Changing trends in the incidence, stage, survival, and screen-detection of colorectal cancer: a population-based study

Long-term prognosis of curative endoscopic submucosal dissection for early colorectal cancer according to submucosal invasion: a multicenter cohort study

Background

Endoscopic submucosal dissection (ESD) can provide a high en bloc resection rate and has been widely applied as curative treatment for early colorectal cancer (ECC). However, surgical treatment is occasionally required, and reports on the long-term prognosis of ESD are insufficient. This study aimed to investigate the long-term outcomes of ECC removal by ESD, including local recurrence and metastasis.

Methods

This multicenter study was conducted retrospectively on 450 consecutive patients with ECC who were treated with ESD between November 2003 and December 2013. Clinical, pathological, and endoscopic data were collected to determine tumor depth, resection margin, lymphovascular invasion, and recurrence.

Results

The median follow-up period was 53.8 (12–138 months). The en bloc resection rate was 85.3% (384) and in intramucosal cancer being 84.1% and in superficial submucosal invasion (SM1) cancer being 89.8% (p = 0.158). The curative resection rate was 76.0% (n = 342), and there was no statistical difference between the two groups (77.3% vs. 71.4%, p = 0.231). The overall recurrence free survival rate (RFS) was 98.7% (444/450). In patients with curative resection, there was no statistically significant difference in RFS according to invasion depth (intramucosal: 99.3% vs. SM1: 97.1%, p = 0.248).

Conclusions

Patients with curatively resected ECC treated with ESD showed favorable long-term outcomes. Curatively resected SM1 cancer has a RFS similar to that of intramucosal cancer.

Influence of early colorectal cancer component on the positive margins after endoscopic resection: a retrospective study

Background

Endoscopic treatment methods for early colorectal cancer (ECRC) mainly depend on the size and morphology. It is unclear whether different endoscopic resection methods could achieve curative resection for ECRC confined in the mucosa. The study was designed to compare the rate of positive vertical margin (VM) of ECRC with advanced adenomas (AAs) including adenoma > 1 cm, villous adenoma, high-grade intraepithelial neoplasia/dysplasia stratified by different endoscopic resection methods.

Methods

Rate of positive VM for 489 ECRCs including Intramucosal (pTis) and superficial submucosal invasion (pT1) carcinomas were compared with those of 753 AAs stratified by different endoscopic resection methods using Chi-squared test. Multivariate logistic model was performed to investigate the risk factors of positive VM for different endoscopic resection methods.

Results

The pTis ECRC exhibited a similar rate of positive VM as that of AAs for en bloc hot snare polypectomy (HSP, 0% Vs. 0.85%, P = 0.617), endoscopic mucosal resection (EMR, 0.81% vs. 0.25%, P = 0.375) and endoscopic submucosal dissection (ESD, 1.82% Vs. 1.02%, P = 0.659). The pTis carcinoma was not found to be a risk factor for positive VM by en bloc EMR (P = 0.349) or ESD (P = 0.368). The en bloc resection achieved for pT1a carcinomas exhibited similar to positive VM achieved through ESD (2.06% Vs. 1.02%, P = 1.000) for AAs. Nonetheless, EMR resulted in higher risk of positive VM (5.41% Vs. 0.25%, P < 0.001) for pT1a carcinomas as compared to AAs. The pT1a invasion was identified as a risk factor for positive VM in polyps with en bloc EMR (odds ratio = 23.90, P = 0.005) but not ESD (OR = 2.96, P = 0.396).

Conclusion

Collectively, the pTis carcinoma was not found to be a risk factor for positive VM resected by en bloc HSP, EMR or ESD. Additionally, ESD may be preferred over EMR for pT1a carcinomas with lower rate of positive VM.

Risk Factors for Lymph Node Metastasis in Pathological T1b Colorectal Cancer

BACKGROUND/AIM

The rate of lymph node metastasis (LNM) of colorectal carcinoma (CRC) with a submucosal (SM) invasion depth of 1000 µm or more can reach 12.5%, which is the most common reason for additional resection in daily practice. Other studies have reported that the rate of LNM is less than 2%, regardless of the depth of invasion, if the lesions show good histology, lymphovascular infiltration is negative, and tumor budding is limited. The purpose of this study was to investigate new risk factors for LNM in T1b colorectal cancer.

PATIENTS AND METHODS

The 239 patients who were diagnosed with pathological T1b CRC after colorectal surgical resection at the Osaka Police Hospital in Japan between January 2008 and December 2018 were retrospectively reviewed in this study.

RESULTS

The LNM rate was 11.3% (27/239). The variables identified as being significant factors using multivariate analysis were: i) lymphatic invasion (Ly)-positive [odds ratio (OR)=5.97; 95% confidence interval (CI)=2.27-15.74], ii) female gender (OR=3.49; 95%CI=1.38-8.85), and iii) left-sided colorectal involvement (OR=4.98; 95%CI=1.22-20.39). If none of these risk factors were present with T1b, the LNM rate was 0% (0/28).

CONCLUSIONS

Ly-positive, female gender, and left-sided colorectal involvement could be risk factors for LNM in T1b CRC.

Cost-Effectiveness of Multitarget Stool DNA Testing vs Colonoscopy or Fecal Immunochemical Testing for Colorectal Cancer Screening in Alaska Native People

OBJECTIVE

To estimate the cost-effectiveness of multitarget stool DNA testing (MT-sDNA) compared with colonoscopy and fecal immunochemical testing (FIT) for Alaska Native adults.

PATIENTS AND METHODS

A Markov model was used to evaluate the 3 screening test effects over 40 years. Outcomes included colorectal cancer (CRC) incidence and mortality, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). The study incorporated updated evidence on screening test performance and adherence and was conducted from December 15, 2016, through November 6, 2019.

RESULTS

With perfect adherence, CRC incidence was reduced by 52% (95% CI, 46% to 56%) using colonoscopy, 61% (95% CI, 57% to 64%) using annual FIT, and 66% (95% CI, 63% to 68%) using MT-sDNA. Compared with no screening, perfect adherence screening extends life by 0.15, 0.17, and 0.19 QALYs per person with colonoscopy, FIT, and MT-sDNA, respectively. Colonoscopy is the most expensive strategy: approximately $110 million more than MT-sDNA and $127 million more than FIT. With imperfect adherence (best case), MT-sDNA resulted in 0.12 QALYs per person vs 0.05 and 0.06 QALYs per person by FIT and colonoscopy, respectively. Probabilistic sensitivity analyses supported the base-case analysis. Under varied adherence scenarios, MT-sDNA either dominates or is cost-effective (ICERs, $1740-$75,868 per QALY saved) compared with FIT and colonoscopy.

CONCLUSION

Each strategy reduced costs and increased QALYs compared with no screening. Screening by MT-sDNA results in the largest QALY savings. In Markov model analysis, screening by MT-sDNA in the Alaska Native population was cost-effective compared with screening by colonoscopy and FIT for a wide range of adherence scenarios.

Korean colonoscopy screening pilot study (K-cospi) for screening colorectal cancer: study protocol for the multicenter, community-based clinical trial

BACKGROUND

The Korean National Cancer Screening Program has been providing annual fecal immunochemical test for colorectal cancer (CRC) to adults aged 50 years and older since 2004. The Korean Colonoscopy Screening Pilot Study was developed to evaluate the effectiveness of colonoscopy screening for CRC incidence and mortality, screening-related complications, and acceptability of colonoscopy as a primary modality for the national CRC screening program.

METHODS

This study and its protocols have been approved by the Korean Public Institutional Review Board and the National Cancer Center Institutional Review Board. We obtain written informed consent from all participants. The target population is males and females aged 50-74 years living within the pilot sites. A total of 26,640 participants will be recruited for colonoscopy screening. Subjects who have been diagnosed with CRC, who are currently undergoing treatment for CRC, or who have undergone colonoscopy screening within the past 5 years are not allowed to participate. All participants need to complete baseline questionnaires. This pilot study is currently conducted by 104 endoscopists from 57 national cancer screening institutions (42 primary, 10 secondary, and 5 tertiary institutions) located in Goyang-si, Gimpo-si, and Paju-si. The number of endoscopists, medical institutions, and districts participating in the pilot study will be expanded, if necessary. Participating endoscopists at each medical institution perform colonoscopy and report the colonoscopy results to a centralized electronic case report system. We conduct a telephone survey after 7 days and 4 weeks post-colonoscopy to assess for procedure-related complications and satisfaction of the participants. In case of abnormal findings from colonoscopy screening, we track the results from follow-up diagnostic tests. Data from this pilot study will be linked to the diagnostic workup results, the Korean Cancer Registry, and death certificate data for analysis of the performance, long-term effects, and cost-effectiveness of colonoscopy.

DISCUSSION

The results will provide critical information to determine whether the introduction of colonoscopy as the primary modality of the Korean National Cancer Screening Program would be acceptable and feasible. Trial registration Korean Clinical Research Information Service registry, KCT0004142. Registered on 15 July 2019, http://cris.nih.go.kr/cris/en/search/search_result_st01.jsp?seq=16227.

Retrospective analysis of LNM risk factors and the effect of chemotherapy in early colorectal cancer: A Chinese multicenter study

Background

Estimating the risk of lymph node metastasis (LNM) is crucial for determining subsequent treatments following curative resection of early colorectal cancer (ECC). This multicenter study analyzed the risk factors of LNM and the effectiveness of postoperative chemotherapy in patients with ECC.

Methods

We retrospectively analyzed the data of 473 patients with ECC who underwent general surgery in five hospitals between January 2007 and October 2018. The correlations between LNM and sex, age, tumor size, tumor location, endoscopic morphology, pathology, depth of invasion and tumor budding (TB) were directly estimated based on postoperative pathological analysis. We also observed the overall survival (OS) and recurrence in ECC patients with and without LNM after matching according to baseline measures.

Results

In total, 473 ECC patients were observed, 288 patients were enrolled, and 17 patients had LNM (5.90%). The univariate analysis revealed that tumor size, pathology, and lymphovascular invasion were associated with LNM in ECC (P = 0.026, 0.000, and 0.000, respectively), and the multivariate logistic regression confirmed that tumor size, pathology, and lymphovascular invasion were risk factors for LNM (P = 0.021, 0.023, and 0.001, respectively). There were no significant differences in OS and recurrence between the ECC patients with and without LNM after matching based on baseline measures (P = 0.158 and 0.346, respectively), and no significant difference was observed between chemotherapy and no chemotherapy in ECC patients without LNM after surgery (P = 0.729 and 0.052).

Conclusion

Tumor size, pathology, and lymphovascular invasion are risk factors for predicting LNM in ECC patients. Adjuvant chemotherapy could improve OS and recurrence in patients with LNM but not always in ECC patients without LNM.

Stool-Based Tests for Colorectal Cancer Screening: Performance Benchmarks Lead to High Expected Efficacy

PURPOSE OF REVIEW

Participation goals for colorectal cancer (CRC) screening in the USA have not been met. Non-invasive screening strategies may improve CRC screening participation. We highlight recent literature on stool-based screening performance and expectations for emerging non-invasive screening tests.

RECENT FINDINGS

Stool-based CRC screening detects screen-relevant colorectal neoplasia and outperforms a currently available plasma assay. Though modestly sensitive for CRC, adherence to annual fecal immunochemical testing (FIT) is sub-optimal. Multi-target stool DNA (MT-sDNA) has greater adherence, superior sensitivity for screen-relevant lesions (including those in the proximal colon and sessile serrated architecture), and equivalent specificity to FIT over a 3-year period. Stool-based CRC screening tests are anticipated to reduce the incidence and mortality of CRC through detection of early-stage cancers and high-risk polyps. These endpoints in performance will need to be met by emerging blood sample-based tests in order have meaningful impact in clinical practice.

Novel biomarkers for the diagnosis and prognosis of colorectal cancer

Colorectal cancer (CRC) is among the most common malignancies and remains a major cause of cancer-related death worldwide. Despite recent advances in surgical and multimodal therapies, the overall survival of advanced CRC patients remains very low. Cancer progression, including invasion and metastasis, is a major cause of death among CRC patients. The underlying mechanisms of action resulting in cancer progression are beginning to unravel. The reported molecular and biochemical mechanisms that might contribute to the phenotypic changes in favor of carcinogenesis include apoptosis inhibition, enhanced tumor cell proliferation, increased invasiveness, cell adhesion perturbations, angiogenesis promotion, and immune surveillance inhibition. These events may contribute to the development and progression of cancer. A biomarker is a molecule that can be detected in tissue, blood, or stool samples to allow the identification of pathological conditions such as cancer. Thus, it would be beneficial to identify reliable and practical molecular biomarkers that aid in the diagnostic and therapeutic processes of CRC. Recent research has targeted the development of biomarkers that aid in the early diagnosis and prognostic stratification of CRC. Despite that, the identification of diagnostic, prognostic, and/or predictive biomarkers remains challenging, and previously identified biomarkers might be insufficient to be clinically applicable or offer high patient acceptability. Here, we discuss recent advances in the development of molecular biomarkers for their potential usefulness in early and less-invasive diagnosis, treatment, and follow-up of CRC.

Role of Endoscopic Resection Versus Surgical Resection in Management of Malignant Colon Polyps: a National Cancer Database Analysis

BACKGROUND

Endoscopic resection (polypectomy) or surgery, are the main approaches in management of malignant colon polyps. There are very few large population-based studies comparing outcomes between the two.

METHODS

Using the National Cancer Database, we identified patients ≥ 18 years with the first diagnosis of T1N0M0 malignant polyp from 2004 to 2015. Patients with a positive resection margin were excluded. Outcomes were compared between those who had surgery versus those who had polypectomy. Overall survival was compared using Kaplan-Meier curves. Multivariate Cox proportional hazards analysis was performed to generate hazard ratios, adjusted for patient, demographic, and tumor factors.

RESULTS

A total of 31,062 patients met the inclusion criteria, out of which 2593 (8.3%) underwent polypectomy alone and 28,469 (91.7%) had surgery. Overall survival was significantly better in the surgical group compared with the polypectomy group. One-year and 5-year survival for surgery were 95.8% and 86.1% respectively compared with 94.2% and 80.6% for polypectomy (p < .0001). Hazard ratio for surgery after adjusting for various clinical-, demographic-, and tumor-level factors was 0.53 (p < .0001).

CONCLUSION

Our study is the largest population-based analysis of patients with T1N0M0 malignant colon polyps. Overall survival was higher in patients who underwent surgery compared with polypectomy. This remained consistent even after adjusting for multiple patient and tumor factors between the two groups.

Minimally invasive transanal surgery is safe after incomplete polypectomy of low risk T1 rectal cancer: a systematic review

AIM

In patients who have undergone a polypectomy of a malignant rectal polyp without histopathological risk factors other than an involved or unclear resection margin, additional local excision is often performed. Evidence to support this approach is lacking. The aim of this systematic review and meta-analysis was to determine the outcome in terms of local recurrence, disease-free survival (DFS) and overall survival (OS) of additional local excision following incomplete polypectomy for low risk T1 rectal cancer.

METHODS

A comprehensive search for published studies was performed. Only studies in which there was incomplete (or ≤ 1 mm) removal of pT1 rectal polyps or in which the resection plane could not be assessed were included. For each included study data on tumour stage, histological factors, surgical technique, local recurrence rate, 5-year DFS and 5-year OS were extracted. The PROSPERO registration number is CRD42017062702.

RESULTS

A total of 580 studies were retrieved by the search in the MEDLINE database, Embase and the Cochrane Library. After careful appreciation, four studies were included in the analysis, comprising 102 patients of whom the majority had undeterminable (Rx) resection margins. Local excision via transanal endoscopic microsurgery was reported most frequently. Only 1% of patients developed a local recurrence. One study reported 5-year DFS and 5-year OS of 96% and 87% respectively.

CONCLUSION

This study supports the use of additional local excision techniques for rectal cancer patients who underwent an incomplete polypectomy for a malignant rectal polyp in the absence of risk factors other than an uncertain resection margin.

Periodontitis is associated with an increased risk for proximal colorectal neoplasms

Interval colorectal cancers detected after colonoscopy are known to be highly associated with proximal colorectal neoplasms (CRNs). This cross-sectional study investigated whether periodontitis could be a risk factor for proximal CRNs in healthy individuals. A total of 2504 subjects who received a colonoscopy and dental exam were enrolled in this study. We divided the subjects into the periodontitis group (n = 216) and the control group (n = 2288). The periodontitis group was defined as subjects who had one or more teeth with a probing pocket depth (PPD) ≥4 mm. The prevalence of proximal CRNs was significantly higher in the periodontitis group (25.0%) than in the control group (12.3%) (P < 0.001). Independent risk factors for proximal CRNs in the multivariate analysis were periodontitis, smoking, age, waist circumference, and triglycerides, and those for proximal advanced CRNs were periodontitis, age, and family history of CRC. However, periodontitis was not a risk factor for overall CRNs and advanced CRNs. Periodontitis was associated with an increased risk of proximal CRNs (odds ratio [OR], 1.525; 95% confidence intervals [95% CI], 1.071–2.172) and proximal advanced CRNs (OR, 2.671; 95% CI, 1.088–6.560). Periodontitis might be associated with proximal CRNs and proximal advanced CRNs.

Use of the Rochester Epidemiology Project for Clinical Research in Colon and Rectal Surgery

The Rochester Epidemiology Project (REP), a longitudinal population-based database, is the largest epidemiologic database in the world. Originally established at Mayo Clinic in Rochester, Minnesota, the REP has been instrumental in defining the natural history of disease states and the impact of treatment in a well-defined population. In the United States, the REP has made important contributions to the colon and rectal literature, largely because healthcare is fragmented with no unique identifier to longitudinally follow-up with a patient throughout the system over his or her lifespan. Investigation with the REP has provided insight to the economic burden associated with inflammatory bowel disease, the benefit of screening for colorectal cancer, and the natural history of Mekel's and diverticular disease. In addition to practice changing research, the REP can be used as a model for future linkage systems in the United States.

Outcome differences between recanalized malignant central airway obstruction from endoluminal disease versus extrinsic compression

We compared the outcome of Nd:YAG laser therapy with stent placement for malignant central airway obstruction (CAO) at our center over a 10-year period. This is a retrospective review of patients undergoing Nd:YAG laser therapy or self-expanding metal stent (SEMS) placement for malignant CAO between November 2007 and October 2017. Seventy-two patients were recanalized for malignant CAO. The median (range) age was 63 (23-86) years, with 49 (68%) males. Patients underwent either laser therapy alone (N = 36), stent placement alone (N = 30), or both (N = 6). The wavelength of Nd:YAG laser used was 1064 nm, and median (range) laser energy used was 25 (15-35) W, in 377 (115-1107) pulses. Fifty-one (71%) patients died with median survival of 7.2 months. In subgroup analysis, 21 (58.3%) vs. 25 (83.3%), p = 0.03 patients died in the "laser resection" vs. "stent placement" group with longer median survival of 12.4 months in the former vs. 4.5 months, p = 0.0004 in the later. Esophageal cancer and left main bronchus involvement were significantly more common (10 (33.3%) vs. 0, p = 0.0001, and 16 (53.3%) vs. 8 (22.2%), p = 0.01), in the stent placement vs. laser resection group, respectively. Trachea or main bronchi involvement and respiratory failure on presentation requiring mechanical ventilation correlated with poorer survival. The immediate restoration of luminal patency, complication rate, and 30-day mortality was similar among the two groups. The median (range) energy used for laser therapy was 25 (15-35) W. Median of 377 pulses was used for the duration of 287.5 s. The results were compared using a Wilcoxon two-sample test, and Fischer exact test with p values considered indicative of a significant difference if less than 0.05. In patients requiring recanalization of malignant CAO, the extrinsic compression from esophageal cancer, trachea or main bronchi involvement, respiratory failure on presentation requiring mechanical ventilation, and stent placement correlated with poorer survival. Interventional pulmonology training program should emphasize on dedicated training in laser therapy as it is associated with improved survival.

Improving diagnosis, prognosis and prediction by using biomarkers in CRC patients (Review)

Colorectal cancer (CRC) is among the most common cancers. In fact, it is placed in the third place among the most diagnosed cancer in men, after lung and prostate cancer, and in the second one for the most diagnosed cancer in women, following breast cancer. Moreover, its high mortality rates classifies it among the leading causes of cancer‑related death worldwide. Thus, in order to help clinicians to optimize their practice, it is crucial to introduce more effective tools that will improve not only early diagnosis, but also prediction of the most likely progression of the disease and response to chemotherapy. In that way, they will be able to decrease both morbidity and mortality of their patients. In accordance with that, colon cancer research has described numerous biomarkers for diagnostic, prognostic and predictive purposes that either alone or as part of a panel would help improve patient's clinical management. This review aims to describe the most accepted biomarkers among those proposed for use in CRC divided based on the clinical specimen that is examined (tissue, faeces or blood) along with their restrictions. Lastly, new insight in CRC monitoring will be discussed presenting promising emerging biomarkers (telomerase activity, telomere length and micronuclei frequency).

Histopathologic risk factors for lymph node metastasis in patients with T1 colorectal cancer

PURPOSE

Evaluating the risk of lymph node metastasis (LNM) is critical for determining subsequent treatments following endoscopic resection of T1 colorectal cancer (CRC). This study analyzed histopathologic risk factors for LNM in patients with T1 CRC.

METHODS

This study involved 745 patients with T1 CRC who underwent endoscopic (n = 97) or surgical (n = 648) resection between January 2001 and December 2015 at the National Cancer Center, Korea. LNM in endoscopically resected patients, which could not be evaluated directly, was estimated indirectly based on follow-up results and histopathologic reports of salvage surgery. The relationships of depth of submucosal invasion, histologic grade, budding, vascular invasion, and background adenoma with LNM were evaluated statistically.

RESULTS

Of the 745 patients, 91 (12.2%) were found to be positive for LNM. Univariate and multivariate analyses identified deep submucosal invasion (P = 0.010), histologic high grade (P < 0.001), budding (P = 0.034), and vascular invasion (P < 0.001) as risk factors for LNM. Among the patients with one, two, three, and four risk factors, 6.0%, 18.7%, 36.4%, and 100%, respectively, were positive for LNM.

CONCLUSION

Deep submucosal invasion, histologic high grade, budding, and vascular invasion are risk factors for LNM in patients with T1 colorectal cancer. If any of these risk factors are present, additional surgery following endoscopic resection should be determined after considering the potential risk of LNM and each patient's situation.

Long-term Recurrence-free Survival After Standard Endoscopic Resection Versus Surgical Resection of Submucosal Invasive Colorectal Cancer: A Population-based Study

BACKGROUND & AIMS

There is controversy over the optimal management for T1 colorectal cancer (T1 CRC). This study compared initial endoscopic resection with or without additional surgery, or initial surgery for T1 CRC, and assessed risk factors for lymph node metastases (LNMs) and long-term recurrence.

METHODS

We performed a registration study that included all patients diagnosed with T1 CRC from 1995 through 2011 in the southeast area of The Netherlands (n = 1315). High-risk histology (with regard to LNM) was defined as the presence of poor differentiation, lymphangio-invasion, and/or deep submucosal invasion. The primary outcome measure was the combined rate of local and distant CRC recurrence during a mean follow-up period of 6.6 years. Logistic regression and Cox proportional hazards regression analyses were performed to evaluate independent risk factors for LNM and CRC recurrence, respectively.

RESULTS

Endoscopic resection was performed in 590 patients (44.9%); of these, 220 (16.7%) underwent additional surgery. Initial surgery was performed in 725 patients (55.1%). The risk of LNM was higher in T1 CRC with histologic risk factors (15.5% vs 7.1% without histologic risk factors; odds ratio, 2.21; 95% confidence interval, 1.33-3.70). Thirty-day mortality did not differ between patients who received additional surgery (0.9%) and those who underwent only endoscopic resection (1.4%; P = .631). Rates of CRC recurrence were 6.2% (9.8/1000 patient-years) after only endoscopic resection vs 6.4% (9.4/1000 patient-years) after additional surgery (P = .912), and 3.4% (5.2/1000 patient-years) after initial surgery (P = .031). In multivariate analysis, this difference was not significant. The only independent risk factor for long-term recurrence was a positive resection margin (hazard ratio, 6.88; 95% confidence interval, 2.27-20.87).

CONCLUSIONS

Based on a population analysis of patients diagnosed with T1 CRC, additional surgery after endoscopic resection should be considered only for patients with high-risk histology or a positive resection margin.

Absence of the Epithelial Glycocalyx As Potential Tumor Marker for the Early Detection of Colorectal Cancer

Detection of cancer at an early stage is pivotal for successful treatment and long term survival, yet early diagnosis requires sensitive and specific markers that can be easily detected by screening procedures. Differences in the surface structure of tumor and healthy cells, if sufficiently pronounced and discernible, may serve that purpose. We analyzed the luminal surface of healthy and neoplastic human colorectal tissues for the presence and architecture of the glycocalyx—a dense network of highly glycosylated proteins—using transmission electron microscopy. The ultrastructural analyses showed that 93% of healthy mucosae were covered by an intact glycocalyx. Contrarily, on over 90% of the surface of neoplastic cells the glycocalyx was absent. The sensitivity and specificity of our marker “absence of a glycocalyx” are excellent, being 91% (83–96%) and 96% (89–99%) for adenocarcinomas and 94% (73–100%) and 92% (85–97%) for precancerous polyps (means and 95% confidence intervals). Using a cell culture model we could demonstrate that a particulate probe targeting a cell surface receptor usually concealed beneath the glycocalyx can bind selectively to glycocalyx-free areas of a tumor cell layer. We propose that the absence of a glycocalyx may serve as novel type of tumor marker. If the absence of the glycocalyx can be detected e.g. via binding of imaging probes to non-shielded surface receptors of anomalously differentiated cells, this tumor marker could be used to enable early diagnosis of colorectal cancer.

Post-Colonoscopy Complications: A Systematic Review, Time Trends, and Meta-Analysis of Population-Based Studies

OBJECTIVES

Many studies around the world addressed the post-colonoscopy complications, but their pooled prevalence and time trends are unknown. We performed a systematic review and meta-analysis of population-based studies to examine the pooled prevalence of post-colonoscopy complications ("perforation", "bleeding", and "mortality"), stratified by colonoscopy indication. Temporal variability in the complication rate was assessed.

METHODS

We queried Pubmed, Embase, and the Cochrane library for population-based studies examining post-colonoscopy complications (within 30 days), performed from 2001 to 2015 and published by 1 December 2015. We determined pooled prevalence of perforations, post-colonoscopy bleeding, post-polypectomy bleeding, and mortality.

RESULTS

We retrieved 1,074 studies, of which 21 met the inclusion criteria. Overall, pooled prevalences for perforation, post-colonoscopy bleeding, and mortality were 0.5/1,000 (95% confidence interval (CI) 0.4-0.7), 2.6/1,000 (95% CI 1.7-3.7), and 2.9/100,000 (95% CI 1.1-5.5) colonoscopies. Colonoscopy with polypectomy was associated with a perforation rate of 0.8/1,000 (95% CI 0.6-1.0) and a post-polypectomy bleeding rate of 9.8/1,000 (95% CI 7.7-12.1). Complication rate was lower for screening/surveillance than for diagnostic examinations. Time-trend analysis showed that post-colonoscopy bleeding declined from 6.4 to 1.0/1,000 colonoscopies, whereas the perforation and mortality rates remained stable from 2001 to 2015. Overall, considerable heterogeneity was observed in most of the analyses.

CONCLUSIONS

Worldwide, the post-colonoscopy complication rate remained stable or even declined over the past 15 years. The findings of this meta-analysis encourage continued efforts to achieve and maintain safety targets in colonoscopy practice.

Characteristics and outcomes of endoscopically resected colorectal cancers that arose from sessile serrated adenomas and traditional serrated adenomas

Background/Aims

The efficacy and safety of endoscopic resection of colorectal cancer derived from sessile serrated adenomas or traditional serrated adenomas are still unknown. The aims of this study were to verify the characteristics and outcomes of endoscopically resected early colorectal cancers developed from serrated polyps.

Methods

Among patients who received endoscopic resection of early colorectal cancers from 2008 to 2011, cancers with documented pre-existing lesions were included. They were classified as adenoma, sessile serrated adenoma, or traditional serrated adenoma according to the baseline lesions. Clinical characteristics, pathologic diagnosis, and outcomes were reviewed.

Results

Overall, 208 colorectal cancers detected from 198 patients were included: 198 with adenoma, five with sessile serrated adenoma, and five with traditional serrated adenoma. The sessile serrated adenoma group had a higher prevalence of high-grade dysplasia (40.0% vs. 25.8%, P<0.001) than the adenoma group. During follow-up, local recurrence did not occur after endoscopic resection of early colorectal cancers developed from serrated polyps. In contrast, two cases of metachronous recurrence were detected within a short follow-up period.

Conclusions

Cautious observation and early endoscopic resection are recommended when colorectal cancer from serrated polyp is suspected. Colorectal cancers from serrated polyp can be treated successfully with endoscopy.

Screening for Colorectal Cancer Using a Multitarget Stool DNA Test: Modeling the Effect of the Intertest Interval on Clinical Effectiveness

BACKGROUND

A multitarget stool DNA (mt-sDNA) test was recently approved for colorectal cancer (CRC) screening for men and women, aged ≥ 50 years, at average risk of CRC. The guidelines currently recommend a 3-year interval for mt-sDNA testing in the absence of empirical data. We used clinical effectiveness modeling to project decreases in CRC incidence and related mortality associated with mt-sDNA screening to help inform interval setting.

MATERIALS AND METHODS

The Archimedes model (Archimedes Inc., San Francisco, CA) was used to conduct a 5-arm, virtual, clinical screening study of a population of 200,000 virtual individuals to compare the clinical effectiveness of mt-sDNA screening at 1-, 3-, and 5-year intervals compared with colonoscopy at 10-year intervals and no screening for a 30-year period. The study endpoints were the decrease in CRC incidence and related mortality of each strategy versus no screening. Cost-effectiveness ratios (US dollars per quality-adjusted life year [QALY]) of mt-sDNA intervals were calculated versus no screening.

RESULTS

Compared with 10-year colonoscopy, annual mt-sDNA testing produced similar reductions in CRC incidence (65% vs. 63%) and related mortality (73% vs. 72%). mt-sDNA testing at 3-year intervals reduced the CRC incidence by 57% and CRC mortality by 67%, and mt-sDNA testing at 5-year intervals reduced the CRC incidence by 52% and CRC mortality by 62%. At an average price of $600 per test, the annual, 3-year, and 5-year mt-sDNA screening costs would be $20,178, $11,313, and $7388 per QALY, respectively, compared with no screening.

CONCLUSION

These data suggest that screening every 3 years using a multitarget mt-sDNA test provides reasonable performance at acceptable cost.

Assessment and model guided cancer screening promotion by village doctors in China: a randomized controlled trial protocol

Background

Proven cost-effectiveness contrasted by low uptake of cancer screening (CS) calls for new methodologies promoting the service. Contemporary interventions in this regard relies primarily on strategies targeting general or specific groups with limited attention being paid to individualized approaches. This trial tests a novel package promoting CS utilization via continuous and tailored counseling delivered by primary caregivers. It aims at demonstrating that high risk individuals in the intervention arm will, compared to those in the delayed intervention condition, show increased use of CS service.

Methods/Design

The trial adopts a quasi-randomized controlled trial design and involves 2160 high risk individuals selected, via rapid and detailed risk assessments, from about 72,000 farmers aged 35+ in 36 administrative villages randomized into equal intervention and delayed intervention arms. The CS intervention package uses: a) village doctors and village clinics to deliver personalized and thus relatively sophisticated CS counseling; b) two-stage risk assessment models in identifying high risk individuals to focus the intervention on the most needed; c) standardized operation procedures to guide conduct of counseling; d) real-time effectiveness and quality monitoring to leverage continuous improvement; e) web-based electronic system to enable prioritizing complex determinants of CS uptake and tailoring counseling sessions to the changing needs of individual farmers. The intervention arm receives baseline and semiannual follow up evaluations plus CS counseling for 5 years; while the delayed intervention arm, only the same baseline and follow-up evaluations for the first 5 years and CS counseling starting from the 6th year if the intervention proved effective. Evaluation measures include: CS uptake by high risk farmers and changes in their knowledge, perceptions and self-efficacy about CS.

Discussion

Given the complexity and heterogeneity in the determinant system of individual CS service seeking behavior, personalized interventions may prove to be an effective strategy. The current trial distinguishes itself from previous ones in that it not only adopts a personalized strategy but also introduces a package of pragmatic solutions based on proven theories for tackling potential barriers and incorporating key success factors in a synergetic way toward low cost, effective and sustainable CS promotion.

Trial registration

ISRCTN33269053

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1688-9) contains supplementary material, which is available to authorized users.

Molecular markers for colorectal cancer screening

Colorectal cancer (CRC), although a significant cause of morbidity and mortality worldwide, has seen a declining incidence and mortality in countries with programmatic screening. Faecal occult blood testing and endoscopic approaches are the predominant screening methods currently. The discovery of the adenoma-carcinoma sequence and a greater understanding of the genetic and epigenetic changes that drive the formation of CRC have contributed to innovative research to identify molecular markers for highly accurate, non-invasive screening tests for CRC. DNA, proteins, messenger RNA and micro-RNA have all been evaluated. The observation of tumour cell exfoliation into the mucocellular layer of the colonic epithelium and proven stability of DNA in a harsh stool environment make stool DNA a particularly promising marker. The development of a clinically useful stool DNA test has required numerous technical advances, including optimisation in DNA stabilisation, the development of assays with high analytical sensitivity, and the identification of specific and broadly informative molecular markers. A multitarget stool DNA test, which combines mutant and methylated DNA markers and a faecal immunochemical test, recently performed favourably in a large cross-sectional validation study and has been approved by the US Food and Drug Administration for the screening of asymptomatic, average-risk individuals. The ultimate way in which molecular marker screening assays will be used in clinical practice will require additional studies to determine optimal screening intervals, factors affecting compliance, management of false-positive results, and the use of these assays in high-risk populations, as well as other considerations.

Epidemiology of Colorectal Adenomas and Histopathological Assessment of Endoscopic Specimens in the Colorectum

BACKGROUND

Colorectal cancer is one of the most frequently observed neoplasms in the world. It develops from intraepithelial neoplasia of the colorectal mucosa, and these precursor lesions are also known as adenoma. As the precursor lesion is known and can be detected easily, efficient screening strategies are available for a reliable prevention of colorectal adenocarcinoma, e.g. by colonoscopy.

METHODS

Literature databases (PubMed) were searched selectively for the keywords 'colorectal adenoma', 'epidemiology', and 'resection techniques'. The results are presented in the following text, also taking into account our own experience and the current S3 guidelines.

RESULTS

Endoscopic resection samples are one of the specimens most frequently assessed by pathologists. Therefore, gastroenterologists expect standardized and well-structured pathology reports, stating relevant information concerning the removed lesions and recommendations for clinical management. These aspects are summarized in the evidence-based S3 guideline.

CONCLUSION

As a consequence of colorectal adenoma resection during screening procedures, the carcinoma incidence is decreasing. For further advancements in successful prevention, knowledge of different precursor lesions (conventional adenoma, serrated adenoma) is important, but also structured communication between the different disciplines engaged in colorectal cancer screening.

Principles of Cancer Staging for Clinical Obstetrics and Gynecology

Cancer represents a complex group of diseases characterized by uncontrolled growth and the ability to metastasize. Cancer may affect any part of the body, and within the female reproductive systems, there exist a variety of cancers each associated with different presenting symptoms, clinical course, etiology, and natural history of disease. The essential features of each cancer include the presenting site of disease (topography), the histopathologic (morphology), molecular and genetic tumor profile, and the anatomic disease extent (stage). Without knowing these features, it is impossible to discuss investigation, treatment, and prognosis in cancer.

Complete resection of colorectal adenomas: what are the important factors in fellow training?

BACKGROUND

The complete removal of adenomatous polyps is important for reducing interval cancer after colonoscopy.

AIMS

To identify factors affecting the completeness of colonoscopic polypectomies and to evaluate the experience level of fellows who achieve competence compared with that of experts.

METHODS

Medical records of 1,860 patients who underwent at least one polypectomy for an adenomatous polyp at Seoul National University Hospital between March 2011 and February 2013 were retrospectively reviewed. A total of 3,469 adenomatous polyps were included. The lateral and deep margins of the resected polyps were evaluated to check the resection completeness.

RESULTS

Of the 3,469 adenomatous polyps, 1,389 (40.0 %) were removed by two experts and 2,080 (60.0 %) were removed by seven fellows. In the expert-treated group, larger size [odds ratio (OR) 2.81 for ≥20 mm, 95 % confidence interval (CI) 1.64-4.84, P < 0.001] and right-sided location (OR 1.31, 95 % CI 1.05-1.63, P = 0.019) were associated with incomplete resection. In the fellow-treated group, not only polyp characteristics [right-sided location (OR 1.41, 95 % CI 1.18-1.69, P < 0.001)], but also the cumulative number of procedures was also related to resection completeness. After 300 polypectomies, the complete resection rate of the fellows was comparable to that of the experts.

CONCLUSIONS

In the fellow-treated group, the level of procedure experience was closely associated with the polypectomy outcomes. Meticulous attention is critical to ensure the completeness of polypectomies performed by trainee endoscopists during the training program.

eCROPS-CA: a systematic approach toward effective and sustainable cancer prevention in rural China

Background

Effective prevention against cancers depends heavily on sustained individual efforts practicing protective behaviors and avoiding risk factors in a complex sociocultural context, which requires continuous and personalized supports. Contemporary prevention relies primarily on strategies targeting general population with limited attention being paid to individualized approaches. This study tests a novel package called, in acronym of core intervention components, eCROPS-CA that leverages protective behaviors against over 80% leading cancers among high risk individuals via continuous and tailored counseling by village doctors.

Methods/Design

The study utilizes a quesi-RCT design involving 4320 high risk individuals selected, via rapid and detailed risk assessments, from about 72,000 farmers aged 35+ in 36 administrative villages randomized into equal intervention and delayed intervention arms. The intervention arm receives baseline and semiannual follow up evaluations plus eCROPS-CA for 5 years; while the control arm, only the baseline and follow-up evaluations for the first 5 years and eCROPS-CA starting from the 6^th year if the intervention is proved effective. eCROPS-CA comprises electronic supports and supervision (e), counseling cancer prevention (C), recipe for objective behaviors (R), operational toolkit (O), performance-based incentives (P), and screening and assessment (S). Evaluation measures include: incidence and stage of the leading cancers, cancer-related knowledge, attitudes and practices; easy biophysical indicators (e.g., body mass index, blood pressure); intervention compliance, acceptance of the package.

Discussion

The prevention package incorporates key success factors in a synergetic way toward cost-effectiveness and long-term sustainability. It targets a set rather than any single cancer; choses village doctors as key solution to the widespread lack of professional manpower in implementing personalized and thus relatively sophisticated prevention; adopts real-time monitoring in reaching continuous improvement; utilizes smart web aids to enable prioritizing complex determinants of objective behaviors, linking counseling sessions happened at different time points and hence delivering highly coordinated prevention; uses 2-stage risk assessment models in identifying high risk individuals so as to focus on the most needed; applies standardized operation procedures in simplifying and smoothing behavior intervention yet ensuring delivery of essential steps and key elements.

Trials registry

ISRCTN33269053

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1253-6) contains supplementary material, which is available to authorized users.

Refining and validating a two-stage and web-based cancer risk assessment tool for village doctors in China

The big gap between efficacy of population level prevention and expectations due to heterogeneity and complexity of cancer etiologic factors calls for selective yet personalized interventions based on effective risk assessment. This paper documents our research protocol aimed at refining and validating a two-stage and web- based cancer risk assessment tool, from a tentative one in use by an ongoing project, capable of identifying individuals at elevated risk for one or more types of the 80% leading cancers in rural China with adequate sensitivity and specificity and featuring low cost, easy application and cultural and technical sensitivity for farmers and village doctors. The protocol adopted a modified population-based case control design using 72, 000 non-patients as controls, 2, 200 cancer patients as cases, and another 600 patients as cases for external validation. Factors taken into account comprised 8 domains including diet and nutrition, risk behaviors, family history, precancerous diseases, related medical procedures, exposure to environment hazards, mood and feelings, physical activities and anthropologic and biologic factors. Modeling stresses explored various methodologies like empirical analysis, logistic regression, neuro-network analysis, decision theory and both internal and external validation using concordance statistics, predictive values, etc..

Assessing generalizability of the findings of sigmoidoscopy screening trials: the case of SCORE trial

BACKGROUND

Several reports indicated that volunteers enrolled in preventive trials tend to show a different profile, with respect to sociodemographic characteristics, health-related behaviors, or medical history, compared with the source population. We conducted an incidence and mortality follow-up within a cohort of subjects who had been mailed a recruitment questionnaire in the SCORE trial of sigmoidoscopy (FS) screening for colorectal cancer (CRC) to assess the impact of self-selection in the study of volunteers willing to be screened on the outcomes estimates and on the generalizability of the results.

METHODS

We compared baseline demographics, CRC risk, and overall mortality at 11-year follow-up of responders declaring their interest in screening, with those of nonresponders and of responders not interested in screening using logistic regression and Cox proportional hazards multivariable models.

RESULTS

Both subjects who volunteered in the trial and those who refused were better educated than nonresponders. Men and people younger than age 60 years were more likely to volunteer among responders. At 11-year follow-up, interested responders showed a similar CRC risk as nonresponders, while CRC mortality was substantially reduced (hazard ratio [HR] = 0.70, 95% confidence interval [CI] = 0.54 to 0.91). All-cause mortality was reduced both among interested (HR = 0.61, 95% CI = 0.57 to 0.65) and uninterested responders (HR = 0.81, 95% CI = 0.76 to 0.86).

CONCLUSION

The implementation of an FS population-based screening program would result in a similar reduction in CRC incidence, as observed in the SCORE trial, and likely in a larger impact on CRC mortality.

Detection of colorectal serrated polyps by stool DNA testing: comparison with fecal immunochemical testing for occult blood (FIT)

OBJECTIVES

Precursors to 1/3 of colorectal cancer (CRC), serrated polyps have been under-detected by screening due to their inconspicuous, non-hemorrhagic, and proximal nature. A new multi-target stool DNA test (multi-target sDNA) shows high sensitivity for both CRC and advanced adenomas. Screen detection of serrated polyps by this approach requires further validation. We sought to assess and compare noninvasive detection of sessile serrated polyps (SSP) ≥ 1 cm by sDNA and an occult blood fecal immunochemical test (FIT).

METHODS

In a blinded prospective study, a single stool sample used for both tests was collected from 456 asymptomatic adults prior to screening or surveillance colonoscopy (criterion standard). All 29 patients with SSP ≥ 1 cm were included as cases and all 232 with no neoplastic findings as controls. Buffered stool samples were processed and frozen on receipt; Exact Sciences performed sDNA in batches using optimized analytical methods. The sDNA multi-marker panel targets methylated BMP3 (mBMP3) and NDRG4, mutant KRAS, β-actin, and hemoglobin. FIT (Polymedco OC-FIT Check) was performed in separate lab ≤ 2 days post defecation and evaluated at cutoffs of 50 (FIT-50) and 100 ng/ml (FIT-100).

RESULTS

MEDIAN AGES: cases 61 (range 57-77), controls 62 (52-70), p = NS. Women comprised 59% and 51%, p = NS, respectively. SSP median size was 1.2 cm (1-3 cm), 93% were proximal, and 64% had synchronous diminutive polyps. Among multi-target sDNA markers, mBMP3 proved highly discriminant for detection of SSP ≥ 1 cm (AUC = 0.87, p<0.00001); other DNA markers provided no incremental sensitivity. Hemoglobin alone showed no discrimination (AUC = 0.50, p = NS). At matched specificities, detection of SSP ≥ 1 cm by stool mBMP3 was significantly greater than by FIT-50 (66% vs 10%, p = 0.0003) or FIT-100 (63% vs 0%, p<0.0001).

CONCLUSIONS

In a screening and surveillance setting, SSP ≥ 1 cm can be detected noninvasively by stool assay of exfoliated DNA markers, especially mBMP3. FIT appears to have no value in SSP detection.

Is esophagogastroduodenoscopy necessary in patients with positive fecal occult blood tests and negative colonoscopy?

BACKGROUND

False positives of fecal occult blood tests (FOBT) regarding colorectal cancer detection are common. The aim was to investigate the upper gastrointestinal (GI) condition confirmed by endoscopy in positive FOBT patients without advanced colorectal neoplasia, hemorrhoid, or colitis.

METHODS

The authors reviewed the collective data of 340 positive FOBT patients who underwent both esophagogastroduodenoscopy (EGD) and colonoscopy from January 2005 to October 2011. Demographic data, effects of medications, including antiplatelet agents, nonsteroidal anti-inflammatory drugs, or warfarin on the results of FOBT, presence or absence of GI mucosal lesions confirmed by EGD and colonoscopy, and FOBT titer in 552 positive FOBT patients were analyzed.

RESULTS

On colonoscopy, colorectal cancer was detected in 35 patients (10.3%), advanced adenoma in 22 patients (6.4%). "Negative colonoscopy" included no significant lesions and non-advanced adenomas. In 243 patients with "negative colonoscopy", EGD findings included 3 (1.2%) gastric cancers and 39 (16%) peptic ulcer diseases. Gastric cancers were all found in patients who had no experience of EGD within 2 years; however, the incidence of peptic ulcer disease was not different in patients with or without previous EGD within 2 years. Two or more antiplatelet agents increased false positive rates of FOBT.

CONCLUSIONS

Upper GI evaluation is mandatory in patients with positive FOBTs and negative colonoscopy especially in patients without experience of EGD within 2 years.

Water exchange enhanced cecal intubation in potentially difficult colonoscopy. Unsedated patients with prior abdominal or pelvic surgery: a prospective, randomized, controlled trial

BACKGROUND

Colonoscopy is widely used for management of colorectal diseases. A history of abdominal or pelvic surgery is a well-recognized factor associated with difficult colonoscopy. Although water exchange colonoscopy (WEC) was effective in small groups of male U.S. veterans with such a history, its application in other cultural settings is uncertain.

OBJECTIVE

To investigate the application of WEC in such patients.

DESIGN

Prospective, randomized, controlled, patient-blinded study.

SETTING

Tertiary-care referral center in China.

PATIENTS

Outpatients with prior abdominal or pelvic surgery undergoing unsedated diagnostic, screening, or surveillance colonoscopy.

INTERVENTION

Patients were randomized to examination by either WEC or conventional air colonoscopy (AC).

MAIN OUTCOME MEASUREMENTS

Cecal intubation rate.

RESULTS

A total of 110 patients were randomized to the WEC (n = 55) or AC (n = 55) group. WEC significantly increased the cecal intubation rate (92.7% vs 76.4%; P = .033). The maximum pain scores (± standard deviation) were 2.1 ± 1.8 (WEC) and 4.6 ± 1.7 (AC), respectively (P < .001). Multivariate analysis showed that the colonoscopy method was the only independent predictor of failed colonoscopy (odds ratio 11.44, 95% confidence interval, 1.35-97.09). A higher proportion of patients examined by WEC would be willing to have a repeat unsedated colonoscopy (90.9% vs 72.7%, P = .013).

LIMITATIONS

Single center; unblinded but experienced endoscopists.

CONCLUSION

This randomized, controlled trial confirms that the water exchange method significantly enhanced cecal intubation in potentially difficult colonoscopy in unsedated patients with prior abdominal or pelvic surgery. The lower pain scores and higher proportion accepting repeat of the unsedated option suggest that WEC is promising. It may enhances compliance with colonoscopy in specific populations. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01485133.).

Insulin, insulin-like growth factor 1 and insulin-like growth factor binding protein 3 serum concentrations in patients with adenomatous colon polyps

INTRODUCTION

Insulin stimulates colonic mucosal cells proliferation directly and by influencing the concentration of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3).

AIM

To estimate serum concentrations of insulin, IGF-1, and IGFBP-3 and to determine the relationships between them and colorectal adenoma location, dysplasia grading, histological type, and size.

MATERIAL AND METHODS

The study included 60 patients with colorectal adenomatous polyps found on colonoscopy and confirmed pathologically. The control group consisted of 30 individuals with no positive findings on colonoscopy. All patients had their blood drawn for assessment of insulin, IGF-1, and IGFBP-3 serum concentrations.

RESULTS

One hundred and nine adenomas (6-40 mm in size) were found in 60 study patients. The average age of patients with multiple polyps was significantly higher than that of patients with single pathologies (61.1 vs. 56.7 years respectively (p < 0.05)). A higher adenoma incidence rate was observed in the distal portion of the colon than the proximal one (50 vs. 10 polyps respectively (p < 0.01)). Higher serum levels of IGF-1 and IGFBP-3 were found in patients with adenomatous polyps than in the control group. The average IGF-1 concentration in patients with adenomas located proximally was also significantly higher compared to those located distally (p < 0.05). The insulin concentration was similar in both groups and not related to clinical data of patients.

CONCLUSIONS

The results indicate the role of IGF-1 and IGFBP-3 in early carcinogenesis of the large intestine, and IGF-1 particularly in malignant transformation in the proximal part of the organ.

Increasing trend of colorectal cancer incidence in Korea, 1999-2009

PURPOSE

This study was conducted in order to demonstrate changing trends in colorectal cancer incidence according to sex, age group, and anatomical location in the Korean population.

MATERIALS AND METHODS

Data from the Korea Central Cancer Registry between 1999 and 2009 were analyzed. Annual percent changes (APCs) of sex- and age-specific incidence rates for cancer of the proximal colon (International Statistical Classification of Diseases and Related Health Problems, 10th revision [ICD-10] code C18.0-18.5), distal colon (C18.6-18.7), and rectum (C19-20), and male-to-female incidence rate ratios (IRR) were calculated.

RESULTS

The age-standardized incidence rate (ASR) of colorectal cancer was 27 (per 100,000) in 1999 and increased to 50.2 in 2009 among men (APC, 6.6%). The ASR for women was 17.2 in 1999 and 26.9 in 2009 (APC, 5.1%). The rectum was the most common site of cancer among both men and women during 1999 and 2009. However, the distal colon had the highest APC (10.8% among men and 8.4% among women), followed by the proximal colon (7.9% among men and 6.6% among women), and rectum (5.2% among men and 2.4% among women). The proportion of rectal cancer decreased from 51.5% in 1999 to 47.1% in 2009 among men, and from 50.5% to 42.8% among women. An increase in the male-to-female IRR was observed for distal colon cancer and rectal cancer, whereas the IRR for proximal colon cancer was stable.

CONCLUSION

The rapid increase in colorectal cancer incidence is mainly attributed to the increase in colon cancer, especially distal colon cancer, and may be explained by a transition of risk factors for subsites or by the effect of colorectal cancer screening.

Invasive colorectal cancer within 5 years of negative colonoscopy in a Japanese population

AIM

Colonoscopy provides imperfect protection against colorectal cancer (CRC). In an attempt to improve cancer detection we evaluated the clinical features of invasive CRC detected within 5 years of a negative colonoscopy.

METHOD

The details of colonoscopies performed in a rural hospital in Japan were prospectively recorded at the time of the examination. The patients were followed over 5 years for the subsequent occurrence of cancer.

RESULTS

In a 5-year period, 10148 patients underwent colonoscopy and 202 without previous colonoscopy were diagnosed with invasive CRC. Of 3212 patients with a colonoscopy negative for cancer, nine developed invasive cancer within 5 years. The ratios for invasive CRC detected without/with previous colonoscopy were 60:1 in the rectum, 54:1 in the sigmoid colon, 15:1 in the descending colon, 28:0 in the transverse colon, 31:5 in the ascending colon and 14:1 in the caecum (P=0.041). The ratio between left- and right-sided colonic cancer was also significantly different (129:3 and 45:6, P=0.0078). Six (67%) of the invasive CRCs were in the ascending colon or caecum. Five of six patients with invasive CRC in the ascending colon and caecum had right-sided small adenomas at prior colonoscopy.

CONCLUSION

The majority of early/missed CRCs were right-sided and associated with prior right-sided colonic adenomas. Repeated colonoscopy of patients with right-sided adenomas at a shorter surveillance interval deserves consideration.

Anatomical distribution of colorectal carcinoma in Iran: a retrospective 15-yr study to evaluate rightward shift

BACKGROUND

Although more than two third of colorectal cancers are localized on the left side, recent studies suggest a right ward shift in anatomical distribution with increase in proximal colon cancers. The aim of the present study was to determine the anatomical distribution of colorectal cancer in a referral center over a 15 year period.

METHOD

Records of patients who underwent colectomy in the Cancer Institute of Iran from 1994 to 2009 were retrieved. Data including anatomical localization, year of diagnosis, patient age and gender, tumor histology and differentiation, and disease stage were extracted. Tumors located from the cecum to the distal transverse colon were classified as right side and those occurring from the splenic flexure to the descending colon as left-sided. Cancer of rectum and recto-sigmoid junction were considered as rectal cancers.

RESULTS

A total of 442 patients including 220 (49/8%) men and 222 (50/2%) women with mean age 53 were included. Most patients were in stages II and III (47.1% and 33% respectively). There were 157 (35.5 %) colon cancers and 285 (64.5%) rectal cancers. 43.3% of the colon cancers were right sided and 56.7% were left sided. There was no statistically significant increase in right sided cancer during the period of the study. There were no significant differences in age at diagnosis, gender, grade and stage of tumor between the right and the left sided cancers.

CONCLUSION

No proximal shift over time was identified in our study.

Efficacy of a nationwide screening colonoscopy program for colorectal cancer

BACKGROUND & AIMS

Screening colonoscopy examinations for colorectal cancer are offered in the United States and some European countries. Data on results and adverse effects of screening colonoscopy are limited. In autumn 2002, colonoscopy was introduced as part of a nationwide cancer screening program in Germany; it was offered to the general population for individuals 55 years of age or older. We collected and analyzed data from this program.

METHODS

We performed a prospective cross-sectional study, collecting results from 2,821,392 screening colonoscopies performed at more than 2100 practices by highly qualified endoscopists in Germany from January 2003 to December 2008. Data on participation, colorectal adenoma and cancer detection, and complications were collected using standardized documentation forms. The data generated were centrally processed and evaluated.

RESULTS

The cumulative participation rate was 17.2% of eligible women and 15.5% of eligible men 55-74 years old. The adenoma detection rate (ADR) was 19.4%, with a higher rate in men (25.8% vs 16.7% in women). Advanced adenomas were found in 6.4% of patients. Carcinomas were detected in 25,893 subjects (0.9%); most were of an early UICC stage (I, 47.3%; II, 22.3%; III, 20.7%; IV, 9.6%). The ADRs for gastroenterologists and nongastroenterologists were 25.1% and 22.3%, respectively (adjusted odds ratio, 1.18; 95% confidence interval, 1.16-1.21). The overall complication rate was 2.8/1000 colonoscopies, and the rate of serious complications was 0.58/1000 colonoscopies.

CONCLUSIONS

A nationwide colonoscopy screening program that uses highly qualified endoscopists can detect a significant number of adenomas and early-stage carcinomas. The ADR for gastroenterologists was higher than for nongastroenterologists.

Next-generation stool DNA test accurately detects colorectal cancer and large adenomas

BACKGROUND & AIMS

Technical advances have led to stool DNA (sDNA) tests that might accurately detect neoplasms on both sides of the colorectum. We assessed colorectal neoplasm detection by a next-generation sDNA test and effects of covariates on test performance.

METHODS

We performed a blinded, multicenter, case-control study using archived stool samples collected in preservative buffer from 252 patients with colorectal cancer (CRC), 133 with adenomas ≥ 1 cm, and 293 individuals with normal colonoscopy results (controls); two-thirds were randomly assigned to a training set and one-third to a test set. The sDNA test detects 4 methylated genes, a mutant form of KRAS, and the α-actin gene (as a reference value) using quantitative, allele-specific, real-time target and signal amplification; it also quantifies hemoglobin. We used a logistical model to analyze data.

RESULTS

The sDNA test identified 85% of patients with CRC and 54% of patients with adenomas ≥1 cm with 90% specificity. The test had a high rate of detection for all nonmetastatic stages of CRC (aggregate 87% detection rate for CRC stages I-III). Detection rates increased with adenoma size: 54% ≥ 1 cm, 63% >1 cm, 77% >2 cm, 86% >3 cm, and 92% >4 cm (P < .0001). Based on receiver operating characteristic analysis, the rate of CRC detection was slightly greater for the training than the test set (P = .04), whereas the rate of adenoma detection was comparable between sets. Sensitivities for detection of CRC and adenoma did not differ with lesion site.

CONCLUSIONS

Early-stage CRC and large adenomas can be detected throughout the colorectum and with high levels of accuracy by the sDNA test. Neoplasm size, but not anatomical site, affected detection rates. Further studies are needed to validate the findings in a larger population and optimize the sDNA test.

Correlation between preoperative endoscopic and intraoperative findings in localizing colorectal lesions

BACKGROUND

Colonoscopy findings compared with findings at time of surgery have a discrepancy rate of 3-21%. The objective of our study was to investigate this discrepancy and provide potential resolutions.

METHODS

In this retrospective study, we identified 400 patients who underwent colonoscopy followed by colon resection at our community hospitals in 1999-2006. Discrepancies between colonoscopy and intraoperative findings were noted. Each discrepancy was classified as major if the surgical procedure had to be altered, the lesion was missed, an unnecessary segment was removed, or the incision was extended. A discrepancy was classified as minor if there was no alteration in planned surgery.

RESULTS

Of the 400 cases, 160 (40%) were located in the right colon, 13 (3%) were in the transverse colon, 185 (46%) were in the left colon, and 42 (11%) were in the rectum. A total of 48 (12%) discrepancies between colonoscopy and intraoperative findings were identified: 26 (54%) were major and 22 (46%) were minor. Thirteen (27%) were in the proximal colon (3 major and 10 minor discrepancies), 3 (6.3%) were in the transverse colon (all major), 22 (46%) were in the distal colon (17 major and 5 minor), and 10 (21%) were in the rectum (3 major, 7 minor). Major discrepancies were significantly higher in the left colon (17 of the 185 left-sided lesions; 9.1%) than in the right colon (3/160; 1.9%; P = 0.045).

CONCLUSIONS

In our study, colonoscopy has an error rate of 12% when used to localize tumors; more than half of these patients require significant unanticipated changes in their surgery. The discrepancies are significantly higher in left side of colon.

Changing trends in polypoid colorectal cancer diagnosed by colonoscopy

AIM

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

METHOD

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

RESULTS

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

CONCLUSION

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

The clinical significance of serrated polyps

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

Early detection of colon cancer-the kaiser permanente northwest 30-year history: how do we measure success? Is it the test, the number of tests, the stage, or the percentage of screen-detected patients?

INTRODUCTION

Colorectal cancer (CRC) is the fourth most common malignancy in the Kaiser Permanente Northwest (KPNW) Region. The goals of CRC screening are early diagnosis of cancer in the preclinical state, down-staging of tumors, and increasing survival. This historical review summarizes the screening strategies since 1980 and their impact on early diagnosis, stage, and survival. During this period, the KPNW Tumor Registry documented the stage and survival, and screen-detection status of patients. We have observed that the percentage of screen-detected case measure has provided critical information that has contributed to the present success. CRC screening efforts by the end of 2010 had provided early diagnosis for one-third of patients.

METHODS

KPNW membership has undergone more than 540,000 fecal blood tests, an estimated 130,000 flexible sigmoidoscopies (FS), and more than 100,000 colonoscopies. Since 1980 members older than age 50 years have increased from 48,627 to 137,617. This report represents a review of 5458 patients. Since 1980, 5 distinct periods of CRC screening have been compared. In 1980, the CRC screening practice was primarily office-based fecal occult blood testing (FOBT) and proctosigmoidoscopy. Data from the initial home-based FOBT testing initiative (1985), transitioning to an FS program (1995), adoption of colonoscopy (2005), and subsequent reintroduction of FOBT testing (2006) allows examination of results by period. After ever-increasing promotion of endoscopy, the goal of screening shifted from "screen detection to prevention by polypectomy."

RESULTS

By reexamining the outcomes of the CRC strategies from 1980-2005, the nature of the colonoscopy label of "gold standard" was questioned leading to a return to FOBT testing. Since then, the percentage of screen-detected patients exceeded expectations with a 6-fold increase (5% to 33%) allowing KPNW to reach its highest level of early detection.

DISCUSSION

By examining the KPNW experience, we have come to better understand the significance of effectiveness measures: number of tests, stage of disease, percentage of screen-detected cancers and their relationship to survival. We examined the measures used to assess success and conclude that the current metrics-the number of examinations and disease stage-do not accurately reflect the effectiveness of screening efforts. Early detection of CRC saves lives when a program tests the most at-risk people. Using a good test (FOBT/fecal immunochemical test) that is able to reach more people, rather than the "perfect test" that reaches fewer people, transforms an ineffective program into a successful one. A critical element was the transition of the individual testing to population screening.

Serrated Colorectal Neoplasia

Until very recently, there was general acceptance in the pathology community that all serrated lesions of the colon and rectum without overt cytologic dysplasia were hyperplastic polyps and had no malignant potential. Although there are still several unanswered questions in regard to the relationship between the various serrated lesions, there is a better understanding of the relationship of sessile serrated adenoma to carcinoma. This article discusses hyperplastic polyps, sessile serrated adenoma, traditional serrated adenoma, mixed polyps, and serrated lesions in such conditions as idiopathic inflammatory bowel disease and mechanical trauma. The major focus of the content is on diagnostic features of these lesions.

Molecular detection of colorectal neoplasia

A variety of noninvasive molecular approaches to colorectal cancer screening are emerging with potential to improve screening effectiveness and user-friendliness. These approaches are based on the sensitive assay of molecular markers in stool, blood, and urine samples. New methods, especially next generation stool-based tests, have been shown to detect both colorectal cancers and precancerous lesions with high accuracy. Validation of these technologies in average-risk populations are needed to establish their role for general colorectal cancer screening. This review addresses the biological rationale, technical advances, recent clinical performance data, and remaining issues with molecular screening for colorectal cancer.

Colorectal cancer screening in evolution: Japan and the USA

Colorectal cancer (CRC) is one of the most common cancers in both Japan and the USA. Age-adjusted incidence of CRC has been in decline in the USA since 1985, while rates in Japan have been increasing. The decline in the USA is commonly attributed to CRC screening programs but there is little direct evidence to support this assertion. The current screening recommendations in the USA cover several options including colonoscopy and computerized tomographic colonography (CTC). The Japanese CRC screening program is centered on fecal immunochemistry testing (FIT). The US government Medicare program's approval of colonoscopy as a primary screening test has lead to a large increase in the number of patients undergoing the procedure. However, the benefit achieved from this change in screening program emphasis is not clear. Simulation models demonstrate that a screening program centered on FIT achieves 94% of the benefit that an all-colonoscopy program is able to accomplish but at a lower cost per life year gained. Clinical studies of colonoscopy have failed to demonstrate the 76-90% declines in CRC incidence predicted by the National Polyp Study published in 1993. A potential reason for this failure is the quality of colonoscopy performance. Until more compelling data becomes available demonstrating the utility of colonoscopy as a primary screening modality, there is little incentive to alter the proven cost-effective approach to CRC screening currently in practice in Japan.

Educational inequalities in cancer incidence in Turin, Italy

The objective of this study was to investigate the relationship between cancer incidence and socioeconomic status, and to examine the temporal trends in social inequalities in cancer risk. Educational differentials in the incidence of cancer (25 sites) among adult residents of Turin (Italy) were examined using data from the Turin Longitudinal Study and the Piedmont Cancer Registry. The relationship between cancer incidence and educational level was evaluated over three 5-year periods between 1985 and 1999 using Poisson models. An estimated 17% of malignancies among men in the low-educational group were attributable to education, whereas women with a low educational level were slightly protected. Less-educated men had higher risks of upper aero-digestive tract, stomach, lung, liver, rectal, bladder, central nervous system and ill-defined cancers, and lower risks of melanoma, kidney and prostate cancers. Women with lower educational levels were at higher risk of stomach, liver and cervical cancers, whereas they were less likely to be diagnosed with melanoma, ovarian and breast cancers. For most sites, the educational gradient in risk did not vary substantially over time. The educational inequalities in cancer incidence observed in this cohort appear similar in magnitude and direction to socioeconomic inequalities found in other Western countries; for some cancer sites results partly differ from the results of other studies, and require further investigation. A thorough understanding of the relative burden of well-documented causes of social inequalities in cancer risk is essential to address preventive measures and to direct future research on unexplained social differences.