Distal Polyps Research Articles

Reasons to Decline Colonoscopy or CT Colonography Screening: A Randomized Controlled Trial

Background and aims. In Verona and Turin colorectal cancer screening is performed offering flexible sigmoidoscopy (FS) once in the life in 60 years old (Verona) or 58 years old (Torino) people and immunological faecal occult blood testing (FIT) to people non compliant to sigmoidoscopy. Our aim is to determinate the feasibility and the covering rate of our screening program and the detection rate for adenomas and cancer. Materials and Methods. Subjects are enrolled with a personal invitation letter signed by the GP. Those who report a personal history of colorectal cancer, colorectal polyps or inflammatory bowel disease, colonoscopy within the previous 5 years or a medical condition that would preclude a benefit from screening are excluded from invitation. FS are performed by a gastroenterologist with flexible endoscopes. Bowel preparation is limited to a single enema self-administered at home. Subjects found to have one distal polyp > 5 mm (>= 10 mm in Turin) or at least one adenoma (one advanced adenoma or > 2 adenomas in Turin) at sigmoidoscopy are referred for colonoscopy. People who do not respond to the invitation for FS are invited to FIT (cut off 100 ng/ml). Advanced adenoma (Aad) is defined as an adenoma with high grade dysplasia, or villous component >20%, or size > 9 mm. Results. In the table attached are summarized the results of the two programs. Invitations to FS and to FIT, FS and FIT performed, attendance rate, patients with HR polyps and cancers are reported for males and females. Conclusions. Our experience demonstrates that a screening program with FS offered to people aged 58 to 60 followed by the offer of FIT to non-attenders to FS is feasible. FIT can increase the proportion of people having screening by 25%. The overall coverage is higher in Verona than in Turin, the difference in participation rate being similar for FS and FIT. As in both programmes males show a higher attendance rate to FS, while females show a higher attendance rate to FIT, this strategy allows for achieving a similar coverage in both genders. Furthermore, FIT in people not attending to FS can contribute to detect an additional consistent number of high risk adenomas (0.6%) and cancers (0.1%) in the invited population.

Potential Short-Term Cost-Savings in the Management of Diminutive Distal Colorectal Polyps: Data From a ‘Real-Life’ Dutch Cohort

Potential Short-Term Cost-Savings in the Management of Diminutive Distal Colorectal Polyps: Data From a ‘Real-Life’ Dutch Cohort

Right-sided Colon Polyps Have Worse Histology and are More Often Sessile Than Left-sided Polyps. This Argues for Colonoscopy Being Used for Screening Rather Than Sigmoidoscopy and Fecal Occult Blood Testing. A Retrospective Single Center VA Hospital Study

Purpose: Flexible sigmoidoscopy and fecal occult blood testing (FOBT) is the initial screening modality at our institution for colorectal cancer. Based on positive findings, a decision is made to pursue colonoscopy to evaluate for high risk proximal polyps and cancer. We investigated differences in tumor biology based on polyp location to evaluate if proximal polyps are more aggressive than distal polyps needing more effective initial screening.Table: [1501]Methods: We conducted a retrospective study at Loma Linda VA Medical Center. We reviewed the charts of all average risk veterans who had screening colonoscopy from year 2003 to 2008. Data was collected on 1,079 veterans after applying the exclusion criteria. Chi-square test and student's t-test were used to compare variables. Right-sided polyps were defined as those proximal to splenic flexure and left-sided as those distal to it. Results: Right-sided colon polyps were 70% adenomatous and 11% hyperplastic as compared to left-sided polyps, which were 58% adenomatous and 26% hyperplastic (p<0.0001). There was no statistical difference in the villous or high-grade polyps. Right-sided colon polyps were 79% sessile and 12% pedunculated as compared to left-sided polyps, which were 69% sessile and 19% pedunculated (p=0.002). There was no difference in the size of the left- and right-sided polyps. Left-sided polyps were slightly more numerous (p=0.03). Conclusion: Right-sided colon polyps are 1.2 times more adenomatous whereas left-sided polyps are 2.5 times more hyperplastic. Right-sided polyps are more often sessile and thus harder to remove than pedunculated polyps, which were more common on the left. The worse histology and sessile character makes right-sided polyps more aggressive than left-sided polyps. This argues for colonoscopy being used for colon cancer screening rather than just flexible sigmoidoscopy and FOBT testing.

Risk of Proximal Colonic Neoplasms in Asymptomatic Adults Older Than 50 Years Found to Have Distal Hyperplastic Polyps on Routine Colorectal Cancer Screening

A retrospective case-control study was conducted to evaluate whether hyperplastic polyps (HPs) found in the lower 50 cm of colon could be used as indicators for synchronous proximal neoplasms (SPNs) in the large intestine. Additionally, other characteristics considered included age; sex; ethnicity; history of cancer, cholecystectomy, or appendectomy; current use of aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs); current use of estrogen or hormone replacement therapy (HRT) in women; current smoking status; and the size, number, and location of the distal HP if present. Convenience sampling of medical charts and colonoscopy reports compiled during a ten-year period was used to glean the sample of 1792 participants. Distal HPs in the lower 50 cm of colon were not significantly associated with SPN when patients with HPs were compared with those without any distal polyps at all (odds ratio [OR] = 0.94; 95% confidence interval [CI] = 0.73-1.22). However, significant relationships with proximal neoplasms (adenomas, advanced adenomas, and colon cancer) were noted in patients with a prior diagnosis of cancer (OR = 1.62; 95% CI =1.25-2.11), advancing age (OR = 1.02; 95% CI = 1.01-1.03), non-Caucasian (men only) ethnicity (OR = 0.72; 95% CI = 0.55-0.96), a history (men only) of taking aspirin or NSAIDs (OR = 0.73; 95% CI = 0.56-0.95), and a history (women only) of taking estrogen or receiving HRT (OR = 1.51; 95% CI = 1.04-2.20). Routinely recommending a colonoscopy for every patient with distal HPs found only by screening flexible sigmoidoscopy is neither justified nor necessary. Nevertheless, further investigation (ie, colonoscopy) may be warranted in the aforementioned subgroups.

S1582: Accuracy of Predicting Distal Colorectal Histology in Real-Time Using Narrow Band Imaging Without Optical Magnification

Accurate colonoscopic assessment of histology could avoid resection of distal colorectal hyperplastic polyps, reduce costs and risk.

Endoscopic Management of Large Distal Ureteral Polyp as an Outpatient

This video describes the minimally invasive technique of removing a 5 cm distal ureteral polyp close to 25 years ago with the use of ureteroscopy and a polyp snare. It is of historical significance in that it represents an early example of the creative, safe, and effective value of endourology in replacing open surgery. This is an historical video of an important urological procedure that may be of interest to urologists today. The content of the video reflects the views of the authors, and the techniques and technologies used by the authors, at the time the video was produced. The complete author disclosures are no longer available. Runtime of video: 7 min 29 sec

Abstract B108: Dietary intake of calcium and distal colorectal adenomatous polyps in Korean adults

Abstract Background: Colorectal cancer is fourth in prevalence of carcinoma and fourth most cause of death from malignant neoplasm, which has been increasing in Korea. In this study, we tried to investigate the association of dietary intake of calcium and distal colorectal adenomatous polyps known as precursors of colorectal cancer. Methods: A total of 2,456 subjects who visited a health promotion center in one university hospital in Seoul, Korea, from June 2003 to June 2006 underwent sigmoidoscopy and completed a 24-hour dietary recall. Results: Among the selected 2,408 subjects, the prevalence of distal colorectal adenoma found in sigmoidoscopy was 12.54%. After adjusting for age and total serum cholesterol by multiple logistic regression, the odds ratio of the male subjects who had the highest quintile of dietary intake of calcium was 0.512 (95% CI: 0.305–0.859; P = 0.011) compared with the lowest. Conclusion: In male subjects with the highest quintile of dietary calcium density was associated with a low risk of distal colorectal adenomatous polyps. Citation Information: Cancer Prev Res 2010;3(1 Suppl):B108.

Quantitative evaluation of CpG island methylation in hyperplastic polyps

Microsatellite unstable cancers account for up to 15% of sporadic colon cancers and are predominantly located in the proximal colon. These cancers commonly show MLH1 promoter methylation and the CpG island methylator phenotype (CIMP). A potential precursor of sporadic unstable cancers, the proximal hyperplastic polyp, is also reported to have CIMP and MLH1 methylation. However, this latter finding is not supported by MLH1 protein expression studies. To help resolve this apparent discrepancy, we determined MLH1 promoter methylation and CIMP by quantitative real-time PCR for 29 proximal hyperplastic polyps, 23 distal hyperplastic polyps, and 11 sporadic microsatellite unstable colon cancers. BRAF V600E mutation status was also determined. Positive methylation was defined as the percentage of methylated reference (PMR) >10. Only 1 of 29 proximal hyperplastic polyps showed positive MLH1 methylation (PMR of 13.0). Neither this polyp nor seven other proximal polyps with PMR values between 0 and 10 showed loss of MLH1 protein expression by immunohistochemistry. In contrast, all 11 microsatellite unstable cancers showed high degrees of MLH1 methylation, with PMR values >30. Fourteen of twenty-nine (48%) of the proximal hyperplastic polyps and 1 of 23 (4%) of the distal hyperplastic polyps showed CIMP (P<0.001). Of the unstable cancers, 10 of 11 showed CIMP. The PMR values in the CIMP-positive proximal hyperplastic polyps were significantly lower than those of the unstable cancers for 4 of the 5 CIMP markers (P<0.05). BRAF V600E mutations were seen in 83% of proximal and 74% of distal hyperplastic polyps. Quantitative analysis of MLH1 methylation does not support earlier reports of MLH1 methylation in proximal hyperplastic polyps. However, these lesions do harbor promoter methylation at other CIMP loci, although at a lower level than that seen in unstable cancers. If these polyps are the precursor for sporadic microsatellite unstable cancers, then MLH1 methylation and higher degrees of promoter methylation in general occur at a later stage of carcinogenesis.

Colonoscopic Findings in a True Screening Program for Colorectal Cancer (Without Previous Fecal Occult Blood Testing): The First 500 Procedures

Purpose: Screening for colorectal cancer in average risk population was shown to decrease its incidence and mortality. However, best screening method in this setting has been under considerable debate. Here we present the first results of a colonoscopy-based pilot screening program for colorectal cancer in a north region of Portugal. Methods: The first 500 subjects were screened between 2007 and 2008. The target population included asymptomatic average risk (without family history) population of men and women aged 50-74 years. Screening consisted of left colonoscopy or, whenever possible, complete colonoscopy (without previous fecal occult blood testing). Any polyps found were removed, and biopsies were performed whenever indicated. Results: Screening was performed in 235 men and 265 women with a mean (±SD) age of 59.2±7.2 years. Colonoscopy was complete in 378 subjects (76%). In 135 subjects (27%), 7 carcinomas, 32 high-risk adenomas, 56 low-risk adenomas, and 40 hyperplastic polyps were diagnosed. Lesion size was smaller than 10 mm in 81% of cases. Most detected lesions (64%) were located in the distal colon, followed by the proximal colon (19%) and both locations (17%). All carcinomas were located in the sigmoid. Advanced neoplasm was significantly associated with male gender. Among individuals with no distal polyps (254 with no lesions on colonoscopy and 26 with proximal polyps only), the prevalence of advanced proximal neoplasms was 2%, increasing among patients with advanced distal neoplasms to 20%. When we analyzed the risk that an advanced proximal neoplasm would be detected based only on distal colon examination, we found that 50% of subjects had at least one adenoma and that the lesion was an advanced neoplasm in 40% of subjects. Conclusion: The most common lesions detected in this colonoscopy-based pilot screening program were low-risk adenomas located in the distal colon. Even in asymptomatic average risk individuals, we found a prevalence of 27% of any type of lesion and 1.4% of colon cancer.

Differentiation of Adenomatous from Hyperplastic Histology in Colorectal Polyps by Narrow Band Imaging can be Learned in 20 Minutes

Purpose: Narrow band imaging has been successfully used in differentiating adenomatous from hyperplastic polyps when used with or without optical magnification. There is little published information regarding teaching tools, and there are few data on interobserver variation in identification of histology for either experts or non-experts. Real time histology has been proposed as a means to decrease costs and risks of colonoscopy by not removing small distal colon hyperplastic polyps. We tested whether medical residents with no prior training in endoscopy (n= 12), gastroenterology fellows with varying levels of endoscopic training (n=12) and gastroenterology attendings who were all experienced endoscopists (n=12) could learn and apply endoscopic criteria for differentiation of adenomas from hyperplastic polyps after a short didactic session. Methods: Sessions were held with groups of 3 to 6 individuals. A pre-test of 10 photographs was presented, and each subject scored each photograph as adenoma or hyperplastic or unknown. Subjects were instructed to score the polyp as adenoma or hyperplastic if they were approximately 90% or more confident of the answer. Following the pre-test the subjects were given a 20 minute presentation describing the criteria for differentiation (Gastroenterology 2009;136:1174-81) which included presentation of photographs of 25 polyps. Participants were asked to verbally name the histology, and feedback was given on the responses. After this training a written post-test was given on 25 photographs. Results: The mean percent correct increased from 47.6% on the pre-test to 90.8% on the post-test. Excluding responses of “don't know,” the % correct increased from 59.3% to 91.4%. Residents improved from 37.5% correct to 87.3%. Fellows improved from 60% to 94.3%. Faculty improved from 45.4% to 91.1%. All groups improved significantly (p≤.007). Kappa values for inter-rater agreement increased from pre-test to post-test (-0.01 to 0.62 for residents, .16 to 0.79 for fellows, .08 to .69 for faculty, .05 to .69 overall). Conclusion: A brief didactic session can achieve high accuracy and good interobserver agreement in the use of narrow band imaging to differentiate colorectal polyp histology. Disclosure: Olympus - speakers bureau.

Colorectal Cancer Prevention

Purpose: Narrow band imaging has been successfully used in diff erentiating adenomatous from hyperplastic polyps when used with or without optical magnifi cation. Th ere is little published information regarding teaching tools, and there are few data on interobserver variation in identifi cation of histology for either experts or non-experts. Real time histology has been proposed as a means to decrease costs and risks of colonoscopy by not removing small distal colon hyperplastic polyps. We tested whether medical residents with no prior training in endoscopy (n=12), gastroenterology fellows with varying levels of endoscopic training (n=12) and gastroenterology attendings who were all experienced endoscopists (n=12) could learn and apply endoscopic criteria for diff erentiation of adenomas from hyperplastic polyps aft er a short didactic session.

M1939 COX-2 Polymorphisms in Colorectal Carcinogenesis: A Strategy for Individualized Chemoprevention

development of multiple serrated polyps and lesser numbers of adenomas. Nine cancers and ninety-three polyps (39 common hyperplastic polyps (HP), 35 advanced serrated polyps comprising 27 SSA, 1 serrated adenoma (SA) and 7 mixed polyps (MP), and 19 traditional adenomas (TA)) from 31 patients were stained for MUC6. Staining was positive in 69% of SSA, 86% of MP, and negative in a single SA. Overall, staining was positive in 70% of advanced serrated polyps which was significantly greater than the level seen in common HP (70% vs 38%; P=0.0065). MUC6 staining, where present, was confined to the crypt bases. All TA and normal mucosa were negative. Four of nine CRC (44%) stained positive for MUC6 and 75% of these were proximal contrasting with 20% of distal CRC. There was no association between MUC6 expression by CRC and mismatch repair deficiency. More proximal serrated polyps stained positively for MUC6 than distal serrated polyps, 66% and 30% respectively (P=0.008). This study suggests that MUC6 lacks the specificity originally observed by Owens et al, with staining present in 38% of HP. Though our findings were obtained in Caucasian patients with HPS, they are consistent with those of Mochizuka and colleagues (Histochem Cell Biol 2007; 128:445-55) who found MUC6 expression was expressed in common HP and SSA but not in traditional SA or normal mucosa in a series of Japanese patients where HPS was not targeted. Our findings further demonstrate that the expression of MUC6 is significantly more frequent in lesions arising in the proximal colon, whether or not advanced morphology was observed. MUC6 is frequently expressed in SSAs and to a lesser extent in HP and therefore does not provide a surrogate marker for advanced morphology in serrated polyps. The correlation of MUC6 expression with proximal location may suggest that a subset of common serrated polyps in the proximal colon may be developmentally related to their more advanced counterparts.

Prevalence of Proximal Neoplasms Among Asymptomatic Patients According to Distal Colorectal Findings

Colorectal cancer has been described in association with hyperplastic polyposis. Only half of proximal colon cancers are associated with distal adenomas. To compare the prevalence of proximal and advanced neoplasia between patients with distal hyperplastic polyps only; with distal adenomas with or without hyperplastic polyps; and with no distal polyps, we retrospectively analyzed data of 1,064 adults who underwent colonoscopy. Of these patients, 3% had neoplasia. Proximal neoplasia occurred in 0.8% of 945 patients with no distal polyps, compared to none of 19 with distal hyperplastic polyps (P > 0.05) and 6% with distal adenomas (P > 0.05). Proximal advanced neoplasia occurred in 0.6% patients with no distal polyps, compared with none with distal hyperplastic polyps (P > 0.05) and 6% with distal adenomas (P > 0.05). In conclusion, patients with distal hyperplastic polyps, unlike those with distal adenomas, do not exhibit an increased risk for proximal neoplasia or proximal advanced neoplasia compared to those with no distal polyps.

A thousand total colonoscopies: what is the relationship between distal and proximal findings?

Flexible sigmoidoscopy is indicated for colorectal cancer screening. The decision about who needs total colonoscopy based on distal findings is still controversial because of the uncertainty of the associations between distal and proximal findings. The purpose of the study was to characterize distal findings in patients with total colonoscopy, to investigate its importance as markers of advanced proximal lesions and to evaluate the usefulness of a clinical Predictive Index, already published in the literature, in the identification of these lesions. Retrospective analysis of the patients submitted to total colonoscopy between January 2006 and February 2007, with selection of 1000 consecutive cases with reference to polyps. We analysed demographic data, indication for the exam and morphological and histological characteristics of the polyps. Advanced lesion was defined as any adenoma larger than 10 mm or any polyp with villous characteristics, high grade dysplasia or cancer. The Predictive Index was obtained through the assignment of points to 3 categories: sex, age and distal findings, which result in 3 groups: low, intermediate and high risk. The mean age of patients was 64,69 years and 65,1% were male. Distal and proximal polyps were identified in 829 (82,9%) and 369 (36,9%) patients, respectively. Advanced distal lesion was found in 342 patients (34,2%) and advanced proximal lesion in 98 (9,8%). 587 patients (58,7%) were in the high risk group. In the group of patients with advanced proximal lesion, a third presented low and intermediate risk, 52% had no distal polyps, 88,7% had less than three distal polyps and 71,4% had no advanced distal lesion. Sensitivity values for these four categories ranged between 11,2% and 66,6%. If the decision to perform total colonoscopy is based on distal colonic findings or on the Predictive Index, the ability to identify advanced proximal lesion is markedly reduced, endangering the aim of a screening program.

Dietary Intake of Calcium and Distal Colorectal Adenomatous Polyps in Korean Adults

Background: Colorectal cancer is fourth in prevalence of carcinoma and fourth most cause of death from malignant neoplasm, which has been increasing in Korea. In this study, we tried to investigate the association of dietary intake of calcium and distal colorectal adenomatous polyps known as precursors of colorectal cancer. Methods: A total of 2,456 subjects who visited a health promotion center in one university hospital in Seoul, Korea, from June 2003 to June 2006 underwent sigmoidoscopy and completed a 24-hour dietary recall. Results: Among the selected 2,408 subjects, the prevalence of distal colorectal adenoma found in sigmoidoscopy was 12.54%. After adjusting for age and total serum cholesterol by multiple logistic regression, the odds ratio of the male subjects who had the highest quintile of dietary intake of calcium was 0.512 (95% CI: 0.305-0.859; P = 0.011) compared with the lowest. Conclusion: In male subjects with the highest quintile of dietary calcium density was associated with a low risk of distal colorectal adenomatous polyps.

Narrow-Band Imaging Without Optical Magnification for Histologic Analysis of Colorectal Polyps

The ability to determine colorectal polyp pathology by endoscopy could reduce the risks of polypectomy and the cost of pathologic evaluation. This study evaluated the ability of the Olympus Exera 180 high-definition colonoscope (Olympus America, Inc, Center Valley, PA), with narrow-band imaging, to predict colorectal polyp histology. A library of 320 endoscopic photographs with correlated histologic information was used to identify endoscopic features associated with adenomatous and hyperplastic histology. These features were tested in a prospective study of 451 consecutively identified colorectal polyps. Polyps were observed endoscopically and assigned a designation of high or low confidence. The primary end points were the predictive value of high-confidence endoscopic interpretations of adenoma and hyperplastic histology for polyps 5 mm and smaller in size. Endoscopic predictions of adenoma and hyperplastic histology were made with high confidence for 80% and 83% of cases, respectively. High-confidence predictions were more likely than low-confidence predictions to be correct (P<.001). High-confidence predictions of adenoma and hyperplastic histology were correct for 91% and 95%, respectively, of polyps 5 mm and smaller in size. Introduction of confidence levels to the endoscopic interpretation of colorectal polyp histology allows sufficient accuracy for the use of the Exera narrow-band imaging system in the identification of distal hyperplastic polyps that do not need resection, as well as to plan postpolypectomy surveillance without pathologic evaluation of polyps 5 mm in size or smaller.

Low Yield of Repeat Colonoscopy at 5 Years in Average-Risk People

How often should patients undergo screening colonoscopy if their initial exams revealed no polyps or only small distal hyperplastic polyps? Current

Ureteral Fibroepithelial Polyp

Fibroepithelial polyps of the ureter are a rare benign neoplasm that can mimic other ureteral pathologies and lead to inaccurate diagnosis and treatment. The sonographic features of a vermiform and mobile solid ureteral mass may be suggestive of the diagnosis. We report a case of distal ureteral fibroepithelial polyp incidentally discovered at pelvic sonography in a young woman. Case Report A 39-year-old woman with a history of irregular menstrual bleeding was referred for pelvic sonogram for evaluation of possible uterine polyps. The patient reported occasional colicky right flank pain. Pelvic sonogram showed an incidental vermiform solid mass in the urinary bladder near the right ureterovesical orifice (Figure 1). The mass was mobile, and appeared to arise from the right distal ureter, with portion of the mass protruding into the urinary bladder. A small amount of color flow was detected in the mass with color Doppler imaging. While the predominant mass was detected within the bladder, its exophytic and vermiform shape were felt to be atypical for a primary bladder tumor. No focal bladder wall thickening or hydroureteronephrosis was seen on sonography. The uterus and adnexa were normal. The patient subsequently underwent CT urography for further evaluation of the ureteral and bladder mass. CT showed an elongated filling defect with a corkscrew appearance within the distal one third of the right ureter, with the mass protruding into the bladder (Figure 2). The filling defect measured at least 8cm in length with smooth margin, and showed mild enhancement. On the CT, there was mild right hydronephrosis. Both the sonographic and CT findings were consistent with a ureteral fibroepithelial polyp. The patient subsequently underwent cystoscopy and ureteroscopy which confirmed the presence of a right distal ureteral polyp. The polyp was ureteroscopically excised intact (Figure 3), and histology confirmed a fibroepithelial polyp.

Hyperplastic Polyps and the Risk of Adenoma Recurrence in the Polyp Prevention Trial

Recent studies have suggested that some hyperplastic polyps may be associated with an increased risk of colorectal cancer. Prospective information on the risk of adenoma recurrence associated with hyperplastic polyps is limited. We sought to investigate whether the coexistence of hyperplastic polyps with adenomas increases the risk of adenoma recurrence. We used unconditional logistic regression models to examine the association between baseline hyperplastic polyps and subsequent adenoma recurrence during a 3-year follow-up evaluation, among 1637 participants in the Polyp Prevention Trial. A total of 437 participants (26.7%) had hyperplastic polyps coexisting with adenomas at baseline. Of these, 132 (30.2%) had at least one hyperplastic polyp in the proximal colon, whereas 305 (69.8%) had only distal hyperplastic polyps. When compared with subjects without any hyperplastic polyps at baseline, there was no statistically significant association between the presence of baseline hyperplastic polyps and recurrence of any adenoma (odds ratio [OR], 1.19; 95% confidence interval [CI], 0.94-1.51) or advanced adenoma (OR, 1.25; 95% CI, 0.78-2.03). Also, there was no association between hyperplastic polyp location and adenoma recurrence (OR, 1.01; 95% CI, 0.69-1.48) for any proximal hyperplastic polyp (OR, 1.26; 95% CI, 0.96-1.65) and for distal hyperplastic polyps. The coexistence of hyperplastic polyps with adenomas, irrespective of location, does not confer an increased risk of adenoma recurrence beyond that of adenomas alone within 3 years of follow-up evaluation. Prospective long-term studies on adenoma recurrence risk associated with hyperplastic polyps in screening populations are needed.

Hallazgos colonoscópicos del estudio piloto de cribado de cáncer colorrectal realizado en Cataluña

to evaluate lesions detected in two screening rounds performed in a pilot screening programme for colorectal cancer in Catalonia, Spain. a colorectal cancer screening programme was initiated in 2000. The target population included men and women aged 50-69 years. Screening consisted of biennial guaiac-based fecal occult blood testing (FOBT), and colonoscopy for participants with a positive FOBT. Any polyps found were removed, and biopsies were performed for any masses. colonoscopies were performed in 442 of 495 people with positive FOBT. In 213 (48.2%), 36 invasive cancers, 121 high-risk adenomas, 29 low-risk adenomas, and 27 hyperplastic polyps were diagnosed. Lesion size was smaller than 10 mm in 25.8% of cases. Most detected lesions (37.2%) were located in the distal colon, followed by the proximal colon (5.7%) and both locations (5.2%). Advanced neoplasm was significantly associated with male gender and distal location. The prevalence of advanced proximal neoplasms among patients with no distal polyps was 5.1%. the most common lesions detected by colonoscopy were high-risk adenomas located in the distal colon. FOBT is a suitable method for detecting small precancer lesions during population screening, and is thus a key factor in reducing the incidence of colorectal cancer.