Use of surveillance colonoscopy among individuals with removal of high-risk polyps according to the US Multi-Society Task Force recommendations.

BACKGROUND: Individuals with colorectal polypectomy are recommended to undergo surveillance colonoscopies at certain intervals to prevent subsequent colorectal cancer. Use of postpolypectomy surveillance according to the 2006 US Multi-Society Task Force (USMSTF) recommendations in an integrated health care system was investigated. METHODS: Use of surveillance colonoscopies was prospectively assessed among 3691 patients with removal of high-risk polyps at a screening colonoscopy during 2007-2012 in the Mass General Brigham Colonoscopy Cohort. With the follow-up up to 2017, the compliance with, overuse, and underuse of postpolypectomy surveillance according to the 2006 USMSTF recommendations was assessed. Surveillance use according to demographic factors was also investigated. RESULTS: During a median follow-up of 4.4 years (5th percentile, 95th percentile, 1.0, 9.9) 2360 (64%) patients had undergone a surveillance colonoscopy, among whom 758 (21%) were considered compliant with the USMSTF recommendations. A substantial underuse of surveillance colonoscopies of 62% was observed. Older age and lower income were associated with a higher incidence of underuse, whereas having a family history of colorectal cancer were associated with lower incidence of underuse. Overuse of surveillance colonoscopies was present in 17% of patients but showed no significant associations with demographic factors. CONCLUSION: Substantial underuse of surveillance in patients with high-risk polyps was observed, particularly those with low income and older age. Efforts are needed to improve delivery and use of surveillance colonoscopy. PLAIN LANGUAGE SUMMARY: The US Multi-Society Task Force recommends follow-up surveillance colonoscopy after polyp removal in the bowel, with intervals depending on the most severe findings. Adherence to surveillance recommendations in a large study with up to 10 years of follow-up among patients with high-risk polyps was investigated. Only 21% of patients adhered to the surveillance recommendations, whereas 62% showed delayed or no use of surveillance. Findings highlight the need for improved use of surveillance colonoscopy among patients at high risk of colorectal cancer.

Declining Colectomy Rates for Nonmalignant Colorectal Polyps in a Large, Ethnically Diverse, Community-Based Population.

INTRODUCTION: Despite studies showing improved safety, efficacy, and cost-effectiveness of endoscopic resection for nonmalignant colorectal polyps, colectomy rates for nonmalignant colorectal polyps have been increasing in the United States and Europe. Given this alarming trend, we aimed to investigate whether colectomy rates for nonmalignant colorectal polyps are increasing or declining in a large, integrated, community-based healthcare system with access to advanced endoscopic resection procedures. METHODS: We identified all individuals aged 50-85 years who underwent a colonoscopy between 2008 and 2018 and were diagnosed with a nonmalignant colorectal polyp(s) at the Kaiser Permanente Northern California integrated healthcare system. Among these individuals, we identified those who underwent a colectomy for nonmalignant colorectal polyps within 12 months after the colonoscopy. We calculated annual colectomy rates for nonmalignant colorectal polyps and stratified rates by age, sex, and race and ethnicity. Changes in rates over time were tested by the Cochran-Armitage test for a linear trend. RESULTS: Among 229,730 patients who were diagnosed with nonmalignant colorectal polyps between 2008 and 2018, 1,611 patients underwent a colectomy. Colectomy rates for nonmalignant colorectal polyps decreased significantly from 125 per 10,000 patients with nonmalignant polyps in 2008 to 12 per 10,000 patients with nonmalignant polyps in 2018 (P < 0.001 for trend). When stratified by age, sex, and race and ethnicity, colectomy rates for nonmalignant colorectal polyps also significantly declined from 2008 to 2018. DISCUSSION: In a large, ethnically diverse, community-based population in the United States, we found that colectomy rates for nonmalignant colorectal polyps declined significantly over the past decade likely because of the establishment of advanced endoscopy centers, improved care coordination, and an organized colorectal cancer screening program.

Total Vitamin D Intake and Risks of Early-Onset Colorectal Cancer and Precursors.

BACKGROUND & AIMS: Vitamin D has been implicated in colorectal cancer (CRC) pathogenesis, but it remains unknown whether total vitamin D intake is associated with early-onset CRC and precursors diagnosed before age 50. METHODS: We prospectively examined the association between total vitamin D intake and risks of early-onset CRC and precursors among women enrolled in the Nurses' Health Study II. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for early-onset CRC were estimated with Cox proportional hazards model. Multivariable-adjusted odds ratios (ORs) and 95% CIs for early-onset conventional adenoma and serrated polyp were estimated with logistic regression model. RESULTS: We documented 111 incident cases of early-onset CRC during 1,250,560 person-years of follow-up (1991 to 2015). Higher total vitamin D intake was significantly associated with a reduced risk of early-onset CRC (HR for ≥450 IU/day vs <300 IU/day, 0.49; 95% CI, 0.26-0.93; P for trend = .01). The HR per 400 IU/day increase was 0.46 (95% CI, 0.26-0.83). The inverse association was significant and appeared more evident for dietary sources of vitamin D (HR per 400 IU/day increase, 0.34; 95% CI, 0.15-0.79) than supplemental vitamin D (HR per 400 IU/day increase, 0.77; 95% CI, 0.37-1.62). For CRC precursors, the ORs per 400 IU/day increase were 0.76 (95% CI, 0.65-0.88) for conventional adenoma (n = 1,439) and 0.85 (95% CI, 0.75-0.97) for serrated polyp (n = 1,878). CONCLUSIONS: In a cohort of younger women, higher total vitamin D intake was associated with decreased risks of early-onset CRC and precursors.

Arachidonic acid-derived hydroxyeicosatetraenoic acids are positively associated with colon polyps in adult males: a cross-sectional study.

Oxylipids are potent lipid mediators associated with inflammation-induced colon carcinomas and colon tumor survival. Therefore, oxylipid profiles may be useful as novel biomarkers of colon polyp presence. The aim of this study was to investigate the relationship between plasma non-esterified oxylipids and the presence of colon polyps. A total of 123 Caucasian men, ages 48 to 65, were categorized into three groups: those with no polyps, those with one or more hyperplastic polyps, and those with one or more adenomas. Plasma non-esterified oxylipids were analyzed using solid phase extraction and quantified using a targeted HPLC tandem mass spectrometric analysis. Statistical analyses included Kruskal-Wallis one-way ANOVA with Dunn's test for multiple comparison and generalized linear models to adjust for confounding factors such as age, anthropometrics, and smoking status. In general, monohydroxy omega-6-derived oxylipids were significantly increased in those with polyps. Concentrations of 5-hydroxyeicosatetraenoic acid (HETE) and 11-HETE were significantly higher in those with hyperplastic polyps and adenomas compared to those with no polyps. Arachidonic acid-derived HETEs were significantly associated with colon polyp types, even after adjusting for age, smoking, and body mass index or waist circumference in regression models. Since many of these oxylipids are formed through oxygenation by lipoxygenases (i.e., 5-, 12-, and 15-HETE, and 15- hydroxyeicosatrienoic acid [HETrE]) or auto-oxidative reactions (i.e., 11-HETE), this may indicate that lipoxygenase activity and lipid peroxidation are increased in those with colon polyps. In addition, since oxylipids such as 5-, 12-, and 15-HETE are signaling molecules involved in inflammation regulation, these oxylipids may have important functions in inflammation-associated polyp presence. Future studies should be performed in a larger cohorts to investigate if these oxylipids are useful as potential biomarkers of colon polyps.

Calcium and vitamin D supplementation and increased risk of serrated polyps: results from a randomised clinical trial.

OBJECTIVE: Serrated lesions such as sessile serrated adenomas or polyps (SSA/Ps) are important colorectal cancer precursors, but aetiological factors for these lesions are largely unknown. We aimed to determine the effects of calcium and vitamin D supplementation on the incidence of serrated polyps (SPs) in general and hyperplastic polyps and SSA/Ps specifically. DESIGN: Participants with one or more adenoma at baseline were randomised to receive 1200 mg/day of elemental calcium, 1000 IU/day of vitamin D3, both or neither agent. Treatment continued for 3 or 5 years, when risk of polyps was determined from surveillance colonoscopy (treatment phase). Outcomes after treatment ceased were also assessed (observational phase). Adjusted risk ratios (aRRs) of SPs were determined via multivariable generalised linear models. RESULTS: SPs were diagnosed in 565 of 2058 (27.5%) participants during the treatment phase and 329/1108 (29.7%) during the observational phase. In total, 211 SSA/Ps were identified during follow-up. In the treatment phase, there was no effect of either calcium or vitamin D on incidence of SSA/Ps. However, during the later observational phase, we observed elevated risks of SSA/Ps associated with calcium alone and calcium+vitamin D treatment (aRR (95% CI): 2.65 (1.43 to 4.91) and 3.81 (1.25 to 11.64), respectively). CONCLUSION: In a large multicentre chemoprevention study, we found evidence that calcium and vitamin D supplementation increased the risk of SSA/Ps. This appeared to be a late effect: 6-10 years after supplementation began. These possible risks must be weighed against the benefits of calcium and vitamin D supplementation. : Trial registration NUMBER: NCT00153816; Results.

Sonographic diagnosis of colorectal polyps in children: Diagnostic accuracy and multi-factor combination evaluation.

This study was established to evaluate the diagnostic value of ultrasonography in screening colorectal polyps in children and to discuss the necessity of colonic preparation before an ultrasonic examination.In this study, 288 children with colorectal polyps managed at our hospital between January 2007 and December 2016 were retrospectively reviewed. All patients were examined before and after basic colon preparation. The colorectal polyps were confirmed by colonoscopy/laparotomy and histopathology. Among all 288 patients, solitary polyps were identified in 278 patients (96.52%), and multiple polyps were identified in 10 patients (43 polyps) (3.48%) by colonoscopy/laparotomy and histopathology.By ultrasonic examination, 264 cases (264/278) were detected as solitary polyp and 9 cases (9/10) as multiple polyps (31 polyps). In 278 solitary polyps, 180 (64.74%) were detected by ultrasonic examination without a colon preparation. Following glycerine enema (10-20 mL) treatment, 264 (94.96%) cases were detected by ultrasonic examination. The sensitivity and specificity of ultrasonography with glycerine enema for the detection of colorectal polyps were 94.96% and 100%, respectively. Colon preparation significantly increased the proportion of polyps identified by ultrasonography (P < .0001), as well as the diagnostic rate of polyps in rectum, sigmoid colon and descending colon (P < .05).Ultrasonography can be the primary diagnostic method for screening colorectal polyps in children on the strength of its safety, validity, and accuracy. Basic colon preparation with glycerine enema is recommended for children, which enable the detection of intraluminal lesions before ultrasonic examination.

The impact of the national bowel screening program in the Netherlands on detection and treatment of endoscopically unresectable benign polyps.

BACKGROUND: In January 2014, a national bowel cancer screening program started in the Netherlands. The program is being implemented in phases until 2019. Due to this program, an increase in patients referred for a colorectal resection for benign, but endoscopically unresectable polyps, is expected. So far, most resections are performed according to oncological principles despite no pre-operative histological diagnosis of malignancy. The aim of this study was to analyze the increase in referred patients during the first year of the screening program and to compare pathological results and clinical outcome of resections of patients undergoing resection for benign polyps before and after implementation of screening. METHODS: Patients referred for colorectal resection without biopsy-proven cancer between January 2009 and January December 2014 were identified from a prospectively maintained database. Patients with endoscopically macroscopic features of carcinoma were excluded. RESULTS: Seventy-six patients were included. Forty-seven patients (61.8%) were operated on in the 5 years prior to implementation of the screening program, and 29 patients (38.2%) were operated during the first year of implementation of the screening program. The overall malignancy rate before the introduction of the program was 14.1 and 6.6% after it had started (p = .469). All resections were performed laparoscopically; the conversion rate was 3.9% (n = 3). The overall mortality rate was 2.7% (n = 2), major complications (Clavien-Dindo > 3b) occurred in 11.8% (n = 9) of patients. The anastomotic leakage rate was 3.9% (n = 3). CONCLUSIONS: The number of patients referred for benign polyps tripled after introduction of the screening program. With an overall major morbidity and mortality rate of 11.8%, it seems valid to discuss whether an endoscopic excision with advanced techniques with or without laparoscopic assistance would be preferable in this patient group, accepting a 6.6% reoperation rate for additional oncological resection with lymph node sampling in patients in whom a malignancy is found on histological analysis of the complete polyp.

Rectosigmoid malakoplakia.

We present a rare case of rectosigmoid malakoplakia treated with fluoroquinolone.

Genetic variation in SLC7A2 interacts with calcium and magnesium intakes in modulating the risk of colorectal polyps.

Solute carrier family 7, member 2 (SLC7A2) gene encodes a protein called cationic amino acid transporter 2, which mediates the transport of arginine, lysine and ornithine. l-Arginine is necessary for cancer development and progression, including an important role in colorectal cancer pathogenesis. Furthermore, previous studies found that both calcium and magnesium inhibit the transport of arginine. Thus, calcium, magnesium or calcium:magnesium intake ratio may interact with polymorphisms in the SLC7A2 gene in association with colorectal cancer. We conducted a two-phase case-control study within the Tennessee Colorectal Polyps Study. In the first phase, 23 tagging single-nucleotide polymorphisms in the SLC7A2 gene were included for 725 colorectal adenoma cases and 755 controls. In the second phase conducted in an independent set of 607 cases and 2113 controls, we replicated the significant findings in the first phase. We observed that rs2720574 significantly interacted with calcium:magnesium intake ratio in association with odds of adenoma, particularly multiple/advanced adenoma. In the combined analysis, among those with a calcium:magnesium intake ratio below 2.78, individuals who carried GC/CC genotypes demonstrated higher odds of adenoma [OR (95% CI):1.36 (1.11-1.68)] and multiple/advanced adenoma [OR (95% CI): 1.68 (1.28, 2.20)] than those who carried the GG genotype. The P values for interactions between calcium:magnesium intake ratio and rs2720574 were .002 for all adenomas and <.001 for multiple/advanced adenoma. Among those with the GG genotype, a high calcium:magnesium ratio was associated with increased odds of colorectal adenoma [OR (95% CI): 1.73 (1.27-2.36)] and advanced/multiple adenomas [1.62 (1.05-2.50)], whereas among those with the GC/CC genotypes, high calcium:magnesium ratio was related to reduced odds of colorectal adenoma [0.64 (0.42-0.99)] and advanced/multiple adenomas [0.55 (0.31-1.00)].

Reproductive factors and risk of colorectal polyps in a colonoscopy-based study in western Washington State.

BACKGROUND: Oral contraceptives (OC) are associated with a decreased risk of colorectal cancers; however, a recent study reported an increased risk of small colorectal adenomas associated with OC use. To determine if these results were replicable in a different study population, we investigated the relationship between OC use and other reproductive factors and risk of colorectal polyps in a case-control study in western Washington. METHODS: Study participants were 24-79-year-old female enrollees at an integrated health care system in western Washington who were diagnosed as having adenomas (n = 299), serrated polyps (n = 337), both types of polyps (n = 105) or as polyp-free controls (n = 615) through an index colonoscopy and completed a structured interview to collect reproductive history information. Multivariable polytomous logistic regression was used to compare case groups to controls and to each other; odds ratios (OR) and 95% confidence intervals were estimated. RESULTS: There was no association between OC use, duration of use, or recency of use and the risk of either adenomas or serrated polyps [adjusted OR for OC ever use (95% CI) 0.85 (0.58-1.23) and 0.96 (0.66-1.40), respectively], and associations did not differ by lesion severity within the adenoma or serrated pathways. Further, no associations were observed between other reproductive factors and risk of colorectal polyp subtypes. CONCLUSIONS: Our results suggest that reproductive factors, including OC use, are not associated with early colorectal cancer precursor lesions.

A randomized controlled trial of an educational video to improve quality of bowel preparation for colonoscopy.

BACKGROUND: High-quality bowel preparation is necessary for colonoscopy. A few studies have been conducted to investigate improvement in bowel preparation quality through patient education. However, the effect of patient education on bowel preparation has not been well studied. METHODS: A randomized and prospective study was conducted. All patients received regular instruction for bowel preparation during a pre-colonoscopy visit. Those scheduled for colonoscopy were randomly assigned to view an educational video instruction (video group) on the day before the colonoscopy, or to a non-video (control) group. Qualities of bowel preparation using the Ottawa Bowel Preparation Quality scale (Ottawa score) were compared between the video and non-video groups. In addition, factors associated with poor bowel preparation were investigated. RESULT: A total of 502 patients were randomized, 250 to the video group and 252 to the non-video group. The video group exhibited better bowel preparation (mean Ottawa total score: 3.03 ± 1.9) than the non-video group (4.21 ± 1.9; P < 0.001) and had good bowel preparation for colonoscopy (total Ottawa score <6: 91.6 % vs. 78.5 %; P < 0.001). Multivariate analysis revealed that males (odds ratio [OR] = 1.95, P = 0.029), diabetes mellitus patients (OR = 2.79, P = 0.021), and non-use of visual aids (OR = 3.09, P < 0.001) were associated with poor bowel preparation. In the comparison of the colonoscopic outcomes between groups, the polyp detection rate was not significantly different between video group and non-video group (48/250, 19.2 % vs. 48/252, 19.0 %; P = 0.963), but insertion time was significantly short in video group (5.5 ± 3.2 min) than non-video group (6.1 ± 3.7 min; P = 0.043). CONCLUSION: The addition of an educational video could improve the quality of bowel preparation in comparison with standard preparation method. TRIAL REGISTRATION: Clinical Research Information Service KCT0001836 . The date of registration: March, 08(th), 2016, Retrospectively registered.

Usefulness of oil lubrication during colonoscopy: A comparative study with the conventional technique.

BACKGROUND: The different forms of lubrication are among the most simple, accessible, and economic techniques that have been implemented for improving the diagnostic performance of colonoscopy. AIM: To determine whether the use of oil improved the number of complete colonoscopies, facilitated the procedure, reduced pain, or improved the study's diagnostic performance, compared with the conventional lubrication technique. PATIENTS AND METHODS: One hundred and seventy-five patients referred for colonoscopy were alternately allocated to receive treatment with the standard lubrication method with chlorhexidine gel (group 1) or lubrication with corn oil administered through the working channel (group II). The number of complete colonoscopies, the length of time needed to reach the cecum, the degree of difficulty estimated by the endoscopist and the assistant, the level of pain at the end of the study estimated by the patient, and the endoscopic findings were all determined. RESULTS: Eighty-eight patients made up group I and 87 made up group II. No statistically significant differences were found between the two groups in relation to general characteristics, the number of complete colonoscopies (93 vs. 97%, respectively), the time needed to reach the cecum (8:00 vs. 8:41min, respectively), the level of pain at the end of the study, or the detection of polyps. The degree of difficulty was slightly lower in group II, but with no statistical significance. CONCLUSIONS: Lubrication with oil during colonoscopy did not improve the number of complete colonoscopies, did not facilitate the study, nor did it reduce pain or increase the diagnostic performance of the study, when compared with the conventional technique.

Alternatives to Incomplete Colonoscopy.

A thorough and complete colonoscopy is critically important in preventing colorectal cancer. Factors associated with difficult and incomplete colonoscopy include a poor bowel preparation, severe diverticulosis, redundant colon, looping, adhesions, young and female patients, patient discomfort, and the expertise of the endoscopist. For difficult colonoscopy, focusing on bowel preparation techniques, appropriate sedation and adjunct techniques such as water immersion, abdominal pressure techniques, and patient positioning can overcome many of these challenges. Occasionally, these fail and other alternatives to incomplete colonoscopy have to be considered. If patients have low risk of polyps, then noninvasive imaging options such as computed tomography (CT) or magnetic resonance (MR) colonography can be considered. Novel applications such as Colon Capsule™ and Check-Cap are also emerging. In patients in whom a clinically significant lesion is noted on a noninvasive imaging test or if they are at a higher risk of having polyps, balloon-assisted colonoscopy can be performed with either a single- or double-balloon enteroscope or colonoscope. The application of these techniques enables complete colonoscopic examination in the vast majority of patients.

Identifying Patients with Colon Neoplasias with Gas Discharge Visualization Technique.

OBJECTIVE: To perform an initial assessment of the potential of using the gas discharge visualization (GDV) technique to identify patients with colon neoplasias. METHODS: The GDV camera (also known as the electrophotonic imaging camera) was used to assess the participants. Colonoscopy was performed on all 78 participants, followed by a GDV scan. The control group consisted of 22 people. An endoscopic examination identified colon tumors in the remaining 56 participants. Participant ages ranged from 45 to 86 years (mean, 64.6 ± 1.2 years). The study analyzed GDV images of each patient's fingers, presenting a whole-body view, as well as separate sectors corresponding to the organs in question. RESULTS: There was a significant number of differences between the control group and the patients with colon tumors. The dynamic of the parameters was examined as the level of tumor dysplasia (neoplasia) varied. The values of the following parameters decreased in the control group as compared to the patients with cancerous polyps: normalized luminescence area, internal noise, contour radius, and average luminescence intensity. The values of the following parameters increased in the control group: radius of the inscribed circle, contour line length, area of luminescence, contour line fractality, contour line entropy, and form coefficients. CONCLUSION: This pilot study demonstrated a statistical difference between the GDV parameters of patients with colon tumors and the control group. These findings warrant a more in-depth study of the potential for GDV technique in screening programs.

The 5-year outcome of patients having incomplete colonoscopy.

AIM: Incomplete colonoscopy indicated for the detection of neoplasia occurs in 2-23% of patients, but there is little information on the long-term outcome of such patients. METHOD: All patients who underwent colonoscopy over 5 years at the Royal Liverpool University Hospital with a follow-up of up to 5 years were identified. RESULTS: The risk of colorectal cancer (CRC) was 2.9% (312/10 580) for all patients undergoing colonoscopy. For a failed colonoscopy, the risk was five-fold higher [14.3% (99/693)]. The mean age of the patients was 61 years and 58% were female. Following incomplete colonoscopy the risk of finding additional CRC, advanced colonic neoplasia and extracolonic neoplasia on subsequent investigation was 6.2%, 3.2% and 1.9%. The diagnostic yield on subsequent investigation for CRC or colonic polyps was 7% for repeat colonoscopy, 13.4% for computed tomography colonography, 10.3% for standard computed tomography and 1.8% for barium enema. In the 363 patients who were not offered a subsequent investigation, there was no further instance of CRC or CRC-related mortality over a 36-month period. CONCLUSION: Although the risk of CRC is higher in patients who have had a failed colonoscopy, a protocol approach of subsequent investigation should not replace clinical assessment on whether another test is necessary in the light of the good outcome of patients who were not subsequently investigated.

Segmental sigmoid polyposis as a colonoscopic indicator of an ileosigmoid fistula in Crohn's ileitis.

BACKGROUND AND AIMS: Ileosigmoid fistulas (ISFs) are frequently undiagnosed prior to surgery. This study was designed to describe a polyp or cluster of polyps limited to the sigmoid colon as a marker of ISF in patients with ileitis. This novel finding will increase a gastroenterologist's opportunity to detect them preoperatively and their prognostic implication of worsening ileitis. METHODS: The medical records of patients with Crohn's disease and ISF were reviewed to determine whether colonoscopy had revealed polyposis limited to the sigmoid colon and its frequency. RESULTS: Thirty-seven patients with Crohn's ileitis complicated by ISF were identified from our database. Twenty had one or more sigmoid polyps without polyps elsewhere in the colon suggesting the site of fistula exit. Fifteen of the patients had ISF and five had ileorectal fistula (IRF). The fistula was detected by various means, including colonoscopy, sigmoidoscopy, small bowel X-ray series, barium enema, computed tomography, and magnetic resonance enterography. The ISF was generally diagnosed prior to the recognition and significance of the segmental polyps. These polyps were inflammatory or hyperplastic on pathologic review. CONCLUSION: Most ISFs and IRFs are now found preoperatively by imaging and some are incidental surgical findings. The segmental sigmoid polyps that we describe should help the gastroenterologist to be suspicious of ISF. The polyps are a surrogate marker for the progression of the fistula and the underlying ileitis as they tend to appear after the fistula has matured and lead to increased intensity of medical therapy well before surgical intervention is required.

The Modified Mayo Clinic technique: Emphasis on plausible significant reduction of colon cancer.

OBJECTIVE: To compare the ability to detect colonic polyps using a modified Mayo Clinic (MMC) barium enema technique with that of the usual gold standard optical colonoscopy (OC). METHODS: Patients considered at an average or increased risk of colorectal cancer were initially screened using the MMC technique. Patients who refused OC, those who had isolated rectal lesions and those with incomplete OC were excluded. Patients with mass lesions in the right colon or left colon were further assessed using OC. RESULTS: A total of 142 consecutive patients were examined using the MMC technique. Of these, 18 patients were found to have mass lesions in the right or left colon and were further evaluated using OC. Sensitivity and specificity of the MMC technique for detecting colonic polyps/cancers of ≥ 0.3 cm were 87.5% and 80.0%, respectively. Most significantly, for detecting polyps of ≥ 1.0 cm, the false-negative rate was 0%. CONCLUSIONS: The MMC technique may provide an alternative screening method to OC for the detection of colorectal polyps, particularly in countries where resources are scarce.

Imaging in colonic cancer.

Whilst the diagnosis of colonic cancer is always based on visually guided flexible colonoscopy, which is the only technique that provides a histological diagnosis, the pre-treatment assessment of the cancer involves computed tomography. This can determine the exact site of the cancer in the colon, its dimensions and juxta-colonic extension and is used to investigate for liver, mesenteric or lung metastases.