A Chak1, A B Post, G S Cooper. 1. Division of Gastroenterology, University Hospitals of Cleveland, Case Western Reserve University School of Medicine, Ohio 44106, USA.
Abstract
OBJECTIVES: We prospectively evaluated the ability of various indications for colonoscopy to predict colorectal cancer. METHODS: Indications and findings were prospectively recorded for 1223 consecutive colonoscopies performed during an 18-month period at a University Hospital. Colonoscopies performed on 981 patients for indications which included colorectal cancer in the differential diagnosis were included in the study. A group of 653 patients was randomly selected to derive a model predictive of colorectal cancer at colonoscopy; the remaining 328 patients were used to validate the model. RESULTS: Colorectal cancer was found in 44/981 patients (4.5%). Univariate analysis of the derivation set showed that age > 55, occult bleed, anemia, iron deficiency, weight loss, and abnormal CT scan were associated with finding colorectal cancer at colonoscopy in the derivation set, p < 0.05. History of polyps was negatively associated with finding colorectal cancer. Stepwise selection was used to develop a predictive model by using three independent variables-age > 55, iron deficiency, and weight loss. Assigning a score of 1 to each variable, cancer was present in 0% [95% confidence intervals (CI), 0-0.6%], 5.3% (95% CI, 2.3-8.3%), and 17.9% (95% CI, 4.8-31%) of patients in the validation sample with a score of 0, 1, and > or = 2, respectively (p < 0.001 by chi2 for trend). The model was predictive of finding colorectal cancer at colonoscopy, independent of the location or stage of the cancer. CONCLUSIONS: Age, iron deficiency, and weight loss are important independent predictors of colorectal cancer in patients referred for colonoscopy.
OBJECTIVES: We prospectively evaluated the ability of various indications for colonoscopy to predict colorectal cancer. METHODS: Indications and findings were prospectively recorded for 1223 consecutive colonoscopies performed during an 18-month period at a University Hospital. Colonoscopies performed on 981 patients for indications which included colorectal cancer in the differential diagnosis were included in the study. A group of 653 patients was randomly selected to derive a model predictive of colorectal cancer at colonoscopy; the remaining 328 patients were used to validate the model. RESULTS:Colorectal cancer was found in 44/981 patients (4.5%). Univariate analysis of the derivation set showed that age > 55, occult bleed, anemia, iron deficiency, weight loss, and abnormal CT scan were associated with finding colorectal cancer at colonoscopy in the derivation set, p < 0.05. History of polyps was negatively associated with finding colorectal cancer. Stepwise selection was used to develop a predictive model by using three independent variables-age > 55, iron deficiency, and weight loss. Assigning a score of 1 to each variable, cancer was present in 0% [95% confidence intervals (CI), 0-0.6%], 5.3% (95% CI, 2.3-8.3%), and 17.9% (95% CI, 4.8-31%) of patients in the validation sample with a score of 0, 1, and > or = 2, respectively (p < 0.001 by chi2 for trend). The model was predictive of finding colorectal cancer at colonoscopy, independent of the location or stage of the cancer. CONCLUSIONS: Age, iron deficiency, and weight loss are important independent predictors of colorectal cancer in patients referred for colonoscopy.
Authors: Barbara-Ann Adelstein; Petra Macaskill; Siew F Chan; Peter H Katelaris; Les Irwig Journal: BMC Gastroenterol Date: 2011-05-30 Impact factor: 3.067