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.     

First-degree relatives of patients with advanced colorectal adenomas have an increased prevalence of colorectal cancer.

BACKGROUND & AIMS: The risk of colorectal cancer in relatives of patients with adenomatous colonic polyps is not well defined. This study assessed whether finding colonic neoplasia during screening colonoscopy was related to the family history of colorectal cancer among the participants' parents and siblings. METHODS: Self-reported family history of colorectal cancer was recorded for all participants in a screening colonoscopy study. The size and location of all polyps were recorded before their removal and histologic examination. Participants were grouped according to the most advanced lesion detected. RESULTS: Three thousand one hundred twenty-one patients underwent complete colonoscopic examination. Subjects with adenomas were more likely to have a family history of colorectal cancer than were subjects without polyps (odds ratio [OR], 1.36; 95% confidence interval [CI], 1.09-1.70). The finding of a small (<1 cm) tubular adenoma as the most advanced lesion was associated with only a modest increase in the OR of colorectal cancer in family members (OR, 1.26; 95% CI, 0.99-1.61), but the presence of an advanced adenoma was associated with a higher OR (OR, 1.62;5% CI, 1.16-2.26). Younger age of adenoma diagnosis was not related to a higher prevalence of a family history of colorectal cancer. CONCLUSIONS: Relatives patients with advanced colorectal adenomas have an increased risk of colorectal cancer. Individuals with advanced colorectal adenomas should be counseled about the increased risk of colorectal cancer among their relatives.     

Risk of colorectal adenomas in patients with a family history of colorectal cancer: some implications for screening programmes.

BACKGROUND AND AIMS: Most colorectal cancers (CRC) arise in colorectal adenomas. A case-control study was conducted to see whether a family history of CRC is associated with a higher prevalence of colorectal adenomas. SUBJECTS: Subjects were drawn from all patients who underwent colonoscopy at the Royal Brisbane Hospital between 1980-1982 and 1985, and included 141 cases with colorectal adenomas diagnosed at colonoscopy and 882 controls who were free of polyps at colonoscopy. METHODS: The prevalence of family history of CRC was compared between patients with adenomas and negative colonoscopy controls. RESULTS: Overall, patients with one first degree relative with CRC were at no greater risk for adenomas at colonoscopy than patients with no family history (odds ratio (OR) = 0.8, 95% confidence intervals (CI) = 0.4, 1.5). Patients with two or more affected first degree relatives had a more than doubled risk for adenomas (OR = 2.3, 95% CI = 0.5, 8.2), and were also more likely to carry moderately or severely dysplastic adenomas (OR = 14.1, 95% CI = 2.0, 62.9). CONCLUSIONS: These findings are consistent with the hypothesis that some families, in addition to those with familial adenomatous polyposis, have an increased susceptibility to develop colorectal adenomas, and that adenomas in such families may have a greater tendency to undergo malignant transformation.     

Colonoscopic screening of first-degree relatives of patients with large adenomas: increased risk of colorectal tumors

BACKGROUND & AIMS: The risk of developing colorectal neoplasia is not well established among family members of individuals with large adenomas, and screening strategies remain under debate in this population. This study aimed at quantifying the risk of colorectal adenomas and cancers using colonoscopic screening in first-degree relatives of patients with large adenomas. METHODS: This case-control study was performed in 18 endoscopic units of French nonuniversity hospitals. A colonoscopy was offered to first-degree relatives of 306 index cases with adenomas > or =10 mm if they were alive, aged 40-75 years, and could be contacted by the index case. Among them, 168 were examined and matched for age, sex, and geographical area with 2 controls (n = 307). Controls were randomly selected from 1362 consecutive patients aged 40-75 years having undergone a colonoscopy for minor symptoms. RESULTS: The prevalence of large adenomas and cancers was 8.4% and 4.2%, in relatives and controls, respectively. Odds ratios (ORs) associated with a history of large adenomas in relatives were 2.27 (95% confidence interval [CI], 1.01-5.09) for cancers or large adenomas, 1.21 (95% CI, 0.68-2.15) for small adenomas, and 1.56 (95% CI, 0.96-2.53) for all colorectal neoplasia. The risk of large adenomas and cancers was higher in relatives of index cases younger than 60 years (OR, 3.82; 95% CI, 0.92-15.87) and when the index case had large distal adenomas (OR, 3.14; 95% CI, 1.27-7.73). CONCLUSIONS: First-degree relatives of patients with large adenomas are at increased risk of developing colorectal cancers or large adenomas. This result has implications for screening in this high-risk population.     

Colonic Adenomas in Asymptomatic Women with a History of Breast Cancer

One hundred ninety-three asymptomatic women with a personal history of breast cancer underwent screening colonoscopy. One hundred sixty-eight women had breast cancer as their only potential risk factor for colonic neoplasia, and 25 had a family history of colorectal neoplasia in addition to their personal history of breast cancer. Among women with breast cancer, increasing age and body weight were each predictive of an increasing prevalence of colonic adenomas. The prevalence of colonic adenomas in women aged 50–75 yr whose only potential risk factor was breast cancer was 18%, and was identical to the prevalence of colonic adenomas in 186 asymptomatic average-risk control women aged 50-75 yr (odds ratio 1.0. 95% CI 0.54-1.87). We conclude that a personal history of breast cancer does not predict a higher prevalence of colonic adenomas.     

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.     

Risk factors for colorectal adenomas among immediate family members of patients with colorectal cancer in Taiwan: a case-control study

OBJECTIVES: The incidence of colorectal cancer or adenoma among first-degree relatives of patients with colorectal cancer is significantly high. However, a well defined screening and surveillance consensus has not been developed for these families in Taiwan. We conducted this study to evaluate the colorectal adenoma prevalence pattern in screened immediate family members in Taiwan, and to derive implications for future screening programs. METHODS: A total of 234 immediate family members (aged 51.6 +/- 21.5 yr) of 186 patients with colorectal cancer were offered a colonoscopy. Each relative examined was then paired with two control subjects for age, sex, and symptoms. The prevalence of colorectal adenomas was then compared using multiple logistic regression analysis. RESULTS: The estimated risk of developing adenomas among immediate family members of patients with colorectal cancer was significantly increased (OR = 2.33; 95% CI, 1.43-3.78; p < 0.001). This trend was more striking for men (OR = 2.46; 95% CI, 1.40-4.31; p = 0.001). Immediate family members were at an increased risk for high-risk adenomas (> or = 1.0 cm, with a villous component, and/or with severe dysplasia) (OR = 4.5; 95% CI, 1.91-10.60; p = 0.002), and developed adenomas at an earlier age than did controls. Individuals with index cancer relatives diagnosed at < 50 yr of age or male relatives posed a higher risk of developing colorectal adenomas. CONCLUSIONS: The prevalence of colorectal adenoma in persons with a colorectal cancer family history in Taiwan is similar to that reported in Western countries. This high-risk population should be offered a screening colonoscopy beginning at 40 yr of age.     

Ki-ras proto-oncogene mutations in sporadic colorectal adenomas: relationship to histologic and clinical characteristics

BACXKGROUND & AIMS: The goal of this study was to examine the relationship between Ki-ras mutations in colorectal adenomas and characteristics of both the subject (age, gender, and family/personal history of colonic neoplasia) and the adenoma (multiplicity, size, location, and histologic features). METHODS: Ki-ras mutations were detected by direct sequencing in 738 adenomatous polyps removed at baseline from 639 participants in a nutritional trial of adenoma recurrence. RESULTS: Ki-ras mutations were detected in 17.2% of the adenomas. Ki-ras mutations were unrelated to gender, family, or personal history of colonic neoplasia, location within the colorectum, or adenoma multiplicity, but were more common in older subjects (P = 0.01 for trend), in larger adenomas (P < 0.0001 for trend), in adenomas with villous histology (odds ratio [OR], 3.2; 95% confidence interval [CI], 2.1-4.9 vs. tubular), and in adenomas with high-grade dysplasia (32.0% vs. 13.6%; OR, 3.0; 95% CI, 1.9-4.6 vs. low-grade dysplasia). Multivariate analysis showed Ki-ras mutations to be independently associated with subject age (P = 0.01 for trend), tubulovillous/villous histology (OR, 2.3; 95% CI, 1.5-3.7), and high-grade dysplasia (OR, 1.9; 95% CI, 1.2-3.1). Adenoma size was not independently related to Ki-ras mutation. CONCLUSIONS: Ki-ras mutations are associated with the histologic features of adenoma progression (villous histology and high-grade dysplasia) rather than with adenoma growth.     

Predictors of advanced proximal neoplasia in persons with abnormal screening flexible sigmoidoscopy.

BACKGROUND & AIMS: The relationship between distal and proximal colonic findings is uncertain. Thus, there is no consensus on which findings on screening flexible sigmoidoscopy should trigger colonoscopy. METHODS: We analyzed data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial to assess the relationship between distal and proximal colonic findings. RESULTS: A total of 8802 subjects had an abnormal baseline sigmoidoscopy and colonoscopy follow-up. Subjects with <10-mm single or multiple tubular adenomas had similar risks for advanced proximal neoplasia as subjects with hyperplastic polyps or other benign lesions (3%-5%). Subjects with large (>or=10 mm), villous, or severely dysplastic distal adenomas had similarly elevated risks for advanced proximal neoplasia (11%-12%). Multivariate logistic modeling showed a significantly increased risk for advanced proximal neoplasia associated with the presence of a large tubular (odds ratio [OR], 2.6; 95% confidence interval [CI], 2.0-3.4) or villous distal adenoma (OR, 2.7; 95% CI, 2.1-3.5) but not with the presence of one (OR, 1.05; 95% CI, 0.8-1.3) or multiple (OR, 0.8; 95% CI, 0.5-1.2) <10-mm tubular distal adenomas. CONCLUSIONS: Among subjects with a polypoid lesion on screening flexible sigmoidoscopy, those with small tubular distal adenomas are at similar risk for advanced proximal neoplasia as those without distal adenomas. Subjects with a large, villous, or dysplastic distal adenoma are at increased risk. A strategy that encourages individuals with small tubular adenomas on sigmoidoscopy to undergo follow-up colonoscopy and excludes those with nonadenomatous lesions is of questionable validity, because both groups are at similar risk for advanced proximal neoplasia.     

Moderate Alcohol Consumption Protects Against Colorectal Adenomas in Smokers

Background Although some studies have shown an association between alcohol consumption and colorectal adenomas, the effect of moderate alcohol consumption is not well defined, nor is the interaction between alcohol and smoking. Aim To investigate the relationship between different levels of alcohol consumption and colorectal adenomas and to determine whether smoking modifies this relationship. Methods Eligible patients who underwent a complete colonoscopy were included (179 cases and 466 controls). Alcohol consumption was obtained from a lifestyle questionnaire. Patients were divided into three groups: (1) Abstainers: 0 drinks/week; (2) Moderate drinkers: > 0 to <7 drinks/week; (3) Heavy drinkers: > 7 drinks/week. Odds ratios (OR) were calculated using logistic regression, controlling for gender, age, body mass index, use of non-steroidal anti-inflammatory medications. Results were stratified by the number of years smoked. Results The proportion of patients with adenomas was 29.6% in abstainers, 22.1% in moderate drinkers, and 36.7% in heavy drinkers. The relationship between alcohol consumption and colorectal adenomas varied significantly by smoking history. For individuals who had never smoked, heavy drinkers were at significantly increased odds of having an adenoma compared to moderate drinkers (OR 3.08; 95% CI: 1.50–6.32), while no difference was seen for abstainers (OR 0.99; 95% CI: 0.52–1.89). Similarly, among individuals who had smoked 1–14 years, heavy drinkers were at increased odds of having an adenoma compared to moderate drinkers (OR 2.61; 95% CI: 1.04–6.51), and no difference was seen for abstainers (OR 1.02; 95% CI: 0.33–3.10). Somewhat unexpectedly, among individuals who had smoked for 15 or more years, abstainers were at increased odds of having an adenoma compared to moderate drinkers (OR 2.04; 95% CI: 0.91–4.59), while heavy drinkers were not at increased odds of having an adenoma (OR 0.73; 95% CI: 0.27–1.97). Conclusions Consumption of less than seven alcohol drinks per week does not increase the risk of having a colorectal adenoma. We found evidence in this study that moderate alcohol consumption among long-term smokers may potentially decrease the risk of an adenoma compared to abstainers.     

New occurrence and recurrence of neoplasms within 5 years of a screening colonoscopy

OBJECTIVE: The fear that colorectal adenomas were missed on initial colonoscopy or that new adenomas have developed is often a rationale for repeating a colonoscopic examination. The aim of this study was to delineate risk factors associated with recurrence of colorectal adenomas after an initial baseline screening colonoscopy. METHODS: The study population comprised 875 subjects who underwent a baseline screening colonoscopy followed by a second examination 1-5 yr later. Multiple logistic regression was used to assess the influence of potential risk factors on the occurrence or recurrence of colorectal adenomas, the strength of the influence being expressed as an OR with a 95% CI. RESULTS: Colorectal adenomas were detected in 484 of all patients (55%) at baseline colonoscopy. Within a 1- to 5-yr time interval, 181 patients (37%) had recurrent adenomas (adenomas were removed during the first colonoscopy) and 73 patients (19%) had newly developed adenomas (adenomas were absent on the first colonoscopy). The occurrence of adenomas at baseline screening colonoscopy was the only factor associated with an increased risk for the recurrence of adenomas at follow-up (OR = 2.51, 95% CI = 1.77-3.55). Recurrence was associated with multiple baseline adenomas (4.45, 2.98-6.64) and baseline adenomas larger than 1 cm (2.62, 1.99-3.11). Recurrence was not associated with histology type or family history of colorectal cancer. There was a significant trend for adenomas to recur in the same proximal or distal segment as the baseline adenomas (p = 0.02). CONCLUSIONS: Colon adenomas tend to recur with greater frequency if the adenomas removed at baseline were either large or multiple. Although patients with large adenomas or multiple adenomas at baseline screening colonoscopy are at a 2.6- to 4.5-fold risk for recurrence of adenomas, the rate of de novo adenoma formation in patients without baseline adenomas may be large enough to warrant repeat colonoscopy at some time in the future. The exact timing of the follow-up colonoscopy needs to be determined.     

Colonic Neoplasia in Asymptomatic Persons with Negative Fecal Occult Blood Tests: Influence of Age, Gender, and Family History

Six hundred twenty-one asymptomatic persons with negative fecal occult blood tests (ages 50–75 yr), including 496 with no known risk factors for colorectal cancer and 125 with a single first-degree relative with a history of colonic neoplasia developed after age 40, underwent screening colonoscopy. Three Dukes A cancers were detected in average-risk persons. The overall prevalence of adenomatous polyps was 27%. Multiple logistic regression analysis revealed that increasing age and male gender were both strong predictors of colonic neoplasia ( p < 0.001). A positive family history of a single first-degree relative with colorectal cancer was not associated with an increased prevalence of colonic neoplasia ( p = 0.29), although an effect may be present if the relative was <60 yr at diagnosis. Overall 16% of males and 7% of women > 60 yr had at least one adenoma that was large (>1 cm in size), villous or tubulovillous, or had grade 3 dysplasia. We conclude that the prevalence of colonic neoplasia in asymptomatic persons with negative fecal occult blood tests is substantial, particularly in elderly males. A family history of a single first-degree relative diagnosed at age >60 yr with colorectal cancer is not associated with an increased prevalence of colonic adenomas.     

Interval faecal occult blood testing in a colonoscopy based screening programme detects additional pathology

BACKGROUND: Colonoscopic based surveillance is recommended for patients at increased risk of colorectal cancer. The appropriate interval between surveillance colonoscopies remains in debate, as is the "miss rate" for colorectal cancer within such screening programmes. AIMS: The main aim of this study was to determine whether a one-off interval faecal occult blood test (FOBT) facilitates the detection of significant neoplasia within a colonoscopic based surveillance programme. Secondary aims were to determine if invitees were interested in participating in interval screening, and to determine whether interval lesions were missed or whether they developed rapidly since the previous colonoscopy PATIENTS: Patients enrolled in a colonoscopic based screening programme due to a personal history of colorectal neoplasia or a significant family history. METHODS: Patients within the screening programme were invited to perform an immunochemical FOBT (Inform). A positive result was followed by colonoscopy; significant neoplasia was defined as colorectal cancer, adenomas either > or =10 mm or with a villous component, high grade dysplasia, or multiplicity (>/=3 adenomas). Participation rates were determined for age, sex, and socioeconomic subgroups. Colonoscopy recall databases were examined to determine the interval between previous colonoscopy and FOBT offer, and correlations between lesion characteristics and interval time were determined. RESULTS: A total of 785 of 1641 patients invited (47.8%) completed an Inform kit. A positive result was recorded for 57 (7.3%). Fifty two of the 57 test positive patients completed colonoscopy; 14 (1.8% of those completing the FOBT) had a significant neoplastic lesion. These consisted of six colorectal cancers and eight significant adenomas. CONCLUSIONS: A one off immunochemical faecal occult blood test within a colonoscopy based surveillance programme had a participation rate of nearly 50% and appeared to detect additional pathology, especially in patients with a past history of colonic neoplasia.     

Withdrawal time in excellent or very poor bowel preparation qualities

AIM: To evaluate association(s) between withdrawal time and polyp detection in various bowel preparation qualities. METHODS: Retrospective cohort analysis of screening colonoscopies performed between January 2005 and June 2011 for patients with average risk of colorectal cancer. Exclusion criteria included patients with a personal history of adenomatous polyps or colon cancer, prior colonic resection, significant family history of colorectal cancer, screening colonoscopy after other abnormal screening tests such as flexible sigmoidoscopy or barium enema, and screening colonoscopies during in-patient care. All procedures were performed or directly supervised by gastroenterologists. Main measurements were number of colonic segments with polyps and total number of colonic polyps.RESULTS: Multivariate analysis of 8331 colonosco-pies showed longer withdrawal time was associated with more colonic segments with polyps in good(adjusted OR = 1.16; 95%CI: 1.13-1.19), fair(OR = 1.13; 95%CI: 1.10-1.17), and poor(OR = 1.18; 95%CI: 1.11-1.26) bowel preparation qualities. A higher number of total polyps was associated with longer withdrawal time in good(OR = 1.15; 95%CI: 1.13-1.18), fair(OR = 1.13; 95%CI: 1.10-1.16), and poor(OR = 1.20; 95%CI: 1.13-1.29) bowel preparation qualities. Longer withdrawal time was not associated with more colonic segments with polyps or greater number of colonic polyps in bowel preparations with excellent(OR = 1.07, 95%CI: 0.99-1.26; OR = 1.11, 95%CI: 0.99-1.24, respectively) and very poor(OR = 1.02, 95%CI: 0.99-1.12; OR = 1.05, 95%CI: 0.99-1.10, respectively) qualities.CONCLUSION: Longer withdrawal time is not associated with higher polyp number detected in colonoscopies with excellent or very poor bowel preparation quality.     

Is there a role for sigmoidoscopy in symptomatic patients? Analysis of a study correlating distal and proximal colonic neoplasias detected by colonoscopy in a symptomatic population

BACKGROUND: Colonoscopy is the gold standard exam to investigate patients with colonic complaints. However, its availability is limited in developing countries. Sigmoidoscopy has been advocated as a first procedure in colorectal cancer screening strategies, in order to select those who need colonoscopy. AIM: To study the correlation between distal and proximal colonic neoplasias in symptomatic patients 50 years or older and patients 40 to 49 years old who underwent colonoscopy at a gastrointestinal endoscopy unit in 1999 and 2000 with the purpose to evaluate its role in a symptomatic population. METHODS: All colonoscopies performed in our Department in 1999-2000 were reviewed. The distal colon was defined as the colonic segment aboral to the splenic flexure. Advanced neoplasias were defined as adenomas larger than 10 millimeters and adenocarcinomas. RESULTS: Of the 2,701 colonoscopies retrieved, 1,125 were enrolled in this study. Prevalence rates for adenoma, advanced adenoma and carcinoma were 28.9%, 4.6% and 4% in the group of 830 patients 50 years or older (mean age 65 years, 491 women). The finding of one small (<10 mm) adenoma in the distal bowel doubled the likelihood of finding a proximal neoplasia (OR = 2.12, 95% CI, 1.27-3.54), and multiple (OR = 3.99, 95% CI, 1.72-9.28) or advanced (OR = 3.73, 95% CI, 1.81-7.7) adenomas increased this risk even further. Of the patients without adenoma or carcinoma in the distal colon, 1.93% had proximal advanced neoplasia. In the group of 40 to 49-year-old patients (n = 395; mean age 44.8 years, 208 women) the prevalence of adenomas (14.9%), advanced adenomas (3.4%), and carcinomas (1.7%) was lower. CONCLUSIONS: The likelihood of finding a proximal lesion is greater in patients with distal neoplasias. This likelihood is further increased when adenomas are multiple or larger than 10 mm. One out of 52 patients 50 years or older with an apparently normal distal colon has advanced proximal neoplasia. Sigmoidoscopy is not an adequate exam for symptomatic patients aged 50 years or older.     

Flexible sigmoidoscopy may be ineffective for secondary prevention of colorectal cancer in asymptomatic,average-risk men

Asymptomatic men (N=114) 50 years of age or older had screening for colorectal neoplasia with flexible sigmoidoscopy followed by colonoscopy regardless of the sigmoidoscopic result. Our study objective was to determine the prevalence of patients having isolated adenomatous polyps in a proximal colonic segment in the absence of a distal index neoplasm within reach of the sigmoidoscope. Through the combined use of sigmoidoscopy and colonoscopy, adenomatous polyps were detected in 47 of 114 individuals (41%). A total of 88 adenomas was found. Seventeen patients had isolated neoplasms in proximal colonic segments in the absence of distal adenomas. These patients represented 15% of screened subjects (17 of 114) and 20% of individuals who lacked adenomas on sigmoidoscopy (17 of 84). The majority of proximal neoplasms were small (<1.0 cm), tubular adenomas. Flexible sigmoidoscopy may be ineffective for screening asymptomatic men for neoplasia. However, it remains to be determined if a 20% miss rate (for those with a normal sigmoidoscopic examination) is significant and whether small proximal adenomas are worth finding.     

Five-year colon surveillance after screening colonoscopy

BACKGROUND & AIMS: Outcomes of colon surveillance after colorectal cancer screening with colonoscopy are uncertain. We conducted a prospective study to measure incidence of advanced neoplasia in patients within 5.5 years of screening colonoscopy. METHODS: Three thousand one hundred twenty-one asymptomatic subjects, age 50 to 75 years, had screening colonoscopy between 1994 and 1997 in the Department of Veterans Affairs. One thousand one hundred seventy-one subjects with neoplasia and 501 neoplasia-free controls were assigned to colonoscopic surveillance over 5 years. Cohorts were defined by baseline findings. Relative risks for advanced neoplasia within 5.5 years were calculated. Advanced neoplasia was defined as tubular adenoma greater than > or =10 mm, adenoma with villous histology, adenoma with high-grade dysplasia, or invasive cancer. RESULTS: Eight hundred ninety-five (76.4%) patients with neoplasia and 298 subjects (59.5%) without neoplasia at baseline had colonoscopy within 5.5 years; 2.4% of patients with no neoplasia had interval advanced neoplasia. The relative risk in patients with baseline neoplasia was 1.92 (95% CI: 0.83-4.42) with 1 or 2 tubular adenomas <10 mm, 5.01 (95% CI: 2.10-11.96) with 3 or more tubular adenomas <10 mm, 6.40 (95% CI: 2.74-14.94) with tubular adenoma > or =10 mm, 6.05 (95% CI: 2.48-14.71) for villous adenoma, and 6.87 (95% CI: 2.61-18.07) for adenoma with high-grade dysplasia. CONCLUSIONS: There is a strong association between results of baseline screening colonoscopy and rate of serious incident lesions during 5.5 years of surveillance. Patients with 1 or 2 tubular adenomas less than 10 mm represent a low-risk group compared with other patients with colon neoplasia.     

What does sigmoidoscopy really miss?

The relative effectiveness of flexible sigmoidoscopy compared with colonoscopy to screen for colorectal cancer depends on the magnitude of the association between findings in the proximal and distal colon and the false-negative rate of screening sigmoidoscopy for proximal neoplasia. Lewis et al. performed a systematic review and meta-analysis of screening colonoscopy studies. Published studies through July 31, 2000 of asymptomatic patients undergoing screening colonoscopy were identified from the MEDLINE database. The authors generated pooled estimates of the odds ratio for the association between findings in the distal and proximal colon and the prevalence of isolated proximal adenomatous neoplasia. With the sigmoid–descending colon junction used to identify the beginning of the distal colon, the pooled odds ratio for the association between distal adenomatous polyps and any proximal neoplasia was 2.40 (95% confidence interval [Cl] = 1.42–4.05). Diminutive distal adenomatous polyps were also associated with proximal neoplasia (odds ratio = 2.36; 95% CI = 1.30–4.29). Distal hyperplastic polyps were not associated with proximal neoplasia (odds ratio = 1.44; 95% CI = 0.79–6.62). The prevalence of isolated advanced proximal neoplasia in the three studies was 2%, 3%, and 5%, respectively. When the sigmoid–descending colon junction is used to identify the beginning of the distal colon, this yields a pooled estimate of isolated proximal neoplasia of 16.3% (95% CI = 13.6%–19.1%). Distal adenomatous polyps, including diminutive distal adenomatous polyps, are associated with an increasing prevalence of synchronous proximal neoplasia. From 2% to 5% of patients undergoing screening colonoscopy might have isolated advanced proximal neoplasia.     

Increased prevalence of colorectal neoplasia in korean patients with sporadic duodenal adenomas: a case-control study

Background/Aims

Recent data from Western populations have suggested that patients with sporadic duodenal adenomas are at a higher risk for the development of colorectal neoplasia. In this study, we compared the frequency of colorectal neoplasia in patients with sporadic duodenal adenomas to healthy control subjects.

Methods

This retrospective case-control study used the databases of 3 teaching hospitals in Gyeonggi-do Province, South Korea. The colonoscopy findings of patients with sporadic duodenal adenomas were compared with those of age- and gender-matched healthy individuals who had undergone gastroduodenoscopies and colonoscopies during general screening examinations.

Results

Between 2001 and 2008, 45 patients were diagnosed endoscopically with sporadic duodenal adenomas; 26 (58%) of these patients received colonoscopies. Colorectal neoplasia (42% vs 21%; odds ratio [OR], 2.8; 95% confidence interval [CI], 1.1 to 7.4) and advanced colorectal adenoma (19% vs 3%; OR, 9.0; 95% CI, 1.6 to 50.0) were significantly more common in patients with sporadic duodenal adenomas than in healthy control subjects.

Conclusions

Compared with healthy individuals, patients with sporadic duodenal adenomas were at a significantly higher risk for developing colorectal neoplasia. Such at-risk patients should undergo routine screening colonoscopies.     

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.