Prognostic significance of high-grade dysplasia in colorectal adenomas

A population-based analysis on the incidence of metachronous colon cancer after endoscopic resection of advanced adenomas with high-grade dysplasia: does location matter?

BACKGROUND

Advanced adenomas (AAs) with high-grade dysplasia (HGD) represent a risk factor for metachronous neoplasia, with guidelines recommending short-interval surveillance. Although the worse prognosis of proximal (vs distal) colon cancers (CCs) is established, there is paucity of evidence on the impact of laterality on the risk of subsequent neoplasia for these AAs.

METHODS

Adults with HGD adenomas undergoing polypectomy were identified in the Surveillance, Epidemiology, and End Results database (2000-2019). Cumulative incidence of malignancy was estimated using the Kaplan-Meier method. Fine-Gray models assessed the effect of patient and disease characteristics on CC incidence.

RESULTS

Of 3199 patients, 26% had proximal AAs. A total of 65 cases of metachronous adenocarcinoma were identified after polypectomy of 35 proximal and 30 distal adenomas with HGD. The 10-year cumulative incidence of CC was 2.3%; when stratified by location, it was 4.8% for proximal vs 1.4% for distal adenomas. Proximal location was significantly associated with increased incidence of metachronous cancer (adjusted hazard ratio, 3.32; 95% CI, 2.05-5.38).

CONCLUSION

Proximal location of AAs with HGD was associated with >3-fold increased incidence of metachronous CC and shorter time to diagnosis. These data suggest laterality should be considered in the treatment and follow-up of these patients.

Diagnostic performance of endocytoscopy with normal pit-like structure sign for colorectal low-grade adenoma compared with conventional modalities

Objectives

A "resect-and-discard" strategy has been proposed for diminutive adenomas in the colorectum. However, this strategy is sometimes difficult to implement because of the lack of confidence in differentiating low-grade adenoma (LGA) from advanced lesions such as high-grade adenoma or carcinoma. To perform real-time precise diagnosis of LGA with high confidence, we assessed whether endocytoscopy (EC) diagnosis, considering normal pit-like structure (NP-sign), an excellent indicator of LGA, could have additional diagnostic potential compared with conventional modalities.

Methods

All the neoplastic lesions that were observed by non-magnifying narrow-band imaging (NBI), magnifying NBI (M-NBI), magnifying pit pattern, and EC prior to pathological examination between 2005 and 2018 were retrospectively investigated. The neoplastic lesions were classified into two categories: LGA and other neoplastic lesions. We assessed the differential diagnostic ability of EC with NP-sign between LGA and other neoplastic lesions compared with that of NBI, M-NBI, pit pattern, and conventional EC in terms of sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (AUC).

Results

A total of 1376 lesions from 1097 patients were eligible. The specificity (94.9%), accuracy (91.5%), and area under the receiver operating characteristic curve (0.95) of EC with NP-sign were significantly higher than those of NBI, M-NBI, pit pattern, and conventional EC.

Conclusions

EC diagnosis with NP-sign has significantly higher diagnostic performance for predicting colorectal LGA compared with the conventional modalities and enables stratification of neoplastic lesions for "resect-and-discard" with higher confidence.

Lymphoglandular Complex-Like Colorectal Carcinoma-A Series of 20 Colorectal Cases, Including Newly Reported Features of Malignant Behavior

Distinguishing colon carcinoma that is surrounded by well-circumscribed lymphoid tissue from adenomas involving lymphoglandular complexes can be difficult. We assessed a multi-institutional international cohort of 20 colorectal carcinomas with associated prominent lymphoid infiltrates, which we referred to as lymphoglandular complex-like carcinoma (LGCC). We collected clinical and endoscopic features, including lesion size, endoscopic appearance, location, procedure, follow-up, AJCC stage, and mismatch repair status. We recorded the presence of the following histologic features: haphazard gland distribution, gland angulation, gland fusion, solid nest formation, single-cell formation, stromal desmoplasia, presence of lymphovascular invasion and perineural invasion, presence of lamina propria, cytologic atypia as low- or high-grade, presence of goblet cells in the invasive component, and the presence of a surface lesion. Most cases (9 of 13) were described endoscopically as sessile polyps with an average size of 1.56 cm. Most cases (90%) were associated with a surface lesion, of which the majority were tubular adenomas, though a subset was associated with sessile serrated lesions with dysplasia (3 of 18). All cases of LGCC demonstrated haphazard gland distribution and either gland angulation, fusion, or solid nest formation. A portion of cases demonstrated single-cell infiltration (35%) and desmoplasia (50%), and rarely lymphovascular invasion was present (5%). A subset (10%) of cases invaded beyond the submucosa. Deficient mismatch repair was present in 22% (2 of 9) of cases for which it was performed. In cases of colectomy or completion colectomy, nodal metastasis was present in 38% (3 of 8). No cases demonstrated disease recurrence or disease-specific mortality. Overall, LGCC represents an enigmatic subset of carcinomas that is important to distinguish from adenomas involving lymphoglandular complexes due to its varying prognostic outcomes.

Recurrence rates of advanced colorectal neoplasia (ACN) in subjects with baseline ACN followed up at different surveillance intervals

BACKGROUND

Current clinical guidelines recommend that a baseline finding of advanced colorectal neoplasia (ACN) should be followed-up within 1-3 years.

AIM

We compared the recurrence rate of ACN at 1 year vs. 3 years among individuals with ACN detected and polypectomised at baseline colonoscopy.

METHODS

We extracted data from eligible patients in a Chinese population database from 2008 to 2018. The outcome variables included recurrence of advanced adenoma and advanced neoplasia, respectively, at follow-up colonoscopy. Binary logistic regression modeling was constructed to examine the association between length of surveillance and the outcome variables, controlling for risk factors of colorectal cancer, including age, gender, smoking, alcohol drinking, body mass index and chronic diseases.

RESULTS

We included 147,270 subjects who have received a baseline colonoscopy from our dataset. They were aged 69.3 years and 59.7% of them were male subjects. The crude 1-year and 3-year recurrence rate of ACN was 7.57% and 7.74%. From a binary logistic regression model, individuals with surveillance colonoscopy performed at 3 years did not have significantly higher recurrence rate of ACN than those followed-up at 1 year.

CONCLUSIONS

No statistically significantly difference in recurrence of ACN between individuals who received workup at 1vs. 3 years. These findings support a 3-year surveillance period after baseline ACN was polypectomised.

Baseline Characteristics and Longitudinal Outcomes of Traditional Serrated Adenomas: A Cohort Study

BACKGROUND AND AIMS

Traditional serrated adenomas (TSAs) may confer increased risk for colorectal cancer (CRC). Our objective with this study was to examine clinical characteristics and long-term outcomes associated with TSA diagnosis.

METHODS

We conducted a retrospective cohort study of U.S. Veterans ≥18 years of age with ≥1 TSA between 1999 and 2018. Baseline characteristics, colonoscopy findings, and diagnosis of incident and fatal CRC were abstracted. Advanced neoplasia was defined by CRC or adenoma with high-grade dysplasia, villous histology, or size ≥1 cm. Follow-up was through CRC diagnosis, death, or end of study (December 31, 2018).

RESULTS

A total of 853 Veterans with a baseline TSA were identified; 74% were ≥60 years of age, 96% were men, 14% were Black, and 73% were non-Hispanic White. About 64% were current or former smokers. Over 2044 total person-years at follow-up, there were 11 incident CRC cases and 1 CRC death. Cumulative CRC incidence was 1.34% (95% confidence interval [CI], 0.67%-2.68%), and cumulative CRC death was 0.12% (95% CI, 0.00%-0.35%). Among the subset of 378 TSA patients with ≥1 surveillance colonoscopy, 65.1% had high-risk neoplasia on follow-up. CRC incidence among TSA patients was significantly higher than in a comparison cohort of patients with normal baseline colonoscopy at baseline (hazard ratio, 3.70; 95% CI, 1.63-8.41) and similar to a comparison cohort with baseline conventional advanced adenoma (hazard ratio, 0.86; 95% CI, 0.45-1.64).

CONCLUSION

Individuals with TSA have substantial risk for CRC based on their cumulative CRC incidence, as well as significant risk of developing other high-risk neoplasia at follow-up surveillance colonoscopy. These data underscore importance of current recommendations for close colonoscopy surveillance after TSA diagnosis.

A computer-aided diagnosis system using white-light endoscopy for the prediction of conventional adenoma with high grade dysplasia

OBJECTIVES

We developed a computer-aided diagnosis system called ECRCCAD using standard white-light endoscopy (WLE) for predicting conventional adenomas with high-grade dysplasia (HGD) to optimise the patients' management decisions during colonoscopy.

METHODS

Pretraining model was used to fine-tune the model parameters by transfer learning. 2,397 images of HGD and 2,487 low-grade dysplasia (LGD) images were randomly assigned (8:1:1) to the training, optimising, and internal validation dataset. The prospective validation dataset is the frames accessed from colonoscope videoes. One independent rural hospital provided an external validation dataset. Histopathological diagnosis was used as the standard criterion. The capability of the ECRCCAD to distinguish HGD was assessed and compared with two expert endoscopists.

RESULTS

The accuracy, sensitivity and specificity for diagnosis of HGD in the internal validation set were 90.5%, 93.2%, 87.9%, respectively. While 88.2%, 85.4%, 89.8%, respectively, for the external validation set. For the prospective validation set, ECRCCAD achieved an AUC of 93.5% in diagnosing HGD. The performance of ECRCCAD in diagnosing HGD was better than that of the expert endoscopist in the external validation set (88.2% vs. 71.5%, P < 0.0001).

CONCLUSION

ECRCCAD had good diagnostic capability for HGD and enabled a more convenient and accurate diagnosis using WLE.

The anti-tumor effects of CT-26 derived exosomes enriched by MicroRNA-34a on murine model of colorectal cancer

AIMS

As conventional therapeutics failed to provide satisfied outcomes against one of the most prevalent cancers, colorectal cancer (CRC), we purposed to implicate MicroRNA (miR)-34a, as a major tumor suppressor, to be delivered by tumor-derived exosomes (TEXs) and investigated its anti-tumor functions in-vivo.

MAIN METHODS

TEXs were isolated from CT-26 cell line and loaded with miR-34a mimic. Then, mice bearing CRC were treated with miR-34a-enriched TEX (TEX-miR-34a) and then examined for the relative tumor-suppressive impacts of the TEX as well as its potential in promoting an anti-tumor immune response.

KEY FINDINGS

TEX-miR-34a significantly reduced tumor size and prolonged survival of mice bearing CRC. TEX-miR-34a was able to diminish gene expressions related to invasion, angiogenesis and immune evasion. It was also capable of inducing T cell polarization toward CD8+ T subsets among tumor-infiltrating lymphocytes, draining lymph nodes (DLNs) and spleen cells. Moreover, cytotoxic T cells were professionally induced in mice receiving TEX-miR-34a and the secretion of interleukin (IL)-6, IL-17A and tumor necrosis factor (TGF)-β was reduced in DLNs. However, the enhanced levels of interferon-γ were evaluated in DLN and spleen displaying the polarization of anti-tumor immune responses. Interestingly, mice receiving TEX alone showed a noticeable reduction in certain oncogenic gene expressions as well as IL-17A secretion in DLNs.

SIGNIFICANCE

TEX-miR-34a demonstrated the potential to induce beneficial anti-tumor immune responses and TEXs, aside from the delivery function of miRNA, revealed certain anti-tumor beneficial characteristics which could introduce TEX-miR-34a as a promising approach in CRC combination therapies.

Long term outcomes of colon polyps with high grade dysplasia following endoscopic resection

BACKGROUND

The risk of recurrent colonic adenoma associated with high-grade dysplasia (HGD) colon polyps at baseline colonoscopy remains unclear. We conducted a clinical cohort study with patients who underwent polypectomy during screen colonoscopy to assess recurrent colonic adenoma risk factors.

METHODS

11,565 patients at our facility underwent screen colonoscopy between September 1998 and August 2007. Data from patients with HGD colon polyps who had undergone follow-up colonoscopy were included for analysis.

RESULTS

Data from 211 patients was included. Rates of metachronous adenoma and advanced adenoma at follow-up were 58% and 20%, respectively. Mean follow-up period was 5.5 ± 1.8 (3-12) years. Univariate logistic regression analysis revealed that an adenoma count of ≥ 3 at baseline colonoscopy was strongly associated with overall recurrence, multiple recurrence, advanced recurrence, proximal recurrence, and distal adenoma recurrence with odds ratios of 4.32 (2.06-9.04 95% CI), 3.47 (1.67-7.22 95% CI), 2.55 (1.11-5.89 95% CI), 2.46 (1.16-5.22 95% CI), 2.89 (1.44-5.78 95% CI), respectively. Multivariate analysis revealed gender (male) [P = 0.010; OR 3.09(1.32-7.25 95% CI)] and adenoma count ≥ 3 [P = 0.002; OR 3.08(1.52-6.24 95% CI)] at index colonoscopy to be significantly associated with recurrence of advanced adenoma.

CONCLUSION

Recurrence of colonic adenoma at time of follow-up colonoscopy is common in patients who undergo polypectomy for HGD colon adenomas during baseline colonoscopy. Risk of further developing advanced adenomas is associated with gender and the number of colon adenomas present.

Evidenced-Based Screening Strategies for a Positive Family History

The most commonly recognized high-risk group for colorectal cancer (CRC) is individuals with a positive family history. It is generally recognized that those with a first-degree relative (FDR) with CRC are at a 2-fold or higher risk of CRC or advanced neoplasia. FDRs of patients with advanced adenomas have a similarly increased risk. Accordingly, all major US guidelines recommend starting CRC screening by age 40 in these groups. Barriers to screening this group include patient lack of knowledge on family and polyp history, provider limitations in collecting family history, and insufficient application of guidelines.

Increased Risk of Colorectal Cancer Tied to Advanced Colorectal Polyps: An Untapped Opportunity to Screen First-Degree Relatives and Decrease Cancer Burden

Advanced adenomas represent a subset of colorectal polyps that are known to confer an increased risk of colorectal neoplasia to the affected individual and their first-degree relatives (FDRs). Accordingly, professional guidelines suggest earlier and more intensive screening for FDRs of those with advanced adenomas similar to FDRs of those with colorectal cancer (CRC). Although the risk to family members is less clear among patients with advanced serrated polyps, they are often considered in the same category. Unfortunately, there is a growing concern that patients, endoscopists, and primary care providers are unaware of the familial risk associated with these polyps, leaving a wide gap in screening these high-risk individuals. Herein, we propose a standardized language around advanced colorectal polyps and present a detailed review of the literature on associated familial risk. We outline the challenges to implementing the current screening recommendations and suggest approaches to overcome these limitations, including a proposed new colonoscopy quality metric to capture communication of familial CRC risk. Improving screening in these high-risk groups has the potential to substantially reduce the burden of CRC.

Biodegradable fluorescent nanoparticles for endoscopic detection of colorectal carcinogenesis

Early and comprehensive endoscopic detection of colonic dysplasia - the most clinically significant precursor lesion to colorectal adenocarcinoma - provides an opportunity for timely, minimally-invasive intervention to prevent malignant transformation. Here, the development and evaluation of biodegradable near-infrared fluorescent silica nanoparticles (FSN) is described that have the potential to improve adenoma detection during fluorescence-assisted white-light colonoscopic surveillance in rodent and human-scale models of colorectal carcinogenesis. FSNs are biodegradable (t_1/2 of 2.7 weeks), well-tolerated, and enable detection and delineation of adenomas as small as 0.5 mm² with high tumor-to-background ratios. Furthermore, in the human-scale, APC ^1311/+ porcine model, the clinical feasibility and benefit of using FSN-guided detection of colorectal adenomas using video-rate fluorescence-assisted white-light endoscopy is demonstrated. Since nanoparticles of similar size (e.g., 100-150-nm) or composition (i.e., silica, silica/gold hybrid) have already been successfully translated to the clinic, and, clinical fluorescent/white light endoscopy systems are becoming more readily available, there is a viable path towards clinical translation of the proposed strategy for early colorectal cancer detection and prevention in high-risk patients.

Further Defining the 2012 Multi-Society Task Force Guidelines for Surveillance of High-risk Adenomas: Is a 3-Year Interval Needed for All Patients?

GOALS

We set out to determine whether variation from this 3-year follow-up interval was associated with the finding of subsequent high-risk adenoma (HRA).

BACKGROUND

HRAs include the following: (1) an adenoma measuring ≥10 mm, (2) ≥3 adenomas found during a single procedure, and (3) an adenoma with high-grade dysplasia or villous architecture. The current Multi-Society Task Force guideline for timing of surveillance colonoscopy after removal of a HRA is 3 years.

STUDY

In 2016, we analyzed 495 patients who had a HRA removed during a 2008 colonoscopy. We compared the frequency of finding another HRA at follow-up intervals. We used the current guidelines as our referent group and performed logistical regression to identify whether any patient characteristics, procedural factors, or type of HRA predicted the development of HRAs on follow-up colonoscopy.

RESULTS

Individuals who followed-up at a median of 4.5 years did not have more HRA on follow-up compared with those who followed-up at 3 years (25.2% vs. 21.0%, P=0.062). These groups had similar baseline characteristics. Older individuals, male gender, having a history of polyps, and piecemeal resection of an HRA predicted future HRAs. The removal of ≥3 adenomas in 2008 as well as a combination of multiple, large, and advanced polyps showed a higher risk of future HRAs.

CONCLUSIONS

The 2012 Multi-Society Task Force recommendation of 3-year follow-up after removal of HRAs may not apply to all patients. We showed that a combination of patient demographics, procedural factors, and pathology best determines the surveillance colonoscopy interval.

Quantitative risk of positive family history in developing colorectal cancer: A meta-analysis

BACKGROUND

Positive family history is a risk factor for development of colorectal cancer. Despite numerous studies on the topic, the absolute risk in patients with a positive family history remains unclear and therefore studies are lacking to validate non-invasive screening methods in individuals with positive family history.

AIM

To quantify the risk of colorectal cancer in individuals with a positive family history.

METHODS

A comprehensive electronic literature search was performed using PubMed from January 1955 until November 2017, EMBASE from 1947 until 2018, and Cochrane Library without date restrictions. Two independent reviewers conducted study selection, data extraction and quality assessment. A meta-analysis of Mantel-Haenzel relative risks was performed using the random effects model. Newcastle-Ottawa scale was used to score the quality of selected papers. Funnel plot and Egger’s regression test was performed to detect publication bias. Subgroup analysis was performed comparing Asian and non-Asian studies. Sensitivity analyses were performed to rule out the effect of the timing of the study, overall quality, the main outcome and the effect of each individual study in overall result.

RESULTS

Forty-six out of 3390 studies, including 906981 patients were included in the final analysis. 41 of the included studies were case-control and 5 were cohort. A positive family history of colorectal cancer in first-degree relatives was associated with significantly increased risk of colorectal cancer with a relative risk of 1.87 (95%CI: 1.68-2.09; P < 0.00001). Cochrane Q test was significant (P < 0.00001, I² = 90%). Egger’s regression test showed asymmetry in the funnel plot and therefore the Trim and Fill method was used which confirmed the validity of the results. There was no difference between Asian versus non-Asian studies. Results remained robust in sensitivity analyses.

CONCLUSION

Individuals with a positive family history of colorectal cancer are 1.87 times more likely to develop colorectal cancer. Screening guidelines should pay specific attention to individuals with positive family history and further studies need to be done on validating current screening methods or developing new modalities in this high-risk population.

Decrease of variation in the grading of dysplasia in colorectal adenomas with a national e-learning module

AIMS

Variation in health-care is undesirable, as this is potentially harmful for patients. In the Netherlands, an e-learning module was developed to standardise pathological evaluation of colorectal adenomas. We studied the effect of e-learning on interlaboratory variability in grading of dysplasia in screened conventional colorectal adenomas.

METHODS AND RESULTS

A cross-sectional retrospective study was performed, including all colorectal adenomas from the Dutch population-based colorectal cancer screening programme, retrieved from the Dutch Pathology Registry (PALGA) from January 2014 to July 2015. The e-learning tool, commissioned by the National Institute for Public Health, was implemented among screening pathologists from October 2014. Proportions of high-grade dysplasia (HGD) were compared before (January-July 2014) and after implementation (October 2014-July 2015) of the e-learning module. Interlaboratory variation was assessed by multilevel mixed-effects analysis. In total, 20 713 colonoscopies (20 546 patients) were performed after a positive faecal immunochemical screening test, resulting in the inclusion of 56 355 conventional adenomas from 37 pathology laboratories. Before implementation, 12 614 adenomas were diagnosed, including 4.3% with HGD. After implementation, 43 741 adenomas were diagnosed, and the HGD proportion decreased to 3.9%. Univariable analysis showed less deviant proportions of HGD after implementation in 62% of the laboratories (P = 0.019). Multilevel analysis confirmed decreased variation in the risk of diagnosing HGD (P = 0.021).

CONCLUSIONS

Interlaboratory variability in grading HGD in colorectal adenomas after a positive screening test decreased after implementation of an e-learning module for pathologists. We therefore conclude that e-learning has a favourable influence on decreasing diagnostic variability, making this a relevant strategy for health-care standardisation.

The effect of small or diminutive adenomas at baseline colonoscopy on the risk of developing metachronous advanced colorectal neoplasia: KASID multicenter study

BACKGROUND

The clinical significance of diminutive or small adenomas remains ill defined.

AIMS

We evaluated the clinical impact of diminutive or small adenomas at baseline on the risk of developing metachronous advanced colorectal neoplasia (CRN).

METHODS

This multicenter, retrospective cohort study included 2252 patients with 1 or more colorectal adenomas at baseline and subsequent follow-up colonoscopy. Baseline colonoscopy findings were classified into 5 groups: 1 or 2 tubular adenomas (TAs) (<10 mm); 3-10 diminutive TAs (≤5 mm); 3-10 TAs, including 1 or 2 small adenomas (6-10 mm); 3-10 TAs, including 3 or more small adenomas; and advanced adenoma.

RESULTS

In multivariate analysis, after adjusting for possible confounding variables (age at baseline, sex, body mass index, smoking habits, family history of colorectal cancer, regular use of aspirin or NSAIDs, and adenoma location), 3-10 TAs including 3 or more small adenomas (hazard ratio [HR] = 2.36, p = 0.034) and advanced adenoma (HR = 2.14, p < 0.001) were independent predictors for the risk of developing metachronous advanced CRN. However, 3-10 diminutive TAs or 3-10 TAs, including 1 or 2 small adenomas, were not associated with this outcome.

CONCLUSIONS

Multiplicity of diminutive TAs, without advanced lesions, showed no clinical significance for risk of developing metachronous advanced CRN.

Colonoscopy surveillance for high risk polyps does not always prevent colorectal cancer

AIM

To determine the frequency and risk factors for colorectal cancer (CRC) development among individuals with resected advanced adenoma (AA)/traditional serrated adenoma (TSA)/advanced sessile serrated adenoma (ASSA).

METHODS

Data was collected from medical records of 14663 subjects found to have AA, TSA, or ASSA at screening or surveillance colonoscopy. Patients with inflammatory bowel disease or known genetic predisposition for CRC were excluded from the study. Factors associated with CRC developing after endoscopic management of high risk polyps were calculated in 4610 such patients who had at least one surveillance colonoscopy within 10 years following the original polypectomy of the incident advanced polyp.

RESULTS

84/4610 (1.8%) patients developed CRC at the polypectomy site within a median of 4.2 years (mean 4.89 years), and 1.2% (54/4610) developed CRC in a region distinct from the AA/TSA/ASSA resection site within a median of 5.1 years (mean 6.67 years). Approximately, 30% (25/84) of patients who developed CRC at the AA/TSA/ASSA site and 27.8% (15/54) of patients who developed CRC at another site had colonoscopy at recommended surveillance intervals. Increasing age; polyp size; male sex; right-sided location; high degree of dysplasia; higher number of polyps resected; and piecemeal removal were associated with an increased risk for CRC development at the same site as the index polyp. Increasing age; right-sided location; higher number of polyps resected and sessile endoscopic appearance of the index AA/TSA/ASSA were significantly associated with an increased risk for CRC development at a different site.

CONCLUSION

Recognition that CRC may develop following AA/TSA/ASSA removal is one step toward improving our practice efficiency and preventing a portion of CRC related morbidity and mortality.

Risk factors for intraepithelial neoplasia in patients with colorectal adenoma

AIM

To identify risk factors for intraepithelial neoplasia in colorectal adenoma by analyzing the clinical, endoscopic, and histopathological features of patients with colorectal adenoma.

METHODS

The clinical, endoscopic, and histopathological features of 657 patients with colorectal adenomatous polyps diagnosed by colonoscopy from January 2014 to April 2016 at Wuhan Union Hospital were retrospectively analyzed. The patients were divided into an intraepithelial neoplasia group and a non-intraepithelial neoplasia group according to the pathological diagnosis. χ² test was applied for univariate analysis between the two groups. Multivariate Logistic regression analysis was used to identify the risk factors for intraepithelial neoplasia and its malignancy degree in adenoma.

RESULTS

Most of colorectal adenomas were located in the left colon. The total incidence of intraepithelial neoplasia in colorectal adenoma was 22.68%. Age, polyp diameter, length of pedicle, and pathologic type were identified to be risk factors for intraepithelial neoplasia in adenoma, which could be incorporated in Logistic regression equation: logit P = -4.384 + 0.796X2 (age) + 0.324X3 (polyp diameter) + 1.296X4 (pedicle condition) + 0.944X7 (pathology type). Gender, age, and polyp size were identified to be risk factors for high-grade intraepithelial neoplasia in adenoma, which could be incorporated in Logistic regression equation: logit P = -2.939 + 1.036X1 (gender) + 0.853X2 (age) + 1.023X3 (polyp diameter). Total cholesterol (TC) and triglyceride (TG) in the low-grade and high-grade intraepithelial neoplasia groups were both significantly higher than those in the non-intraepithelial neoplasia group (P < 0.05). Low-density lipoprotein cholesterol (LDL-C) and uric acid (URIC) in the high-grade intraepithelial neoplasia group were both significantly higher than those in the non-intraepithelial neoplasia group (P < 0.05). There was no significant difference in the high-density lipoprotein cholesterol (HDL-C) or CEA among the three groups.

CONCLUSION

There is a greater risk of intraepithelial neoplasia among patients older than 40, having villous adenoma with diameter > 1 cm and pedicle. Male, polyp diameter, and age are risk factors for high-grade intraepithelial neoplasia in colorectal adenoma. The occurrence of intraepithelial neoplasia in adenoma may be related to blood lipids and uric acid levels.

Diagnostic performance of Japan NBI Expert Team classification for differentiation among noninvasive, superficially invasive, and deeply invasive colorectal neoplasia

BACKGROUNDS AND AIMS

The Japan NBI Expert Team (JNET) classification is the first universal narrow-band imaging magnifying endoscopic classification of colorectal tumors. Considering each type in this classification, the diagnostic ability of Type 2B is the weakest. Generally, clinical behavior is believed to be different in each gross type of colorectal tumor. We evaluated the differences in the diagnostic performance of JNET classification for each gross type (polypoid and superficial) and examined whether the diagnostic performance of Type 2B could be improved by subtyping.

METHODS

We analyzed 2933 consecutive cases of colorectal lesions, including 136 hyperplastic polyps/sessile serrated polyps, 1926 low-grade dysplasias (LGDs), 571 high-grade dysplasias (HGDs), and 300 submucosal (SM) carcinomas. We classified lesions as polypoid and superficial type and compared the diagnostic performance of the classification system in each type. Additionally, we subtyped Type 2B into 2B-low and 2B-high based on the level of irregularity in surface and vessel patterns, and we evaluated the relationship between the subtypes and histology, as analyzed separately for polypoid and superficial types. We also estimated interobserver and intraobserver variability.

RESULTS

The diagnostic performance of JNET classification did not differ significantly between polypoid and superficial lesions. Ninety-nine percent of Type 2B-low lesions were LGDs, HGDs, or superficial submucosal invasive (SM-s) carcinomas. In contrast, 60% of Type 2B-high lesions were deep submucosal invasive (SM-d) carcinomas. The results were not different between each gross type. Interobserver and intraobserver agreements for Type 2B subtyping were good, with kappa values of .743 and .786, respectively.

CONCLUSIONS

Type 2B subtyping may be useful for identifying lesions that are appropriate for endoscopic resection. JNET classification and Type 2B sub classification are useful criteria, regardless of gross type.

The association between location, age and advanced colorectal adenoma characteristics: a propensity-matched analysis

PURPOSE

Evidence supports an association between certain colorectal adenoma characteristics and predisposition to cancer. The association between anatomical location of colorectal adenoma, age and advanced adenomas needs attention. The objective of this study was to evaluate the possible association between occurrence of sporadic advanced adenomas with location and age.

MATERIALS AND METHODS

A cross-sectional study using baseline data from index colonoscopy from a randomized controlled trial evaluating chemopreventive treatment against recurrence of colorectal adenomas was performed. Inclusion criteria for patients were one adenoma of >1 cm in diameter or multiple adenomas of any size, or an adenoma of any size and familial disposition for colorectal cancer. Multivariate regression and propensity score-matched analyses were used to correlate location of adenomas and age with advanced adenoma features.

RESULTS

In this study, 2149 adenomas were removed in 1215 patients. Advanced colorectal adenomas primarily occurred in the anal part of the colon. Older age was associated with more adenomas and more oral occurrence of adenomas, as well as a higher risk of advanced adenomas. Surprisingly, specifically for the oral adenomas the risk of advanced adenoma seems to be lower for older patients compared with younger.

CONCLUSIONS

This study presents new results with regard to association between age, location of adenomas and risk of advanced adenomas. The results indicate that sigmoidoscopy for screening purposes may be obsolete, and add to the existing literature on which future guidelines for screening may be based.

Surveillance after endoscopic and surgical resection of colorectal cancer

With the increase in colorectal cancer burden, surveillance following endoscopic and surgical resection is an essential issue. The aim of surveillance programs is improvement of patient survival by early detection of residual tumor tissue or local recurrence, metachronous colorectal tumors, and metastases. Appropriate surveillance should be determined according to this risk of factors. In current guidelines, only surveillance colonoscopy is recommended after endoscopic resection of polyps with high-grade dysplasia, whereas intensive, multimodality surveillance using colonoscopy, radiological imaging and tumor marker measurements is recommended following surgical resection of invasive colorectal cancer. Detailed recommendations, including the timing of surveillance, are described based on high-quality evidence. However, there are still many unresolved issues for which more high-quality evidence is required.

SEPT9 and SHOX2 DNA methylation status and its utility in the diagnosis of colonic adenomas and colorectal adenocarcinomas

Background

Colorectal cancer (CRC) appear to arise from precursor lesions in a well-characterized adenoma-carcinoma sequence. Significant efforts have been invested to develop biomarkers that identify early adenocarcinomas and adenomas with high-grade dysplasia, since these are believed to harbor a particularly high risk for malignant transition and thus require resection. Promoter methylation of SEPT9 and SHOX2 has been suggested as a biomarker for various solid malignant tumors. Hence, the present study aimed to test their biomarker potential in CRC and precursor lesions.

Results

Assessment of promoter methylation of SEPT9 distinguished adenomas and CRC from controls as well as advanced from non-advanced adenomas (all p < 0.001). Correspondingly, SHOX2 methylation levels in adenomas and colorectal carcinomas were significantly higher compared to those in normal control tissues (p < 0.001). Histologic transition from adenomas to CRC was paralleled by amplification of the SEPT9 gene locus.

Conclusions

SEPT9/SHOX2 methylation assays may help to distinguish colorectal cancer and adenomas from normal and inflammatory colonic tissue, as well as advanced from non-advanced adenomas. Further studies need to validate these findings before introduction in clinical routine.

Altered plasma levels of decanoic acid in colorectal cancer as a new diagnostic biomarker

Colorectal cancer (CRC) is one of the most common tumors in developed countries. The five-year survival rate decreases depending on how advanced the CRC is when first diagnosed. Screening has been proven to greatly reduce mortality from colorectal cancer, but an ideal screening tool is far from being established. Here, we aimed to discover and validate early CRC biomarkers by means of an untargeted/targeted metabolomic approach. A preliminary untargeted analysis of plasma lipids performed on a small patient cohort (30 plasma samples) revealed some alterations that occurred in the presence of this tumor. In particular, medium-chain fatty acids with between six and twelve carbon atoms (C6-C12) were found to be the lipid class that showed the most marked changes upon the development of CRC. In order to evaluate the utility of this lipid class as diagnostic CRC biomarkers, a further study based on a wider cohort of patients (117 plasma samples) was performed. Using a targeted approach, these fatty acids were quantified in plasma samples by means of fast gas chromatography coupled to a time-of-flight analyzer. Plasma samples from patients with CRCs at different tumor stages were analyzed and compared to those from healthy subjects, ulcerative colitis patients, high-grade dysplasia adenoma patients, and breast cancer patients in order to test the specificity and sensitivity of these possible biomarkers. Results revealed significant differences among the considered groups in terms of their C6, C8, C10, and C12 fatty acid plasma concentrations. In particular, receiver operating characteristic (ROC) curves obtained for the C10 fatty acid gave an area under the curve of 0.8195 along with a sensitivity of 87.8 % and a specificity of 80 %, strongly suggesting that it could be a valuable early diagnostic biomarker of CRC.

Multi-Target Stool DNA Test: Is the Future Here?

Colorectal cancer (CRC) screening reduces CRC incidence and mortality and is widely recommended. However, despite these demonstrated benefits, a large percentage of the population remains unscreened. The multi-target stool DNA (MT-sDNA) test is a new, non-invasive option for CRC screening that has a high accuracy rate in detection of colorectal neoplasia and offers great opportunity to enhance screening uptake. This review provides the current state of the art knowledge about the use of MT-sDNA in CRC screening.

Pathology of premalignant colorectal neoplasia

Colorectal cancer is a heterogeneous oncological disease that develops through several molecular pathways. Each pathway is associated with specific neoplastic precursor lesions. Classification of colorectal polyps and the molecular features of associated colorectal cancers have undergone significant changes. An understanding of colorectal carcinogenesis and the molecular features of colorectal carcinomas is now regarded as necessary for personalized treatment and management of patients with colon cancer, and even for patients undergoing screening colonoscopy for early detection and prevention of colorectal cancer. In the present review, we describe the pathological and molecular features of epithelial precursor lesions involved in the early phases of colorectal carcinogenesis.

A novel method for screening colorectal cancer by infrared spectroscopy of peripheral blood mononuclear cells and plasma

BACKGROUND

Early detection of colorectal cancer (CRC) can reduce mortality and morbidity. Current screening methods include colonoscopy and stool tests, but a simple low-cost blood test would increase compliance. This preliminary study assessed the utility of analyzing the entire bio-molecular profile of peripheral blood mononuclear cells (PBMCs) and plasma using Fourier transform infrared (FTIR) spectroscopy for early detection of CRC.

METHODS

Blood samples were prospectively collected from 62 candidates for CRC screening/diagnostic colonoscopy or surgery for colonic neoplasia. PBMCs and plasma were separated by Ficoll gradient, dried on zinc selenide slides, and placed under a FTIR microscope. FTIR spectra were analyzed for biomarkers and classified by principal component and discriminant analyses. Findings were compared among diagnostic groups.

RESULTS

Significant changes in multiple bands that can serve as CRC biomarkers were observed in PBMCs (p = ~0.01) and plasma (p = ~0.0001) spectra. There were minor but statistically significant differences in both blood components between healthy individuals and patients with benign polyps. Following multivariate analysis, the healthy individuals could be well distinguished from patients with CRC, and the patients with benign polyps were mostly distributed as a distinct subgroup within the overlap region. Leave-one-out cross-validation for evaluating method performance yielded an area under the receiver operating characteristics curve of 0.77, with sensitivity 81.5% and specificity 71.4%.

CONCLUSIONS

Joint analysis of the biochemical profile of two blood components rather than a single biomarker is a promising strategy for early detection of CRC. Additional studies are required to validate our preliminary clinical results.

Expression and significance of survivin in colorectal high grade and low grade adenomas

We examined immunohistochemically the expression pattern of a potential tumor biomarker survivin in a panel of 116 tubular adenomatous polyps to determine its association with clinicomorphological parameters such as age of patients, size of polyps, degree of dysplasia and polyp localization. In each section, the subcellular localization of survivin antigen and the intensity of staining were assessed. Overall, survivin was expressed in 90 cases (77.6%). Cytoplasmic positivity was observed in 46/116 cases (39.7%), while nuclear and combined nuclear and cytoplasmic reaction in 44/116 cases (37.9%). High grade dysplasia was diagnosed in 52 cases (44.8%) and low grade dysplasia in 64 cases (55.2%). Statistical analysis revealed a significant correlation between subcellular survivin localization and the degree of dysplasia, size of polyps and colon localization. On the other hand, survivin expression pattern did not correlate with the age of patients. Statistically significant trend was confirmed between intensity of survivin immunoreaction and tumor size and dysplasia grade, and also the trend between negative/strong survivin intensity and polyp localization. Another statistically significant association was found between the degree of dysplasia and the size of polyps. Our findings revealed that survivin is frequently expressed in different subcellular compartments of adenoma cells. Our recent results suggest that the nuclear and combined nuclear and cytoplasmic survivin localizations are strongly associated with poor prognostic parameters in the assessment of colon adenomas. Thus, survivin may represent a promising biomarker in immunohistochemical evaluation of these lesions.

Multi-target stool DNA test: a new high bar for noninvasive screening

Stool DNA testing has evolved into what is now a highly accurate and well-validated test for the screen detection of colorectal neoplasia. An optimized and automated multi-target stool DNA test (MT-sDNA) has achieved the same high point-sensitivities as reported for colonoscopy and significantly higher sensitivity than by fecal immunochemical blood testing for detection of early-stage cancer and advanced precancer. Thus, MT-sDNA sets a new high criterion standard for the noninvasive screen detection of colorectal neoplasia. With clinical application, MT-sDNA has potential to meaningfully address current gaps in our approach to CRC screening through benefits of its high accuracy on screening effectiveness, user-friendly features on patient compliance, and easy mail-out distribution on test access. The US Food and Drug Administration and Center for Medicaid and Medicare Services have recently completed their parallel reviews of MT-sDNA, which has just become available for clinical use. This review summarizes the recent clinical validation data on MT-sDNA, addresses central clinical questions at this front end of implementation, and touches on innovative future applications of stool DNA testing.

Novel risk stratification for recurrence after endoscopic resection of advanced colorectal adenoma

BACKGROUND

Advanced colorectal adenoma (ACA) refers to adenomas with the following predictive characteristics: ≥1 cm in diameter, and/or villous component, and/or high-grade dysplasia. ACA has high risk of transforming to colorectal cancer, and the recurrence rate is relatively high.

OBJECTIVE

To assess the outcomes of patients with ACA undergoing endoscopic resection and to identify risk factors for local recurrence and development of metachronous advanced neoplasm.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care medical center.

PATIENTS

From 2005 to 2011, the records of 3625 patients who underwent colonoscopic polypectomy at Seoul National University Hospital were retrospectively reviewed. Patients with synchronous colorectal cancers, inflammatory bowel disease, previous colorectal resection, loss to follow-up, and incomplete resection were excluded.

INTERVENTION

Endoscopic resection for ACA.

MAIN OUTCOME MEASUREMENTS

Local recurrence and metachronous advanced neoplasm.

RESULTS

The study included 917 patients with 1206 ACAs. The median duration of follow-up was 28.5 months (interquartile range, 12.8-51.7). Independent risk factors for local recurrence included ACA with 2 or more predictive characteristics (adjusted hazard ratio [HR], 2.46; 95% confidence interval [CI], 1.11-5.48; P = .027) and piecemeal resection (adjusted HR, 6.96; 95% CI, 1.58-30.71; P = .010). Independent risk factors for metachronous advanced neoplasm were male gender (adjusted HR, 1.65; 95% CI, 1.02-2.65; P = .041), ≥3 adenomas (adjusted HR, 2.56; 95% CI, 1.72-3.82; P < .001), and ≥3 ACAs (adjusted HR, 1.44; 95% CI, 1.01-2.06; P = .045).

LIMITATIONS

Retrospective design.

CONCLUSION

ACAs with 2 or more predictive characteristics recurred locally at a higher rate than ACAs with 1 predictive characteristic. These results suggest that patients who are found to have ACAs with 2 or more predictive factors at index colonoscopy are at higher risk for local recurrence, and follow-up colonoscopy should be performed sooner.

Immunochemical faecal occult blood tests in primary care and the risk of delay in the diagnosis of colorectal cancer

OBJECTIVE

To evaluate the value, risks, and shortcomings of immunochemical faecal occult blood tests (iFOBTs) in the diagnosis of colorectal cancer (CRC) and adenomas with high-grade dysplasia (HGD) in patients initially presenting to primary care.

DESIGN

A retrospective population-based study.

SETTING AND SUBJECTS

All 495 cases of CRC and adenomas with HGD diagnosed in the county of Jämtland, Sweden from 2005 to 2009.

RESULTS

Of 495 patients 323 (65%) initially presented to primary care. IFOBTs were performed in 215 of 323 (67%) patients. The sensitivity of iFOBT for CRC and adenomas with HGD was 88% (83% when patients with a history of rectal bleeding were excluded). Of 34 patients with anaemia found en passant, 10 had negative iFOBTs. Time to diagnosis was longer for patients with negative iFOBTs (p < 0.0005).

CONCLUSION

IFOBT might be helpful in selecting which patients to refer for colonoscopy. However, iFOBT has a limited sensitivity as a diagnostic test for CRC and adenomas with HGD. Relying only on iFOBT for colonoscopy referral could delay diagnosis, especially for patients with anaemia found en passant.

Features of adenoma and colonoscopy associated with recurrent colorectal neoplasia based on a large community-based study

BACKGROUND & AIMS

We investigated adenoma and colonoscopy characteristics that are associated with recurrent colorectal neoplasia based on data from community-based surveillance practice.

METHODS

We analyzed data of 2990 consecutive patients (55% male; mean age 61 years) newly diagnosed with adenomas from 1988 to 2002 at 10 hospitals throughout The Netherlands. Medical records were reviewed until December 1, 2008. We excluded patients with hereditary colorectal cancer (CRC) syndromes, a history of CRC, inflammatory bowel disease, or without surveillance data. We analyzed associations among adenoma number, size, grade of dysplasia, villous histology, and location with recurrence of advanced adenoma (AA) and nonadvanced adenoma (NAA). We performed a multivariable multinomial logistic regression analysis to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

During the surveillance period, 203 (7%) patients were diagnosed with AA and 954 (32%) patients with NAA. The remaining 1833 (61%) patients had no adenomas during a median follow-up of 48 months. Factors associated with AA during the surveillance period included baseline number of adenomas (ORs ranging from 1.6 for 2 adenomas; 95% CI: 1.1-2.4 to 3.3 for ≥5 adenomas; 95% CI: 1.7-6.6), adenoma size ≥10 mm (OR = 1.7; 95% CI: 1.2-2.3), villous histology (OR = 2.0; 95% CI: 1.2-3.2), proximal location (OR = 1.6; 95% CI: 1.2-2.3), insufficient bowel preparation (OR = 3.4; 95% CI: 1.6-7.4), and only distal colonoscopy reach (OR = 3.2; 95% CI: 1.2-8.5). Adenoma number had the greatest association with NAA. High-grade dysplasia was not associated with AA or NAA.

CONCLUSIONS

Large size and number, villous histology, proximal location of adenomas, insufficient bowel preparation, and poor colonoscopy reach were associated with detection of AA during surveillance based on data from community-based practice. These characteristics should be used jointly to develop surveillance policies for adenoma patients.

Advanced precancerous lesions (APL) in the colonic mucosa

Colorectal cancer is a leading cause of cancer death worldwide. Most colorectal cancers are preventable. Surveillance colonoscopy is used to detect and remove precancerous lesions. Although the majority of precancerous lesions develop sporadically, some have an inherited component. In this review, we summarize the clinical, pathologic, and molecular features of advanced precancerous lesions of the colon. The most common and clinically important intestinal polyposis syndromes, and their genetics, are also discussed. Finally, current recommendations regarding the treatment and surveillance of precancerous lesions, both in the sporadic and in inherited setting, are reviewed.

A follow-up study of 166 cases of advanced colorectal adenomas after polypectomy

AIM: To investigate the characteristics of recurrence of advanced colorectal adenomas after polypectomy.

METHODS: The clinical data for patients with advanced colorectal adenoma who underwent polypectomy from January 2004 to January 2009 were collected and reevaluated. The patients who had follow-up data were included in the study.

RESULTS: A total of 497 patients with diagnosed advanced colorectal adenoma were collected, and follow-up data were available in 166 patients. These patients ranged in age from 32 to 82 years (average, 61.64 ± 11.07 years), and 128 cases had an age of ≥ 55 years (128/166, 77.11%). Ninety-four (94/166, 56.63%) patients were males. The most common initial manifestations of advanced adenomas were hematochezia (71/166, 46.38%) and lobular changes (75/166, 54.82%). The interval between polypectomy and first reexamination was 1-28 months. There were 102 (102/166, 61.45%) recurrences in all. Advanced colorectal adenomas in the left hemicolon more likely recurred in the left hemicolon, while those in the right hemicolon more likely recurred in the right hemicolon. No pathological differences were found between recurrent adenomas and original ones (P > 0.05). The hazard curve of Cox model suggested that the risk of recurrence increased gradually from 6 months after polypectomy.

CONCLUSION: Advanced colorectal adenomas may recur after polypectomy. No pathological differences were found between recurrent adenomas and original ones. Colonoscopy should be performed 6 mo after polypectomy for detection of possible recurrence.