comparison of the clinical manifestations and risk factors of colorectal cancer and adenomas: results from a colonoscopy-based study in southern Chinese

Background and aims Colorectal cancer (CRC) is one of the most common gastrointestinal tumors in the world. This study aimed to compare the clinical manifestations and risk factors of CRC and adenomas in native patients of Guangzhou. Methods Patients who underwent colonoscopy for the first time at Nanfang Hospital between July 2008 and July 2009 were recruited. Data on demographic information, main clinical manifestations, results of endoscopies and pathology, and possible risk factors of colorectal tumor were collected. Chi-square test and logistic regression were used to compare the clinical characteristics and risk factors for CRC and adenomas. Results Hematochezia and body weight loss were more frequent in proximal and distal CRC groups, respectively (P ≤ 0.05). Older age [odds ratio (OR), 1.079; 95% confidence interval (CI), 1.065-1.093], smoking status (OR, 1.712; 95% CI, 1.158-2.531), BMI = 18.5-24.9 and ≥ 25.0 (OR, 2.384; 95% CI, 1.250-4.549; OR, 2.162; 95% CI, 1.044-4.478, respectively) were significant risk factors for advanced adenoma, while female (OR, 0.638; 95% CI, 0.429-0.949) and using aspirin (OR, 0.188; 95% CI, 0.042-0.845) were significant protective factors. Hyperlipemia (OR, 0.109; 95% CI, 0.013-0.886) was identified as a protective factor for proximal CRC. Smoking (OR, 1.717; 95% CI, 1.093-2.696), drinking (OR, 1.817; 95% CI, 1.145-2.883), DM history (OR, 2.204; 95% CI, 1.044-4.652) were identified as independent risk factors for distal CRC, and using aspirin (OR, 0.190; 95% CI, 0.043-0.840) was a protective factor. Drinking (OR, 3.288; 95% CI, 1.546-6.994; OR, 1.862; 95% CI, 1.037-3.343, respectively) was an independent risk factor for both poorly to moderately differentiated CRC and well-differentiated CRC. Besides, DM (OR, 3.761; 95% CI, 1.615-8.762) and hypertension (OR, 0.384; 95% CI, 0.178-0.828) were identified as independent risk factor and protective factor for well-differentiated CRC, respectively. Conclusions Hematochezia and body weight loss were representative manifestations for distal and proximal CRC, respectively. For southern Chinese the most important influential factors for colorectal tumor are age, smoking, drinking, nutritional state, DM, hypertension, and the use of aspirin.