Prevalence of advanced histological features and synchronous neoplasia in patients with flat adenomas

Multicentre randomised controlled trial comparing standard and high resolution optical technologies in colorectal cancer screening

BACKGROUND AND OBJECTIVES

The UK bowel cancer screening programme (BCSP) has been established for the early detection of colorectal cancer offering colonoscopy to patients screened positive by faecal occult blood tests. In this multisite, prospective, randomised controlled trial, we aimed to compare the performance of Standard Definition Olympus Lucera (SD-OL) with Scope Guide and the High Definition Pentax HiLine (HD-PHL).

PATIENTS AND METHODS

Subjects undergoing a colonoscopy as part of the UK National BCSP at four UK sites were randomised to an endoscopy list run using either SD-OL or HD-PHL. Primary endpoints were polyp and adenoma detection rate (PDR and ADR, respectively) as well as polyp size, morphology and histology characteristics.

RESULTS

262 subjects (168 males, mean age 66.3±4.3 years) were colonoscoped (133 patients with HD-PHL while 129 with SD-OL). PDR and ADR were comparable within the two optical systems. The HD-PHL group resulted in a PDR 55.6% and ADR 43.6%; the SD-OL group had PDR 56.6% and ADR 45.7%. HD-PHL was significantly superior to SD-OL in detection of flat adenomas (18.6% vs 5.2%, p<0.001), but not detection of pedunculated or sessile polyps. Patient comfort, use of sedation and endoscopist perception of procedural difficulty resulted similar despite the use of Scope Guide with SD-OL.

CONCLUSION

PDR and ADR were not significantly different between devices. The high-resolution colonoscopy system HD-PHL may improve polyp detection as compared with standard resolution technology in detecting flat adenomas. This advantage may have clinically significant implications for missed lesion rates and post-colonoscopy interval colorectal cancer rates.

Could Mycobacterium avium subspecies paratuberculosis cause Crohn's disease, ulcerative colitis…and colorectal cancer?

Infectious agents are known causes of human cancers. Schistosoma japonicum and Schistosoma mansoni cause a percentage of colorectal cancers in countries where the respective Schistosoma species are prevalent. Colorectal cancer is a complication of ulcerative colitis and colonic Crohn’s disease, the two main forms of idiopathic inflammatory bowel disease (IIBD). Mycobacterium avium subspecies paratuberculosis (MAP), the cause of a chronic intestinal disease in domestic and wild ruminants, is one suspected cause of IIBD. MAP may therefore be involved in the pathogenesis of IIBD-associated colorectal cancer as well as colorectal cancer in individuals without IIBD (sporadic colorectal cancer) in countries where MAP infection of domestic livestock is prevalent and MAP’s presence in soil and water is extensive. MAP organisms have been identified in the intestines of patients with sporadic colorectal cancer and IIBD when high magnification, oil immersion light microscopy (×1000 total magnification rather than the usual ×400 total magnification) is used. Research has demonstrated MAP’s ability to invade intestinal goblet cells and cause acute and chronic goblet cell hyperplasia. Goblet cell hyperplasia is the little-recognized initial pathologic lesion of sporadic colorectal cancer, referred to as transitional mucosa, aberrant crypt foci, goblet cell hyperplastic polyps or transitional polyps. It is the even lesser-recognized initial pathologic feature of IIBD, referred to as hypermucinous mucosa, hyperplastic-like mucosal change, serrated epithelial changes, flat serrated changes, goblet cell rich mucosa or epithelial hyperplasia. Goblet cell hyperplasia is the precursor lesion of adenomas and dysplasia in the classical colorectal cancer pathway, of sessile serrated adenomas and serrated dysplasia in the serrated colorectal cancer pathway, and of flat and elevated dysplasia and dysplasia-associated lesions or masses in IIBD-associated intestinal cancers. MAP’s invasion of intestinal goblet cells may result in the initial pathologic lesion of IIBD and sporadic colorectal cancer. MAP’s persistence in infected intestines may result in the eventual development of both IIBD-associated and sporadic colorectal cancer.

FICE vs Narrow Band Imaging for In Vivo Histologic Diagnosis of Polyps

BACKGROUND AND OBJECTIVES

Gastrointestinal cancers are the most frequently occurring cancers worldwide. Diagnosis and removal of polyps during screening endoscopy decreases the prevalence of colon cancer and cancer-related mortality, and it is considered to be the gold standard in gastrointestinal system cancer prevention. Technological innovations in endoscopy have led to revolutionary developments in many areas. Flexible spectral imaging color enhancement (FICE) and narrow-band imaging (NBI) are forms of digital chromoendoscopy and enhance the endoscopic images without the need for a dye. This study seeks to evaluate the efficacy of FICE and NBI on polyp screening and real-time histologic diagnosis with endoscopy and to compare them.

METHODS

A total of 134 patients (male/female = 72/62) and 161 polyps were evaluated with FICE or NBI, and real-time histologic diagnosis predictions were classified as neoplastic or nonneoplastic, according to Kudo's pit pattern classification. Pathological results and real-time endoscopic diagnoses were statistically interpreted for both FICE and NBI. Positive predictive value, negative predictive value, sensitivity, specificity, and accuracy rates were calculated and compared for both modalities.

RESULTS

When both systems were compared, the negative predictive value of NBI was found to be higher than that of FICE statistically (P < .001). Specificity and positive predictive value in the FICE group were higher than in the NBI group, but the difference was not statistically significant (P = .082 and P = .153, respectively).

CONCLUSIONS

Aside from being safe in polyp detection, digital chromoendoscopy also helps the endoscopist in selecting the type of simultaneous intervention (eg, polypectomy, endomucosal resection, or submucosal dissection) by enabling endoscopic histologic diagnosis.

Outcome of EMR as an alternative to surgery in patients with complex colon polyps

BACKGROUND AND AIMS

Patients with complex colon polyps were traditionally referred for surgery to avoid adverse events associated with endoscopic resection. Recent advances in endoscopic imaging as well as endoscopic hemostasis and clip closure allow for the use of EMR as an alternative to surgery for such lesions. To determine the outcome of treatment of complex colon polyps with EMR as an alternative to surgery, we conducted a retrospective observational study.

METHODS

Two hundred three patients with complex colon polyps were referred to an EMR center as an alternative to surgery. Patients underwent a protocol-driven EMR. The primary endpoint was the complete resection rate. Secondary endpoints were safety, residual adenoma rate, and incidence of missed synchronous polyps.

RESULTS

EMR was performed in 155 patients and was deferred in 48 patients who were referred to surgery. EMR specimens revealed benign polyps in 149 and cancer in 6 patients. EMR adverse events occurred in 7 patients, requiring hospitalization in 5 of them. None of the patients died as a result of their adverse events. Surveillance colonoscopy at 4 to 6 months after resection of a benign lesion in 137 patients revealed residual adenoma at the scar site in 6 patients and additional synchronous precancerous lesions in 117 patients that were not removed by the referring endoscopist. None underwent surgery for failure of EMR. The overall precancerous lesion burden was 2.83 per patient, the adenoma burden was 2.13 per patient, and the serrated polyp burden was .69 per patient.

CONCLUSIONS

EMR can be used instead of surgery for complex colon polyps in 75% of patients with few adverse events and few residual adenomas at resection sites. In addition, careful repeat examination of the entire colon for synchronous lesions overlooked by the referring endoscopist is required for most patients. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01827241.).