Screening and surveillance for the early detection of colorectal cancer and adenomatous polyps, 2008: a joint guideline from the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology

Diagnostic Performance of Multitarget Stool DNA and CT Colonography for Noninvasive Colorectal Cancer Screening

BackgroundMultitarget stool DNA (mt-sDNA) screening has increased rapidly since simultaneous approval by the U.S. Food and Drug Administration and Centers for Medicare and Medicaid Services in 2014, whereas CT colonography screening remains underused and is not covered by Centers for Medicare and Medicaid Services.PurposeTo report postapproval clinical experience with mt-sDNA screening for colorectal cancer (CRC) and compare results with CT colonography screening at the same center.Materials and MethodsIn this retrospective cohort study, asymptomatic adults underwent clinical mt-sDNA screening during a 5-year interval (2014-2019). Electronic medical records were searched to verify test results and document subsequent optical colonoscopy and histopathologic findings. A similar analysis was performed for CT colonography screening during a 15-year interval (2004-2019), with consideration of thresholds for positivity of both 6-mm and 10-mm polyp sizes. χ² or two-sample t tests were used for group comparisons.ResultsA total of 3987 asymptomatic adult patients (mean age, 64 years ± 9 [standard deviation]; 2567 women) underwent mt-sDNA screening and 9656 patients (mean age, 57 years ± 8; 5200 women) underwent CT colonography. Test-positive rates for mt-sDNA and for 6-mm- and 10-mm-threshold CT colonography were 15.2%, 16.4%, and 6.7%, respectively. Optical colonoscopy follow-up rates for positive results of mt-sDNA and 6-mm- and 10-mm-threshold CT colonography were 13.1%, 12.3%, and 5.9%, respectively. Positive predictive values (PPVs) for any neoplasm 6 mm or greater, advanced neoplasia, and CRC for mt-sDNA were 54.2%, 22.7%, and 1.9% respectively; for 6-mm-threshold CT colonography, PPVs were 76.8%, 44.3%, and 2.7%; for 10-mm-threshold CT colonography, PPVs were 84.5%, 75.2%, and 5.2%, respectively (P < .001 for mt-sDNA vs CT colonography for all except 6-mm CRC at CT colonography). For mt-sDNA versus 6-mm-threshold CT colonography, overall detection rates for advanced neoplasia were 2.7% and 5.0%, respectively (P < .001); corresponding detection rates for CRC were 0.23% and 0.31%, respectively (P = .43).ConclusionThe detection rates of advanced neoplasia at CT colonography screening were greater than those of multitarget stool DNA. Detection rates were similar for colorectal cancer.© RSNA, 2020See also the editorial by Yee in this issue.

An RCT to Increase Breast and Colorectal Cancer Screening

INTRODUCTION

Adherence to breast and colorectal cancer screenings reduce mortality from these cancers, yet screening rates remain suboptimal. This 2 × 2 RCT compared 3 theory-based interventions to usual care to simultaneously increase breast and colon cancer screening in women who were nonadherent to both screenings at study entry.

DESIGN

RCT.

SETTING/PARTICIPANTS

Women (n=692) who were nonadherent to both breast and colon cancer screenings and aged 51-75 years were recruited. Enrollment, intervention delivery, and data collection were completed between 2013 and 2017, and data analyzed in 2018.

INTERVENTION

The randomized intervention included the following 4 groups: 3 intervention arms (personally tailored messages using a web-based intervention, phone delivery by a trained navigator, or both) compared with usual care. Women at an average risk for colon cancer were allowed to select either colonoscopy or stool test as their preferred colon cancer screening. Mammography was promoted for breast cancer screening.

MAIN OUTCOME MEASURES

Outcome data at 6 months included self-report and medical records for screening activity.

RESULTS

All intervention arms significantly increased receipt of either a mammogram or stool test compared with control (web: p<0.0249, phone: p<0.0001, web + phone: p<0.0001). When considering receipt of both mammogram and stool test, all intervention arms were significantly different from usual care (web: p<0.0249, phone: p<0.0003, web + phone: p<0.0001). In addition, women who were adherent to mammography had a 4.5 times greater odds of becoming adherent to colonoscopy.

CONCLUSIONS

The tailored intervention simultaneously supporting both breast and colon cancer screenings significantly improved rates of obtaining one of the screenings and increased receipt of both tests.

TRIAL REGISTRATION

This study is registered with the clinical trials identifier NCT03279198 at www.clinicaltrials.gov.

Determinants of Participation and Detection Rate of Colorectal Cancer From a Population-Based Screening Program in China

Colorectal cancer (CRC) screening has been widely implemented in Europe and the USA. However, there is little evidence of participation and diagnostic yields in population-based CRC screening in China. The participation rate and detection of colorectal lesions in this program were reported and related factors were explored. The analysis was conducted in the context of the Cancer Screening Program in Urban China, which recruited 282,377 eligible participants aged 40–74 years from eight cities in Henan province from 2013 to 2019. A total of 39,834 participants were evaluated to be high risk for CRC by an established risk score system and were subsequently recommended for colonoscopy. Of 39,834 with high risk for CRC, 7,454 subjects undertook colonoscopy (participation rate of 18.71%). We found that 50–64 years, high level of education, marriage, former smoking, current alcohol drinking, low levels dietary intake of vegetables, high levels dietary intake of processed meat, lack of physical activity, fecal occult blood test positive result, history of colonic polyp, history of colorectitis, and family history of CRC were associated with increased participation of colonoscopy screening. Overall, 17 CRC (0.23%), 95 advanced adenoma (1.27%), 478 non-advanced adenomas dysplasia (6.41%), 248 hyperplastic polyp (3.33%), and 910 other benign lesions (12.21%) were detected. The findings from the study will provide important references for designing effective population-based CRC screening strategies in the future. Given the relatively low participation rate, there was room for improvement in the yield of CRC screening.

A Transparent and Adaptable Method to Extract Colonoscopy and Pathology Data Using Natural Language Processing

Key variables recorded as text in colonoscopy and pathology reports have been extracted using natural language processing (NLP) tools that were not easily adaptable to new settings. We aimed to develop a reliable NLP tool with broad adaptability. During 1996-2016, Kaiser Permanente Northern California performed 401,566 colonoscopies with linked pathology. We randomly sampled 1000 linked reports into a Training Set and developed an NLP tool using SAS® PERL regular expressions. The NLP tool captured five colonoscopy and pathology variables: type, size, and location of polyps; extent of procedure; and quality of bowel preparation. We used a Validation Set (N = 3000) to confirm the variables' classifications using manual chart review as the reference. Performance of the NLP tool was assessed using the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and Cohen's κ. Cohen's κ ranged from 93 to 99%. The sensitivity and specificity ranged from 95 to 100% across all categories. For categories with prevalence exceeding 10%, the PPV ranged from 97% to 100% except for adequate quality of preparation (prevalence 92%), for which the PPV was 65%. For categories with prevalence below 10%, the PPVs ranged from 62% to 100%. NPVs ranged from 94% to 100% except for the "complete" extent of procedure, for which the NPV was 73%. Using information from a large community-based population, we developed a transparent and adaptable NLP tool for extracting five colonoscopy and pathology variables. The tool can be readily tested in other healthcare settings.

HOXC10 is significantly overexpressed in colorectal cancer

Colorectal cancer (CRC) is one of the most common types of cancer in world and has a high rate of mortality. The majority of cases of CRC are sporadic; however, factors such as age, a family history of inflammatory diseases, diet, lifestyle and genetics increase the risk. HOX genes and lncRNAs are two classes of genes, and alterations in the expression levels of these genes are significantly associated with numerous different types of cancer. In the present study, the expression levels of HOXC10, HOXC-AS3, HOTAIR, HOXC13 and HOXC13-AS in tumor tissues were compared with normal healthy tissues in patients with CRC. Paired tumor and normal tissues were collected from 39 patients with CRC, and reverse transcription-quantitative PCR was used the expression of HOXC-AS3, HOXC13 and HOXC10 in the tumor tissues compared with the respective normal tissues. Expression of these genes were increased in the tumor tissues compared with normal tissues; however, the difference was only significant for HOXC10. Additionally, there was a strong and significant correlation between the expression of HOTAIR and HOXC13, a moderate and significant correlation between the expression of HOTAIR and HOXC13-AS, and between HOXC13 and HOXC13-AS genes. The expression of HOXC10 was significantly higher in tumor tissues compared with the normal tissues; whereas the upregulation of HOXC-AS3 and HOXC13 were not significant. Only the correlation between the expression of HOTAIR and HOXC13 was strong and significant. As HOXC10 expression was significantly upregulated in the tumor tissues relative to normal tissues, it may serve as a biomarker for the diagnosis of CRC and as a potential therapeutic target.

Evolution of colorectal cancer screening research in the past 25 years: text-mining analysis of publication trends and topics

BACKGROUND

There is a growing research effort in the field of colorectal cancer (CRC) screening, with varying topics and shifting research foci over the years. The aim of this study was to apply a text-mining technique to evaluate trends in publications for CRC screening in the last 25 years.

METHODS

We retrieved MEDLINE/PubMed datasets from 1992-2017. We selected keywords from Medical Subject Headings to include CRC screening related publications. For each article, we extracted the following data: title, journal, publication date, abstract, article type, citation frequency, and country of origin. Articles were categorized into topics using word combination and title match technique.

RESULTS

In 1992-2017, 14,119 CRC screening related papers were published. The US had the highest number of papers (n = 4824) and China had the highest growth rate in publications. Overall, the most researched topic was "screening and surveillance programs" (38%). The topics of "quality assurance" (r = 0.87) and "racial disparities" (r = 0.91) have gained increased research attention over the years. In total, 11 of the 20 most cited articles in the field were published in The New England Journal of Medicine.

CONCLUSION

The number of publications devoted to CRC screening has grown, with high-quality research reaching top-tier journals. A surge in the number of publications has been increasing in countries previously less involved in research in the field. Screening programs remain the most researched topic, and quality indicators is attracting a growing attention. Text-mining analysis of CRC screening research contributes to an understanding of publication trends and topics and can point to the need for potential future investigations.

Characteristics and publication status of gastrointestinal endoscopy clinical trials registered in ClinicalTrials.gov

BACKGROUND AND AIMS

This study aimed to examine the fundamental characteristics of gastrointestinal (GI) endoscopy trials and evaluate their publication status.

METHODS

A cross-sectional analysis was performed in the ClinicalTrials.gov database, and then the PubMed, Medline, Google Scholar, and Embase databases were searched. A dataset containing GI endoscopy clinical studies from ClinicalTrials.gov registered until November 24, 2017, was downloaded. Data of observational and interventional studies were extracted and analyzed. Publications in peer-reviewed journals were examined for completed trials, and factors associated with publication were identified.

RESULTS

A total of 1338 of 253,777 clinical trials were assigned into GI endoscopy, of which 1018 were interventional and 320 were observational studies. Of all the trials, those from the USA comprised the largest percentage (n = 377, 28.18%). The most common field for registered trials was gastroscopy (n = 436, 32.6%), followed by colonoscopy (n = 215, 16.1%), endoscopic ultrasound (n = 186, 13.9%), endoscopic retrograde cholangiopancreatography (n = 176, 13.1%), and novel endoscopic procedure (n = 103, 7.7%). A total of 501 trials were completed before November 25, 2015, 281 (56.1%) of which were published. The median time from study completion to publication was 21 months (interquartile range, 12-32 months). Trials that were comprised of medium sample sizes (150-1000 subjects), conducted in Europe or Asia and other countries, and single or quadruple blinded were more likely to be published.

CONCLUSIONS

GI endoscopy is rapidly evolving in clinical applications. Most clinical trials in GI endoscopy are published promptly. These findings demonstrated that investigators are active in performing and communicating the results of clinical trials in the field of GI endoscopy. In the future, the sample size calculation should be presented in detail in the registration system to maintain trial reporting transparency.

Exploring MR regression patterns in rectal cancer during neoadjuvant radiochemotherapy with daily T2- and diffusion-weighted MRI

Background

To date, only limited magnetic resonance imaging (MRI) data are available concerning tumor regression during neoadjuvant radiochemotherapy (RCT) of rectal cancer patients, which is a prerequisite for adaptive radiotherapy (RT) concepts. This exploratory study prospectively evaluated daily fractional MRI during neoadjuvant treatment to analyze the predictive value of MR biomarkers for treatment response.

Methods

Locally advanced rectal cancer patients were examined with daily MRI during neoadjuvant RCT. Contouring of the tumor volume was performed for each MRI scan by using T2- and diffusion-weighted-imaging (DWI)-sequences. The daily apparent-diffusion coefficient (ADC) was calculated. Volumetric and functional tumor changes during RCT were analyzed and correlated with the pathological response after surgical resection.

Results

In total, 171 MRI scans of eight patients were analyzed regarding anatomical and functional dynamics during RCT. Pathological complete response (pCR) could be achieved in four patients, and four patients had a pathological partial response (pPR) following neoadjuvant treatment. T2- and DWI-based volumetry proved to be statistically significant in terms of therapeutic response, and volumetric thresholds at week two and week four during RCT were defined for the prediction of pCR. In contrast, the average tumor ADC values widely overlapped between both response groups during RCT and appeared inadequate to predict treatment response in our patient cohort.

Conclusion

This prospective exploratory study supports the hypothesis that MRI may be able to predict pCR of rectal cancers early during neoadjuvant RCT. Our data therefore provide a useful template to tailor future MR-guided adaptive treatment concepts.

Prevalence of Helicobacter pylori among Sudanese patients diagnosed with colon polyps and colon cancer using immunohistochemistry technique

Objectives

Infection with the bacteria Helicobacter pylori has been classified as class one carcinogen associated with increasing susceptibility of gastritis and gastric carcinoma. This study is aiming at investigating the prevalence of H. pylori among colon polyps and colon cancer patients. A descriptive cross-sectional hospital-based study was conducted between February and June 2017. Sixty-nine formalin-fixed paraffin blocks collected from colon polyps and colon cancer patients to detect H. pylori using immunohistochemistry technique.

Results

Of the 69 patients included in the study, 39 (56.5%) males and 30 (43.5%) were females, their age ranged from 21 to 80 years with a mean age of 47.1 ± 19.7. Of the 69 colon polyps and colon cancer patients, 44 (63.8%) were diagnosed as adenocarcinoma, 10 (14.5%) colitis, 15 (21.7%) juvenile polyposis syndrome. The results of immunohistochemistry technique showed the presence of 16 (23.2%) positive patients for H. pylori infection. Of these 16, 13 (81.3%) patients were diagnosed with adenocarcinoma and 3 (18.7%) patients were diagnosed with juvenile polyps. The results of H. pylori detection among the different colon polyps and colon cancer patients were showing a statistically significant association for H. pylori infection and adenocarcinoma, P value 0.028.

Calculating the Starting Age for Screening in Relatives of Patients With Colorectal Cancer Based on Data From Large Nationwide Data Sets

BACKGROUND & AIMS

Although colorectal cancer (CRC) screening guidelines acknowledge the need for earlier screening for high-risk individuals, such as those with family history of CRC, there is limited information on how many years earlier these high-risk individuals should be screened; current practice is based on weak evidence. We aimed to provide risk-adapted recommendations on the starting age of CRC screening for individuals with different family histories.

METHODS

We collected data from nationwide family-cancer data sets in Sweden and calculated risk-adapted starting ages of screening for individuals with different family histories of CRC. Family history was defined as a dynamic (time-dependent) variable, allowing for changes during the follow-up period of 1958 through 2015.

RESULTS

During a follow-up of 12,829,251 individuals with genealogy information, 173,796 developed CRC. The 10-year cumulative risk for the average-risk population at age 50 years (the guideline-recommended age for screening) was 0.44%. Individuals with different family histories of CRC attained this equivalent 0.44% risk 3-29 years earlier than their peers in the general population without such a family history. For example, individuals with 1 affected first-degree relative diagnosed before age 45 years reached the corresponding risk level 16 years earlier.

CONCLUSIONS

We determined risk-adapted starting ages of CRC screening for close or distant relatives of patients with CRC, using high quality nationwide data sets. These findings might be used in counselling individuals about the appropriate age to start CRC screening, to optimize screening practice, and to supplement guidelines for CRC screening.

The Impact of Colorectal Cancer Screening in a Veteran Hospital Population

Colon and rectal cancer is the second most common cause of cancer death in the United States. Screening effectively decreases colorectal cancer mortality. This study aims to evaluate the impact of colorectal cancer screening within a Veterans Affairs Medical Center and treatment outcomes. Institutional Review Board approval was obtained for a retrospective analysis of all colorectal cancer cases that were identified through the Tumor Registry of the Robley Rex VA Medical Center from 2000 to 2009. Data collected included age at diagnosis, race, risk factors, diagnosis by screening versus symptomatic evaluation, screening test, tumor location and stage, operation performed, operative mortality, and survival. A value of P < 0.05 on Fisher's exact, χ2, analysis of variance, or Cox regression analyses was considered significant. Three hundred fifty-four patients with colorectal cancer (255 colon, 99 rectal) were identified. One hundred twenty-one patients (34%) were diagnosed by screening. In comparison with those diagnosed by symptom evaluation (n = 233), these patients had earlier stage cancers, were more likely to have a curative intent procedure, and had improved 5-year survival rates. Older patients (older than 75 years old) were more likely to present with symptoms. High-risk patients were more likely to have colonoscopic screening than fecal occult blood testing. More blacks had Stage IV disease than nonblacks. Curative intent 30-day operative mortality was 2.1 per cent for colectomy and 0 per cent for rectal resection. Screening for colorectal cancer in the veteran population allows for better survival, detection at an earlier stage, and higher likelihood of resection.

Diagnosis Setting and Colorectal Cancer Outcomes: The Impact of Cancer Diagnosis in the Emergency Department

BACKGROUND

The rate of diagnosis of colorectal cancer (CRC) in the emergency department (ED), its characteristics, and its effect on outcomes have been poorly described.

MATERIALS AND METHODS

Chart review was conducted to identify presenting clinical setting leading to diagnosis, symptoms, and history of colonoscopy for patients diagnosed with CRC at a single institution from 2012-2014. Patients diagnosed with CRC as a result of an ED visit (EDDx) were compared with those diagnosed after presentation to other settings (non-EDDx).

RESULTS

Of 638 patients meeting inclusion criteria, 271 (42.4%) were EDDx patients. These patients were more likely to be older than 80 y (29.89% versus 19.35%), have Medicare (59.78% versus 42.78%) or Medicaid (23.62% versus 12.81%) insurance, have stage IV cancer (45.02% versus 18.26%), and were symptomatic at the time of presentation (94.83% versus 64.03%). EDDx patients were less likely to ever have had a colonoscopy (21.77% versus 41.69%). In a model adjusted for patient demographics, cancer stage, presence of symptoms, and history of prior colonoscopy, EDDx was associated with increased mortality (hazard ratio, 1.89; 95% confidence interval, 1.3-2.8). On stratifying survival by stage, it was found that for all stages, EDDx was associated with decreased survival.

CONCLUSIONS

More than 40% of patients with CRC received their diagnosis through the ED. EDDx was associated with a nearly twofold mortality risk increase. EDDx should be considered a marker of poor outcomes for CRC and may be related to unaccounted patient-level or systems-level factors. Efforts should be made to identify modifiable risks of cancer diagnosis in the ED to improve cancer outcomes.

Cost-Effectiveness of Colonoscopy-Based Colorectal Cancer Screening in Childhood Cancer Survivors

BACKGROUND

Childhood cancer survivors (CCS) are at increased risk of developing colorectal cancer (CRC) compared to the general population, especially those previously exposed to abdominal or pelvic radiation therapy (APRT). However, the benefits and costs of CRC screening in CCS are unclear. In this study, we evaluated the cost-effectiveness of early-initiated colonoscopy screening in CCS.

METHODS

We adjusted a previously validated model of CRC screening in the US population (MISCAN-Colon) to reflect CRC and other-cause mortality risk in CCS. We evaluated 91 colonoscopy screening strategies varying in screening interval, age to start, and age to stop screening for all CCS combined and for those treated with or without APRT. Primary outcomes were CRC deaths averted (compared to no screening) and incremental cost-effectiveness ratios (ICERs). A willingness-to-pay threshold of $100 000 per life-years gained (LYG) was used to determine the optimal screening strategy.

RESULTS

Compared to no screening, the US Preventive Services Task Force's average risk screening schedule prevented up to 73.2% of CRC deaths in CCS. The optimal strategy of screening every 10 years from age 40 to 60 years averted 79.2% of deaths, with ICER of $67 000/LYG. Among CCS treated with APRT, colonoscopy every 10 years from age 35 to 65 years was optimal (CRC deaths averted: 82.3%; ICER: $92 000/LYG), whereas among those not previously treated with APRT, screening from age 45 to 55 years every 10 years was optimal (CRC deaths averted: 72.7%; ICER: $57 000/LYG).

CONCLUSIONS

Early initiation of colonoscopy screening for CCS is cost-effective, especially among those treated with APRT.

3D-GLCM CNN: A 3-Dimensional Gray-Level Co-Occurrence Matrix-Based CNN Model for Polyp Classification via CT Colonography

Accurately classifying colorectal polyps, or differentiating malignant from benign ones, has a significant clinical impact on early detection and identifying optimal treatment of colorectal cancer. Convolution neural network (CNN) has shown great potential in recognizing different objects (e.g. human faces) from multiple slice (or color) images, a task similar to the polyp differentiation, given a large learning database. This study explores the potential of CNN learning from multiple slice (or feature) images to differentiate malignant from benign polyps from a relatively small database with pathological ground truth, including 32 malignant and 31 benign polyps represented by volumetric computed tomographic (CT) images. The feature image in this investigation is the gray-level co-occurrence matrix (GLCM). For each volumetric polyp, there are 13 GLCMs, computed from each of the 13 directions through the polyp volume. For comparison purpose, the CNN learning is also applied to the multi-slice CT images of the volumetric polyps. The comparison study is further extended to include Random Forest (RF) classification of the Haralick texture features (derived from the GLCMs). From the relatively small database, this study achieved scores of 0.91/0.93 (two-fold/leave-one-out evaluations) AUC (area under curve of the receiver operating characteristics) by using the CNN on the GLCMs, while the RF reached 0.84/0.86 AUC on the Haralick features and the CNN rendered 0.79/0.80 AUC on the multiple-slice CT images. The presented CNN learning from the GLCMs can relieve the challenge associated with relatively small database, improve the classification performance over the CNN on the raw CT images and the RF on the Haralick features, and have the potential to perform the clinical task of differentiating malignant from benign polyps with pathological ground truth.

Development of FamilyTalk: an Intervention to Support Communication and Educate Families About Colorectal Cancer Risk

IFamily members of individuals with colorectal cancer (CRC) may be at increased risk of developing the disease. However, the majority of CRC can be prevented through colonoscopy screening and family members may not be aware if they are recommended to pursue earlier screening because of their family history of CRC. As such, tools must be developed to effectively communicate potential changes to the recommended age for colonoscopy screening and other important CRC-related information to family members. We modified and adapted a successful intervention for families with melanoma to be appropriate for families with CRC to increase communication and screening in family members. The multistep process included the following: (1) developing a paper version of the intervention, (2) piloting the paper version among families with CRC, (3) developing the web-based version, and (4) testing the intervention for usability. Qualitative data was collected and analyzed for pilot testing. Usability testing utilized both qualitative and quantitative data. Patients with CRC liked the paper version and had multiple suggestions, including adding a better introduction, sections on genetics and family history, and clearer communication assistance. The web-based tool was well received and improved upon the linear book format with links, better section instructions, and more proactive communication tools for families. These processes produced materials that satisfied individuals from various families with assistance and support for communicating about CRC. Evaluating the effects of the tools in rigorous research projects is the next step.

Colorectal cancer in patients under age 50: a five-year experience

OBJECTIVE

to evaluate the clinical characteristics of patients with colorectal cancer under the age of 50 treated at a public hospital in Brasilia over 5 years.

METHODS

we conducted a longitudinal, retrospective study, with 184 patients undergoing surgical procedures at the Asa Norte Regional Hospital (HRAN), including those who underwent only biopsy, between January 2013 and January 2018. We divided the patients into two groups: under the age of 50 (n=39) and age equal to or greater than 50 years (n=145). We compared the groups as to age, sex, symptoms, time between symptom onset and diagnosis, family and personal history, tumor location, histopathological characteristics, applied surgical management, staging and mortality.

RESULTS

the group of patients under the age of 50 had more individuals with stage III and IV (p=0.041), more frequent poorly differentiated tumors (10.25% versus 3.52%; p=0.153), and higher incidences of compromised surgical margins (p=0.368), angiolymphatic (p=0.07) and perineural (p=0.007) invasion, which denotes more advanced disease in this group of patients.

CONCLUSIONS

the study showed the low effectiveness of population screening methods for colorectal cancer currently used in this population, given the high incidence of the disease and late diagnosis in both groups.

The effect of using fecal testing after a negative sigmoidoscopy on the risk of death from colorectal cancer

OBJECTIVE

To examine whether receiving a fecal occult blood test after a negative sigmoidoscopy reduced mortality from colorectal cancer.

METHODS

We used a nested case-control design with incidence-density matching in historical cohorts of 1,877,740 50-90-year-old persons during 2006-2012, in an integrated health-system setting. We selected 1758 average risk patients who died from colorectal cancer and 3503 matched colorectal cancer-free persons. Colorectal cancer-specific death was ascertained from cancer and mortality registries. Screening histories were determined from electronic and chart-audit clinical data in the 5- to 10-year period prior to the reference date. We evaluated receipt of subsequent fecal occult blood test within five years of the reference date among patients with negative sigmoidoscopy two to six years before the reference date.

RESULTS

Of the 5261 patients, 831 patients (204 colorectal cancer deaths/627 controls) had either negative sigmoidoscopy only (n = 592) or negative sigmoidoscopy with subsequent screening fecal occult blood test (n = 239). Fifty-six (27.5%) of the 204 patients dying of colorectal cancer and 183 (29.2%) of the 627 colorectal cancer-free patients received fecal occult blood test following a negative sigmoidoscopy. Conditional regressions found no significant association between fecal occult blood test receipt and colorectal cancer death risk, overall (adjusted odds ratio = 0.93, confidence interval: 0.65-1.33), or for right (odds ratio = 1.02, confidence interval: 0.65-1.60) or left-colon/rectum (odds ratio = 0.77, confidence interval: 0.39-1.52) cancers. Similar results were obtained in sensitivity analyses with alternative exposure ascertainment windows or timing of fecal occult blood test.

CONCLUSIONS

Our results suggest that receipt of at least one fecal occult blood test during the several years after a negative sigmoidoscopy did not substantially reduce mortality from colorectal cancer.

Proteomic Characterization of Colorectal Cancer Cells versus Normal-Derived Colon Mucosa Cells: Approaching Identification of Novel Diagnostic Protein Biomarkers in Colorectal Cancer

In the western world, colorectal cancer (CRC) is the third most common cause of cancer-related deaths. Survival is closely related to the stage of cancer at diagnosis striking the clinical need for biomarkers capable of early detection. To search for possible biological parameters for early diagnosis of CRC we evaluated protein expression for three CREC (acronym: Cab45, reticulocalbin, ERC-55, calumenin) proteins: reticulocalbin, calumenin, and ERC-55 in a cellular model consisting of a normal derived colon mucosa cell line, NCM460, and a primary adenocarcinoma cell line of the colon, SW480. Furthermore, this cellular model was analyzed by a top-down proteomic approach, 2-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) for novel putative diagnostic markers by identification of differentially expressed proteins between the two cell lines. A different colorectal carcinoma cell line, HCT 116, was used in a bottom-up proteomic approach with label-free quantification (LFQ) LC-MS/MS. The two cellular models gave sets of putative diagnostic CRC biomarkers. Various of these novel putative markers were verified with increased expression in CRC patient neoplastic tissue compared to the expression in a non-involved part of the colon, including reticulocalbin, calumenin, S100A6 and protein SET. Characterization of these novel identified biological features for CRC patients may have diagnostic potential and therapeutic relevance in this malignancy characterized by a still unmet clinical need.

Colorectal Adenomas-Genetics and Searching for New Molecular Screening Biomarkers

Colorectal cancer (CRC) is a malignant disease with an incidence of over 1.8 million new cases per year worldwide. CRC outcome is closely related to the respective stage of CRC and is more favorable at less advanced stages. Detection of early colorectal adenomas is the key to survival. In spite of implemented screening programs showing efficiency in the detection of early precancerous lesions and CRC in asymptomatic patients, a significant number of patients are still diagnosed in advanced stages. Research on CRC accomplished during the last decade has improved our understanding of the etiology and development of colorectal adenomas and revealed weaknesses in the general approach to their detection and elimination. Recent studies seek to find a reliable non-invasive biomarker detectable even in the blood. New candidate biomarkers could be selected on the basis of so-called liquid biopsy, such as long non-coding RNA, microRNA, circulating cell-free DNA, circulating tumor cells, and inflammatory factors released from the adenoma into circulation. In this work, we focused on both genetic and epigenetic changes associated with the development of colorectal adenomas into colorectal carcinoma and we also discuss new possible biomarkers that are detectable even in adenomas prior to cancer development.

Potential impact of family history-based screening guidelines on the detection of early-onset colorectal cancer

BACKGROUND

Initiating screening at an earlier age based on cancer family history is one of the primary recommended strategies for the prevention and detection of early-onset colorectal cancer (EOCRC), but data supporting the effectiveness of this approach are limited. The authors assessed the performance of family history-based guidelines for identifying individuals with EOCRC.

METHODS

The authors conducted a population-based, case-control study of individuals aged 40 to 49 years with (2473 individuals) and without (772 individuals) incident CRC in the Colon Cancer Family Registry from 1998 through 2007. They estimated the sensitivity and specificity of family history-based criteria jointly recommended by the American Cancer Society, the US Multi-Society Task Force on CRC, and the American College of Radiology in 2008 for early screening, and the age at which each participant could have been recommended screening initiation if these criteria had been applied.

RESULTS

Family history-based early screening criteria were met by approximately 25% of cases (614 of 2473 cases) and 10% of controls (74 of 772 controls), with a sensitivity of 25% and a specificity of 90% for identifying EOCRC cases aged 40 to 49 years. Among 614 individuals meeting early screening criteria, 98.4% could have been recommended screening initiation at an age younger than the observed age of diagnosis.

CONCLUSIONS

Of CRC cases aged 40 to 49 years, 1 in 4 met family history-based early screening criteria, and nearly all cases who met these criteria could have had CRC diagnosed earlier (or possibly even prevented) if earlier screening had been implemented as per family history-based guidelines. Additional strategies are needed to improve the detection and prevention of EOCRC for individuals not meeting family history criteria for early screening.

Factors Influencing Colorectal Cancer Screening Among Thais in the U.S

This study examined factors related to colorectal cancer (CRC) screening uptake among Thais in the United States. A total of 121 Thais between 50 and 75 years of age, who were married and living in southern California participated in the survey (mean age = 61 years). Out of all the participants, only 21% of the participants had fecal occult blood tests, 21% had sigmoidoscopy, and 45% had colonoscopy that were within the recommended period. Overall, 55% of participants met CRC screening adherence criteria. Participants who had had regular checkups in the previous 2 years without having any symptoms were 16 times more likely to have obtained CRC screening than their counterparts (OR 16.01, CI 3.75-68.75) in the multivariable logistic regression model. Other significant predictors of screening adherence included older age (OR 1.08, 95% CI 1.00-1.17), having lived in the U.S. 15 years or longer (OR 6.65, 95% CI 1.55-28.59), having had at least some college education (OR 3.74, 95% CI 1.23-11.37), and higher levels of perceived self-efficacy (OR 1.88, 95% CI 1.01-3.50) to obtain CRC screening. Targeted interventions for Thais who are less likely receive CRC screening could be effective in improving CRC screening. Interventions to improve the populations' awareness of the importance of preventive measures when they are not sick could be also effective.

Neutral, Negative, or Negligible? Changes in Patient Perceptions of Disease Risk Following Receipt of a Negative Genomic Screening Result

Most individuals who undergo genomic screening will receive negative results or results not sufficient to warrant a clinical response. Even though a majority of individuals receive negative results, little is known about how negative results may impact individuals' perception of disease risk. Changes in risk perception (specifically reductions in perceived risk) may affect both probands and their family members if inaccurate information is communicated to family members. We surveyed patients who received negative results as part of their participation in a genomic screening study and assessed their perceptions of disease risk following receipt of results. Participants had either hyperlipidemia or colon polyps (or both) and received their negative genomic screening results by mail. Of 1712 total individuals recruited, 1442 completed the survey (84.2% completion rate). Approximately one quarter of individuals believed their risk for heart disease to be lower and approximately one third of individuals believed their risk for colon cancer to be lower after receiving and evaluating their negative genomic screening result. 78% of those who believed their risk for one or both diseases had declined had already shared or intended to share their result with family members. Our study suggests patients may interpret a negative genomic screening result as implying a reduction in their overall disease risk.

Multilayer feature selection method for polyp classification via computed tomographic colonography

Polyp classification is a feature selection and clustering process. Picking the most effective features from multiple polyp descriptors without redundant information is a great challenge in this procedure. We propose a multilayer feature selection method to construct an optimized descriptor for polyp classification with a feature-grouping strategy in a hierarchical framework. First, the proposed method makes good use of image metrics, such as intensity, gradient, and curvature, to divide their corresponding polyp descriptors into several feature groups, which are the preliminary units of this method. Then each preliminary unit generates two ranked descriptors, i.e., their optimized variable groups (OVGs) and preliminary classification measurements. Next, a feature dividing-merging (FDM) algorithm is designed to perform feature merging operation hierarchically and iteratively. Unlike traditional feature selection methods, the proposed FDM algorithm includes two steps for feature dividing and feature merging. At each layer, feature dividing selects the OVG with the highest area under the receiver operating characteristic curve (AUC) as the baseline while other descriptors are treated as its complements. In the fusion step, the FDM merges some variables with gains into the baseline from the complementary descriptors iteratively on every layer until the final descriptor is obtained. This proposed model (including the forward step algorithm and the FDM algorithm) is a greedy method that guarantees clustering monotonicity of all OVGs from the bottom to the top layer. In our experiments, all the selected results from each layer are reported by both graphical illustration and data analysis. Performance of the proposed method is compared to five existing classification methods by a polyp database of 63 samples with pathological reports. The experimental results show that our proposed method outperforms other methods by 4% to 23% gains in terms of AUC scores.

Identification of potential metabolite markers for colon cancer and rectal cancer using serum metabolomics

Background

To determine the metabolic characteristics of patients with colon cancer (CC) and rectal cancer (RC) using gas chromatography‐mass spectrometry (GC‐MS)‐based metabolomics.

Methods

In this study, serum samples were collected from 22 CC patients and 23 RC patients preoperatively and postoperatively and 45 healthy volunteers (HVs), and subjected to metabolomics analysis by GC‐MS. Differential metabolites in the preoperative RC and CC samples and HVs were identified as potential biomarkers and evaluated for their utilities by receiver operating characteristic analyses.

Results

The different metabolic markers between CC and RC patients were identified, which may assist in distinguishing the two types of cancers. The area under the curve (AUC) was 0.805 for combination of d‐glucose and d‐mannose for CC diagnosis, and 0.889 for combination of 2‐aminobutanoic acid, 3‐hydroxypyridine, d‐glucose, d‐mannose, isoleucine, l‐tryptophan, urea, and uric acid for RC diagnosis. The combinations of metabolite markers showed a better predictability than CEA and CA199 two commonly used protein markers for CRC diagnosis in clinical practice. Combining the metabolite markers with these two protein markers effectively improved the diagnostic accuracy with the AUC reaching 0.936 and 0.937 for CC and RC diagnosis, respectively.

Conclusions

Metabolic profiles are different in the blood samples between CC and RC patients. The study has established a panel of metabolic markers as a predictive and multiplexing signature for CC and RC diagnosis.

Colorectal cancer prevention by a CLEAR principles-based colonoscopy protocol: an observational study

BACKGROUND AND AIMS

Colorectal cancer (CRC) prevention by colonoscopy has been lower than expected. We studied CRC prevention outcomes of a colonoscopy protocol based on Clean the colon, Look Everywhere, and complete Abnormality Removal (CLEAR) principles.

METHODS

This observational follow-up study studied patients provided screening colonoscopy at a free-standing private ambulatory surgery center in South Carolina by 80 endoscopists from October 2001 to December 2014, followed through December 2015. The colonoscopy protocol, optimized for polyp clearance, featured in-person bowel preparation instructions reinforced by phone, polyp search and removal throughout insertion and gradual withdrawal with circumferential tip movements, and a team approach using all personnel present to maximize polyp detection, patient safety, and clear-margin polypectomy including requesting repeat inspection or additional tissue removal. Outcome measures were postscreening lifetime CRC risk relative to Surveillance Epidemiology and End Results (SEER)-18 and interval cancer rate (postcolonoscopy CRCs among cancer-free patients at screening).

RESULTS

Of 25,862 patients (mean age, 58.1 years; 52% black; 205,522 person-years of observation), 159 had CRC at screening and 67 patients developed interval CRC. The interval CRC rate was 3.34 per 10,000 person-years of observation, 5.79 and 2.24 among patients with and without adenomas, respectively. The rate was similar among older patients (mean age 68.5 years at screening) and with prolonged follow-up. Postscreening lifetime CRC risk was 1.6% (bootstrap 95% confidence interval, 1.3%-1.8%) versus 4.7% in SEER-18, 67% lower. Subgroups with mean screening ages of 50 and 68.5 years showed risk reductions of 80% and 72%, respectively. The adverse event rate was less than usually reported rates: perforation 2.6 per 10,000, bleeding with hospitalization 2.4 per 10,000, and no deaths.

CONCLUSIONS

A colonoscopy protocol optimized for polyp clearance prevented 67% of CRC compared with a SEER-18 population given ongoing population screening.

Actual and estimated adenoma detection rates: a 2-year monocentric colonoscopic screening outcome in Shenzhen, China

Background and Aim

While adenoma detection rate (ADR) is an important quality metric for screening colonoscopy, it remains difficult to be accessed due to the lack of integrated endoscopy and pathology databases. Hence, the use of an adenoma‐to‐polyp detection rate quotient and polyp detection rate (PDR) has been proposed to predict ADR. This study aimed to examine the usefulness of estimated ADR across different colonic segments in two age groups for Shenzhen people in China.

Methods

We retrospectively analyzed 7329 colonoscopy procedures performed by 12 endoscopists between January 2012 and February 2014. The PDR, actual ADR, and estimated ADR of the entire, proximal, and distal colon, and within each colonic segment, in two patient age groups: <50 and ≥50 years, were calculated for each endoscopist.

Results

The overall polyp and adenoma prevalence rates were 19.1 and 9.3%, respectively. The average age of adenoma‐positive patients was significantly higher than that of adenoma‐negative patients (54 ± 12.6 years vs 42.9 ± 13.2 years, respectively). A total of 1739 polyps were removed, among which 826 were adenomas. More adenomatous polyps were found in the proximal colon (60.4%, 341/565) than in the distal colon (40.9%, 472/1154). Overall, both actual and estimated ADR correlated strongly at the entire colon level and within most colonic segments, except for the cecum and rectum. In both age groups, these parameters correlated strongly within the traverse colon and descending colon.

Conclusion

Caution should be exercised when predicting ADR within the sigmoid colon and rectum.

Electronic cleansing of tagged residue in CT colonography: what radiologists need to know

CT colonography (CTC) is the radiological examination of choice for the diagnosis of colorectal neoplasia. Faecal tagging is considered a mandatory part of bowel preparation. However, the colonic mucosa, obscured by tagged residue, is not accessible to endoluminal 3D views and requires time-consuming 2D evaluation. Electronic cleansing (EC) software algorithms can overcome this limitation by digitally subtracting tagged residue from the colonic lumen. Ideally, this enables a seamless 3D endoluminal evaluation. Despite this benefit, EC is a potential source of a wide range of artefacts. Accurate EC requires proper CTC examination technique and faecal tagging. The digital subtraction process has been shown to affect the relevant morphological features of both colonic anatomy and colonic lesions, if submerged under faecal residue. This article summarises the potential effects of EC on CTC imaging, the consequences for reporting and patient management, and strategies to avoid pitfalls. Furthermore, potentially negative effects on clinical reporting and patient management are shown, and problem-solving techniques, as well as recommendations for the appropriate use of EC techniques, are presented. Radiologists using EC should be familiar with EC-related effects on polyp size and also with correct measurement techniques.

Impact of Social Support on Colorectal Cancer Screening among Adult Hispanics/Latinos: A Randomized Community-based Study in Central Pennsylvania

In the United States, the five-year survival rate of colorectal cancer for Latinos is lower than it is for White, non-Latinos. Differences in survival are due, in part, to Latinos being diagnosed at a later stage. An ethnic gap in the use of colorectal cancer screening contributes to the difference in survival. We developed, implemented, and evaluated a targeted colorectal cancer screening intervention to increase colorectal cancer screening uptake by sex, ethnicity, and geography. We measured actual colorectal cancer screening uptake in both arms as a method to determine completion rates. We used a randomized, community-based, participatory design to test the impact of social support (intervention) on completion of a provider-recommended, take-home fecal immunochemical test (FIT) kit screening test among average-risk, urban, and rural Pennsylvania Latino adults age 50 and older not currently adherent to national colorectal cancer screening guidelines (n = 264). Participants in each arm attended a community-based educational program offered at eight sites. Among the 264 participants, 154 (58%) returned a completed usable FIT kit screening test. A higher return rate was observed among participants in the social support arm (66.0%) compared with the control (47.2%). Participants in the social support arm were statistically significant 2.67 times as likely to return a completed FIT kit. Of these, 27 (17.5%) had a positive FIT kit screening test result. The results of this study suggest that social support is an effective method to increase colorectal cancer screening rates among Latinos. Future studies should examine dissemination and implementation of community-based strategies among Latinos that include social support.

Evaluation of Low-Dose Multidetector Computed Tomography Whole Gastroenterography With Oral Administration of Contrast Agents

PURPOSE

To evaluate the degree of gastric, enteric, colonic, and rectal filling in multidetector computed tomography (MDCT) whole gastroenterography.

METHODS

In this prospective study involving 124 patients, 78 and 46 patients underwent MDCT whole gastroenterography using positive and neutral oral contrast agents, respectively. The degree of filling of the stomach, small and large bowel, was qualitatively analyzed by experienced radiologists using a 3-point scoring system.

RESULTS

The majority of patients received a score of ≥2 for small intestine filling using both positive and neutral contrast agents (90.5% and 78.2%, respectively), and <9% of the patients had a score of 0. The highest score for the degree of filling in the small intestine was observed in the ileum, followed by the duodenum and jejunum. There was a significant difference in the degree of filling achieved with positive and neutral contrast agents in the duodenum (P = .013) and jejunum (P = .047). More than 74% of cases had an optimal filling of the stomach, whereas >80% of the cases had an optimal filling of the colorectal segments. Only ≤5.1% had a score of 0 for the analyzed segments of the colorectum. Positive and neutral contrast agents were associated with similar degree of filling in the stomach and colon segments without a significant difference in the extent of contrast agent filling (P > .05).

CONCLUSIONS

Multidetector computed tomography whole gastroenterography was found to be a simple, safe, noninvasive, painless, and effective modality for the diagnosis of stomach and bowel complications in clinical settings.

Biomarkers for detecting colorectal cancer non-invasively: DNA, RNA or proteins?

Colorectal cancer (CRC) is a global problem affecting millions of people worldwide. This disease is unique because of its slow progress that makes it preventable and often curable. CRC symptoms usually emerge only at advanced stages of the disease, consequently its early detection can be achieved only through active population screening, which markedly reduces mortality due to this cancer. CRC screening tests that employ non-invasively detectable biomarkers are currently being actively developed and, in most cases, samples of either stool or blood are used. However, alternative biological substances that can be collected non-invasively (colorectal mucus, urine, saliva, exhaled air) have now emerged as new sources of diagnostic biomarkers. The main categories of currently explored CRC biomarkers are: (1) Proteins (comprising widely used haemoglobin); (2) DNA (including mutations and methylation markers); (3) RNA (in particular microRNAs); (4) Low molecular weight metabolites (comprising volatile organic compounds) detectable by metabolomic techniques; and (5) Shifts in gut microbiome composition. Numerous tests for early CRC detection employing such non-invasive biomarkers have been proposed and clinically studied. While some of these studies generated promising early results, very few of the proposed tests have been transformed into clinically validated diagnostic/screening techniques. Such DNA-based tests as Food and Drug Administration-approved multitarget stool test (marketed as Cologuard®) or blood test for methylated septin 9 (marketed as Epi proColon® 2.0 CE) show good diagnostic performance but remain too expensive and technically complex to become effective CRC screening tools. It can be concluded that, despite its deficiencies, the protein (haemoglobin) detection-based faecal immunochemical test (FIT) today presents the most cost-effective option for non-invasive CRC screening. The combination of non-invasive FIT and confirmatory invasive colonoscopy is the current strategy of choice for CRC screening. However, continuing intense research in the area promises the emergence of new superior non-invasive CRC screening tests that will allow the development of improved disease prevention strategies.

Low Colorectal Cancer Screening Uptake and Persistent Disparities in an Underserved Urban Population

Colorectal cancer screening has increased substantially in New York City in recent years. However, screening uptake measured by telephone surveys may not fully capture rates among underserved populations. We measured screening completion within 1 year of a primary care visit among previously unscreened patients in a large urban safety-net hospital and identified sociodemographic and health-related predictors of screening.We identified 21,256 patients ages 50 to 75 who were seen by primary care providers (PCP) in 2014, of whom 14,425 (67.9%) were not up-to-date with screening. Because PCPs facilitate the majority of screening, we compared patients who received screening within 1 year of an initial PCP visit to those who remained unscreened using multivariable logistic regression.Among patients not up-to-date with screening at study outset, 11.5% (1,658 patients) completed screening within 1 year of a PCP visit. Asian race, more PCP visits, and higher area-level income were associated with higher screening completion. Factors associated with remaining unscreened included morbid obesity, ever smoking, Elixhauser comorbidity index of 0, and having Medicaid/Medicare insurance. Age, sex, language, and travel time to the hospital were not associated with screening status. Overall, 39.9% of patients were up-to-date with screening by 2015.In an underserved urban population, colorectal cancer screening disparities remain, and overall screening uptake was low. Because more PCP visits were associated with modestly higher screening completion at 1 year, additional community-level education and outreach may be crucial to increase colorectal cancer screening in underserved populations.

HCT116 colorectal liver metastases exacerbate muscle wasting in a mouse model for the study of colorectal cancer cachexia

Colorectal cancer (CRC) is often accompanied by formation of liver metastases (LM) and skeletal muscle wasting, i.e. cachexia. Despite affecting the majority of CRC patients, cachexia remains underserved, understudied and uncured. Animal models for the study of CRC-induced cachexia, in particular models containing LM, are sparse; therefore, we aimed to characterize two new models of CRC cachexia. Male NSG mice were injected subcutaneously (HCT116) or intrasplenically (mHCT116) with human HCT116 CRC tumor cells to disseminate LM, whereas experimental controls received saline (n=5-8/group). Tumor growth was accompanied by loss of skeletal muscle mass (HCT116: -20%; mHCT116: -31%; quadriceps muscle) and strength (HCT116: -20%; mHCT116: -27%), with worsened loss of skeletal muscle mass in mHCT116 compared with HCT116 (gastrocnemius: -19%; tibialis anterior: -22%; quadriceps: -21%). Molecular analyses revealed elevated protein ubiquitination in HCT116, whereas mHCT116 also displayed elevated Murf1 and atrogin-1 expression, along with reduced mitochondrial proteins PGC1α, OPA1, mitofusin 2 and cytochrome C. Further, elevated IL6 levels were found in the blood of mHCT116 hosts, which was associated with higher phosphorylation of STAT3 in skeletal muscle. To clarify whether STAT3 was a main player in muscle wasting in this model, HCT116 cells were co-cultured with C2C12 myotubes. Marked myotube atrophy (-53%) was observed, along with elevated phospho-STAT3 levels (+149%). Conversely, inhibition of STAT3 signaling by means of a JAK/STAT3 inhibitor was sufficient to rescue myotube atrophy induced by HCT116 cells (+55%). Overall, our results indicate that the formation of LM exacerbates cachectic phenotype and associated skeletal muscle molecular alterations in HCT116 tumor hosts.

Economic Evaluation of Tailored Web versus Tailored Telephone-Based Interventions to Increase Colorectal Cancer Screening among Women

Screening for colorectal cancer is cost-effective, but many U.S. women are nonadherent, and the cost-effectiveness of web-based tailored screening interventions is unknown. A randomized controlled trial, COBRA (Increasing Colorectal and Breast Cancer Screening), was the source of information for the economic evaluation. COBRA compared screening among a Usual Care group to: (i) tailored Phone Counseling intervention; (ii) tailored Web intervention; and (iii) tailored Web + Phone intervention groups. A sample of 1,196 women aged 50 to 75 who were nonadherent to colorectal cancer screening were recruited from Indiana primary care clinics during 2013 to 2015. Screening status was obtained through medical records at recruitment with verbal confirmation at consent, and at 6-month follow-up via medical record audit and participant self-report. A "best sample" analysis and microcosting from the patient and provider perspectives were applied to estimate the costs and effects of the interventions. Statistical uncertainty was analyzed with nonparametric bootstrapping and net benefit regression analysis. The per participant cost of implementing the Phone Counseling, Web-based, and Web + Phone Counseling interventions was $277, $314, and $336, respectively. The incremental cost per person screened for the Phone Counseling compared with no intervention was $995, while the additional cost of Web and the Web + Phone compared with Phone Counseling did not yield additonal persons screened. Tailored Phone Counseling significantly increased colorectal cancer screening rates compared with Usual Care. Tailored Web interventions did not improve the screening rate compared with the lower cost Phone Counseling intervention.

Advanced X-ray Imaging Technology

Since their discovery by Wilhelm Conrad Röntgen in 1895, X-rays have become the most widely available, typically fastest, and usually most cost-effective medical imaging modality today. From the early radiographic approaches using X-ray films as detectors, the portfolio of medical X-ray imaging devices developed into a large range of dedicated instrumentation for various applications. While X-ray imaging has come a long way, there are some physical properties of X-rays, which have not yet been fully exploited, and which may offer quite some room for further enhancements of current X-ray imaging equipment. Firstly, X-ray imaging today is mainly black and white, despite the fact that X-ray generators actually create a full spectrum of X-ray energies, and that the interactions of X-rays that occur within the human body are not the same for all energies and every material. Exploiting these spectral dependencies allows to not only obtain a black and white CT image, but also to obtain more molecularly specific information, which is relevant particularly in oncological precision radiology. The second aspect of X-rays, and so far in radiology mainly neglected and unused, is the physical fact that X-rays can also be interpreted in the wave picture, and not only as presently been done in the particle picture. If interpreted as waves, X-rays-just like visible light-experience a phase shift in matter, and this-if exploited correctly-can produce a new class of X-ray images, which then depict the wave interactions of X-rays with matter, rather than only the attenuating properties, as done until now.

Multi-scale characterizations of colon polyps via computed tomographic colonography

Texture features have played an essential role in the field of medical imaging for computer-aided diagnosis. The gray-level co-occurrence matrix (GLCM)-based texture descriptor has emerged to become one of the most successful feature sets for these applications. This study aims to increase the potential of these features by introducing multi-scale analysis into the construction of GLCM texture descriptor. In this study, we first introduce a new parameter - stride, to explore the definition of GLCM. Then we propose three multi-scaling GLCM models according to its three parameters, (1) learning model by multiple displacements, (2) learning model by multiple strides (LMS), and (3) learning model by multiple angles. These models increase the texture information by introducing more texture patterns and mitigate direction sparsity and dense sampling problems presented in the traditional Haralick model. To further analyze the three parameters, we test the three models by performing classification on a dataset of 63 large polyp masses obtained from computed tomography colonoscopy consisting of 32 adenocarcinomas and 31 benign adenomas. Finally, the proposed methods are compared to several typical GLCM-texture descriptors and one deep learning model. LMS obtains the highest performance and enhances the prediction power to 0.9450 with standard deviation 0.0285 by area under the curve of receiver operating characteristics score which is a significant improvement.

Validation of an automated adenoma detection rate calculating system for quality improvement of colonoscopy

Purpose

This study aimed to validate an automated calculating system developed for determining the adenoma detection rate (ADR).

Methods

To calculate the automated ADR, the data linking processes were as follows: (1) matching the selected colonoscopy results with the pathological results, (2) matching the polyp number from colonoscopy with that from pathology and confirming the histopathological results of each colonic polyp, and (3) confirming the histopathological results, especially the adenoma status of each colonic polyp. To verify the accuracy of the automated ADR calculating system, we manually calculated the ADR for 3 months through medical record review. Accuracy was calculated by measuring the error rate for each value. The cause of error was analyzed by additional order and chart review.

Results

After excluding 318 cases, 2,543 patients (1,351 men and 1,192 women; median age, 57.9 years) who underwent colonoscopy were included in this study. When the automated calculating system was used, polyps were found in 1,336 cases (52.6%) and adenomas were found in 1,003 cases (39.4%). When the manual calculating system was used, polyps were found in 1,327 cases (52.2%) and adenomas were found in 1,003 cases (39.4%). The accuracies of the polyp detection rate and ADR according to the automated calculating system were 99.3% and 100%, respectively.

Conclusion

We developed a system to automatically calculate the ADR by extracting hospital electronic medical record results and verified that it provided satisfactory results. It may help to improve colonoscopy quality.

Associations between area-level deprivation, rural residence, physician density, screening policy and late-stage colorectal cancer in Canada

BACKGROUND

Important social disparities in colorectal screening exist in Canada. Few studies have assessed disparities further along the cancer control continuum. Here we assess the associations between social and material deprivation, physician density, rural residence, and the absence of provincial mail-based screening programs and colorectal cancer (CRC) stage at diagnosis.

METHODS

Colorectal cancer cases and stage data ("local or regional" if stage 0, I, or II, "late" if stage III or IV) were obtained through the Canadian Cancer Registry (2011-2015, N = 54,745). Cases were linked to 2006 Canadian Census Dissemination Area-level data on rural/urban status, exposure to a provincial mail-based screening program, and social and material deprivation (Pampalon Index quintile groups); and to Scott's Medical Database 2011 physician density data (<7 vs. ≥ 7/10,000). Age, sex, and predictor-adjusted Generalized estimating equation (GEE) Poisson models were used to determine independent associations between predictors and late-stage at diagnosis.

RESULTS

Half of CRC cases are diagnosed at stage III or IV (51 %), with younger age groups experiencing higher late-stage prevalence (57 % among those aged 18-49). The covariate-adjusted late-stage prevalence was 2-percentage points higher in most materially- and socially-deprived areas (95 % CI: 1 %, 4 %, in both, respectively) and in provinces with no mail-based screening programs (95 % CI: 1 %, 2 %). No significant differences were observed according to rural residence or physician density.

CONCLUSIONS

Social disparities in late-stage CRC diagnosis are modest. Continued surveillance of these disparities may be warranted as provinces continue to promote early cancer detection through screening, and stage distributions may change overtime.

Computer-assisted assessment of colonic polyp histopathology using probe-based confocal laser endomicroscopy

INTRODUCTION

Probe-based confocal laser endomicroscopy (pCLE) is a promising modality for classifying polyp histology in vivo, but decision making in real-time is hampered by high-magnification targeting and by the learning curve for image interpretation. The aim of this study is to test the feasibility of a system combining the use of a low-magnification, wider field-of-view pCLE probe and a computer-assisted diagnosis (CAD) algorithm that automatically classifies colonic polyps.

METHODS

This feasibility study utilized images of polyps from 26 patients who underwent colonoscopy with pCLE. The pCLE images were reviewed offline by two expert and five junior endoscopists blinded to index histopathology. A subset of images was used to train classification software based on the consensus of two GI histopathologists. Images were processed to extract image features as inputs to a linear support vector machine classifier. We compared the CAD algorithm's prediction accuracy against the classification accuracy of the endoscopists.

RESULTS

We utilized 96 neoplastic and 93 non-neoplastic confocal images from 27 neoplastic and 20 non-neoplastic polyps. The CAD algorithm had sensitivity of 95%, specificity of 94%, and accuracy of 94%. The expert endoscopists had sensitivities of 98% and 95%, specificities of 98% and 96%, and accuracies of 98% and 96%, while the junior endoscopists had, on average, a sensitivity of 60%, specificity of 85%, and accuracy of 73%.

CONCLUSION

The CAD algorithm showed comparable performance to offline review by expert endoscopists and improved performance when compared to junior endoscopists and may be useful for assisting clinical decision making in real time.

The global, regional, and national burden of colorectal cancer and its attributable risk factors in 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

Data about the global, regional, and country-specific variations in the levels and trends of colorectal cancer are required to understand the impact of this disease and the trends in its burden to help policy makers allocate resources. Here we provide a status report on the incidence, mortality, and disability caused by colorectal cancer in 195 countries and territories between 1990 and 2017.

METHODS

Vital registration, sample vital registration, verbal autopsy, and cancer registry data were used to generate incidence, death, and disability-adjusted life-year (DALY) estimates of colorectal cancer at the global, regional, and national levels. We also determined the association between development levels and colorectal cancer age-standardised DALY rates, and calculated DALYs attributable to risk factors that had evidence of causation with colorectal cancer. All of the estimates are reported as counts and age-standardised rates per 100 000 person-years, with some estimates also presented by sex and 5-year age groups.

FINDINGS

In 2017, there were 1·8 million (95% UI 1·8-1·9) incident cases of colorectal cancer globally, with an age-standardised incidence rate of 23·2 (22·7-23·7) per 100 000 person-years that increased by 9·5% (4·5-13·5) between 1990 and 2017. Globally, colorectal cancer accounted for 896 000 (876 300-915 700) deaths in 2017, with an age-standardised death rate of 11·5 (11·3-11·8) per 100 000 person-years, which decreased between 1990 and 2017 (-13·5% [-18·4 to -10·0]). Colorectal cancer was also responsible for 19·0 million (18·5-19·5) DALYs globally in 2017, with an age-standardised rate of 235·7 (229·7-242·0) DALYs per 100 000 person-years, which decreased between 1990 and 2017 (-14·5% [-20·4 to -10·3]). Slovakia, the Netherlands, and New Zealand had the highest age-standardised incidence rates in 2017. Greenland, Hungary, and Slovakia had the highest age-standardised death rates in 2017. Numbers of incident cases and deaths were higher among males than females up to the ages of 80-84 years, with the highest rates observed in the oldest age group (≥95 years) for both sexes in 2017. There was a non-linear association between the Socio-demographic Index and the Healthcare Access and Quality Index and age-standardised DALY rates. In 2017, the three largest contributors to DALYs at the global level, for both sexes, were diet low in calcium (20·5% [12·9-28·9]), alcohol use (15·2% [12·1-18·3]), and diet low in milk (14·3% [5·1-24·8]).

INTERPRETATION

There is substantial global variation in the burden of colorectal cancer. Although the overall colorectal cancer age-standardised death rate has been decreasing at the global level, the increasing age-standardised incidence rate in most countries poses a major public health challenge across the world. The results of this study could be useful for policy makers to carry out cost-effective interventions and to reduce exposure to modifiable risk factors, particularly in countries with high incidence or increasing burden.

FUNDING

Bill & Melinda Gates Foundation.

Incidence of colorectal cancer in Eritrea: Data from the National Health Laboratory, 2011-2017

Introduction

Recent studies have reported a significant increase in the prevalence of colorectal cancer (CRC) in Sub-Saharan Africa (SSA). Further, several studies employing disparate modelling algorithms have projected a significant rise in the frequency of CRC cases in the region. However, lack of good quality data on multiple themes related to CRC including incidence, among others, continues to be a problem in the region. Therefore, this study was designed to collect data on the incidence of CRC in Eritrea.

Methods

We conducted a retrospective analysis using data captured between 2011 and 2017 at the National Health Laboratory (NHL) in Asmara, Eritrea.

Results

241 colorectal cases were identified in the Eritrean National Health Laboratory (NHL) database between 2011 and 2017. In the final analysis we included 94 patients confirmed cases giving an average of 18.8 patients per annum. The average age ± Standard deviation (SD) was 57.62 ± 17.14 with a male: female ratio of 58/36 (1: 1.61). The minimum and maximum age of the patients was 19 and 90 years, respectively. The rectum to colon ratio was 47/47 (1:1). The proportion of patients < 50 years in this cohort was significant. The age-standardized incidence rate (ASIR) in the study period was between 0.97 per 100 000 to 2.21 per 100 000. Similarly, the cumulative ASIR was 9.97 per 100 000. Analysis of trends did not reveal shifts over the study period (P<0.05). However, a strong correlation between incidence and age was established.

Conclusion

This study suggests that the incidence of CRC in Eritrea is relatively low. A significant number of patients were less than 50 years of age. Even then it’s our opinion that this study may underestimate the incidence of CRC.

Risk Factors for Colorectal Cancer in Korea: A Population-Based Retrospective Cohort Study

Purpose

The incidence of colorectal cancer in Korea has recently increased, making it the second most common cancer in men and the third most common cancer in women. Risk factors for colorectal cancer have been studied worldwide, but risk factors specific for the Korean population have not been established. In this study, we investigated incidence trends and risk factors of colorectal cancer in Korea.

Methods

A total of 8,846,749 subjects were included. Colorectal cancer incidence was investigated using Korea National Health Insurance Service claim data from 2004 to 2014. Colorectal cancer diagnoses were obtained by evaluating colorectal cancer diagnostic codes and the cancer registry for cost sharing. Risk factor identification for colorectal cancer was obtained from National Health Examination data from 2004 to 2005. Cox proportional hazard model statistical analysis was used to determine risk factors of colorectal cancer.

Results

The incidence of colorectal cancer gradually increased from 2006 to 2014 (from 45.4/100,000 to 54.5/100,000). There was a predominance among men (1.47:1), but incidence trends were similar in both sexes. Old age, high body mass index, and no history of colonoscopy were identified as risk factors in both sexes. High fasting blood glucose, familial history of cancer, frequent alcohol intake, and current smoker were identified as risk factors, especially in men.

Conclusion

The incidence of colorectal cancer has been increasing in Korea. Colonoscopy screening was a protective factor for colorectal cancer, and active use of colonoscopy may reduce incidence. Early diagnosis and care are important, particularly for the high-risk group.

Perceived life expectancy and colorectal cancer screening intentions and behaviour: A population-based UK study

The relationships between perceived life expectancy (PLE), cancer screening intentions and behaviour are not well understood, despite the importance of remaining life expectancy for the early diagnosis benefits of screening. This study investigates the relationships between PLE and each of: the intention to complete faecal occult blood test (FOBt) screening, ‘ever’ uptake of FOBt screening, and repeat uptake of FOBt screening for colorectal cancer. Data were from the population-representative Attitudes, Behaviour and Cancer UK Survey II (ABACUS II) in England in 2015. Eligible respondents for the present analysis were aged 60–70 years (FOBt eligible age range), who completed the survey question on perceived life expectancy (N = 824). We used logistic regression models to estimate the associations between PLE and the intention to complete screening, ‘ever’ uptake of screening, and repeat uptake of screening, with adjustment for age, gender, occupation-based social grade, marital status, ethnicity, and smoking status. PLE was positively associated with repeated uptake of FOBt (adjusted OR = 2.55; 95% CI: 1.04–6.30 for expecting to live to ≥90 years versus <80 years). Older adults may base decisions to continually participate in cancer screening on their expectations of remaining life expectancy. Future research should investigate the feasibility and acceptability of individualised cancer screening recommendations that take life expectancy into account.

Variations in Screening Adenoma Detection Rate by Specialty of Physicians in a Predominately African American Population

BACKGROUND

Screening colonoscopy aims to interrupt the adenoma-carcinoma sequence by removing all precancerous adenomatous polyps. Adenomatous polyp detection rate (ADR) can vary between endoscopists as well as between race, age, and risk of colorectal cancer (CRC). The purpose of this study was to compare ADR among academic gastroenterologists (A-GI), non-A-GI, and surgeons for endoscopies performed in the same endoscopic suite of a large medical center with a predominately African American (AA) population.

METHODS

All screening colonoscopies performed in 2014 for patients aged 62-76 years were identified using the electronic medical records data. Patients with average risk and high risk of CRC defined as having a 'personal history of polyps' or 'family history of CRC', and history of ulcerative colitis and Fecal Occult Blood Test/Fecal Immunochemical Test (FOBT/FIT) positivity were included. Patients with incomplete colonoscopy (defined as failing to achieve cecal intubation or poor preparation) and unrecovered tissue biopsy were excluded. ADR was calculated for three groups of endoscopists: A-GIs, non-A-GIs, and surgeons.

RESULTS

A total of 573 screening colonoscopies was analyzed. The endoscopists comprised five A-GIs, eight non-A-GIs, and six surgeons. The majority of patients were of AA decent (71%), female (54%) with an average age of 66 years. Patients classified as average risk comprised 79% of the population. Most of the colonoscopies were performed by A-GI (n=339), followed by non-A-GI (n=144), and surgeons (n=90). The ADR for A-GI was 50% as compared to 32% for non-A-GI (p<0.001) and 25% for surgeons (p<0.001). Also, A-GI were more likely to identify ≥3 adenomas during screening colonoscopies. Significant differences were observed (p<0.001) in the mean time of colonoscopy for A-GI (30 mins) non-A-G (14 mins), and surgeons (18 mins).

CONCLUSION

Significant variation in the ADR between endoscopists belonging to different specialties were observed. Although all appear to achieve acceptable ADR (ie at least 25 for men and 15 for women), academic gastroenterologists had better performance than non-academic GI and surgeons. This may be explained by a significantly longer average duration of procedures for the highest ADR group.

Outcomes associated with use of the Cancer Risk Intake System among primary care safety-net patients identified as needing colorectal cancer screening

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Guideline-based CRC screening is low among average- and elevated-risk individuals.

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Cancer Risk Intake System (CRIS) generates tailored CRC screening recommendations.

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44% of elevated- and 90% of average-risk patients received guideline-based orders.

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Only about half of elevated-risk group underwent guideline-concordant colonoscopy.

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Half of the average-risk group received guideline-concordant screening.

Despite demonstrated primary and secondary prevention benefits, screening for colorectal cancer (CRC) is sub-optimal. We implemented the Cancer Risk Intake System (CRIS) among a convenience sample of patients presenting for primary care in Dallas County safety-net clinics. CRIS, which assesses individuals’ CRC risks and generates guideline-based screening recommendations for them and their providers, had been found in a randomized trial to facilitate risk-based screening, compared to usual care. Here, of 924 patients ages ≥50 who used CRIS, 699 were identified as needing screening, with 39.2% needing colonoscopy rather than FIT. However, following use of CRIS and patients’ and providers’ receipt of guideline-concordant recommendations, 20.9% elevated-risk patients received no screening orders, only 44.1% received guideline-concordant colonoscopy orders, and less than half of these (48.4%) completed colonoscopy. Guideline-concordant screening orders were more common for average-risk patients (62.5% received orders for FIT and 26.6% for colonoscopy). However, like their elevated-risk counterparts who received screening orders, more than half of average-risk patients in each order group (52.3% for FIT and 52.8% for colonoscopy) did not complete screening. We found no correlates for receiving screening orders, but higher comorbidity scores were associated with less screening completion among the average-risk group. We had hoped CRIS would facilitate risk-based screening but, although orders for and receipt of colonoscopy were more common for elevated- than average-risk patients, they were still suboptimal in this clinical setting with a “FIT-first” strategy. A stronger intervention may be necessary to increase guideline-concordant recommendations and screening among patients 50 and older.

Technical Note: Increased photon starvation artifacts at low helical pitch in ultra-low-dose CT

PURPOSE

The aim of this study was to demonstrate that a low helical pitch causes increased photon starvation artifacts at ultra-low-dose CT.

METHODS

A cylindrical water phantom with a diameter of 30 cm was scanned on two different generation CT scanners: a 64-slice scanner (Sensation 64, Siemens Healthcare) and a 192-slice scanner (Somatom Force, Siemens Healthcare) at multiple effective mAs levels (mAs/pitch = 200, 100, 50, 25, and 12). The corresponding CTDI_vol values were 4.1, 2.0, 1.0, 0.5 mGy, on the 64-slice scanner and 3.8, 1.9, 1.0, 0.5 mGy on the 192-slice scanner, for the selected effective mAs values. For each dose setting, the scan was repeated at four helical pitches: 1.2, 0.9, 0.6, and the lowest achievable pitch on each scanner. The tube current was automatically adjusted by the scanner so that the effective mAs, and thus CTDI_vol , were kept the same for different pitches. All CT data sets were reconstructed with a slice thickness of 3mm and a medium smooth kernel. Images acquired at the same dose level but different helical pitches were visually inspected to assess photon starvation artifacts and noise levels.

RESULTS

At the same radiation dose, image noise increased with the decreasing helical pitch. The increase was more severe on the old-generation 64-slice scanner. Photon starvation artifacts were evident at 200 effective mAs on the 64-slice scanner at 80 kV. On the 192-slice scanner there was no visible photon starvation artifacts at both 200 and 50 effective mAs (CTDI_vol  = 4.1 mGy and 1.0 mGy, respectively); nor was there a visible impact from the lower helical pitch. Only when the dose was lowered to be extremely low (~0.26 mGy, achievable at 70 kV), did photon starvation artifacts become evident.

CONCLUSIONS

A low helical pitch may increase image noise and photon starvation artifacts compared to a higher pitch for the same dose level, particularly at ultra-low dose CT.

Demographic and Clinicopathological Patterns of Colorectal Cancer at the National Cancer Institute, Sudan

Background:

Colorectal cancer is a common type of cancer worldwide, including in Sudan. However, few studies have assessed its demographic, clinical and pathological patterns in the Sudanese population.

Objective:

To assess the demographic, clinical and pathological patterns in patients with colorectal cancer at National Cancer Institute, University of Gezira, Sudan.

Methods:

This retrospective, cross-sectional study analyzed the data of all colorectal cancer patients who presented to National Cancer Institute, University of Gezira, between January 2016 and December 2017. National Cancer Institute, University of Gezira, is one of the two National Cancer Institutes in Sudan and receives patients from across Sudan. The demographic, clinical and pathological information were extracted from the patients’ files.

Results:

A total of 163 colorectal cancer patients who presented to National Cancer Institute during the study period and met the inclusion criteria were included in this study. Most patients were aged >40–69 years (58.8%), were male (53.4%) and from Central Sudan (65.6%). About 44% of the patients were diagnosed 6–12 months from the disease onset and 26.8% after >12 months. Change in bowel habits (51.5%), rectal bleeding (42.3%) and abdominal pain (32.5%) were the most common clinical presentations. About 58% of the patients did not undergo per rectal examination during their initial presentation. Rectum was the most common site of tumor (58.9%), and the majority of patients had Grade I adenocarcinoma (50.3%). Duke's Class B (38%) and Class C (31%) were the most common stages of the patients’ tumor, and signet ring carcinoma was found in 4.9% of the patients.

Conclusion:

This study found that in Sudan, colorectal cancer patients most commonly present late after the onset of symptoms, with an advanced stage and aggressive pattern as well as the proportion of younger patients is high. Further, per rectal examination is often not performed during the initial presentation.