Canadian Journal of Gastroenterology最新文献

Background: The long-term natural history of early stage colon cancer and the outcome of long-term colonoscopic surveillance in routine specialist clinical practice after removal of the incident cancers have not been fully defined. In the present long-term evaluation up to 25 years, metachronous neoplasia, including both advanced adenomas and carcinomas, was defined.

Methods: All early stage colorectal cancer patients evaluated consecutively from a single clinical practice underwent follow-up colonoscopic evaluations after removal of the incident cancer and clearing of neoplastic disease. Colonoscopic surveillance was planned for two phases - initially on an annual basis for five years, followed by continued surveillance every three years up to 25 years with removal of any metachronous neoplastic lesion.

Results: A total of 128 patients (66 men and 62 women) with 129 incident early stage colorectal cancers were evaluated. Virtually all patients were symptomatic, usually with clinical evidence of blood loss. Incident early cancers were located throughout the colon, especially in the rectosigmoid, and showed no pathological evidence of nodal or other metastases. All patients evaluated during the first five years did not experience recurrent disease or have metachronous cancer detected. After five years, a total of 94 patients were evaluated up to 25 years; six of these patients were found to have seven metachronous colon cancers. All developed cancer more than seven years after removal of the incident colorectal cancer, including six asymptomatic adenocarcinomas, of which only one had evidence of single node involvement. Another patient in this cohort developed a poorly differentiated neuroendocrine carcinoma of the colon. In addition, 45% of patients had a total of 217 adenomas removed, including 11% of patients with 33 advanced adenomas. Among 14 patients with advanced adenomas, seven (50%) developed ≥1 late metachronous cancers.

Conclusions: Following removal of an incident symptomatic early stage colorectal cancer, the risk of later metachronous neoplasia persists for an extended period more than five years after removal of the incident colorectal cancer. Moreover, risk for late metachronous cancer appears to be predicted by the presence of multiple adenomas or advanced adenomas; most metachronous cancers in this cohort were detected using colonoscopy before onset of symptoms and at an early stage.

Postprandial reactive hypoglycemia, early satiety and diarrhea are well-recognized side effects following full or partial gastrectomy or gastric bypass. It has only recently been realized, however, that patients with normal gastric anatomy may experience similar symptoms and signs due to primary accelerated gastric emptying (Middleton syndrome). In previous case studies, patients responded well to the use of dietary modification (frequent small-volume meals) alone. The authors describe two patients with this syndrome who continued to experience symptoms of reactive postprandial hypoglycemia despite dietary intervention but became asymptomatic following the addition of the alpha-glucosidase inhibitor acarbose.

Background: Many patients referred for an elevated serum ferritin level <1000 µg⁄L are advised that they likely have iron overload and hemochromatosis.

Aims: To determine the prevalence of HFE mutations in the hemochromatosis gene for 11 serum ferritin concentration intervals from 200 µg⁄L to 1000 µg⁄L in Caucasian participants in a primary care, population-based study.

Methods: The Hemochromatosis and Iron Overload Screening study screened 99,711 participants for serum ferritin levels, transferrin saturation and genetic testing for the C282Y and H63D mutations of the HFE gene. This analysis was confined to 17,160 male and 27,465 female Caucasian participants because the HFE C282Y mutation is rare in other races. Post-test likelihood was calculated for prediction of C282Y homozygosity from a ferritin interval. A subgroup analysis was performed in participants with both an elevated serum ferritin level and transferrin saturation.

Results: There were 3359 male and 2416 female participants with an elevated serum ferritin level (200 µg⁄L to 1000 µg⁄L for women, 300 µg⁄L to 1000 µg⁄L for men). There were 69 male (2.1%) and 87 female (3.6%) C282Y homozygotes, and the probability of being a homozygote increased as the ferritin level increased. Post-test likelihood values were 0.3% to 16% in men and 0.3% to 30.4% in women.

Conclusions: Iron loading HFE mutations are unlikely to be the most common cause of an elevated serum ferritin level in patients with mild hyperferritinemia. Patients should be advised that there are many causes of an elevated serum ferritin level including iron overload.

Background: Serological studies suggest that celiac disease may be present in approximately 0.5% to 1% of the North American population. Screening data based on small intestinal biopsy performed during routine endoscopic evaluations are not available.

Methods: Patients referred between January 1982 and December 2011 for evaluation of gastrointestinal symptoms and requiring elective investigative upper endoscopic evaluation underwent duodenal biopsies to determine whether changes of adult celiac disease were present.

Results: A total of 9665 patients, including 4008 (41.5%) males and 5657 (68.5%) females, underwent elective endoscopies and duodenal biopsies. Of these, 234 (2.4%) exhibited changes of celiac disease including 73 males (1.8%) and 161 females (2.8%). During the first 20 years, the number of biopsy-positive patients in five-year intervals progressively decreased and, subsequently, during the next 10 years, the number progressively increased.

Conclusions: Celiac disease is far more common in specialist practice than has been suggested in the evaluation of healthy populations using serological screening studies. Endoscopic duodenal biopsy is an important method of identifying underlying celiac disease and should be routinely considered in all patients undergoing an elective endoscopic evaluation. Noninherited factors, possibly environmental, may play a role in the appearance of biopsy-defined celiac disease and alter detection over time.

Background: Autoimmune hepatitis may have cholestatic features that are outside the classical phenotype and that resemble findings in other immune-mediated liver diseases. These cholestatic phenotypes have been designated 'overlap syndromes'.

Objectives: To recognize the overlap syndromes in adults and manage them appropriately.

Methods: The MEDLINE database was reviewed for published experiences from 1984 to 2013.

Results: Patients with autoimmune hepatitis may exhibit features of primary biliary cirrhosis (7% to 13%), primary sclerosing cholangitis (6% to 11%) or a cholestatic syndrome without other diagnostic features (5% to 11%). These mixed phenotypes may represent classical autoimmune hepatitis with atypical features, transition states in the evolution of classical cholestatic syndromes, concurrent separate diseases or pathogenically distinct disorders. The 'Paris criteria' have been endorsed for the diagnosis of the overlap syndrome with primary biliary cirrhosis, and treatment with conventional immunosuppressive therapy alone or in combination with low-dose ursodeoxycholic acid can be guided by the serum alkaline phosphatase level. The overlap syndrome with primary sclerosing cholangitis or with cholestasis without diagnostic features is commonly treated with immunosuppressive therapy and ursodeoxycholic acid. Responses are variable and commonly incomplete (20% to 100% improvement) depending on the degree of cholestasis.

Discussion: The overlap syndromes are clinical descriptions rather than pathological entities, and the dominant component of the disease determines its designation and therapy. Cholestatic findings in autoimmune hepatitis influence the response to immunosuppressive therapy.

Conclusion: The overlap syndromes must be considered in patients with autoimmune hepatitis and cholestatic findings, concurrent inflammatory bowel disease or steroid-refractory disease.

Background: Traditional therapy with pegylated interferon and ribavirin combined with the new protease inhibitors boceprevir or telaprevir has demonstrated improved outcomes in hepatitis C virus (HCV)-infected patients. Prevalence data regarding pre-existing drug-resistant variants to these two new virus inhibitors in the Canadian population are not available.

Objective: To detect pre-existing mutations conferring resistance to boceprevir and⁄or telaprevir in Canadian patients infected with HCV genotype 1a.

Methods: Resistance-associated mutations (RAMs) were evaluated in 85 patients infected with HCV genotype 1a who had not yet received antiviral therapy. The NS3 protease gene was sequenced and common RAMs were identified based on a recently published list.

Results: The overall prevalence of pre-existing RAMs to boceprevir and telaprevir was higher compared with other similar studies. All of the observed RAMs were associated with a low level of resistance. A surprisingly high proportion of patients had the V55A RAM (10.6%). None of the mutations associated with a high level of resistance were observed. The simultaneous presence of two low-level resistance mutations (V36L and V55A) was observed in only one patient. Three other patients had both T54S RAM and V55I mutations, which may require a higher concentration of the protease drugs. The prevalence of various mutations in Aboriginal Canadian patients was higher (37.5%) compared with Caucasians (16.39%) (P=0.038).

Conclusions: The present study was the first to investigate pre-existing drug resistance to boceprevir⁄telaprevir in Canadian HCV-infected patients. A relatively high proportion of untreated HCV genotype 1a patients in Manitoba harbour low-level RAMs, especially patients of Aboriginal descent, which may contribute to an increased risk of treatment failure.

Background: Open-access (OA) colonoscopy may increase efficiency and decrease wait times; however, because the patient is seen for the first time at the endoscopy appointment, previous processes, such as information about the procedure, preparation and appropriate triage, may be suboptimal.

Objective: To identify factors associated with OA colonoscopy and to determine the relationship between OA colonoscopy and an important quality measure, incomplete colonoscopy.

Methods: A population-based analysis of all adult outpatients undergoing a first-time colonoscopy between 1997 and 2007 in Ontario was performed. Colonoscopy was considered to be OA if there were no visits in the preceding five years with the physician performing the colonoscopy. Using logistic regression, patient, physician and institution factors associated with OA colonoscopy were identified. Using propensity score matching, the relationship between OA colonoscopy and incomplete colonoscopy in 2006 was examined.

Results: A total of 1,079,259 colonoscopies were performed. Of these, 14% were OA in 1997 compared with 26% in 2007. Patients 50 to 69 years of age, those from higher-income neighbourhoods and those with less comorbidity were more likely to undergo OA colonoscopy. The odds of receiving OA colonoscopy were six times greater in a nonhospital clinic compared with a community hospital. Colonoscopy was more likely to be complete if the procedure was OA (OR 1.3 [95% CI 1.2 to 1.4]; P<0.0001).

Conclusions: Rates of OA colonoscopy have increased substantially since 1997. Institution type was most strongly associated with OA colonoscopy. Colonoscopy completeness, a recognized quality indicator, does not appear to be compromised by OA colonoscopy.