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Ian Craig Lawrance

Publications and source records attributed to Ian Craig Lawrance.

5 recordsLinked to original sources
PubMed2006

Poor correlation between clinical impression, the small colonic polyp and their neoplastic risk.

BACKGROUND AND OBJECTIVES: Significance of the small colonic polyp is unclear and its removal is frequently determined by the proceduralist's clinical impression. Our aims were to determine if clinical discernment is accurate, and the likelihood that lesions < 10 mm are histologically advanced. METHOD: We prospectively collected 1988 lesions from 854 subjects (2215 consecutive colonoscopies). Lesion size, location, patient age, sex and the colonoscopist's clinical impression was recorded. RESULTS: Clinical assessment for neoplasia had a sensitivity of 87.4%, specificity of 65.0%, positive predictive value of 76.0% and negative predictive value of 80.2%, resulting in an accuracy of 73.4%. Factors predictive of correct clinical impression were polyp size, location in the rectum and being pedunculated, but not the patient's age, sex or the endoscopist's experience. Of the 1434 lesions < or = 5 mm in size, 44.5% were neoplastic and 3.5% were histologically advanced. Of the 266 lesions 6-9 mm, 79.3% were neoplastic, 19.9% were histologically advanced, five demonstrated high-grade dysplasia and three were malignant. Only two patients with an adenocarcinoma or high-grade dysplasia in a polyp <10 mm had a lesion > or =10 mm elsewhere in the colon. Of the 288 lesions > or =10 mm in size, 92.7% were neoplastic, 29.5% had a villous component, 6.9% demonstrated high-grade dysplasia and 29.2% were malignant. Factors predictive of neoplasia were patient age, polyp size and sessile nature of the lesion. CONCLUSION: Polyps < 10 mm had a significant risk of neoplasia and advanced histology and, in general, clinical impression correlated poorly with neoplasia. Removal of all lesions proximal to the rectum, regardless of size, should therefore be considered.

Adenocarcinoma↗
PubMed2005

A comparative study of goblet cell and pancreatic exocine autoantibodies combined with ASCA and pANCA in Chinese and Caucasian patients with IBD.

BACKGROUND: The incidence of Crohn's disease (CD) and ulcerative colitis (UC) is increasing, but differentiating between them is often extremely difficult. Pancreatic (PAB) and goblet cell autoantibodies (GAB) are specific for CD and UC, respectively, but with low sensitivity. In combination with anti-Saccharomyces cerevisiae (ASCA) and anti-neutrophil cytoplasmic antibodies (pANCA) testing, these antibodies may improve differentiation between the diseases. This study determined the sensitivity, specificity, and positive and negative predictive values (PPV and NPV) of PAB and GAB +/- ASCA and pANCA testing in Chinese and Caucasian IBD populations. RESULTS: Patients were recruited from Caucasian and Chinese populations (CD, n = 100; UC, n = 99; controls, n = 100). PAB was highly specific for CD, and detection was greater in patients less than 35 years old and in Chinese compared with Caucasian patients with CD (CD, 46% versus 22%, P = 0.018; UC, 2% versus 6%; controls, 0% versus 2%). GAB detection was poor in all groups (<2%). PAB showed a PPV of 93% to differentiate all patients with CD from patients with UC, but only 62% for those with isolated colonic disease. The PPV of PAB increased to 100%, specificity was 100%, and sensitivity was 21% for isolated colonic disease when combined with pANCA and ASCA. PAB expression was not associated with stricturing or perforating CD. CONCLUSIONS: This study identified that GAB was not useful in our patients with IBD. PAB expression was highly specific for CD and more sensitive in Chinese than Caucasian patients with CD. The combination of PAB, pANCA, and ASCA testing improved the differentiation between UC and CD, particularly in isolated colonic disease, compared with pANCA and ASCA testing alone.

Adolescent↗
PubMed2004

A prospective comparative study of ASCA and pANCA in Chinese and Caucasian IBD patients.

BACKGROUND: Inflammatory bowel disease manifests throughout all ethnic groups. Antisaccharomyces cerevisiae (ASCA) and antineutrophil cytoplasmic antibodies (pANCA) can aid in the differentiation between Crohn's disease (CD) and ulcerative colitis (UC), but their sensitivity may vary between races. OBJECTIVES: This study compared the sensitivity, specificity, and positive and negative predictive values (PPV, NPV) of pANCA and ASCA between Chinese and Caucasian IBD populations and identified disease subtype associations. RESULTS: Three hundred patients were prospectively recruited from Caucasian and Chinese populations (CD, n = 50, UC, n = 50, controls, n = 50 each). pANCA detection was greater in Caucasian than Chinese UC patients (p= 0.046). ASCA IgG detection was similar, but IgA was lower in Chinese CD patients (p < 0.001). Differentiation between UC and CD (+ve pANCA/-ve ASCA) demonstrated a PPV of 92% in isolated colonic disease. Logistic regression in CD identified positive pANCA had a lower association with ileal (OR = 6.8, p= 0.0067) and complicated disease (OR = 5.5, p= 0.015). Caucasian CD patients with positive ASCA IgA/IgG had a greater association with ileal (OR = 6.7, p= 0.022) or complicated disease (OR = 9.4, p= 0.0073) and in Chinese CD patients positive ASCA IgA/IgG was associated with isolated ileal disease (OR = 16.8, p= 0.032). Linear regression demonstrated that higher ASCA titers predicted complicated CD and isolated ileal disease. CONCLUSIONS: This study identified that pANCA is more sensitive in Caucasian than Chinese UC and that ASCA IgA has a low yield in Chinese CD. pANCA and ASCA are useful for differentiating between UC and CD in both populations, and ASCA IgG and IgA titers have potential use in determining the risk of developing complicated CD.

Adult↗