal to splenic flexure whereas L-sided cancers include rectal cancers. Patients were included only if they had a clearing colonoscopy performed either before or within 6 months after the operation. Findings of surveillance colonoscopy performed up to 5 years after colonic resection were included in the analysis.

Results

Eight hundred and sixty-three CRC patients underwent curative surgical resection during the study period. Three hundred and twenty-seven patients (107 R-sided and 220 L-sided) fulfilled the inclusion criteria and had at least 1 postoperative surveillance colonoscopy performed. The proportion of patients who had polyp and adenoma on surveillance colonoscopy was significantly higher among patients with L-sided than R-sided cancers (polyps: 30.9% vs. 19.6%, P=0.03; adenomas: 25.5% vs. 13.1%, P=0.01). The mean number of adenoma per patient on surveillance colonoscopy was also higher for patients with L-sided than R-sided tumors (0.52; 95% confidence interval [CI], 0.37–0.68 vs. 0.22; 95% CI, 0.08–0.35; P<0.01). Multivariate analysis showed that L-sided cancers, age, male gender and longer follow-up were independent predictors of adenoma detection on surveillance colonoscopy.

Conclusions

Patients with Lsided cancer had a higher rate of metachronous polyps and adenoma than those with R-sided cancer on surveillance colonoscopy.

Occlusive stenosis - atypical presentation of right colon cancer

Colorectal cancers are one of the most frequent malignancies worldwide. Significant differences are described in relation to the location of tumors within the colon. Thus, between right and left colon cancer there are epidemiological, clinical, genetic, evolutionary and prognostic differences. Considering these premises, right and left colon cancers can be seen as distinct pathological entities. In right colon cancer the initial phases are often asymptomatic and the presence of symptoms is in relation to advanced phases and complications. We report the case of a 64-year-old man with no significant medical history who was admitted and operated as an emergency for stenotic and perforated tumor of the right colon. Operative exploration revealed distended small bowel loops and caecum up to the ascending colon where a stenosing tumor is found. The tumor extends to a small bowel loop and also exhibit a perforation. Right hemicolectomy was performed, with favorable postoperative evolution and discharge on 7th day.

Dietary fat and fiber interactively modulate apoptosis and mitochondrial bioenergetic profiles in mouse colon in a site-specific manner

We have demonstrated that the combination of bioactive components generated by fish oil (containing n-3 polyunsaturated fatty acids) and fermentable fiber (leading to butyrate production) act coordinately to protect against colon cancer. This is, in part, the result of an enhancement of apoptosis at the base of the crypt across all stages (initiation, promotion, and progression) of colon tumorigenesis. As mitochondria are key organelles capable of regulating the intrinsic apoptotic pathway and mediating programmed cell death, we investigated the effects of diet on mitochondrial function by measuring mucosal cardiolipin composition, mitochondrial respiratory parameters, and apoptosis in isolated crypts from the proximal and distal colon. C57BL/6 mice (n=15/treatment) were fed one of two dietary fats (corn oil and fish oil) and two fibers (pectin and cellulose) for 4 weeks in a 2×2 factorial design. In general, diet modulated apoptosis and the mucosal bioenergetic profiles in a site-specific manner. The fish/pectin diet promoted a more proapoptotic phenotype - for example, increased proton leak (Pinteraction=0.002) - compared with corn/cellulose (control) only in the proximal colon. With respect to the composition of cardiolipin, a unique phospholipid localized to the mitochondrial inner membrane where it mediates energy metabolism, fish oil feeding indirectly influenced its molecular species with a combined carbon number of C68 or greater, suggesting compensatory regulation. These data indicate that dietary fat and fiber can interactively modulate the mitochondrial metabolic profile and thereby potentially modulate apoptosis and subsequent colon cancer risk.

Position change during colonoscopy improves caecal intubation rate, mucosal visibility, and adenoma detection in patients with suboptimal caecal preparation

Introduction

Most colonoscopies are completed in the left lateral (LL) position but in cases of suboptimal caecal preparation, changing the patient's position to supine (S) and, if needed, to right lateral (RL) improves caecal intubation rate, mucosal visibility, and adenoma detection.

Aim

To determine if position change during colonoscopy facilitates optimal visualisation of the caecum.

Material and methods

A total of 359 patients were grouped into three categories based on the initial caecal intubation position. After caecal intubation, caecal visibility was scored on a four-point scale depending on the number of imaginary quadrants of the caecum completely visualized - Arya Caecal Prep Score. A score of 1 or 2 was unsatisfactory, while 3 or 4 was considered satisfactory. In patients with unsatisfactory score, position was changed from LL to S and then RL and visibility was scored again.

Results

The initial caecal intubation in the LL position was achieved in 66.8% of patients, S in 28.5%, and RL in 4.8% of patients. 84.5% (300/355) of patients had an acceptable visualisation score at the initial caecal intubation position. Of the 55 patients with unsatisfactory caecum visualisation scores in the initial intubation position, 30 (8.5%) had satisfactory scores after the first position change (95% CI: 5.77-11.84). Twenty-five (7.04%) subjects required two position changes (95% CI: 4.61-10.22%). An additional 9.3% (11/118) of adenomas were detected in caecum and ascending colon following position change.

Conclusions

Changing patient position improves caecal intubation rate, mucosal visibility, and adenoma detection.

Differences in Cancer-Specific Mortality of Right- Versus Left-Sided Colon Adenocarcinoma: A Surveillance, Epidemiology, and End Results Database Analysis

Purpose

Studies have shown an increased risk for all-cause mortality with right-sided colon cancer (RCC) as compared with left-sided colon cancer (LCC). However, these studies were unable to directly account for mortality events unrelated to cancer, known as other-cause mortality. We investigated the difference in cancer-specific mortality (CSM) between RCC and LCC at localized, regional, and metastatic stages, according to the Fine and Gray proportional hazards model, while accounting for other-cause mortality as a competing risk.

Methods

Using the SEER database, we identified 90,635 patients with LCC (ie, involving the splenic flexure, descending, sigmoid, and rectosigmoid colon) and 112,679 patients with RCC (ie, involving the cecum, ascending, hepatic flexure, and transverse colon) diagnosed from 1998 to 2013. We performed a competing risk analysis for CSM using the Fine and Gray proportional hazard model, adjusting for age, sex, race, tumor grade, surgery status, year of diagnosis, and tumor laterality, with two-sided testing and a statistical significance threshold of 0.05.

Results

Compared with LCC, RCC demonstrated statistically significant decreased CSM at the localized stage (adjusted hazards ratio [AHR], 0.865; P < .001), equivalent CSM at the regional stage (AHR, 0.990; P = .440), and increased CSM at the metastatic stage (AHR, 1.175; P < .001).

Conclusion

Using a competing risk model, we have shown that RCC, compared with LCC, is associated with lower CSM at the localized stage, equivalent CSM at the regional stage, and higher CSM at the metastatic stage. This pattern may correlate with variation in genetic factors, including known decreased prevalence of microsatellite instability in RCC with regional and metastatic disease.

The ethnic distribution of sessile serrated polyps in the United States is inversely associated with Helicobacter pylori prevalence

AIM

Little is known about the epidemiology of sessile serrated polyps (SSP). Our study aimed to investigate the influence of Helicobacter pylori gastritis and patient demographic characteristics (age, gender, ethnicity) on the prevalence of SSP using a large national database of patients undergoing bi-directional endoscopy.

METHOD

De-identified patient data were extracted from the Miraca Life Sciences electronic database of histopathological reports. Using multivariate logistic regression analysis, the influence of H. pylori gastritis and demographic characteristics on the occurrence of SSP were expressed as odds ratios (OR) with their 95% confidence intervals (CI).

RESULTS

The total study population comprised 228 506 subjects, of whom 28 890 carried a diagnosis of H. pylori gastritis and 11 285 SSP. Age (OR 4.35, 95% CI: 3.82-4.96), female gender (0.92, 0.88-0.95) and H. pylori gastritis (0.94, 0.88-0.99) exerted the strongest influence on the occurrence of SSP. In comparison with the population comprising Caucasians and African Americans, SSP were less common among subjects of Hispanic (0.67, 0.62-0.73), East Asian (0.59, 0.50-0.69), Indian (0.43, 0.27-0.64) or Middle Eastern descent (0.61, 0.41-0.87). All these ethnic subgroups were also characterized by a higher prevalence of H. pylori than the comparison group. A low prevalence of H. pylori was significantly associated with a high prevalence of SSP (R²  = 0.82, P < 0.001).

CONCLUSION

The prevalence of SSP within the United States is characterized by a marked ethnic variation. The inverse correlation between the prevalence of H. pylori and SSP suggests that gastric infection with H. pylori may be partly responsible for the observed ethnic distribution of SSP.

Definition of colorectal anastomotic leakage: A consensus survey among Dutch and Chinese colorectal surgeons

AIM

To determine the level of consensus on the definition of colorectal anastomotic leakage (CAL) among Dutch and Chinese colorectal surgeons.

METHODS

Dutch and Chinese colorectal surgeons were asked to partake in an online questionnaire. Consensus in the online questionnaire was defined as > 80% agreement between respondents on various statements regarding a general definition of CAL, and regarding clinical and radiological diagnosis of the complication.

RESULTS

Fifty-nine Dutch and 202 Chinese dedicated colorectal surgeons participated in the online survey. Consensus was found on only one of the proposed elements of a general definition of CAL in both countries: ‘extravasation of contrast medium after rectal enema on a CT scan’. Another two were found relevant according to Dutch surgeons: ‘necrosis of the anastomosis found during reoperation’, and ‘a radiological collection treated with percutaneous drainage’. No consensus was found for all other proposed elements that may be included in a general definition.

CONCLUSION

There is no universally accepted definition of CAL in the Netherlands and China. Diagnosis of CAL based on clinical manifestations remains a point of discussion in both countries. Dutch surgeons are more likely to report ‘subclinical’ leaks as CAL, which partly explains the higher reported Dutch CAL rates.

Distribution of colorectal polyps: Implications for screening

BACKGROUND

During the last decades data from different studies reported modifications of the topographic distribution of colorectal cancers (CRCs), with an increased frequency of tumours in proximal colonic segments. Given the documented link between adenomas and CRC, a proximal migration of adenomas over time could be expected as well.

AIM

To evaluate available evidence about the prevalence of adenomas and of sessile serrated polyps across colonic segments, the changing trends in their distribution across the colon and the diagnostic performance of screening tests currently adopted in population based screening programs for lesions located in different colonic segments.

METHODS

Literature search on PubMed, Embase, and Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects with reference to preferred reporting items for systematic reviews and meta-analysis (PRISMA), considering all adult human studies in English, published between January 2000 and February 2017.

RESULTS

Cross-sectional analysis of endoscopy and pathology data-bases are consistently showing a trend toward an increase with age of the proportion of adenomas located in the proximal colon. Several observational studies analysed the site distribution of adenomas, testing the hypothesis of a proximal shift of these lesions, and most of them reported an increase in the proportion of right-sided adenomas over time, although a similar trend was not confirmed by others. Also the quality of the retrieved evidence was low. Both endoscopy and FIT are showing a different level of sensitivity for lesions arising in different colonic segments, depending also on screenees characteristics.

CONCLUSION

Available evidence is supporting the hypothesis of an increase in the proportion of right-sided adenomas with age, while a similar increase has not been reported for SSP/A, at least among subjects aged 50 or older. The trend toward a proximalization of colorectal adenomas over time, reported by some authors, likely results from improved diagnostic performances and/or the process of population ageing.

Clinical and Biological Features of Interval Colorectal Cancer

Interval colorectal cancer (I-CRC) is defined as a CRC diagnosed within 60 months after a negative colonoscopy, taking into account that 5 years is the "mean sojourn time." It is important to prevent the development of interval cancer. The development of interval colon cancer is associated with female sex, old age, family history of CRC, comorbidities, diverticulosis, and the skill of the endoscopist. During carcinogenesis, sessile serrated adenomas/polyps (SSA/Ps) share many genomic and colonic site characteristics with I-CRCs. The clinical and biological features of I-CRC should be elucidated to prevent the development of interval colon cancer.

Early settlers: which E. coli strains do you not want at birth?

The intestinal microbiota exerts vital biological processes throughout the human lifetime, and imbalances in its composition have been implicated in both health and disease status. Upon birth, the neonatal gut moves from a barely sterile to a massively colonized environment. The development of the intestinal microbiota during the first year of life is characterized by rapid and important changes in microbial composition, diversity, and magnitude. The pioneer bacteria colonizing the postnatal intestinal tract profoundly contribute to the establishment of the host-microbe symbiosis, which is essential for health throughout life. Escherichia coli is one of the first colonizers of the gut after birth. E. coli is a versatile population including harmless commensal, probiotic strains as well as frequently deadly pathogens. The prevalence of the specific phylogenetic B2 group, which encompasses both commensal and extra- or intraintestinal pathogenic E. coli strains, is increasing among E. coli strains colonizing infants quickly after birth. Fifty percent of the B2 group strains carry in their genome the pks gene cluster encoding the synthesis of a nonribosomal peptide-polyketide hybrid genotoxin named colibactin. In this review, we summarize both clinical and experimental evidence associating the recently emerging neonatal B2 E. coli population with several pathology and discuss how the expression of colibactin by both normal inhabitants of intestinal microflora and virulent strains may darken the borderline between commensalism and pathogenicity.

Worldwide burden of colorectal cancer: a review

Colorectal cancer is a major public health problem, being the third most commonly diagnosed cancer and the fourth cause of cancer death worldwide. There is wide variation over time among the different geographic areas due to variable exposure to risk factors, introduction and uptake of screening as well as access to appropriate treatment services. Indeed, a large proportion of the disparities may be attributed to socioeconomic status. Although colorectal cancer continues to be a disease of the developed world, incidence rates have been rising in developing countries. Moreover, the global burden is expected to further increase due to the growth and aging of the population and because of the adoption of westernized behaviors and lifestyle. Colorectal cancer screening has been proven to greatly reduce mortality rates that have declined in many longstanding as well as newly economically developed countries. Statistics on colorectal cancer occurrence are essential to develop targeted strategies that could alleviate the burden of the disease. The aim of this paper is to provide a review of incidence, mortality and survival rates for colorectal cancer as well as their geographic variations and temporal trends.

Evaluation of the left-to-right shift of colon tumors in Iran: Is the trend changing?

Background:

Colorectal cancer (CRC) is the second cause of cancer-related deaths worldwide. There have been several studies reporting the proximal tumor shift, especially in Western countries. In the present study, we investigated the clinicopathologic and anatomical distributions of colorectal tumors in Iranian CRC patients.

Materials and Methods:

In this retrospective cohort study, 258 patients with CRC from 2008 to 2013 were evaluated. Comparison of variables was performed using Pearson's chi-square test and Fisher's exact test depending on the nature of the data.

Results:

A total of 258 patients including 124 (48.1%) females and 134 (51.9%) males enrolled in this study. The majority of cancers were detected in the rectosigmoid, i.e., 98 (38%) followed by the left colon, i.e., 84 (32.6%) and the right colon, i.e., 76 (29.5%). In the present study, we observed the significant association between metastases, adjuvant therapy, family history, and history of inflammatory bowel disease (IBD) with tumor, node, and metastasis (TNM) staging (P < 0.001). In univariate analysis, there was a strong association between overall survival (OS) and stage II CRC (P = 0.03). However, the predictive value was lost in multivariate analysis (P = 0.145).

Conclusion:

Unlike the majority of previous studies on Iranian CRC patients, we observed a considerably higher occurrence of right-sided colon cancers (84 versus 76). Although this phenomenon did not reach the statistical significance rate, based on recent studies on Iranian population including the present one, the pattern of anatomical distribution of colorectal tumors has been changed toward the proximal colon. This requires an urgent need to provide other strategies and complementary detecting approaches in order to identify proximal tumors in Iranian CRC patients.

Accuracy of preoperative T and N staging in colon cancer--a national population-based study

AIM

To select patients for neoadjuvant therapy in colon cancer, there is a need to improve pre-therapeutic locoregional staging. There are now data showing that the TN stage can be adequately assessed by preoperative CT in dedicated centres. In Sweden the use of preoperative CT of the abdomen for staging of the primary tumour is increasing. The aim of this study was to determine to what extent the preoperatively reported radiological TN stage correlates with the histopathological TN stage in an entire population.

METHOD

Data were collected on the preoperative cTN stage according to the radiologist and postoperative pTN stage according to the pathologist on all patients operated on for colon cancer in Sweden 2007-2010. The correlation between cTN stage and pTN stage was calculated using kappa statistics.

RESULTS

T stage was compared in 4373 patients with cT and pT stage. The correlation coefficient was 0.44, indicating fair agreement. The cN and pN correlation coefficient was 0.28, indicating a slight correlation. There was no difference in correlation related to age, gender, tumour location, body mass index or emergent vs elective surgery. A slight difference was seen between different geographical regions.

CONCLUSION

Preoperative CT in an unselected population does not result in an accurate cTN staging as previously reported from dedicated centres. To achieve adequate preoperative cTN staging nationally, the education of radiologists and optimization of the radiological method will be necessary.

Recurrence and Five -Year Survival in Colorectal Cancer Patients After Surgery

BACKGROUND

Colorectal cancer (CRC) is a common malignancyworldwide and its outcome is most closely related to the extent of disease at presentation. Early diagnosis of an asymptomatic recurrence increases the likelihood of a complete surgical resection.

OBJECTIVES

The aim of this study was to evaluate the incidence of colorectal cancer recurrence and survival rate within 5 years, after surgery.

PATIENTS AND METHODS

During the 9-year period since 21st Mar, 2004 to 20th Mar, 2013, patients whose primary colorectal cancer were resected in Taleghani hospital, Tehran, Iran were selected in a historical cohort. The necessary data such as demographic, age, gender, family history of CRC, site and size of tumor, stage of tumor, operation details, histological results, treatment method, histopathologic, etc. were collected. Then the recurrence and survival of colorectal cancer within 5 years after operation and their risk factors were evaluated. P value less than 0.05 were considered significant. All analysis was done using SPSS software.

RESULTS

A total of 107 patients underwent resection for colorectal cancer during the study period, with mean age of 53.50 ± 12.68 years (range 24 - 76 years), survival rate of 73.8% (rectum 70.0% and colon 75.9%), and mean survival time of 142.17 ± 21.60 month. The recurrence rate of CRC patients, during five years after surgery was 5.7%. Regional lymph nodes, Distance metastasis and Adjuvant therapy were significant prognosis factors of survival after surgery.

CONCLUSIONS

The rate of recurrence in Iranian patients was low, which could be due to improvement of exactness and expertise of surgeons or better adjuvant therapy. The significant association between survival and adjuvant therapy clarifies this finding. Early diagnosis and primary detection could increase the rate of survival.

Spatial modeling of colonic lesions with geographic information systems

BACKGROUND

Geographic information system (GIS) software has been used in health care systems to display and analyze spatial pattern of diseases and health services.

OBJECTIVES

This study was performed to assess spatial patterns of colon's pathologic lesions based on the pathologic reports and assess whether it is possible to use GIS software in health services.

PATIENTS AND METHODS

Archives of pathology of Namazi and Faghihi hospitals, two main referral centers of south-west of Iran, were obtained and reviewed between January 2009 and September 2011 for biopsy reports of patients who underwent colonoscopy. Abnormal biopsies were categorized into five different subgroups according to the type of pathologic specimens. By GIS, spatial patterns of colon biopsies were plotted in different maps and spatial auto-correlation of colon biopsies was calculated using the Moran's Index.

RESULTS

A total of 4815 biopsies from 2663 different patients were reviewed, 53.8% of which were men. Abnormal biopsies were 2781 of all specimens (57.8%). Neoplastic lesions, inflammatory bowel diseases and polyps were 9.3%, 19.3% and 29.2% of total biopsies, respectively. Pathologic biopsies were more common in the distal colon. Maps of all biopsies and maps of specific pathologies were manifested in GIS.

CONCLUSIONS

Our study showed that left-sided lesions are still more common in the Iranian population. On the other hand, surveying the right side of colon is as important as the distal part, which necessitates total colonoscopy.

The gut microbiota, bacterial metabolites and colorectal cancer

Accumulating evidence suggests that the human intestinal microbiota contributes to the aetiology of colorectal cancer (CRC), not only via the pro-carcinogenic activities of specific pathogens but also via the influence of the wider microbial community, particularly its metabolome. Recent data have shown that the short-chain fatty acids acetate, propionate and butyrate function in the suppression of inflammation and cancer, whereas other microbial metabolites, such as secondary bile acids, promote carcinogenesis. In this Review, we discuss the relationship between diet, microbial metabolism and CRC and argue that the cumulative effects of microbial metabolites should be considered in order to better predict and prevent cancer progression.

Predictive factors of proximal advanced neoplasia in the large bowel

INTRODUCTION

The aim of the study was to evaluate the impact of sex, age, family history and distal findings on the risk of proximal advanced neoplasia (cancer or advanced adenoma) in the large bowel.

MATERIAL AND METHODS

Records for 10 111 asymptomatic participants of the Colonoscopy Screening Program (CSP), recruited from the Warsaw region between 2000 and 2004, were analyzed. A multivariate logistic regression model was used to estimate the impact of sex, age, family history and most advanced distal lesions on the occurrence of proximal advanced neoplasia. To enhance comparability of the study two definitions of the proximal colon were applied - either the splenic flexure (1(st)) or the bend between the descending and sigmoid colon (2(nd) definition) represented the boundary.

RESULTS

One hundred and thirty-three (1(st)) and 167 patients (2(nd) definition) were found to have at least one advanced neoplastic lesion in the proximal part, respectively. Eleven and 14 patients were found to have carcinoma, while in 130 and 163 patients at least one proximal advanced adenoma appeared. Men were at twice as high risk of having advanced neoplasia in the proximal colon than women (OR = 1.94, 95% CI: 1.31-2.87, p = 0.001 or OR = 1.69, 95% CI: 1.20-2.40, p = 0.003, respectively). The presence of distal advanced neoplastic lesions was associated with 3.5 times higher risk of proximal advanced neoplasia (OR = 3.58, 95% CI: 2.00-6.43, p < 0.0001 or OR = 3.41, 95% CI: 1.95-5.96, p < 0.0001), respectively.

CONCLUSIONS

The results may confirm some limitation of flexible sigmoidoscopy in the screening settings in comparison with colonoscopy, at least in men and people with distal advanced neoplasia.

Predictors of CT colonography utilization among asymptomatic medicare beneficiaries

BACKGROUND

Although the Centers for Medicare and Medicaid Services (CMS) denied coverage for screening computed tomography colonography (CTC) in March 2009, little is understood about whether CTC was targeted to the appropriate patient population prior to this decision.

OBJECTIVE

Evaluate patient characteristics and known relative clinical indications for screening CTC among patients who received CTC compared to optical colonoscopy (OC).

DESIGN/PARTICIPANTS

Cross-sectional study of all 10,538 asymptomatic Medicare beneficiaries who underwent CTC between January 2007 and December 2008, compared to a cohort of 160,113 asymptomatic beneficiaries who underwent OC, matched on county of residence and year of examination.

MAIN MEASURES

Patient characteristics and known relative appropriate and inappropriate clinical indications for screening CTC.

KEY RESULTS

CTC utilization was higher among women, patients > 65 years of age, white patients, and those with household income > 75 % (p = 0.001). Patients with relatively appropriate clinical indications for screening CTC were more likely to undergo CTC than OC including presumed incomplete OC (OR 80.7, 95 % CI 76.01-85.63); sedation risk (OR 1.11, 95 % CI 1.05-1.17); and chronic anticoagulation risk (OR 1.46, 95 % CI 1.38-1.54), after adjusting for patient characteristics and known clinical indications. Conversely, patients undergoing high-risk screening, an inappropriate indication, were less likely to receive CTC (OR 0.4, 95 % CI 0.37-0.42). Overall, 83 % of asymptomatic patients referred to CTC had at least one clinical indication relatively appropriate for CTC (8,772/10,538).

CONCLUSION

During the 2 years preceding CMS denial for screening, CTC was targeted to asymptomatic patients with relatively appropriate clinical indications for CTC/not receiving OC. However, CTC utilization was lower among certain demographic groups, including minority patients. These findings raise the possibility that future coverage of screening CTC might exacerbate disparities in colorectal cancer screening while increasing overall screening rates.

Colorectal cancer is reliably excluded in the frail and elderly population by minimal preparation CT

BACKGROUND

This study aimed to retrospectively assess the accuracy of minimal preparation computed tomography (MPCT) in the detection of colorectal cancer (CRC) within the frail and elderly population and to evaluate the relevance of extra-colonic findings (ECF).

METHODS

Radiology reports, clinical notes and follow-up reports from 207 patients who underwent MPCT to investigate for CRC between 2005 and 2009 were analysed. Patients were scanned following the administration of oral contrast for 48 h, without bowel preparation or colonic insufflation. MPCT results were measured against patient outcomes, with a minimum of 2 years of follow-up.

RESULTS

Twelve cases of clinically relevant CRC were confirmed (5.8 %). MPCT correctly identified 11 of these lesions (sensitivity 91.6 %). Thirty-one patients had a possible CRC identified by MPCT, which was not confirmed by further examination (specificity 84.1 %). This results in a positive predictive value of 26.2 % and a negative predictive value of 99.4 %. Five of the patients with colon cancer underwent curative surgery. Sixty-eight clinically relevant ECF were confirmed, including 14 previously undiagnosed extra-colonic malignancies. ECF were considered to account for the presenting complaint in 15.0 % (31/207) of all patients.

CONCLUSIONS

Minimal preparation computed tomography is an effective and reliable investigation for the exclusion of clinically relevant CRC in this population. It provides clinicians with a valuable and pragmatic alternative to colonoscopy and CT colonography when invasive examination or cathartic bowel preparation will be poorly tolerated and small polyps are of limited significance. MPCT has an advantage over purely luminal imaging in the detection of extra-colonic pathology and appears to have an equally important role in the detection of CRC.

Transparent cap colonoscopy versus standard colonoscopy: a systematic review and meta-analysis

Due to the increasing demand for colonoscopy, devices to advance examination techniques are highly sought after. Several studies have examined the use of a transparent cap attached to the tip of the colonoscope, but the data are inconsistent. The aim of our study was to establish whether transparent cap colonoscopy is beneficial in the improvement of caecal intubation rate, time and polyp detection. We undertook a systematic review and meta-analysis in the form of a Cochrane review to evaluate these outcomes. We included fourteen randomised controlled trials that have been published to date. Transparent cap colonoscopy demonstrates a significant reduction in caecal intubation time, by an average of 48 s, when compared to standard colonoscopy. There was no significant difference in caecal intubation rate or polyp detection between the two groups. Despite a significant difference in caecal intubation time, the clinical significance of the transparent cap remains to be seen. We believe further research is needed to investigate this adjunct.

Is proliferative colonic disease presentation changing?

AIM: To compare the site, age and gender of cases of colorectal cancer (CRC) and polyps in a single referral center in Rome, Italy, during two periods.

METHODS: CRC data were collected from surgery/pathology registers, and polyp data from colonoscopy reports. Patients who met the criteria for familial adenomatous polyposis, hereditary non-polyposis colorectal cancer syndrome or inflammatory bowel disease were excluded from the study. Overlap of patients between the two groups (cancers and polyps) was carefully avoided. The χ² statistical test and a regression analysis were performed.

RESULTS: Data from a total of 768 patients (352 and 416 patients, respectively, in periods A and B) who underwent surgery for cancer were collected. During the same time periods, a total of 1693 polyps were analyzed from 978 patients with complete colonoscopies (428 polyps from 273 patients during period A and 1265 polyps from 705 patients during period B). A proximal shift in cancer occurred during the latter years for both sexes, but particularly in males. Proximal cancer increased > 3-fold in period B compared to period A in males [odds ratio (OR) 3.31, 95%CI: 2.00-5.47; P < 0.0001). A similar proximal shift was observed for polyps, particularly in males (OR 1.87, 95%CI: 1.23-2.87; P < 0.0038), but also in females (OR 1.62, 95%CI: 0.96-2.73; P < 0.07).

CONCLUSION: The prevalence of proximal proliferative colonic lesions seems to have increased over the last decade, particularly in males.

Examining the association between socioeconomic status and invasive colorectal cancer incidence and mortality in California

BACKGROUND

Colorectal cancer (CRC) incidence and mortality rates vary across race/ethnicity. Socioeconomic status (SES) also influences CRC rates; however, these associations might be inconsistent across racial/ethnic groups and tumor subsite. We examined associations between area-level SES and CRC incidence and mortality in a population-based registry study of non-Hispanic Whites, African Americans, Hispanics, and Asians/Pacific Islanders from California.

METHODS

Data on 52,608 incident CRC cases (1998-2002) and 14,515 CRC deaths (1999-2001) aged ≥50 years were obtained from the California Cancer Registry. Based on 2000 U.S. Census data, each cancer case and death was assigned a multidimensional census tract-level SES index. SES-specific quintiles of CRC incidence and mortality rates, incidence rate ratios (IRR) and mortality rate ratios, and 95% confidence intervals (CI) were estimated. Analyses were stratified by anatomical site, including left- versus right-sided tumors, race/ethnicity, and stage of disease.

RESULTS

Overall CRC incidence and SES did not show a clear association, yet patterns of associations varied across tumor subsite and race/ethnicity. Positive associations between SES and CRC incidence were found in Hispanics [SES Q5 v. Q1: IRR = 1.54, CI = 1.39-1.69], irrespective of the subsite. For Whites [SES Q5 v. Q1: IRR = 0.80, CI = 0.77-0.83], and African Americans [SES Q5 v. Q1: IRR = 0.83, CI = 0.70-0.97] inverse associations were observed, predominantly for left-sided tumors. Mortality rates declined with increasing SES in Whites, whereas in Hispanics mortality rates significantly increased with SES.

CONCLUSIONS

Our findings show that SES differences in CRC incidence and mortality vary considerably across anatomical subsite and race/ethnicity.

IMPACT

Studies combining area- and individual-level SES information are warranted.

Korean guidelines for postpolypectomy colonoscopy surveillance

Postpolypectomy surveillance has become a major indication for colonoscopy as a result of increased use of screening colonoscopy in Korea. In this report, a careful analytic approach was used to address all available evidences to delineate the predictors for advanced neoplasia at surveillance colonoscopy and we elucidated the high risk findings of the index colonoscopy as follows: 3 or more adenomas, any adenoma larger than 10 mm, any tubulovillous or villous adenoma, any adenoma with high-grade dysplasia, and any serrated polyps larger than 10 mm. Surveillance colonoscopy should be performed five years after the index colonoscopy for those without any high-risk findings and three years after the index colonoscopy for those with one or more high risk findings. However, the surveillance interval can be shortened considering the quality of the index colonoscopy, the completeness of polypectomy, the patient's general condition, and family and medical history.

Subsite-specific colorectal cancer risk in the colorectal endoscopy era

BACKGROUND

Colorectal endoscopy (sigmoidoscopy and colonoscopy) is thought to reduce colorectal cancer (CRC) risk. Since the 1980s, its use has increased in the United States, which may be a reason for decreasing CRC incidence rates.

OBJECTIVE

To investigate the plausibility of a contribution of colorectal endoscopy use to the decrease in CRC risk.

DESIGN

Descriptive analysis of temporal trends.

SETTING

U.S. population from 1978 to 2007.

MAIN OUTCOME MEASUREMENTS

Using incidence data from the Surveillance, Epidemiology and End Results Program, we assessed the subsite-specific cumulative risk of CRC developing until age 79 years.

RESULTS

The cumulative risk of proximal CRC remained relatively stable over the observation period, varying between 2.09% (95% CI, 2.06%-2.11%) and 2.66% (95% CI,2.62%-2.69%) for men and between 1.90% (95% CI, 1.88%-1.93%) and 2.24% (95% CI, 2.21%-2.27%) for women. By contrast, the cumulative risk of distal CRC decreased from 4.68% (95% CI, 4.64%-4.73%) to 3.03% (95% CI, 3.00%-3.06%) for men and from 3.15% (95% CI, 3.11%-3.18%) to 1.93% (95% CI, 1.91%-1.95%) for women, which was largely attributable to the reduced cumulative risk of cancer in the sigmoid colon. The observed pattern was restricted to the population aged 50 to 79 years, whereas the magnitude of the decrease was greater for older age groups and similar across stages.

LIMITATIONS

The study is based on aggregated registry data only; therefore, no inferences about causal effects can be drawn.

CONCLUSIONS

The results show a major reduction of CRC risk, particularly in the sigmoid colon. Increased use of colorectal endoscopy in the population aged 50 years and older along with environmental factors may have contributed to the decreasing risk.

Temporal trends in geographic disparities in small-area-level colorectal cancer incidence and mortality in the United States

OBJECTIVE

We examined the extent of changes in absolute and relative geographic disparities in six colorectal cancer (CRC) indicators using data about persons aged 50 and older from 195 counties in the 1988-2006 Surveillance, Epidemiology, and End Results Program database.

METHODS

County-level trends in six colorectal cancer indicators (overall CRC incidence, descending colon cancer incidence, proximal colon cancer incidence, late-stage CRC incidence, CRC mortality, and 5-year probability of CRC death) were summarized using the estimated annual percentage change. Observed county rates were smoothed using Bayesian hierarchical spatiotemporal methods to calculate measures of absolute and relative geographic disparity and their changes over time.

RESULTS

During the study period, absolute disparity for all six indicators decreased (CRC incidence: 43.2%; proximal colon cancer: 31.9%; descending colon cancer: 52.8%; late-stage CRC: 50.0%; CRC mortality: 57.8%; 5-year CRC-specific probability of death: 12.2%). Relative disparity remained stable for all six indicators over the entire study period.

CONCLUSION

Important progress has been made toward achieving the Healthy People 2010 and NCI strategic objectives for reducing geographic disparities, although absolute and relative disparities remain in CRC.

Proportion of flat- and depressed-type and laterally spreading tumor among advanced colorectal neoplasia

BACKGROUND & AIMS

Flat- and depressed-type neoplasias along with laterally spreading tumors (LSTs) have been reported in colorectal neoplasias. We estimated the prevalence of flat and depressed types and LSTs along with their proportion among advanced neoplasias in a large average-risk population undergoing screening colonoscopy.

METHODS

This was a cross-sectional study performed at a single, general community institution, with subjects who were 40 to 79 years old, asymptomatic, and who had undergone their first colonoscopy for screening between 2003 and 2009 (n = 4910). Among the neoplasias detected, advanced neoplasias were morphologically classified as the polypoid type, flat and depressed type, or LST. We determined the prevalence and proportion for each type among the advanced neoplasias, with morphologies defined according to the Japanese endoscopic classification.

RESULTS

Advanced neoplasias were detected in 7.9% of men, 4.7% of women, and 6.1% of overall subjects. The polypoid type, the flat and depressed types, and the LSTs accounted for 75.3%, 7.5%, and 17.2% of advanced neoplasia, respectively. There was a high proportion of T1 cancers among the depressed types (40%). Approximately 80% of LSTs were located on the right side of the colon and more than 30% of LSTs showed high-grade dysplasia or T1 cancer.

CONCLUSIONS

Most advanced neoplasias detected were of the polypoid type. LSTs accounted for a considerable proportion among advanced neoplasia and tended to be located on the right side of the colon. The influences of any LSTs need to be taken into consideration for preventing colorectal cancer.

Changing trends in polypoid colorectal cancer diagnosed by colonoscopy

AIM

This study analysed trends in polypoid colorectal cancer (PCRC) diagnosed by colonoscopy during the period 1995-2008 and compared the patterns observed in the years 2005-2008 with 1995-1998.

METHOD

In the period 1995-2008, 24,245 colonoscopies were performed and 1041 patients with PCRC were diagnosed: pediculated (n = 220) or sessile (n = 821).

RESULTS

The mean age at diagnosis was 68.3 ± 11.6 years. Males were more likely to have PCRC (males 62.6%vs females 37.4%; P < 0.0001). Significantly more pediculated PCRCs were located in the distal colon (P < 0.001). In the 2005-2008 period the prevalence of PCRC among patients undergoing colonoscopy decreased, the number of polypectomies increased significantly (P < 0.0001) and the pediculated PCRC location changed, with a significant increase in right-sided lesions.

CONCLUSION

The prevalence of PCRC in patients undergoing colonoscopy decreased, with a significant increase in the number of polypectomies in the last decade. Pediculated PCRCs were more often located in the left colon and sessile PCRCs in the right colon. From the period 1995-1998 to 2005-2008 the location of pediculated PCRCs changed, with an increase in right-sided lesions.

The clinical significance of serrated polyps

Colorectal cancer (CRC) is a heterogeneous disorder than arises via multiple distinct pathways, such as the serrated pathway, in which serrated polyps (including variants of hyperplastic polyps) are the precursor lesions. Approximately 15-20% of all CRCs arise via the serrated pathway, and these serrated carcinomas are clinically, morphologically, and molecularly distinct from conventional CRCs. The prevention of serrated carcinomas represents an important clinical challenge. Gastroenterologists need to recognize and remove potential precursor lesions and implement a post-polypectomy surveillance program when appropriate. This article focuses on the characteristics and significance of clinically relevant serrated polyps and addresses implications for CRC prevention practices.

Proximal tumors are associated with greater mortality in colon cancer

BACKGROUND

Colon cancer is the third leading cause of death from cancer in the United States. Recent studies report on increasing proportions of proximal cancers. The etiology behind this epidemiological trend is unclear, and its implication on survival outcomes is unknown. Further analysis of the impact of anatomic site of disease among a large multiethnic population will help facilitate research and education to improve colon cancer screening and treatment.

OBJECTIVE

To investigate the association between proximal tumor location and survival in patients with colon cancer.

DESIGN AND PARTICIPANTS

A large retrospective cohort study in the US utilizing the Surveillance, Epidemiology, and End Results (SEER) cancer registry analyzed survival outcomes of patients with colon cancer. Multivariable logistic regression analyses investigated sex-specific, race/ethnicity-specific, and anatomic site-specific disparities in survival.

MAIN MEASURES

Five-year survival outcomes from colon cancer.

RESULTS

Our study demonstrated significant disparities in survival by sex, race/ethnicity, and anatomic site. Across all time periods and among most cohorts, patients with proximal cancers had significantly worse survival outcomes. When compared to distal cancers, patients with proximal cancers were 13% less likely to survive 5 years (OR 0.87; 95% CI, 0.82-0.91). When compared to non-Hispanic whites, blacks were 30% less likely to survive 5 years (OR 0.70; 95% CI, 0.68-0.73). Stage-specific multivariable regression analysis of localized cancers demonstrated similar findings.

CONCLUSIONS

Significant race-specific, sex-specific, and anatomic site-specific disparities in colon cancer survival exist. Proximal cancers are associated with worse survival odds. These disparities may reflect differences in the genotype and phenotype of colon cancer among these groups. A modified risk assessment tool that incorporates these variations may be more effective in the early detection and treatment of colon cancer.

Maximizing the value of the endoscopist-pathologist partnership in the management of colorectal polyps and carcinoma

Good communication between clinician and pathologist is essential for optimal patient care and management of colorectal polyps and carcinoma. General principles of communication include making sure that the pathologist and endoscopist have all the information needed to make an accurate diagnosis and that the pathologist communicates the diagnosis back to the endoscopist in a clear and timely fashion. The increasing complexity of classification of colorectal polyps and carcinomas has added to the need for clear communication pathways. The first part of this article is devoted to an outline of general communication issues; the second is a discussion of current concepts in colorectal polyps and carcinomas.

Distribution trends of colorectal adenoma and cancer: a colonoscopy database analysis of 11,025 Chinese patients

BACKGROUND AND AIM

A left-to-right shift of colorectal cancer (CRC) has been reported in Western studies. However, few Asian studies have investigated the anatomic distribution of colorectal adenoma and CRC. We aimed to describe the time trends in the distribution of colorectal adenoma and CRC in a Chinese population.

METHODS

A colonoscopy database was reviewed, and all consecutive patients with lower gastrointestinal symptoms who underwent colonoscopy from 1998 to 2009 were identified. Data, including patients' sex, age, symptoms, and the number and anatomic locations of colorectal adenoma and CRC, were documented.

RESULTS

A total of 11,025 patients were included in the final analysis; 1012 and 363 patients were diagnosed with colorectal adenoma and CRC, respectively. Overall, there were more distal than proximal adenomas (54.4% vs 37.9%), and the proportion of proximal adenomas remained stable from 1998-2006 to 2007-2009 (38.2% vs 37.6%). Similarly, there were more distal than proximal CRC (56.5% vs 42.4%), and the proportion of proximal CRC declined from 45.8% in 1998-2006 to 38.4% in 2007-2009. Colorectal adenoma and CRC were equally distributed among both sexes. For elderly patients (> 50 years), there was a non-significant trend towards more proximal adenoma and CRC.

CONCLUSIONS

The present study suggests no distal-to-proximal shift of colorectal adenoma and CRC among the Chinese population in Shanghai over the past 12 years. The distribution pattern of colorectal adenoma and CRC of Chinese patients is different from that of Western patients, who had more colorectal lesions located in the distal part.

Marked variations in proximal colon cancer survival by race/ethnicity within the United States

GOALS

To investigate the race/ethnicity and sex-specific variations in proximal colon cancer survival within the United States.

BACKGROUND

Recent studies suggest a shift toward more proximal distributions of colon cancers. Survival benefits from screening colonoscopy may be limited to left-sided cancers. Identifying groups at greatest risk for mortality from proximal cancers will help to target health care resources to address these disparities.

STUDY

A retrospective cohort study from 1973 to 2004 using a large population-based cancer registry to investigate demographic variations in colon cancer survival.

RESULTS

Marked sex and race/ethnicity-specific variations in proximal colon cancer survival were observed. Overall 5-year survival was greatest in females (5-y survival, females: 44.5% and males: 41.7%, P<0.001) and in Asians (5-y survival, Asians: 50.4%, non-Hispanic whites: 43.1%, blacks: 39.7%, and Hispanics: 46.7%, P<0.001). Compared with females, males had significantly worse 5-year survival outcomes [odds ratios (OR), 0.77; 95% confidence intervals (CI), 0.75-0.79]. Compared with non-Hispanic whites, blacks had worse 5-year survival odds (OR, 0.74; 95% CI, 0.70-0.78) and Asians had better survival outcomes (OR, 1.16; 95% CI, 1.08-1.24).

CONCLUSIONS

There exists significant sex and race/ethnicity-specific disparities in 5-year survival from proximal colon cancer. These differences may be explained by variations in delivery of health care between demographic groups or differences in disease biology specific to each group.

The reduction in colorectal cancer mortality after colonoscopy varies by site of the cancer

BACKGROUND & AIMS

There are limited data on mortality from colorectal cancer (CRC) among patients who have received colonoscopy examinations. We sought to determine CRC mortality among persons undergoing colonoscopies compared with the general population.

METHODS

We identified all individuals who had a colonoscopy as their first lower gastrointestinal endoscopy from April 1, 1987, to September 30, 2007 (24,342 men and 30,461 women), based on information from Manitoba's provincial physicians' billing claims database. Patients were followed until March 31, 2008, death, or migration out of the province (310,718 person-years). Individuals less than 50 years of age or more than 80 years of age at the index colonoscopy or those with prior sigmoidoscopy, inflammatory bowel disease, resective colorectal surgery, or CRC were excluded. CRC mortality after the index colonoscopy was compared with that of the general population by standardized mortality ratios (SMRs). Stratified analyses were performed to determine CRC mortality for different age groups at index colonoscopy and sex, duration of follow-up, medical specialty of the endoscopist, and site of CRC.

RESULTS

There was a 29% reduction in overall CRC mortality (SMR, 0.71; 95% confidence interval [CI], 0.61-0.82], a 47% reduction in mortality from distal CRC (SMR, 0.53; 95% CI, 0.42-0.67), and no reduction in mortality from proximal CRC (SMR, 0.94; 95% CI, 0.77-1.17). The reduction in mortality from distal CRC remained significant for follow-up beyond 10 years (SMR, 0.53; 95% CI, 0.31-0.84).

CONCLUSIONS

In Manitoba, colonoscopies significantly reduce mortality from CRC, but the benefit is not uniform for colorectal tumors that arise in different areas of the colon.