Subsite-specific colorectal cancer risk in the colorectal endoscopy era

Risk of recurrence in high-risk T1 colon cancer following endoscopic and surgical resection: registry-based cohort study

BACKGROUND

Endoscopic resection of T1 colon cancer (CC) is currently limited by guidelines related to risk of lymph node metastases. However, clinical outcome following endoscopic and surgical resection is poorly investigated.

METHOD

A retrospective multicentre national cohort study was conducted on prospectively collected data from the Swedish colorectal cancer registry on all non-pedunculated T1 CC patients undergoing surgical and endoscopic resection between 2009 and 2021. Patients were categorized on the basis of deep submucosal invasion (Sm2-3), lymphovascular invasion (LVI), poor tumour differentiation, and R1/Rx into low- and high-risk cases. The primary outcomes of interest were recurrence rates and disease-free interval (DFI, defined as time from treatment to date of recurrence) according to resection methods and risk factors (sex, age at diagnosis, histologic grade, LVI, perineural invasion, mucinous subtype, submucosal invasion, tumour location, resection margin and nodal positivity in the surgical group).

RESULTS

In total, 1805 patients undergoing endoscopic (488) and surgical (1317) resection with 60.0 months median follow-up were included. Recurrence occurred in 18 (3.7%) endoscopically and 48 (3.6%) surgically resected patients. Adjuvant treatment was administered in 7.4% and 0.2% of the cases respectively in the surgical and endoscopically treated patients. Five-year DFI was 95.6% after endoscopic and 96.2% after surgical resection, with no significant difference when adjusting for confounding factors (HR 1.03, 95% c.i. 0.56 to 1.91, P = 0.920). There were no statistically significant differences in recurrence comparing endoscopic (1.7%) versus surgical (3.6%) low-risk and endoscopic (5.4%) versus surgical (3.8%) high-risk cases. LVI was the only significant risk factor for recurrence in multivariate Cox regression (HR 3.73, 95% c.i. 1.76 to 7.92, P < 0.001).

CONCLUSIONS

This study shows no difference in recurrence after endoscopic and surgical resection in high-risk T1 CC. Although it was not possible to match groups according to treatment, the multivariate analysis showed that lymphovascular invasion was the only independent risk factor for recurrence.

Investigation of vertical margin involvement in endoscopic resection for T1 colorectal cancer

OBJECTIVES

The resection of vertical margin-negative submucosally invasive colorectal cancer (CRC) relies on the pathological risk assessment of lymph node metastasis. However, no large-scale study has clarified the endoscopic resection (ER) outcome for submucosally invasive CRC, focusing on the vertical margin status. This retrospective study aimed to examine vertical margin involvement in ER for submucosally invasive CRC and explore the treatment consequences associated with vertical margin status.

METHODS

We analyzed 395 submucosally invasive CRC cases in 389 patients who underwent ER at our hospital between 2008 and 2020. The presence of residual tumors and simultaneous lymph node metastasis in patients who underwent additional surgery was assessed and compared between the vertical incomplete ER and the vertical margin-negative groups.

RESULTS

Among the patients, 270 were men, with a median age of 69 years. The vertical incomplete ER rate was 21.5%, with positive vertical margins and unclear vertical margins identified in 12.2% and 9.3% of the cases, respectively. Among 154 patients who underwent additional surgery after ER, the vertical incomplete ER group had a significantly higher residual tumor rate than the vertical margin-negative group (P = 0.001). The vertical incomplete ER group had a significantly higher lymph node metastasis rate than the vertical margin-negative group (P = 0.029).

CONCLUSION

This study clarified the substantial risk of vertical incomplete ER in submucosally invasive CRC and revealed the high risk of residual tumor and lymph node metastasis in vertical incomplete ER for submucosal CRC.

Statistical methods for measuring trends in colorectal cancer incidence in registries: A systematic review

Background

Monitoring cancer trends in a population is essential for tracking the disease’s burden, allocating resources, and informing public health policies. This review describes variations in commonly employed methods to estimate colorectal cancer (CRC) incidence trends.

Methods

We performed a systematic literature search in four databases to identify population-based studies reporting CRC incidence trends, published between January 2010 and May 2020. We extracted and described data on methods to estimate trends and assess model validity, and the software used.

Results

This review included 145 articles based on studies conducted in five continents. The majority (93%) presented visual summaries of trends combined with absolute, relative, or annual change estimates. Fourteen (10%) articles exclusively calculated the relative change in incidence over a given time interval, presented as the percentage of change in rates. Joinpoint regression analysis was the most commonly used method for assessing incidence trends (n= 65, 45%), providing estimates of the annual percentage change (APC) in rates. Nineteen (13%) studies performed Poisson regression and 18 (12%) linear regression analysis. Age-period-cohort modeling- a type of generalized linear models- was conducted in 18 (12%) studies. Thirty-nine (37%) of the studies modeling incidence trends (n=104, 72%) indicated the method used to evaluate model fitness. The joinpoint program (52%) was the statistical software most commonly used.

Conclusion

This review identified variation in the calculation of CRC incidence trends and inadequate reporting of model fit statistics. Our findings highlight the need for increasing clarity and transparency in reporting methods to facilitate interpretation, reproduction, and comparison with findings from previous studies.

A systematic review of methods to estimate colorectal cancer incidence using population-based cancer registries

Background

Epidemiological studies of incidence play an essential role in quantifying disease burden, resource planning, and informing public health policies. A variety of measures for estimating cancer incidence have been used. Appropriate reporting of incidence calculations is essential to enable clear interpretation. This review uses colorectal cancer (CRC) as an exemplar to summarize and describe variation in commonly employed incidence measures and evaluate the quality of reporting incidence methods.

Methods

We searched four databases for CRC incidence studies published between January 2010 and May 2020. Two independent reviewers screened all titles and abstracts. Eligible studies were population-based cancer registry studies evaluating CRC incidence. We extracted data on study characteristics and author-defined criteria for assessing the quality of reporting incidence. We used descriptive statistics to summarize the information.

Results

This review retrieved 165 relevant articles. The age-standardized incidence rate (ASR) (80%) was the most commonly reported incidence measure, and the 2000 U.S. standard population the most commonly used reference population (39%). Slightly more than half (54%) of the studies reported CRC incidence stratified by anatomical site. The quality of reporting incidence methods was suboptimal. Of all included studies: 45 (27%) failed to report the classification system used to define CRC; 63 (38%) did not report CRC codes; and only 20 (12%) documented excluding certain CRC cases from the numerator. Concerning the denominator estimation: 61% of studies failed to state the source of population data; 24 (15%) indicated census years; 10 (6%) reported the method used to estimate yearly population counts; and only 5 (3%) explicitly explained the population size estimation procedure to calculate the overall average incidence rate. Thirty-three (20%) studies reported the confidence interval for incidence, and only 7 (4%) documented methods for dealing with missing data.

Conclusion

This review identified variations in incidence calculation and inadequate reporting of methods. We outlined recommendations to optimize incidence estimation and reporting practices. There is a need to establish clear guidelines for incidence reporting to facilitate assessment of the validity and interpretation of reported incidence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01632-7.

Myosin light chain 9 promotes the proliferation, invasion, migration and angiogenesis of colorectal cancer cells by binding to Yes-associated protein 1 and regulating Hippo signaling

Colorectal cancer is a common type of cancer with high incidence and poor prognosis. Increased expression of myosin light chain 9 (MYL9) has been reported in early-stage and recurrent colorectal cancer tissues. This study aimed to investigate the precise role of MYL9 on the progression of colorectal cancer. MYL9 expression in several colorectal cancer cell lines was detected by Western blotting and RT-qPCR. Following MYL9 overexpression or knockdown, MYL9 expression was determined via RT-qPCR. Cell proliferation was detected with Cell Counting Kit-8 assay. Cell invasion, migration and angiogenesis were, respectively, examined with transwell, wound healing and tube formation assays. The binding between MYL9 and Yes-associated protein 1 (YAP1) was verified by a co-immunoprecipitation assay. The expression of YAP1, connective tissue growth factor and cysteine-rich angiogenic inducer 61 was examined by Western blotting. Subsequently, YAP1 silencing or Hippo antagonist was performed to clarify the regulatory mechanisms of MYL9 in colorectal cancer progression. Experimental results showed that MYL9 expression was elevated in colorectal cancer cell lines. MYL9 overexpression promoted cell proliferation, invasion, migration and angiogenesis, while silencing of MYL9 exerted the opposite effects. Results of co-immunoprecipitation assay indicated that MYL9 could bind to YAP1. Further experiments revealed that MYL9 affected the expression of YAP1 and its downstream signaling proteins. Afterward, YAP1 knockdown or the addition of Hippo antagonist inhibited the proliferation, invasion, migration and angiogenesis of colorectal cancer cells. Overall, MYL9 promotes the proliferation, invasion, migration and angiogenesis of colorectal cancer cells by binding to YAP1 and thereby activating Hippo signaling.

Improvements in the Effectiveness of Early Detection in Colorectal Cancer with Open-Label Randomised Study

Introduction: The general objective of this research is to improve the quality of colorectal cancer screening (CRC) by assessing, as an indicator of effectiveness, the ability of colonoscopy to detect more advanced adenomas in the exposed group than in the control group. Material and Methods: The present work is designed as an open-label randomized study on cancer screening, using two groups based on their exposure to the protocol: an exposed to intervention group (EIG, 167), and a control group (CG, 167), without the intervention of the protocol and by 1:1 matching. Results: In 167 patients in the GEI, 449 polyps are visualized and 274 are adenomas (80.58%), of which 100 (36.49%) are advanced adenomas. In the CG (n = 174), there are 321 polyps and 152 adenomas (82.60%). The variables significantly associated by logistic regression to the detection of adenomas are the male sex with an OR of 2.52. The variable time to withdrawal, ≥9 min, is significant at 99% confidence (p = 0.002/OR 34.67) and the fractional dose is significant at 99% (p = 0.009, OR 7.81). Conclusion: Based on the observations made, our study suggests that the intervention in collaboration between primary care and hospital care is effective from a preventive point of view and achieves the objective of effectiveness and quality of the PCCR.

The Roles of Transmembrane Mucins Located on Chromosome 7q22.1 in Colorectal Cancer

Colorectal cancer (CRC) is one of the most common types of cancers. It is associated with a poor prognosis and high mortality. The role of mucins (MUCs) in colon tumorigenesis is unclear, but it might be significant in the progression of malignancy. Some mucins, such as MUC1 and MUC13, act as oncogenes, whereas others, such as MUC2 and MUC6, are tumor suppressors. However, there are still mucins with unidentified roles in CRC. In this review, we discuss the reported roles of mucins in CRC. Moreover, we review the capability of the mucin family to serve as a sensitive and specific histopathological marker for the early diagnosis of CRC. Lastly, the role of mucin genes clustered on chromosome 7q22 in CRC and other cancers is also discussed.

Variants of SMAD1 gene increase the risk of colorectal cancer in the Bangladeshi population

Colorectal cancer is the fourth most common type of malignancy worldwide that may develop due to the accumulation of several genetic variations. Different single nucleotide polymorphisms of SMAD1 gene are assumed to be linked with increased colorectal cancer risk. The current case-control study was conducted to verify the association of genetic polymorphisms of SMAD1 (rs11100883 and rs7661162) with colorectal cancer in the Bangladeshi population. This study was performed on 275 colorectal cancer patients and 300 healthy volunteers using polymerase chain reaction-restriction fragment length polymorphism method. The odds ratios were adjusted for age and sex with logistic regression analysis. In case of SMAD1 rs11100883 polymorphism, GA heterozygous genotype, GA + AA (dominant model), and minor allele "A" were significantly associated with colorectal cancer (adjusted odds ratio = 1.55, 95% confidence interval = 1.09-2.20, p = 0.014; adjusted odds ratio = 1.59, 95% confidence interval = 1.13-2.23, p = 0.008; and odds ratio = 1.35, 95% confidence interval = 1.06-1.73, p = 0.015, respectively) and the significance exists after the Bonferroni correction. Again, single nucleotide polymorphism rs7661162 showed significant association with an elevated colorectal cancer risk for AG heterozygous genotype, AG + GG (dominant model), AG versus AA + GG (overdominant model), and minor allele "G" (adjusted odds ratio = 1.78, 95% confidence interval = 1.24-2.56, p = 0.002; adjusted odds ratio = 1.68, 95% confidence interval = 1.18-2.39, p = 0.004; adjusted odds ratio = 1.76, 95% confidence interval = 1.23-2.53, p = 0.002; and odds ratio = 1.47, 95% confidence interval = 1.08-2.00, p = 0.014, respectively) and significance withstands after the Bonferroni correction. No significant age and gender differences between cases and controls were observed. In silico, gene expression analysis showed that the SMAD1 mRNA level was downregulated in the colon and rectal cancer tissues compared to healthy tissues. In conclusion, our findings indicate that SMAD1 rs11100883 and rs7661162 polymorphisms are responsible for increasing the susceptibility of colorectal cancer development in the Bangladeshi population.

Diagnostic application of water exchange colonoscopy: A meta-analysis of randomized controlled trials

Background

Few well-designed studies have investigated water exchange colonoscopy (WE). We performed a meta-analysis to comprehensively evaluate the clinical utility of WE based on high-quality randomized controlled trials (RCTs) and to compare the impacts of WE, water immersion colonoscopy (WI), and gas-insufflation colonoscopy.

Methods

We searched the Cochrane Library, MEDLINE, Embase, PubMed, Elsevier, CNKI, VIP, and Wan Fang Data for RCTs on WE. We analyzed the results using fixed- or random-effect models according to the presence of heterogeneity. Publication bias was assessed by funnel plots.

Results

Thirteen studies were eligible for this meta-analysis. The colonoscopic techniques included WE as the study group, and WI and air- or CO₂-insufflation colonoscopy as control groups. WE was significantly superior to the control procedures in terms of adenoma detection rate, proportion of painless unsedated colonoscopy procedures, and cecal intubation rate according to odds ratios. WE was also significantly better in terms of maximal pain score and patient satisfaction score according to mean difference.

Conclusions

WE can remarkably improve the adenoma detection rate, proportion of painless unsedated colonoscopy procedures, patient satisfaction, and cecal intubation rate, as well as reducing the maximal pain score in patients undergoing colonoscopy.

The Influence of Screening on Outcomes of Clinically Locally Advanced Rectal Cancer

BACKGROUND

Screening for colorectal cancer has resulted in declining incidence rates of both colon and rectal cancer and it may influence stage at presentation and improve survival. The aim of this study was to assess the impact of screening on patients diagnosed with locally advanced rectal cancer.

METHODS

A retrospective analysis of a consecutive series of patients who underwent neoadjuvant therapy and had an R0-resection for clinical AJCC stage II or stage III disease. All patients received surgery at a single center between 2004 and 2015. Patients diagnosed through screening were compared to patients diagnosed through symptomatic presentation.

RESULTS

Three hundred nine patients were included, of whom 43 (13.9%) were diagnosed through screening. Screened patients had more often a white ethnicity, while there were no other differences in baseline characteristics or median household income. Screened patients had a lower rate of disease recurrence in addition to a longer disease free survival and overall survival.

CONCLUSIONS

Patients with locally advanced rectal cancer diagnosed through screening demonstrated more favorable short and long-term outcomes than patients diagnosed through symptoms. Findings of this study reinforce the need for screening programs in addition to the need for research regarding optimization of screening adherence.

Disparities in Colon Cancer Survival by Insurance Type: A Population-Based Analysis

BACKGROUND

Colon cancer is a common cancer with a relatively high survival for nonmetastatic disease if appropriate treatment is given. A lower survival rate for patients with no or inadequate insurance has previously been documented, but the differences have not been explored in detail on a population level.

OBJECTIVE

The purpose of this study was to examine survival for patients with colon cancer by insurance type.

DESIGN

Complete analysis was used to examine 1-, 2-, and 3-year survival rates.

SETTINGS

This was a population-level analysis.

PATIENTS

Patients were drawn from the in-patients diagnosed with colon cancer at ages 15 to 64 years between 2007 and 2012 in the Surveillance, Epidemiology, and End Results 18 database by insurance type (Medicaid, uninsured, or other insurance) MAIN OUTCOME MEASURE:: This study measured overall survival.

RESULTS

A total of 57,790 cases were included, with insurance information available for 55,432. Of those, 7611 (13.7%), 4131 (7.5%), and 43,690 (78.8%) had Medicaid, no insurance, or other insurance. Patients with Medicaid or without insurance were more likely to have metastatic disease compared with those with other insurance. Survival was higher for patients with insurance other than Medicaid, with 3-year survival estimates of 57.0%, 61.2%, and 75.6% for Medicaid, uninsured, and other insurance. Significant disparities continued to be observed after adjustment for stage, especially for later-stage disease. When only patients with stage I to II disease who had definitive surgery and resection of ≥12 lymph nodes were included in the analysis, the discrepancy was decreased, especially for uninsured patients.

LIMITATIONS

Information on chemotherapy use and biological markers of disease severity are not available in the database.

CONCLUSIONS

Colon cancer survival is lower for patients with no insurance or with Medicaid than for those with private insurance. Differences in rates of definitive surgery and adequate lymph node dissection explain some of this disparity. See Video Abstract at http://links.lww.com/DCR/A585.

Quality is the Key for Emerging Issues of Population-Based Colonoscopy Screening

Colonoscopy is currently regarded as the gold standard and preferred method of screening for colorectal cancer (CRC). However, the benefit of colonoscopy screening may be blunted by low participation rates in population-based screening programs. Harmful effects of population-based colonoscopy screening may include complications induced by colonoscopy itself and by sedation, psychosocial distress, potential over-diagnosis, and socioeconomic burden. In addition, harmful effects of colonoscopy may increase with age and comorbidities. As the risk of adverse events in population-based colonoscopy screening may offset the benefit, the adverse events should be managed and monitored. To adopt population-based colonoscopy screening, consensus on the risks and benefits should be developed, focusing on potential harm, patient preference, socioeconomic considerations, and quality improvement of colonoscopy, as well as efficacy for CRC prevention. As suboptimal colonoscopy quality is a major pitfall of population-based screening, adequate training and regulation of screening colonoscopists should be the first step in minimizing variations in quality. Gastroenterologists should promote quality improvement, auditing, and training for colonoscopy in a population-based screening program.

[Quality is the Key for Emerging Issues of Population-based Colonoscopy Screening]

Colonoscopy is currently regarded as the gold standard and preferred method of screening for colorectal cancer (CRC). However, the benefit of colonoscopy screening may be blunted by low participation rate in population-based screening program. Harmful effects of population-based colonoscopy screening may include complications induced by colonoscopy itself and by sedation, psychosocial distress, potential over-diagnosis and socioeconomic burden. In addition, harmful effect of colonoscopy may increase with age and comorbidity. As the adverse event risk in population-based colonoscopy screening may offset benefit of the screening colonoscopy, the adverse events associated with screening colonoscopy should be well managed and monitored. To adopt population-based colonoscopy screening, consensus for the risk and benefits of screening colonoscopy should be formed for its potential harms, patient preference, socioeconomic considerations, quality improvement of colonoscopy as well as its efficacy for CRC prevention. As the suboptimal colonoscopy quality is a major pitfall of population-based colonoscopy screening, adequate training and provider regulation for screening colonoscopists should be the first step to minimize the variation of quality between colonoscopists. Gastroenterologists should lead quality improvement, auditing, and training associated with colonoscopy in a population-based colonoscopy screening program.

Quality is the key for emerging issues of population-based colonoscopy screening

Colonoscopy is currently regarded as the gold standard and preferred method of screening for colorectal cancer (CRC). However, the benefit of colonoscopy screening may be blunted by low participation rates in population-based screening programs. Harmful effects of population-based colonoscopy screening may include complications induced by colonoscopy itself and by sedation, psychosocial distress, potential over-diagnosis, and socioeconomic burden. In addition, harmful effects of colonoscopy may increase with age and comorbidities. As the risk of adverse events in population-based colonoscopy screening may offset the benefit, the adverse events should be managed and monitored. To adopt population-based colonoscopy screening, consensus on the risks and benefits should be developed, focusing on potential harm, patient preference, socioeconomic considerations, and quality improvement of colonoscopy, as well as efficacy for CRC prevention. As suboptimal colonoscopy quality is a major pitfall of population-based screening, adequate training and regulation of screening colonoscopists should be the first step in minimizing variations in quality. Gastroenterologists should promote quality improvement, auditing, and training for colonoscopy in a population-based screening program.

Colonoscopy and sigmoidoscopy use among older adults in different countries: A systematic review

Screening for colorectal cancer (CRC) by colonoscopy and sigmoidoscopy has been demonstrated to be effective in reducing CRC incidence and mortality, and they are increasingly employed as screening tests and for diagnostic purposes in many countries. We conducted a systematic review to provide up-to-date estimates on the utilization of lower gastrointestinal endoscopy (colonoscopy and sigmoidoscopy) in the general average-risk population in different countries. PubMed and Web of Science were searched for relevant articles published between 1 September 2008 and 31 October 2016. A total of 23 studies from the US and 20 studies from other countries were included in this review. Estimates from the US were highest, continued to increase over the past decade and reached 62% for colonoscopy use within 10years in people aged 50-75years in 2012. Endoscopy use in other countries was substantially lower (12-44% for lifetime colonoscopy use and 13-30% for recent colonoscopy use), except for Germany, where 55% of the screening-eligible population reported colonoscopy utilization within the previous 10years in 2008-2011. Both lifetime and recent endoscopy use increased with age and peaked at approximately 70-75years. Although several European and Asian countries have started to collect endoscopy utilization data through periodic national health surveys, more data are still much needed from non-US countries. With the implementation of CRC screening programs in an increasing number of countries, especially European countries, an increase in endoscopy use and subsequent reduction in CRC incidence and mortality in the years to come might be expected in those countries.

Population-Level Differences in Rectal Cancer Survival in Uninsured Patients Are Partially Explained by Differences in Treatment

BACKGROUND

Rectal cancer (RC) is a common malignancy with a substantial mortality but good survival for patients with optimally treated nonmetastatic disease. Lack of insurance may compromise access to care and therefore compromise survival. Here, we examine RC survival by insurance type.

METHODS

Data from the Surveillance, Epidemiology, and End Results database were used to determine 1- to 3-year survival for patients with RC by insurance type (Medicaid, uninsured, other insurance).

RESULTS

Patients with Medicaid or no insurance presented at later stages and were less likely to receive definitive surgery. Overall 3-year survival was higher for patients with other insurance compared with Medicaid-insured (+22.2% units) and uninsured (+18.8% units) patients. Major differences in survival were still observed after adjustment for stage. When patients with stage II and III RC were considered, 3-year survival was higher for patients with other insurance versus those with Medicaid (+16.2% units) and uninsured patients (+12.2% units). However, when the analysis was limited to patients with stage II and III disease who received radiation therapy followed by definitive surgery, the difference decreased to +11.8% units and +7.3% units, respectively, for Medicaid and no insurance.

CONCLUSION

For patients with stage II and III RC, much of the difference in survival between uninsured patients and those with insurance other than Medicaid can be explained by differences in treatment. Further efforts to determine the cause of residual differences as well as efforts to improve access to standard-of-care treatment for uninsured patients may improve population-level survival for RC. The Oncologist 2017;22:351-358 IMPLICATIONS FOR PRACTICE: Insurance status affects survival for patients with rectal cancer, but a substantial proportion of the difference in survival can be corrected if standard-of-care treatment is given. Every effort should be made to ensure that uninsured or publically insured patients receive standard-of-care treatment with as little delay as possible to improve patient outcomes.

Declining Bowel Cancer Incidence and Mortality in Germany

BACKGROUND

In October 2002, screening colonoscopy from age 55 onward was introduced as part of the German national statutory cancer screening program. Screening colonoscopy is intended to lower both the mortality and the incidence of bowel cancer by enabling the detection and removal of precursor lesions.

METHODS

The authors studied trends in bowel cancer incidence and mortality in Germany from 2003 to 2012 on the basis of data from the epidemiological cancer registries and from cause-of-death statistics.

RESULTS

Over the period of investigation, the age-standardized incidence of bowel cancer (with the European population as a standard) fell from 66.1 to 57.0 cases per 100 000 persons per year (-13.8%) in men and from 42.6 to 36.5 per 100 000 persons per year (-14.3%) in women. In parallel with these changes, the age-standardized mortality from bowel cancer fell by 20.8% in men and by 26.5% in women. In the age groups 55-64, 65-74, and 75-84 years, the cumulative risk of receiving a diagnosis of bowel cancer fell by 17-26%; in persons under age 55, this risk fell by only 3% in men, but increased by 14% in women. Long-term data from the cancer registry in the German federal state of Saarland revealed that the incidence of bowel cancer, but not its mortality, had risen over the decades preceding the study; it was only during the period of investigation that the trend reversed itself.

CONCLUSION

Within 10 years of the introduction of screening colonoscopy in Germany, the incidence of bowel cancer in persons over age 55 fell by 17-26%, after having risen steadily over the preceding decades.

Familial colorectal cancer screening: When and what to do?

Colorectal cancer (CRC) is the third leading cause of death worldwide and represents a clinical challenge. Family members of patients affected by CRC have an increased risk of CRC development. In these individuals, screening is strongly recommended and should be started earlier than in the population with average risk, in order to detect neoplastic precursors, such as adenoma, advanced adenoma, and nonpolypoid adenomatous lesions of the colon. Fecal occult blood test (FOBT) is a non invasive, widespread screening method that can reduce CRC-related mortality. Sigmoidoscopy, alone or in addition to FOBT, represents another screening strategy that reduces CRC mortality. Colonoscopy is the best choice for screening high-risk populations, as it allows simultaneous detection and removal of preneoplastic lesions. The choice of test depends on local health policy and varies among countries.

Expected long-term impact of the German screening colonoscopy programme on colorectal cancer prevention: analyses based on 4,407,971 screening colonoscopies

AIM

Endoscopy based screening programmes for colorectal cancer (CRC) are being implemented in an increasing number of countries. In Germany, screening colonoscopy at age 55 or older has been offered since the end of 2002. We aimed to estimate the long-term impact of this offer on CRC prevention.

METHODS

We estimated numbers of prevented CRC cases by expected age and year of their (prevented) occurrence over four decades (2005-2045) by four state Markov models (non-advanced adenoma, advanced adenoma, preclinical CRC, clinically manifest CRC). Estimates are based on screening colonoscopies reported to the German screening colonoscopy registry in 2003-2012 (N=4,407,971), transition rates between the four states and general population mortality rates.

RESULTS

Numbers of prevented clinically manifest CRC cases are projected to increase from <100 in 2005 to approximately 6500 in 2015, 12,600 in 2025, 15,400 in 2035 and 16,000 in 2045, compared to approximately 58,000 incident cases observed in 2003. The annual number of prevented cases is expected to be higher among men than among women and to strongly vary by age. The vast majority of prevented cases would have occurred at age 75 or older.

CONCLUSIONS

Despite modest participation rates, the German screening colonoscopy programme will lead to substantial reductions in the CRC burden. The reductions will be fully disclosed in the long run only and predominantly affect numbers of incident cases above 75years of age. Screening offers would need to start at younger ages in order to achieve more effective CRC prevention at younger ages.

[Factors influencing the miss rate of polyps in a tandem colonoscopy study]

BACKGROUND/AIMS

The miss rate of colon polyps and its related factors have not been clearly identified yet. This study aims to review the miss rate of polyps both on the patient-level and on the polyp-level and to analyze the factors affecting the miss rate such as those related to the endoscopist, procedure, patient, and polyp.

METHODS

From August 2011 to August 2013, patients who underwent elective second colonoscopy for resection of polyps, the sizes of which were not small enough to be resected by biopsy forceps alone at first colonoscopy, were enrolled retrospectively.

RESULTS

The miss rate on the patient-level was 59.2% (234/395) and on the polyp-level was 27.9% (578/2,068). There was no significant difference in the miss rate depending on the experience of the endoscopists or characteristics of the patients. In terms of the procedure, the miss rate was higher when the colonoscopy was performed in the afternoon (OR 1.632, p=0.046). It was found that the miss rate of polyps increased when the polyps were small (OR 4.595, p<0.001 in <5 mm/OR 3.447, p<0.001 in 5-10 mm), flat or sessile (OR 2.406, p<0.001 in flat/OR 1.768, p=0.002 in sessile), and located in the left colon (OR 1.391, p=0.007).

CONCLUSIONS

The experience of endoscopists did not have influence on the accuracy of polyp detection. However, the fatigue of endoscopists in the afternoon is considered to render polyp detection less accurate. Also, the large curves and folds of the sigmoid colon are regarded as a reason for the higher miss rate of polyps in the left colon.

Prevention, early detection, and overdiagnosis of colorectal cancer within 10 years of screening colonoscopy in Germany

BACKGROUND & AIMS

Screening colonoscopy was introduced in Germany in October 2002. We aimed to quantify its effects on prevention, early detection, and overdiagnosis of colorectal cancer (CRC) in the 10 years since its introduction.

METHODS

We analyzed data from more than 4.4 million screening colonoscopies (conducted on individuals 55-79 years old from 2003 through 2012) available through the national screening colonoscopy registry. CRCs prevented, detected earlier than they would have been without screening, and overdiagnosed (cancers detected at screening colonoscopy that would not have become clinically manifest during the patient's lifetime) were estimated by Markov models. Model parameters included sex-specific and age-specific findings at screening colonoscopy; mortality; rates of transition from nonadvanced to advanced adenoma, advanced adenoma to preclinical cancer, or preclinical cancer to clinically manifest cancer; and protection from screening colonoscopy.

RESULTS

Overall, approximately 180,000 CRCs (1/28 screening colonoscopies) were estimated to have been prevented, and more than 40,000 CRCs (1/121 screening colonoscopies) were detected earlier than they would have been without screening, compared with approximately 4500 overdiagnoses (1/1089 screening colonoscopies). Almost all CRCs prevented or detected earlier than they would have been without screening resulted from screening colonoscopies performed on individuals up to 75 years old (97% and 89%, respectively), whereas 28% of overdiagnoses occurred from screening colonoscopies of individuals older than 75 years old.

CONCLUSIONS

On the basis of a 10-year analysis of data from a national registry in Germany, screening colonoscopies have large potential for prevention and early detection of CRC, with low risk of overdiagnosis.

Virtual gastrointestinal colonoscopy in combination with large bowel endoscopy: Clinical application

Although colorectal cancer (CRC) has no longer been the leading cancer killer worldwide for years with the exponential development in computed tomography (CT) or magnetic resonance imaging, and positron emission tomography/CT as well as virtual colonoscopy for early detection, the CRC related mortality is still high. The objective of CRC screening is to reduce the burden of CRC and thereby the morbidity and mortality rates of the disease. It is believed that this goal can be achieved by regularly screening the average-risk population, enabling the detection of cancer at early, curable stages, and polyps before they become cancerous. Large-scale screening with multimodality imaging approaches plays an important role in reaching that goal to detect polyps, Crohn’s disease, ulcerative colitis and CRC in early stage. This article reviews kinds of presentative imaging procedures for various screening options and updates detecting, staging and re-staging of CRC patients for determining the optimal therapeutic method and forecasting the risk of CRC recurrence and the overall prognosis. The combination use of virtual colonoscopy and conventional endoscopy, advantages and limitations of these modalities are also discussed.

A patient-blinded randomized, controlled trial comparing air insufflation, water immersion, and water exchange during minimally sedated colonoscopy

OBJECTIVES

Minimal sedation obviates patient recovery burdens, but intolerable pain limits success of cecal intubation. Painless or minimally uncomfortable insertion ensures success of cecal intubation, current patient satisfaction, and willingness to repeat future colonoscopy with minimal sedation. Water immersion (WI) and water exchange (WE), when separately compared with air insufflation (AI), significantly reduced insertion pain. To assess comparative effectiveness, we conducted a randomized controlled trial with head-to-head comparison of these three methods. We hypothesized that WE could produce the highest proportion of patients reporting painless insertion.

METHODS

This prospective patient-blinded trial (NCT01535326) enrolled minimally sedated (25 mg intramuscular meperidine) patients randomized to AI, WI, or WE (90 patients/group) to aid insertion. The previously validated primary outcome was the proportion of patients reporting painless insertion.

RESULTS

Painless insertion was reported by 30.0% (AI), 43.3% (WI), and 61.1% (WE) of patients (P<0.001). Multivariate logistic regression analysis revealed that, after adjusting for gender, body mass index, abdominal compression, position change, insertion time to cecum, and length of scope at cecum, only WE was significantly associated with painless insertion compared with AI (odds ratio (OR)=0.08, 95% confidence interval (CI)=0.03-0.24, P<0.001) or WI (OR=0.14, 95% CI=0.05-0.40, P<0.001). Adenoma detection rate (ADR) in the right (cecum and ascending) colon was 11.1% (AI), 14.4% (WI), and 26.7% (WE) (P=0.015). The limitations included single site study with unblinded colonoscopist and assistant.

CONCLUSIONS

This head-to-head comparison of AI vs. WI vs. WE confirmed that WE was superior to WI and AI, with a significantly greater proportion of patients reporting painless insertion. The significantly higher ADR in the right colon in the WE group warrants further investigations.

Colorectal cancer

More than 1·2 million patients are diagnosed with colorectal cancer every year, and more than 600,000 die from the disease. Incidence strongly varies globally and is closely linked to elements of a so-called western lifestyle. Incidence is higher in men than women and strongly increases with age; median age at diagnosis is about 70 years in developed countries. Despite strong hereditary components, most cases of colorectal cancer are sporadic and develop slowly over several years through the adenoma-carcinoma sequence. The cornerstones of therapy are surgery, neoadjuvant radiotherapy (for patients with rectal cancer), and adjuvant chemotherapy (for patients with stage III/IV and high-risk stage II colon cancer). 5-year relative survival ranges from greater than 90% in patients with stage I disease to slightly greater than 10% in patients with stage IV disease. Screening has been shown to reduce colorectal cancer incidence and mortality, but organised screening programmes are still to be implemented in most countries.

Effect of screening sigmoidoscopy and screening colonoscopy on colorectal cancer incidence and mortality: systematic review and meta-analysis of randomised controlled trials and observational studies

OBJECTIVES

To review, summarise, and compare the evidence for effectiveness of screening sigmoidoscopy and screening colonoscopy in the prevention of colorectal cancer occurrence and deaths.

DESIGN

Systematic review and meta-analysis of randomised controlled trials and observational studies.

DATA SOURCES

PubMed, Embase, and Web of Science. Two investigators independently extracted characteristics and results of identified studies and performed standardised quality ratings.

ELIGIBILITY CRITERIA

Randomised controlled trials and observational studies in English on the impact of screening sigmoidoscopy and screening colonoscopy on colorectal cancer incidence and mortality in the general population at average risk.

RESULTS

For screening sigmoidoscopy, four randomised controlled trials and 10 observational studies were identified that consistently found a major reduction in distal but not proximal colorectal cancer incidence and mortality. Summary estimates of reduction in distal colorectal cancer incidence and mortality were 31% (95% confidence intervals 26% to 37%) and 46% (33% to 57%) in intention to screen analysis, 42% (29% to 53%) and 61% (27% to 79%) in per protocol analysis of randomised controlled trials, and 64% (50% to 74%) and 66% (38% to 81%) in observational studies. For screening colonoscopy, evidence was restricted to six observational studies, the results of which suggest tentatively an even stronger reduction in distal colorectal cancer incidence and mortality, along with a significant reduction in mortality from cancer of the proximal colon. Indirect comparisons of results of observational studies on screening sigmoidoscopy and colonoscopy suggest a 40% to 60% lower risk of incident colorectal cancer and death from colorectal cancer after screening colonoscopy even though this incremental risk reduction was statistically significant for deaths from cancer of the proximal colon only.

CONCLUSIONS

Compelling and consistent evidence from randomised controlled trials and observational studies suggests that screening sigmoidoscopy and screening colonoscopy prevent most deaths from distal colorectal cancer. Observational studies suggest that colonoscopy compared with flexible sigmoidoscopy decreases mortality from cancer of the proximal colon. This added value should be examined in further research and weighed against the higher costs, discomfort, complication rates, capacities needed, and possible differences in compliance.

Risk factors for vertical incomplete resection in endoscopic submucosal dissection as total excisional biopsy for submucosal invasive colorectal carcinoma

PURPOSE

Endoscopic submucosal dissection (ESD) for colorectal tumor is a minimally invasive treatment. Histologic information obtained from the entire ESD specimen is important for therapy selection in submucosal invasive colorectal carcinoma (SMca). This study aimed to identify risk factors for vertical incomplete resection (vertical margin-positive [VM+]) when ESD was performed as total excisional biopsy for SMca.

METHODS

From June 2003 through December 2011, 78 SMca cases were resected by ESD at Hiroshima University Hospital. Patient and tumor characteristics, intraoperative variables, and histopathology were compared between the VM+ group and the vertical complete resection (vertical margin-negative) group. The ability of magnifying endoscopy (ME) and endoscopic ultrasonography (EUS) to predict VM+ was assessed.

RESULTS

ESD resulted in VM+ in eight cases (10.3 %), with a greater percentage invading to a depth of ≥2,000 vs. <2,000 μm (P = 0.047). Severe submucosal fibrosis was found in five of the eight cases (62.5 %, P = 0.017). Poor differentiation was seen at the deepest invasive portion in six cases (75.0 %), and two of six cases had an invasion depth <2,000 μm. Of 39 EUS cases, 36 not showing deep invasion close to the muscularis propria were completely resected by ESD.

CONCLUSIONS

Submucosal fibrosis and poor differentiation at the deepest invasive portion may be risk factors for VM+ in colorectal ESD for tumors with submucosal deep invasion. ME plus EUS is more likely to help determine whether ESD is indicated as complete total excisional biopsy for SMca.

PDR or ADR as a quality indicator for colonoscopy

Interval (missed) cancers and lower-than-expected mortality reduction of proximal colon cancers after screening colonoscopy drew attention to quality indicators. Small proximal polyps (prone to be advanced neoplasms) missed by colonoscopy are possible contributing factors. In this issue of AJG, the subject of polyp detection rates (PDRs) and adenoma detection rates (ADRs) in the proximal and distal colon is discussed by one group of investigators to address the issue of monitoring performance and to achieve improvement. The authors observed that these two parameters correlated well in segments proximal to the splenic flexure, but not in the left colon. They suggested that caution should be exercised when using PDR as a surrogate for ADR if data from the rectum and sigmoid were included. Avoidance of missed lesions at the time of colonoscopy may require new adjunct measures to enhance ADR. The impact of new adjunct measures on ADR is mixed. In contrast to water immersion, water exchange during insertion has consistently increased ADR during withdrawal inspection. Water exchange may be a suitable alternative platform to replace insertion by air insufflation in the evaluation of new adjunct measures of quality improvement to increase ADR. Payment reforms may be necessary to bring about inclusion of ADR reporting for monitoring of quality performance.

Water-aided colonoscopy: a systematic review

BACKGROUND

Water-aided methods for colonoscopy are distinguished by the timing of removal of infused water, predominantly during withdrawal (water immersion) or during insertion (water exchange).

OBJECTIVE

To discuss the impact of these approaches on colonoscopy pain and adenoma detection rate (ADR).

DESIGN

Systematic review.

SETTING

Randomized, controlled trial (RCT) that compared water-aided methods and air insufflation during colonoscope insertion.

PATIENTS

Patients undergoing colonoscopy.

INTERVENTION

Medline, PubMed, and Google searches (January 2008-December 2011) and personal communications of manuscripts in press were considered to identify appropriate RCTs.

MAIN OUTCOME MEASUREMENTS

Pain during colonoscopy and ADR. RCTs were grouped according to whether water immersion or water exchange was used. Reported pain scores and ADR were tabulated based on group assignment.

RESULTS

Pain during colonoscopy is significantly reduced by both water immersion and water exchange compared with traditional air insufflation. The reduction in pain scores was qualitatively greater with water exchange as compared with water immersion. A mixed pattern of increases and decreases in ADR was observed with water immersion. A higher ADR, especially proximal to the splenic flexure, was obtained when water exchange was implemented.

LIMITATIONS

Differences in the reports limit application of meta-analysis. The inability to blind the colonoscopists exposed the observations to uncertain bias.

CONCLUSION

Compared with air insufflation, both water immersion and water exchange significantly reduce colonoscopy pain. Water exchange may be superior to water immersion in minimizing colonoscopy discomfort and in increasing ADR. A head-to-head comparison of these 3 approaches is required.

A new method for screening and surveillance colonoscopy: Combined water-exchange and cap-assisted colonoscopy

BACKGROUND & AIMS

Colonoscopy plays an important and central role in current colorectal cancer screening and prevention programs, but it is an imperfect tool. Adjunct techniques may help improve the performance of colonoscopy to increase the detection of polyps with neoplastic potential. This study investigates the novel approach of combined water-exchange and cap-assisted colonoscopy (WCC) and its impact on adenoma detection.

METHODS

A single-center single-colonoscopist consecutive group observational study to compare WCC with conventional air insufflation colonoscopy was performed. Data were collected from 50 consecutive patients undergoing outpatient colorectal cancer screening or polyp surveillance with WCC. Adenoma detection rates (ADR) and adenomas detected per colonoscopy (APC) were compared to a control group of 101 consecutive patients examined with conventional air colonoscopy during the immediate prior period.

RESULTS

Cecal intubation was achieved in all patients. As an emerging and alternative quality metric for colonoscopy, APC was significantly higher in the WCC group (3.08 vs. 1.50, p=0.0021). The conventional quality metric, overall ADR, was higher in the WCC group compared to the air colonoscopy group (70.0% vs. 59.4%, p=0.22). This difference was not statistically significant, likely due to a type II error.

CONCLUSION

The observational data suggest APC is a more sensitive indicator of quality colonoscopy than ADR. WCC shows promise as a novel technique that merges two simple adjunct methods to help improve the performance of colonoscopy. The data suggest larger, prospective studies are necessary to determine the true impact of water-exchange combined with cap-assisted maneuvers.

Indigocarmine added to the water exchange method enhances adenoma detection - a RCT

PURPOSE

Chromoendoscopy with dye spray and the water method both increase adenoma detection.

HYPOTHESIS

Adding indigocarmine to the water method will enhance further the effectiveness of the latter in adenoma detection.

METHODS

Screening colonoscopy was performed with the water method (control) or with 0.008% indigocarmine added (study) by two endoscopists. Randomization was based on computer-generated codes contained in blocks of pre-arranged opaque sealed envelopes. High resolution colonoscopes were used. Upon insertion into the rectum, air was suctioned. With the air pump turned off, water was infused using a blunt needle adaptor connected to the scope channel and a foot pump to facilitate scope insertion until the cecum was reached. Residual stool causing cloudiness was suctioned followed by infusion of clear or colored water (water exchange) to facilitate scope passage with minimal distention of the colonic lumen. Upon seeing the appendix opening under water, water was suctioned and air was insufflated to facilitate inspection on scope withdrawal.

STATISTICS

Sample size calculation revealed 168 patients (84/group) needed to be randomized. Study was IRB-approved and registered (NCT01383265).

RESULTS

There were no significant differences in mean age, gender distribution, BMI, and family history of colon cancer. Cecal intubation success rate was 100% in both groups. The overall adenoma detection rate was 44% (water only) versus 62% (water with indigocarmine), respectively (p=0.03). One cancer was detected in each group.

CONCLUSION

In a RCT, indigocarmine at 0.008% concentration, added to the water method, significantly enhanced further the effectiveness of the latter in detecting adenomas.

The water exchange method for colonoscopy-effect of coaching

The growing popularity of water immersion is supported by its long history as an adjunct to air insufflation; after facilitating colonoscope passage, the infused water is conveniently removed during withdrawal. Water exchange, a modification of water immersion to minimize discomfort in scheduled unsedated patients in the U.S. is new. Even though it may be superior in reducing pain and increasing adenoma detection, the paradigm shift to complete exclusion of air during insertion necessitates removal of infused water containing residual feces, a step often perceived as laborious and time-consuming. The nuances are the efficient steps to remove infused water predominantly during insertion to maintain minimal distension and deliver salvage cleansing. Mastery of the novel maneuvers with practice returns insertion time towards baseline. In this observational study the impact of direct verbal coaching on the primary outcome of intention-to-treat cecal intubation was assessed. The results showed that 14 of 19 (74%) experienced colonoscopists achieved 100% intention-to-treat cecal intubation. Initiation of the examination with water exchange did not preclude completion when conversion to the more familiar air insufflation method was deemed necessary to achieve cecal intubation (total 98%). The overall intention-to-treat cecal intubation rate was 88%, 90% in male and 87% in female. Only 2.7% of bowel preparation was rated as poor during withdrawal. The mean volume of water infused and cecal intubation time was 1558 ml and 18 min, respectively. Direct coaching appears to facilitate understanding of the nuances of the water exchange method. Studies of individual learning curves are necessary.