Association of smoking and flat adenomas: results from an asymptomatic population screened with a high-definition colonoscope.

BACKGROUND: Flat adenomas represent a morphologically distinct class of polyps that may be difficult to detect, and little is known regarding risk factors for these lesions. Identification of risk factors for these lesions may aid in colorectal cancer (CRC) screening, because patients at risk for these lesions may require special imaging techniques. Smoking, an important risk factor for CRC, may be associated with molecular changes that increase the risk for flat adenomas. OBJECTIVE: The aim of this study was to examine the association between smoking and flat adenomas. DESIGN: Prospective cross-sectional study. SETTING: University hospital endoscopy center. PATIENTS: We enrolled asymptomatic patients presenting for CRC screening. INTERVENTIONS: We screened patients with a high-definition (1080i signal) wide-angle (170 degrees field of view) Olympus 180-series colonoscope. We collected demographics, medication use, family history of CRC, diet history, and smoking history. MAIN OUTCOME MEASUREMENTS: Polyp morphology, assessed by using the Japanese Research Society Classification (JRSC). RESULTS: A total of 600 patients were enrolled. We observed that smoking was associated with having a flat adenoma of any size (adjusted odds ratio [OR], 2.53; 95% CI, 1.60-4.00), having only flat adenomas that were > or = 6 mm in diameter (adjusted OR, 3.84; 95% CI, 2.02-7.32), as well as flat advanced adenomas (adjusted OR, 2.81; 95% CI, 1.08-7.30). LIMITATIONS: The study design may not account for some confounding variables and provides no information regarding smoking status at the time of initiation of flat adenomas. CONCLUSION: Smoking was associated with flat adenomas in our population. Our findings may explain the earlier onset of CRC in smokers as well as the advanced stage with which they present, with compared with nonsmokers. Smokers may require screening with high-definition colonoscopes to detect flat adenomas.

Body mass index as a predictor of colorectal neoplasia in ethnically diverse screening population.

BACKGROUND: Recent guidelines from the American College of Gastroenterology for screening for colorectal cancer have included obesity as an important risk factor. The recommendation for screening obese people at earlier age was tempered by the need for more data regarding obesity and colorectal neoplasia. AIMS: We designed a cross-sectional study to further examine the predictive value of obesity for colorectal adenomas in asymptomatic patients. METHODS: We prospectively collected demographic, medical, lifestyle, and dietary history from asymptomatic patients presenting for screening colonoscopy. Patients underwent complete colonoscopy using high-definition colonoscope to detect colorectal adenomas. We defined advanced neoplasia as large (≥ 1 cm) adenoma, villous adenoma, high-grade dysplasia or cancer. RESULTS: Six hundred patients with median age of 56 years completed the study. Over 40% of these patients did not consider themselves Caucasian, and less than 5% had a first-degree relative with colorectal cancer. Overall, 40 patients (6.7%) had advanced neoplasia and 216 (36.3%) had any adenoma. There were 185 obese patients (30.8%), who had a prevalence of 44.3% for any adenoma and 13.0% for advanced neoplasia. After multivariate analysis, obesity [body mass index (BMI) ≥ 30 kg/m(2)] was significantly associated with increased risk of advanced neoplasia [odds ratio (OR) = 3.83; 95% confidence interval (CI): 1.94-7.55]. CONCLUSIONS: Obesity was associated with advanced neoplasia in this screening population. Our data regarding the association of colorectal neoplasia with this modifiable risk factor has implications for screening and prevention of colorectal cancer.

Smokers as a high-risk group: data from a screening population.

GOAL: To determine the number of pack-years exposure associated with a 2-fold increase risk for significant colorectal neoplasia and to examine the risk of smoking in younger patients. BACKGROUND: Cigarette smoking has been shown to be a significant risk factor for colorectal neoplasia and may be used to stratify patients for screening or triaging of screening resources. However, more information is needed regarding the amount of exposure required to significantly increase by 2-fold an individual's risk for colorectal neoplasia. METHODS: Data collected for 2707 patients presenting for screening colonoscopy included tobacco use measured in pack-years and known risk factors for colorectal neoplasia. Our outcome was endoscopically detected significant colorectal neoplasia that included large (>1 cm) tubular adenomas, villous adenomas, multiple (3 or more) adenomas, high-grade dysplasia, and adenocarcinoma. RESULTS: Patients who smoked more than 30 pack-years were more than 2 times more likely to have significant colorectal neoplasia than patients who never smoked (odds ratio: 2.40; 95% confidence interval: 1.65-3.50). For patients aged 40 to 49 years, smokers were more likely than nonsmokers to have significant colorectal neoplasia (odds ratio: 2.71; 95% confidence interval: 1.05-6.97). CONCLUSIONS: Patients who have smoked more than 30 pack-years had a more than 2-fold increase for significant colorectal neoplasia as compared with nonsmokers. The increased risk was also observed in younger patients. Our data have implications for screening guidelines.

Body mass index: a marker for significant colorectal neoplasia in a screening population.

BACKGROUND AND AIMS: Although some studies suggest a positive association between increasing body mass index (BMI) and risk for colorectal neoplasia, the impact on screening has not been examined. We performed a cross-sectional study to examine the association of BMI and colorectal neoplasia in a screening population. METHODS: Data collected for 2493 patients presenting for screening colonoscopy included known risk factors for colorectal neoplasia, demographic information, and lifestyle factors. Our outcome was the endoscopic detection of significant colorectal neoplasia which included adenocarcinoma, high-grade dysplasia, villous tissue, adenomas 1 cm or greater and multiple (>2) adenomas of any size. RESULTS: Overall, we observed an increased risk and prevalence for significant colorectal neoplasia in women as BMI increased (P value for trend <0.002). This relationship was the strongest for the women with a BMI > or =40 (odds ratios=4.26; 95% confidence intervals=2.00-9.11). There was no such relationship in our male population. CONCLUSIONS: Increasing BMI, in our population, was associated with an increase risk for colorectal neoplasia in female patients. This study reinforces the importance of screening colonoscopy especially in obese women.

Tapered colonoscope performs better than the pediatric colonoscope in female patients: a direct comparison through tandem colonoscopy.

BACKGROUND: The pediatric variable-stiffness colonoscope (PVSC) is used by many endoscopists to negotiate the colon that requires a flexible colonoscope; it has a smaller diameter, but may lead to excessive looping. A prototype colonoscope tapers from an adult width to a pediatric diameter at approximately 25 cm. The tapered colonoscope (TC), while retaining the flexibility of the PVSC, has the column strength of the adult colonoscope to help negotiate the proximal colon. OBJECTIVE: Our hypothesis is that use of the TC in female patients would be associated with less looping than the PVSC during the procedure, fewer required maneuvers, and thus a quicker examination. DESIGN: Direct comparison through tandem colonoscopies. SETTING: University endoscopy suite. PATIENTS: Forty unselected female patients. INTERVENTIONS: Tandem colonoscopies with PVSC and TC. MAIN OUTCOME MEASUREMENTS: Time to the cecum and the ability to retroflex in the cecum. RESULTS: Compared with the PVSC, the TC had faster times to achieve cecal intubation (mean [standard deviation], 8.83+/-4.68 minutes versus 6.88+/-4.08 minutes; P=.013) and a higher rate of retroflexion in the cecum (31/40 patients vs 39/40 patients; P<.01). Use of the TC was associated with a decreased need for abdominal pressure (P<.001). CONCLUSIONS: The TC achieved faster cecal intubation rates and had a higher success of cecal retroflexion than a PVSC. This performance likely was because of diminished looping and thus a decreased need for maneuvers. The TC may be preferable to the PVSC for female patients.

Prevalence and risk of colorectal neoplasia in consumers of alcohol in a screening population.

BACKGROUND AND AIMS: Although studies suggest a positive association between alcohol consumption and risk for colorectal neoplasia, the impact on screening has not been fully examined. It is also unclear whether all types of alcohol are associated with an increased risk. We performed a cross-sectional study to examine the impact of regular alcohol consumption on the detection of significant colorectal neoplasia in a screening population. METHODS: Data collected for 2,291 patients presenting for screening colonoscopy: known risk factors for colorectal neoplasia and alcohol drinking pattern. Our outcome was the endoscopic detection of significant colorectal neoplasia, which included adenocarcinoma, high-grade dysplasia, villous tissue, adenomas 1 cm or greater and multiple (>2) adenomas of any size. RESULTS: When compared to abstainers, we found an increased risk for significant neoplasia in those patients who consumed more than eight drinks of spirits alcohol (26.3%; OR = 2.53; 95% CI = 1.10-4.28; p < 0.01) and those who drank more than eight servings of beer per week (21.7%; OR = 2.43; 95% CI = 1.11-5.32; p= 0.02). Consuming one to eight glasses of wine per week was associated with a decreased risk for significant neoplasia (OR = 0.55; 95% CI = 0.34-0.87; p < 0.01). CONCLUSIONS: While there was a more than twofold increased risk of significant colorectal neoplasia in people who drink spirits and beer, people who drank wine had a lower risk. In our sample, people who drank more than eight servings of beer or spirits per week had at least a one in five chance of having significant colorectal neoplasia detected by screening colonoscopy.

Predictors of proximal neoplasia in patients without distal adenomatous pathology.

BACKGROUND: Previous colorectal cancer screening studies have observed that some patients may have advanced proximal neoplasia without distal findings. Since these studies have included only gender, age, and family history as risk factors, they are limited in their ability to identify predictors of isolated proximal neoplasia. METHODS: Data were collected from the charts of 1,988 patients who presented for colonoscopy. Information gathered included endoscopic findings, histology, known risk factors for colorectal neoplasia, and smoking pattern. Our main outcome was the presence of proximal adenomatous neoplasia in patients who had no distal adenomas. We defined significant neoplasia as adenocarcinoma, high-grade dysplasia, villous polyps, adenomas 1 cm or greater or more than two adenomas of any size. RESULTS: Fifty-five patients had isolated significant proximal neoplasia that would have been missed on a flexible sigmoidoscopy. While patients older than 60 yr had a greater risk for this neoplasia (odds ratio = 3.01: 95% CI = 1.66-4.23; p < 0.001), those who took a daily aspirin had a reduced risk (OR = 0.60; 95% CI = 0.30-0.88; p < 0.05). A family history of colorectal cancer increased the patient's risk of having any adenomas (OR = 2.01; 95% CI = 1.33-3.40; p < 0.01) or villous tissue (OR = 2.03; 95% CI = 1.27-3.51; p < 0.05) in the proximal colon without distal findings. Smoking was associated with an increased risk of large (> 1 cm) isolated proximal tubular polyps (OR = 2.71; 95% CI = 1.64-4.46; p < 0.01) as well as isolated significant proximal neoplasia (OR = 2.30; 95% CI = 1.59-3.31; p < 0.01). CONCLUSIONS: Age greater than 60 yr, a history of at least 10 pack-years of smoking, and a family history of colorectal cancer increased the risk of finding significant proximal polyps in patients without distal pathology.

Prevalence of colorectal neoplasia in smokers.

OBJECTIVES: Smoking has been linked with colorectal neoplasia. Previous colonoscopy screening studies have omitted smoking and have examined only gender, age, and family history. Our aim was to use a screening population to measure the prevalence of neoplasia in smokers, the anatomic location of these lesions, and the strength of this association relative to other risk factors. METHODS: Data collected from the charts of 1988 screening colonoscopy patients included colonic findings, histology, risk factors for colorectal neoplasia, and smoking pattern. Current smokers were defined as those who had smoked more than 10 pack-years and were currently smoking or who had quit within the past 10 yr. Our outcomes were any adenomatous lesion and significant colonic neoplasia, which included adenocarcinoma, high grade dysplasia, villous tissue, large (>1 cm) adenomas, and multiple (more than two) adenomas. RESULTS: Multivariate analysis revealed that current smokers were more likely to have any adenomatous lesion (odds ratio [OR] = 1.89; 95% CI = 1.42-2.51; p < 0.001) as well as significant neoplasia (OR = 2.26; 95% CI = 1.56-3.27; p < 0.001) than those who had never smoked. The increased risk for smokers was predominantly for left-sided neoplasia. The risk for significant neoplasia was greater for smokers than for patients with a family history of colorectal cancer (OR = 1.20; 95% CI = 0.75-1.92; p > 0.05). CONCLUSIONS: Smoking is a significant risk factor for colorectal neoplasia in a screening population, especially for significant left-sided lesions. In our sample population, smoking posed a greater risk than family history of colorectal cancer.