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

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

Lack of benefit of active preparation compared with a clear fluid-only diet in small-bowel visualization for video capsule endoscopy: results of a randomized, blinded, controlled trial.

BACKGROUND AND AIMS: Controversy remains regarding the type and amount of precapsule bowel cleansing required for small-bowel video capsule endoscopy (VCE). This study aims to assess the efficacy and tolerance of 2 active preparations and a control group of clear fluids only. METHODS: Patients with clinical indications for VCE were randomized to (1) clear fluids only the evening before VCE, (2) 2 sachets of sodium picosulfate plus magnesium sulfate (P/MC) the evening before, or (3) 2 L of polyethylene glycol (PEG) the evening before. Diet instructions were the same for all 3 groups. Small-bowel cleansing was assessed in 3 ways: a 5-point ordinal scale (primary outcome), the percentage of time the small-bowel view was clear, and a validated computerized assessment of cleansing. RESULTS: In total, 198 patients were randomized and 175 patients completed the trial with a mean age of 49.2 years. There was no clear benefit of active preparation with either P/MC or PEG over clear fluids only in the overall 5-point rating scale or in the distal fourth of each examination. There was no difference in diagnostic yield between groups. Significant differences were seen concerning tolerance of the preparations, with a higher proportion rating it as easy or very easy in the clear fluids-only group (93%) and the P/MC group (67%) than in the PEG group (13%) (P < .0001). CONCLUSIONS: Small-bowel cleansing for VCE remains a controversial topic. This randomized control trial demonstrates no benefit in overall or distal small-bowel visualization with active preparation using either PEG or P/MC compared with clear fluids only. (Clinical trial registration number: NCT00677794.).

A cross-sectional study of global DNA methylation and risk of colorectal adenoma.

BACKGROUND: The methylation of DNA is recognized as a key epigenetic mechanism and evidence for its role in the development of several malignancies is accumulating. We evaluated the relationship between global methylation in DNA derived from normal appearing colon mucosal tissue and blood leukocytes, and colorectal adenoma risk. METHODS: Patients, aged 40 to 65, scheduled for a screening colonoscopy were recruited. During the colonoscopy, two pinch biopsies of healthy, normal appearing mucosa were obtained from the descending colon. A fasting blood sample was also collected. The methylation status of LINE-1 (long interspersed nuclear element-1) repetitive sequences, as a surrogate measure of global methylation, was quantified in DNA extracted from normal colon mucosa and blood leukocytes. Statistical analysis of the relationship between global DNA methylation and adenoma risk was conducted on 317 participants, 108 subjects with at least one pathologically confirmed adenoma and 209 subjects with a normal colonoscopy. RESULTS: A statistically significant inverse relationship was observed between LINE-1 methylation in colon tissue DNA and adenoma risk for males and for both sexes combined for the lowest methylation quartile compared to the highest (adjusted ORs = 2.94 and 2.26 respectively). For blood, although the overall pattern of odds ratio estimates was towards an increase in risk for lower methylation quartiles compared to the highest methylation quartile, there were no statistically significant relationships observed. A moderate correlation was found between LINE-1 methylation levels measured in tissue and blood (Pearson correlation 0.36). CONCLUSIONS: We observed that lower levels of LINE-1 DNA methylation in normal appearing background colon mucosa were associated with increased adenoma risk for males, and for both sexes combined. Though these findings provide some support for a relationship between LINE-1 DNA methylation in colon mucosal tissue and adenoma risk, large prospective cohort studies are needed to confirm results. Until such investigations are done, the clinical usefulness of LINE-1 methylation as a biomarker of increased adenoma risk is uncertain. Regardless, this study contributes to a better understanding of the role of global DNA methylation as an early event in CR carcinogenesis with implications for future etiologic research.

Biomarkers measured in buccal and blood leukocyte DNA as proxies for colon tissue global methylation.

There is increasing interest in clarifying the role of global DNA methylation levels in colorectal cancer (CRC) etiology. Most commonly, in epidemiologic studies, methylation is measured in DNA derived from blood leukocytes as a proxy measure of methylation changes in colon tissue. However, little is known about the correlations between global methylation levels in DNA derived from colon tissue and more accessible tissues such as blood or buccal cells. This cross-sectional study utilized DNA samples from a screening colonoscopy population to determine to what extent LINE-1 methylation levels (as a proxy for genome-wide methylation) in non-target tissue (e.g., blood, buccal cells) reflected methylation patterns of colon mucosal tissue directly at risk of developing CRC. The strongest Pearson correlation was observed between LINE-1 methylation levels in buccal and blood leukocyte DNA (r = 0.50; N = 67), with weaker correlations for comparisons between blood and colon tissue (r = 0.36; N = 280), and buccal and colon tissue (r = 0.27; N = 72). These findings of weak/moderate correlations have important implications for interpreting and planning future investigations of epigenetic markers and CRC risk.