Low-risk Adenomas Research Articles

Natural history of colorectal cancer: a Meta-analysis on global prospective cohort studies

Objective: To acknowledge the availability and rates of annual transition of outcomes during the progression and regression stages of colorectal cancer (CRC) and related diseases, by pooling global follow-up studies on the natural history of CRC. Methods: Till March, 2017, data was collected through systematic literature review over multiple databases, including PubMed, Embase, Cochrane and Chinese Biology Medicine (CBM) disc. Information regarding the characteristics, classification system of health states, related outcomes and incidence rates on CRC or high-risk adenoma for the surveillance cohorts of the studies, were extracted and summarized. Both Meta and sensitivity analyses were performed on those outcomes if they appeared in more than 3 studies, using the random effects model. Annual transition rate with 95%CI was used to estimate each of the outcomes, Quality of the studies was assessed, using the Newcastle-Ottawa Scale. Results: A total of 29 cohort studies were included, with the mean follow-up period as 5.7 years. All studies except one, focused on adenoma-carcinoma pathway and reported the outcome parameters of adenomas by different risk, and some reported the findings on different sizes (n=6) of adenomas. These cohorts were divided into three groups (normal status, with low-risk or high-risk adenoma) according to the status of baseline endoscopic pathologic findings. Their available outcome parameters, corresponding number of involved articles, aggregated sample size and pooled annual transition rates were presented. Six parameters were obtained in the normal cohorts, including those from normal to low-risk adenoma (16 articles, 58 235, 0.030: 0.024-0.037), to high-risk adenoma (17 articles, 62 089, 0.003: 0.002-0.004), to diminutive adenoma (<5 mm, 4 articles, 1 277, 0.021: 0.013-0.029), to small adenoma (6-9 mm, 4 articles, 1 277, 0.006: 0.001-0.010), to large adenoma (≥10 mm, 7 articles, 3 531, 0.002: 0.000-0.003) and to CRC (19 articles, 104 836, 0.000 3: 0.000 2-0.000 5). Three parameters were obtained in low-risk adenoma in cohorts with polypectomy findings, including recurrence (9 articles, 4 788, 0.109: 0.062-0.157) from low-risk adenoma after polypectomy to high-risk adenoma (10 articles, 5 736, 0.009: 0.004-0.013) and to CRC (12 articles, 11 347, 0.000 6: 0.000 4-0.000 8). Three parameters were obtained on high-risk adenoma from cohorts with polypectomy findings, including recurrence (12 articles, 7 030, 0.038: 0.028-0.048) from high-risk adenoma after polypectomy to low-risk adenoma (8 articles, 2 489, 0.133: 0.081-0.185) and CRC (14 articles, 14 899, 0.002: 0.001-0.003). Except for normal to low-risk adenomas, results from the sensitivity analysis for the other parameters showed stable. Of the included studies, two presented incidence rates of CRC in different clinical stages and the another two were focusing on the parameters related to serrated pathway. Conclusions: Globally, follow-up studies reported data on natural history of colorectal cancer is of paucity. Compared to the "adenoma-carcinoma" pathway, transition parameters of the serrated lesion pathway are more limited. This Meta-analysis provided convincing evidence for optimizing the strategies regarding follow-up program on the disease, using the baseline endoscopic findings from global CRC Screening Program. These results also offered strong data-related support for Chinese population- specific interventional model on colorectal cancer.

Comparison of the Uptake of Screening Colonoscopy between Physicians and the General Population in Greece

Aim: To evaluate the uptake of screening colonoscopy among physicians as compared to the general population. Methods: Asymptomatic physicians, aged 45–67 years, at average risk for colorectal cancer (CRC), working in the participating National Health System hospitals were asked to complete a questionnaire regarding the uptake of screening colonoscopy. The results were compared to those in a background healthy population, aged 50–75 years, inhabitants of a Greek county, who were offered a free access to a screening colonoscopy program for CRC. High-risk adenomas were those ≥10 mm in diameter or any adenoma, regardless of size, with villous histology or high-grade dysplasia. Results: Overall, 267 of 782 physicians and 402 of 6,534 nonphysicians underwent a screening colonoscopy (uptake rates 34.2 and 6.2% respectively, p = 0.00001). Screening colonoscopy has yielded 4 adenocarcinomas (1.6%), 14 high-risk adenomas (5.5%), and 61 low-risk adenomas (25.7%) in the physicians’ group. Corresponding figures in the nonphysician arm were 4 (1), 26 (6.5), and 107 (26.6%), respectively. The main reason among physicians for nonadherence was indifference/negligence (n = 213). Conclusion: The proportion of physicians undergoing screening colonoscopy for CRC is significantly higher compared to the general population; however, it does remain suboptimal.

Abstract 4213: Stool-derived eukaryotic RNA (seRNA) assay for noninvasive detection of colorectal cancer and high-risk adenomas

Abstract Colorectal cancer (CRC) is the second leading cause of cancer related deaths in the United States. The high mortality rate for CRC is largely attributable to the frequency of late-stage diagnoses, caused by low patient compliance with screening guidelines. A novel nucleic acid extraction method that isolates stool-derived eukaryotic RNA (seRNA) has permitted development of a colorectal cancer stool diagnostic test (CRC-SDT) that uses a fecal immunochemical test (FIT) and 11 seRNA transcripts to serve as a reliable and noninvasive screening alternative to lower mortality associated with CRC. Stool samples were obtained from 190 individuals prior to undergoing a screening colonoscopy. Patients were diagnosed as either having colorectal cancer, having high-risk adenomas (high-grade dysplasia, villous growth pattern, or &amp;gt;1.0cm in size), or healthy (low-risk adenomas, benign polyps, and/or no findings on a colonoscopy). FITs were obtained for each sample. Samples that had a positive FIT were considered positive for the CRC-SDT. Samples that had a negative FIT underwent seRNA isolation, library preparation (Illumina TruSeq Targeted RNA) and subsequent sequencing (Illumina NextSeq 550). A random forest model was built using 11 transcripts that were differentially expressed (log2 fold-change &amp;gt; 1; ANOVA p &amp;lt; 0.05) between diseased patients (CRC and high-risk adenomas) relative to the healthy cohort. Internal 10-fold cross-validation was performed for the training set and a receiver operating characteristic (ROC) area under the curve (AUC) determined model accuracy for cancer and high-risk adenomas relative to the healthy cohort. Model predictions for an independent hold-out test set were used to determine model accuracy for colorectal cancer and high-risk adenomas. Internal cross-validation for 154 samples attained a ROC AUC of 0.82. The trained model was employed on the independent hold-out test set of 36 samples and model predictions were compared to colonoscopy results. The model attained a 100% sensitivity for CRC (n = 7), a 60% sensitivity for high-risk adenomas (n = 5), and an 88% combined specificity for the healthy cohort (n = 24). CRC-SDT uses 12 biomarkers (FIT and expression from 11 seRNA transcripts) to accurately detect CRC and high-risk adenomas. Use of seRNA biomarkers dramatically improves detection of high-risk adenomas relative to existing noninvasive screening methods for CRC. Citation Format: Erica K. Barnell, Yiming Kang, Katie M. Campbell, Kimberly R. Kruse, Andrew R. Barnell, Elizabeth M. Wurtzler. Stool-derived eukaryotic RNA (seRNA) assay for noninvasive detection of colorectal cancer and high-risk adenomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4213.

Time to colonoscopy, cancer probability, and precursor lesions in the Danish colorectal cancer screening program.

PurposeThe aim of this study was to investigate the effect of response time from the Fecal Immunochemical Test (FIT) based screening invitation to the conclusive screening Optical Colonoscopy (OC) on the risk of detecting colorectal cancer (CRC), advanced stage disease and precursor lesions.Patients and methodsWe used a cross-sectional study design and included all 62,554 screening participants registered in the Danish Colorectal Cancer Screening Database who tested FIT-positive between March 2014 and December 2016. The main exposure was response time, measured as the time from initial invitation to the conclusive OC. Our main outcomes were the probability of being diagnosed with CRC, advanced stage disease or precursor lesions.ResultsOf the 62,554 FIT-positive participants, 53,171 (85%) received an OC and were eligible for analysis (median age 63.7 years, 56% men). In this group, 3,639 cancers were registered, 2,890 of which were registered with a defined stage of disease (79%), and 1,042 (36%) of these were advanced stage (UICC III & IV). In addition, 17,732 high-risk and 10,605 low-risk adenomas were identified. Compared to participants receiving the conclusive examination within 30 days, those receiving the examination more than 90 days after initial invitation were 3.49 times more likely to be diagnosed with any CRC (OR 3.49 [95% CI, 3.13–3.89]) and 2.10 times more likely to have advanced stage disease (OR 2.10 [95% CI, 1.73–2.56]). Those waiting for the longest were also more likely to have one or more high-risk adenomas (OR 1.59 [95% CI, 1.50–1.68]).ConclusionIncreased screening response time was associated with a higher probability of detecting high-risk adenomas, any stage CRC and advanced stage cancer. More research is needed to explain what causes these associations.

Su1699 HIGH-RISK LESIONS ARE A STRONGER PREDICTOR FOR INTERVAL CANCER THAN LOW ADENOMA DETECTION RATE

After index colonoscopy patients with high-risk adenomas (≥2 polyps or ≥10 mm or high-grade dysplasia or villous or tubulovillous histology) should undergo surveillance colonoscopy after 3 years, patients with low-risk adenomas after 10 years. Although endoscopic screening reached high quality standards, interval cancers still occur in a significant number of patients and the underlying risk factors are poorly understood.

Noninvasive Detection of High-Risk Adenomas Using Stool-Derived Eukaryotic RNA Sequences as Biomarkers

Abstract Background and aims Colorectal cancer (CRC) is the second leading cause of cancer related deaths in the United States. Mortality is largely attributable to low patient compliance with screening and a subsequent high frequency of late-stage diagnoses. Noninvasive methods, such as stool- or blood-based diagnostics could improve patient compliance, however, existing techniques cannot adequately detect high-risk adenomas (HRAs) and early-stage CRC. Methods Here we apply cancer profiling using amplicon sequencing of stool-derived eukaryotic RNA for 275 patients undergoing prospective CRC screening. A training set of 154 samples was used to build a random forest model that included 4 feature types (differentially expressed amplicons, total RNA expression, demographic information, and fecal immunochemical test results). An independent hold out test set of 121 patients was used to assess model performance. Results When applied to the 121-patient hold out test set, the model attained a receiver operating characteristic (ROC) area under the curve (AUC) of 0.94 for CRC and a ROC AUC of 0.87 for CRC and HRAs. In aggregate, the model achieved a 91 % sensitivity for CRC and a 73% sensitivity for HRAs at an 89% specificity for all other findings (medium-risk adenomas, low-risk adenomas, benign polyps, and no findings on a colonoscopy). Conclusion Collectively, these results indicate that in addition to early CRC detection, stool-derived biomarkers can accurately and noninvasively identify HRAs, which could be harnessed to prevent CRC development for asymptomatic, average-risk patients.

Characterization of high- and low-risk hepatocellular adenomas by magnetic resonance imaging in an animal model of glycogen storage disease type 1A.

ABSTRACTHepatocellular adenomas (HCAs) are benign tumors, of which the most serious complications are hemorrhage and malignant transformation to hepatocellular carcinoma (HCC). Among the various subtypes of HCA, the β-catenin-activated subtype (bHCA) is associated with greatest risk of malignant transformation. Magnetic resonance imaging (MRI) is an important tool to differentiate benign and malignant hepatic lesions, and preclinical experimental approaches may help to develop a method to identify MRI features associated with bHCA. HCAs are associated with various pathologies, including glycogen storage disease 1a (GSD1a). Here, we utilized a mouse model for GSD1a that develops HCA and HCC, and analyzed the mice in order to distinguish low-risk from high-risk tumors. Animals were scanned by MRI using a hepato-specific contrast agent. The mice were sacrificed after MRI and their lesions were classified using immunohistochemistry. We observed that 45% of the animals developed focal lesions, and MRI identified four different patterns after contrast administration: isointense, hyperintense and hypointense lesions, and lesions with peripheral contrast enhancement. After contrast administration, only bHCA and HCC were hypointense in T1-weighted imaging and mildly hyperintense in T2-weighted imaging. Thus, high-risk adenomas display MRI features clearly distinguishable from those exhibited by low-risk adenomas, indicating that MRI is a reliable method for early diagnosis and classification of HCA, necessary for correct patient management.

Proposal of high-risk adenoma detection rate as an impactful, complementary quality indicator of colonoscopy.

Adenoma detection rate (ADR), a validated quality indicator (QI) of colonoscopy, does not take into account risk stratification of adenomas. Low-risk adenomas are not associated with a significantly increased risk of future colorectal cancer (CRC). On the other hand, high-risk adenomas (HRA) are associated with up to six fold higher risk of future CRC. Therefore, HRA detection rate (HR-ADR) as a QI in addition to ADR may further enhance the efficacy of screening colonoscopy. Our aim was to calculate ADR and HR-ADR in a large cohort of average risk screening colonoscopy patients and propose HR-ADR which correlates with current threshold ADR. This is a retrospective chart review of all colonoscopies performed in patients aged ≥ 50years at our institution between 2012 and 2014. Average risk patients who had complete colonoscopy with good, excellent and adequate bowel preparation were included. Overall and gender-specific ADR and HR-ADR were calculated. HR-ADR was defined as proportion of colonoscopies with HRA. Among 4158 colonoscopies included, ADR was 26.4 ± 10.9% overall, 32.7 ± 14.5% in men, and 22.1 ± 12.6% in women. HR-ADR was 8.0 ± 5.7% overall, 10.2 ± 8.6% in men, and 6.1 ± 6% in women. There was only moderate correlation between ADR and HR-ADR [r = 0.57 (0.40-0.70)]. HR-ADR corresponding with minimum threshold ADR of 30% in men and 20% in women were calculated to be 7% in men and 4% in women. HR-ADR correlates only moderately with ADR. Based on the current threshold ADRs, we propose a benchmark HR-ADR of 7% in men and 4% in women as complementary QI to ADR.

Adherence to post-polypectomy surveillance guidelines: a systematic review and meta-analysis.

Colorectal cancer (CRC) is a major worldwide cause of cancer-related mortality. Colonoscopy programs based on guideline-recommended surveillance intervals have been put in place to reduce the morbidity and mortality associated with CRC. We were interested to evaluate clinical practice adherence to guideline-recommended surveillance intervals, the potential extent of early repeat colonoscopies, and causes of nonadherence to guideline recommendations. We performed a literature search for articles reporting on guideline adherence for surveillance colonoscopies. Exclusion criteria included inflammatory bowel disease and hereditary CRC syndrome cohorts. Primary outcome was correct interval assignment in patients undergoing surveillance colonoscopy. Groups were assessed for adherence according to their respective guideline recommendations (North American or European). 16 studies were included in the analysis. The mean colonoscopy surveillance interval adherence rate was 48.8 % (95 % confidence interval [CI] 37.3 - 60.4). For North American guidelines, surveillance interval assignments were adherent to guideline recommendations in 44.7 % (95 %CI 24.2 - 66.3) of patients after detection of low risk lesions and in 54.6 % (95 %CI 41.4 - 67.4) after detection of high risk lesions. For European guidelines, surveillance interval assignments were adherent to recommendations in 24.4 % (95 %CI 1.1 - 63.4) of patients after detection of low risk lesions and in 73.6 % (95 %CI 35.5 - 98.8) after detection of high risk lesions. The worldwide adherence to surveillance colonoscopy guidelines was low, with more than 50 % of patients undergoing repeat colonoscopies either too early or too late. Early repeat colonoscopies occurred with the highest frequency for patients in whom only hyperplastic polyps or low risk adenomas were found.

Low Sensitivity of Fecal Immunochemical Tests and Blood-Based Markers of DNA Hypermethylation for Detection of Sessile Serrated Adenomas/Polyps.

Early detection and removal of precursor lesions reduce colorectal cancer morbidity and mortality. Sessile serrated adenomas/polyps (SSP) are a recognized precursor of cancer, but there are limited studies on whether current screening techniques detect this pathology. To investigate the sensitivity of fecal immunochemical tests (FIT) and epigenetic biomarkers in blood for detection of SSP. A prospective study offered FIT and a blood test (Colvera for methylated BCAT1 and IKZF1) to adults referred for colonoscopy. Sensitivity of FIT and the blood test were determined for four types of pathology: low-risk conventional adenoma, high-risk adenoma, SSP, and absence of neoplasia. Comparisons were made for FIT positivity at 10 and 20μg hemoglobin (Hb)/g feces. One thousand eight hundred and eighty-two subjects completed FIT and underwent colonoscopy. One thousand four hundred and three were also tested for methylated BCAT1/IKZF1. The sensitivity of FIT (20μg Hb/g feces) for SSP was 16.3%. This was lower than the sensitivity for high-risk adenomas (28.7%, p < 0.05), but no different to that for low-risk adenomas (13.1%) or no neoplasia (8.4%). A positive FIT result for SSP was not associated with demographics, morphology, concurrent pathology or intake of medications that increase bleeding risk. FIT sensitivity for SSP did not significantly increase through lowering the positivity threshold to 10μg Hb/g feces (20.4%, p > 0.05). Sensitivity of the blood test for SSP was 8.8%, and 26.5% when combined with FIT. Both FIT and blood-based markers of DNA hypermethylation have low sensitivity for detection of SSP. Further development of sensitive screening tests is warranted.

Surveillance colonoscopies frequently booked earlier than the National Health and Medical Research Council guidelines: findings of a single centre audit.

To assess the adherence rate of surveillance colonoscopy booking intervals to recommended National Health and Medical Research Council guidelines at The Queen Elizabeth Hospital, Adelaide, Australia. Patients on The Queen Elizabeth Hospital colorectal unit surveillance colonoscopy waiting list were included in this audit. Patient demographics, colonoscopy findings, follow-up plans and pathology results were analysed. Patients were categorized as normal/non-neoplastic finding, low-risk adenomas, high-risk adenomas, personal history of colorectal cancer (CRC) and family history of CRC. Booked colonoscopy within 2 months of guideline recommended interval was considered correct. A total of 467 patients were included (59.1% male; mean age 60 years). Two hundred and fifty-one (53.7%) patients had an incorrect surveillance colonoscopy booking. Twenty-seven patients with a normal/non-neoplastic previous colonoscopy not requiring surveillance colonoscopy were incorrectly booked for a colonoscopy. For the 222 patients booked incorrectly and requiring surveillance colonoscopy, 88.7% were early and 11.3% were late. The proportions of incorrect bookings were highest in the low-risk finding (66.1%) and history of CRC (67.6%) groups. For the 186 patients requiring a 3-year surveillance interval, 38.7% were booked incorrectly. For the 197 patients requiring a 5-year surveillance interval, 63.5% were booked incorrectly, of which 99.2% were early. More 5-year surveillance interval patients were booked at 3 years (n = 79), than at the correct interval of 5 years (n = 72). Adherence to the National Health and Medical Research Council guidelines for surveillance colonoscopy is poor. The majority of deviations represent early follow-up, which is most common among patients with low-risk findings or history of CRC. There is a tendency towards 3-year surveillance among low-risk patients.

Management of Pt1 tumours removed by endoscopy during colorectal cancer screening: Outcome and treatment quality indicators

IntroductionLimited information is available about outcomes of patients with malignant adenomas endoscopically resected at screening. The aim of the study was to evaluate diagnostic and therapeutic quality indicators and to correlate them with clinical and surgical outcomes. Materials and methodsWe reviewed endoscopic and histology characteristics of all pT1 tumours endoscopically removed at the time of colonoscopy assessment in subjects with a positive screening test result in the context of a population-based program. Results392 pT1 tumours were completely removed by endoscopy (en-bloc = 86.7%, piecemeal = 13.3%) and the histology report was considered complete in 83.2% of cases. Treatment was limited to endoscopic excision for 120 patients (30.7%, Group 1), 272 (69.3%, Group 2) underwent radicalisation surgery. In patients who had at least 1 lymph node examined, the rate of nodal involvement was 5.4% (13/239); no metastatic node was found in the 21 (27.6%) out of 76 patients with low-risk adenomas, who underwent surgery. ConclusionRisk of nodal involvement in colorectal pT1 tumours is well predicted by known histologic features also in a screening setting, although it was lower than among patients from clinical series. Surgical overtreatment is still significantly present and there is ample room for improvement regarding diagnostic and therapeutic flow-chart.

Utilization and determinants of follow-up colonoscopies within 6 years after screening colonoscopy: Prospective cohort study.

Previous studies have reported that repeat colonoscopies were often not conducted in the recommended time interval after screening colonoscopy. We prospectively followed participants of screening colonoscopy from Germany for 6 years to investigate utilization and determinants of repeat colonoscopies. In a longitudinal study on the effectiveness of screening colonoscopy in the state of Saarland (Germany), participants who had a screening colonoscopy between 2005 and 2007 were contacted by mail 6 years after screening and requested to fill in a standardized questionnaire on utilization of repeat colonoscopies. For all colonoscopies reported, colonoscopy and histology reports were requested from the physician(s). Of 6,407 screening participants, 2,212 (35%) have utilized another colonoscopy. Among participants with negative findings at screening (no adenomas), 962 (22%) had a subsequent colonoscopy within 6 years from screening, accounting for 43% of all patients with a repeat colonoscopy. Family history of CRC and detection of hyperplastic polyps were found to be determinants of higher repeat colonoscopy use. As many as 44% of the participants with low-risk adenomas (N = 509) and 39% with high-risk adenomas (N = 290) at screening did not utilize surveillance colonoscopy within 6 years. Utilization was better with higher school education, prior cancer screening participation and if high-risk adenomas were detected, lower among current smokers and lowest among participants ≥70 years. New strategies will be required considering determinants of adherence to avoid unnecessary colonoscopies and to improve utilization of surveillance according to recommended time intervals among patients at higher risk of CRC in the future.

Risk of Metachronous Advanced Neoplasia in Patients With Multiple Diminutive Adenomas

Individuals with advanced adenomas or three or more adenomas have a higher risk of metachronous advanced neoplasia (AN) and are recommended to undergo surveillance colonoscopy at shorter intervals. However, it is questionable whether patients with multiple (three or more) non-advanced diminutive adenomas should be considered as high-risk. We analyzed 5482 patients diagnosed with one or more adenomas during their first colonoscopy screening and who underwent a follow-up colonoscopy. Patients were categorized into four groups based on adenoma characteristics at baseline: Group 1, 1-2 non-advanced adenomas; Group 2, ≥3 non-advanced, diminutive (1 to 5 mm) adenomas; Group 3, ≥3 non-advanced, small (6-9 mm) adenomas; and Group 4, advanced adenomas. During a median follow-up of 38 months, the incidence of metachronous AN at surveillance colonoscopy was 5.6%. The incidence of AN was 3.9% in group 1, 5.9% in group 2, 10.6% in group 3, and 22.1% in group 4. The adjusted hazard ratios (HRs) [95% confidence intervals (CIs)] for metachronous AN between group 2, group 3, and group 4, and low risk group 1 were 1.71 (0.99-2.94), 2.76 (1.72-4.44), and 5.23 (3.57-7.68), respectively. Compared with group 4, the adjusted HRs (95% CIs) for group 1, group 2, and group 3 were 0.19 (0.13-0.28), 0.32 (0.18-0.59), and 0.52 (0.31-0.89), respectively. We found that patients with three or more non-advanced diminutive adenomas had a borderline increased risk of metachronous AN compared with patients with low risk adenomas.

Risk of developing metachronous advanced colorectal neoplasia after colonoscopic polypectomy in patients aged 30 to 39 and 40 to 49 years

Current guidelines define postpolypectomy surveillance intervals in patients aged≥50 years. The risk of metachronous colorectal neoplasia (CRN) and the optimal postpolypectomy surveillance interval in patients aged<50 years remain unclear. We compared the risk of metachronous CRN in patients aged 30 to 39, 40 to 49, and≥50 years. We studied patients who underwent≥1 adenoma removal between 2010 and 2014 and follow-up colonoscopic surveillance until2017. Among 10,014 patients studied, 3242, 4606, and 2166 were 30 to 39, 40 to 49, and≥50 years old, respectively. After high-risk adenoma removal, the 3-year risk of metachronous advanced CRN (ACRN) in patients aged 30 to 39 and 40 to 49 years was lower than in patients≥50 years old (1.9% and 3.6% vs 8.1%, respectively; P< .001 and .008). After low-risk adenoma removal, the 5-year risk of metachronous ACRN in patients aged 30 to 39 and 40 to 49 years was lower than in patients≥50 years old (2.8% and 3.3% vs 5.9%, respectively; P= .010 and .031). The risk of metachronous ACRN or≥3 adenomas in patients aged 30 to 39 years was significantly lower than in patients aged 40 to 49 years. Age remained significantly associated with the risk of metachronous ACRN despite adjustments for potential confounders. The risk of metachronous ACRN was lower in patients aged<50 years than in those aged≥50 years; thus, the postpolypectomy surveillance interval may be extendable to >3 and 5 years in high-risk and low-risk adenoma groups, respectively, in patients aged<50 years.

Patient Attitudes Toward Lengthening Colonoscopy Interval After Low-Risk Adenomas

Patients with one or two tubular adenomas <10 mm in size with low-grade dysplasia are said to have low-risk adenomas, and in the current surveillance

Veterans’ Attitudes Towards De-Intensification of Surveillance Colonoscopy for Low-Risk Adenomas

Veterans’ Attitudes Towards De-Intensification of Surveillance Colonoscopy for Low-Risk Adenomas

DCLK1 Expression in Colorectal Polyps Increases with the Severity of Dysplasia.

The expression of doublecortin-like kinase 1 (DCLK1) has been investigated in cancer; however not in precancerous adenomatous polyps. Immunohistological expression of DCLK1 was evaluated in various grades of adenomas, cancerous polyps, and hyperplastic polyps in resected human tissue specimens. Ninety-two specimens were positive for DCLK1 and 134 were negative. Cancerous polyps showed a high DCLK1 positivity rate compared to adenomas (68.4% vs. 36.8%; p<0.01). The rate of DCLK1 positivity was not significantly different among the three grades of adenomas (mild, moderate, and severe). DCLK1 was highly positive in advanced adenomas than low risk adenomas (49.6% vs. 29.3%; p<0.01). The expression of DCLK1 was found in low-grade adenomas and increased with worsening severity of dysplasia. DCLK1 expression was highly observed in advanced adenomas, which had a clinically higher malignant potential.

Use of gas sensors and FOBT for the early detection of colorectal cancer

Among the major challenges of medicine today there is the early detection of tumors, in order to prevent their degeneration into malignant stages and/or metastases. In particular, the colorectal cancer shows a high curability rate, up to 90%, if identified when in stage I. This is the reason why a reliable screening protocol is strictly necessary to avoid colorectal cancer progression. The Protocol discussed here is proposed to implement the clinical validation of a device, consisting of an array of chemoresistive semiconductor gas sensors, capable of identifying the difference between fecal exhalation of healthy subjects and of subjects suffering from high-risk colorectal adenomas or cancers. The analysis done are compared to the results of fecal occult blood test and colonoscopy as a gold standard. The difference among the two classes of fecal samples is due to the presence of tumor gaseous biomarkers, produced by cancerous cells through membrane peroxidation process and metabolic alterations. Our method combines a specific algorithm appositely created for data acquisition with principal component analysis and support vector machine. The test resulted capable of recognizing all the colorectal cancer plus high risk adenomas and the 98% of healthy subjects. The recognition capability of low-risk adenomas is progressively increasing (45%) along with statistics.

Comparison of Flexible Sigmoidoscopy Screening in Average Risk Patients Performed by Nurses Versus Gastroenterologists.

BackgroundScreening sigmoidoscopy is effective in reducing mortality from colorectal cancer. In 2009, Cancer Care Ontario (CCO) launched a nurse-performed screening flexible sigmoidoscopy program at Hotel Dieu Hospital, Kingston, Ontario. Prior to this program, there was a pilot sigmoidoscopy screening program by gastroenterologists in a similar average risk cohort.AimTo compare neoplasia detection rates and associated costs of screening sigmoidoscopy performed by nurses and gastroenterologists.MethodA retrospective chart review was conducted on flexible sigmoidoscopies performed as part of two average risk screening programs performed by gastroenterologists and nurse-endoscopists. Detected polyps were categorized as hyperplastic, low-risk adenomas or high-risk adenomas. Average cost per procedure was estimated based on physician fee for service charges, nurse wage and benefits, physician supervisory fees, pathology costs and administrative expenses.ResultsThere were 538 procedures performed by nurses and 174 by physicians. Adenomas were detected in 18% of nurse-performed procedures versus 9% in physician-performed procedures (p=0.003), with the higher adenoma detection rate restricted to low risk adenomas. One cancer was found in the physician group. Seven physicians performed the 174 sigmoidoscopies, with one physician performing the majority. This physician’s adenoma detection rate was 4.5%, whereas detection rate for the remaining physicians combined was 16.5%. Nurses biopsied more polyps per case (0.96 versus 0.18). Average estimated cost per case was greater for nurses ($387.54 versus $309.37).ConclusionWell-trained nurse-endoscopists can provide an effective service for colorectal cancer screening, but as currently structured in Ontario, the associated cost is higher for nurse-performed procedures.