Risk of developing metachronous colorectal neoplasia after the resection of proximal versus distal adenomas

BackgroundCurrent post-polypectomy guidelines do not consider adenoma location. We compared the risk of metachronous colorectal neoplasia (CRN) according to adenoma location.MethodsWe collected data from 9710 patients who underwent follow-up colonoscopy after adenoma removal. Patients were classified according to baseline adenoma location: distal only (n=4665), proximal only (n=3827), and both sides (n=1218).ResultsThe risk of metachronous CRN in patients with proximal only adenomas was higher than that in those with distal only adenomas (adjusted hazard ratio [aHR]=1.12, 95% confidence interval [CI]=1.04–1.21), while the risk of metachronous advanced CRN (ACRN) was not different between the two groups. Among patients aged <50 years, the risk of metachronous CRN in those with proximal only non-advanced adenomas (NAAs) was higher than that in those with only distal NAAs, while among patients aged ≥ 50 years, the risk in those with proximal only advanced adenomas (AAs) was higher than that in those with distal only AAs. However, the risk of metachronous ACRN did not differ based on adenoma location in patients aged < 50 and ≥ 50 years.ConclusionsProximal adenoma was associated with an increased risk of metachronous CRN, but not with an increased risk of metachronous ACRN, supporting the current guidelines recommending the same surveillance interval for distal and proximal adenoma without discrimination by adenoma location.     

Number of advanced adenomas on index colonoscopy: Important risk factor for metachronous advanced colorectal neoplasia

Background/AimsAlthough the patients with multiple advanced adenomas (AA) in index colonoscopy may have an increased risk for subsequent advanced colorectal neoplasia (CRN), the current guidelines do not consider this factor. We aimed to compare the risk of metachronous advanced CRN according to the number of AAs.MethodsA total of 2250 patients with ≥1 adenoma at index colonoscopy were included. The patients were divided according to the number of AAs (1, 2 and ≥3 AAs). The relative and 3-year absolute risk of metachronous advanced CRN was compared between the AA groups.ResultsThe relative risk of metachronous advanced CRN was higher in the patients with ≥3 AAs than in the patients with one AA (16.7% vs. 6.8%, p = 0.004). The 3-year absolute risk of metachronous advanced CRN was higher in the patients with ≥3 AAs than in the patients with 1–2 AA (19.4% vs. 6.9%, p = 0.04). Having ≥3 AAs (odds ratio, 5.42; 95% confidence interval 1.75–16.83) was a significant risk factor for developing advanced CRN.ConclusionsThe risk of metachronous advanced CRN in the patients with ≥3 AAs was higher than that in the patients with one or two AAs. More intensive surveillances might be needed for these patient groups.     

Surveillance after positive colonoscopy based on adenoma characteristics

BackgroundPatients with adenomatous polyps are at increased risk for developing colorectal cancer based on the characteristics and number of polyps, but less is known about the individual and combined contribution of these factors. This study aimed to better characterize the risk of advanced adenoma and cancer in patients with positive baseline colonoscopy.MethodsPatients who had polyps at baseline colonoscopy were included in this retrospective cohort study (N = 1165) and were categorized into 6 groups: (1) 1–2 non-advanced adenomas (NAA’s), (2) ≥3 NAA’s, (3) advanced tubular adenoma, (4) small tubulovillous adenoma (TVA), (5) large TVA and (6) multiple advanced adenomas (MAA’s). Findings at surveillance colonoscopy were documented in each group.ResultsThe combined incidence of advanced adenoma, ≥3 NAA’s, and colorectal cancer at surveillance colonoscopy was significantly higher in the baseline large TVA (29.2%) than small TVA groups (13.5%, P < 0.001), as well as in the MAA’s group (44.1%) compared with large TVA group (P = 0.02). The incidence of colorectal cancer, however, was not significantly different between the groups.ConclusionsThe size of the polyp and the number of advanced lesions are more important than its histology for predicting the risk of high-risk metachronous lesions at follow-up.     

Prevalence of clinically important histology in small adenomas.

BACKGROUND & AIMS: The prevalence of advanced histology in small polyps has become a crucial issue in optimizing colorectal cancer screening strategies, especially in view of the advent of computed tomography colonography. We evaluated the prevalence of advanced histology in small and diminutive adenomas to clarify their clinical importance in terms of malignant potential. METHODS: Data were reviewed retrospectively from 3291 colonoscopies performed on asymptomatic patients found to have an adenoma on screening with flexible sigmoidoscopy a few weeks before the colonoscopy or who had a family history of colorectal cancer. All polyps were excised endoscopically and sent for pathology testing. Specimens with advanced histology were confirmed by a second reading. RESULTS: Of the 3291 colonoscopies performed, 1235 colonoscopies yielded a total of 1933 small or diminutive adenomatous polyps. Advanced histology including carcinoma was found in 10.1% of small (5-10 mm) adenomas and in 1.7% of diminutive adenomas (< or = 4 mm). Carcinoma was found in .9% of small adenomas, and 0% of diminutive adenomas. Of the 107 patients found to have polyps 2-10 mm with advanced histology, 100 (93%) were referred for colonoscopy because of an adenoma found on a recent screening with flexible sigmoidoscopy. Seven patients underwent colonoscopy for a positive family history of colon cancer; all 7 had a single affected first-degree relative older than age 50. CONCLUSIONS: Adenomas 5-10 mm in size harbor pathologically significant histology, and the need for removal of these lesions must be addressed to optimize colorectal cancer prevention.     

Rectosigmoid findings are not associated with proximal colon cancer： Analysis of 6 196 consecutive cases undergoing total colonoscopy

AIM: To review the risk of proximal colon cancer in patients undergoing colonoscopy. METHODS: We estimated the risk of advanced proximal adenomas and cancers in 6 196 consecutive patients that underwent colonoscopy (mean age 60 years, 65% males, without prior history of colorectal examination). Neoplasms were classified as diminutive adenoma (5 mm or less), small adenoma (6-9 mm), advanced adenoma (10 mm or more, with villous component or high-grade dysplasia) and cancer (invasive adenocarcinoma). The sites of neoplasms were defined as rectosigmoid (rectum and sigmoid colon) and proximal colon (from cecum to descending colon). RESULTS: The trend of the prevalence of advanced proximal adenoma was to increase with severe rectosigmoid findings, while the prevalence of proximal colon cancer did not increase with severe rectosigmoid findings. Among the 157 patients with proximal colon cancer, 74% had no neoplasm in the rectosigmoid colon. Multivariate logistic-regression analysis revealed that age was the main predictor of proximal colon cancer and existence of rectosigmoid adenoma was not a predictor of proximal colon cancer. CONCLUSION: Sigmoidoscopy is inadequate for colorectal cancer screening, especially in older populations.     

Risk of advanced metachronous colorectal adenoma during long-term follow-up

Background  According to the adenoma–carcinoma concept, all colorectal adenomas are to be removed and all patients have to undergo regular surveillance examinations. But there is still shortage on information on the long-term results of follow-up colonoscopy after polypectomy. Methods  Between 1978 and 2003, more than 20,000 polyps were prospectively documented at the Erlangen Registry of Colorectal Polyps. A total of 1,091 patients undergoing periodic surveillance examinations are studied for differences between initial and metachronous lesions of the colorectum. Statistical analysis using χ ²-testing of adenoma characteristics found in four subsequent recurrence periods and calculation of the relative risk (RR) for the development of metachronous adenomas of advanced pathology was performed. Results  In comparison with the initial findings, metachronous adenomas are, in general, significantly smaller ones (p < 0.00001), more frequently tubular lesions (p < 0.00001) and bearing less often high-grade dysplasia (p < 0.00001). Adenomas of advanced pathology were significantly less often found during follow-up than at baseline examination (p < 0.0001). These differences are found between the initial and four subsequent generations of metachronous adenomas. Patients with adenomas of advanced pathology at baseline have a significantly higher risk for metachronous adenomas of advanced pathology (RR 1.51; 95%CI 1.04–1.93) at the first recurrence. Conclusions  Metachronous adenomas show uniform characteristics of being small tubular lesions rarely bearing high-grade dysplasia. Thus, regular surveillance examinations can provide sufficient colorectal carcinoma prevention.     

Comparative study of conventional colonoscopy and pan-colonic narrow-band imaging system in the detection of neoplastic colonic polyps: a randomized, controlled trial

Background. Detection and removal of adenomas by colonoscopy is an important means for preventing cancer; however, small adenomas may be missed during colonoscopy. The narrow-band imaging (NBI) system clearly enhances the microvasculature in neoplastic lesions, making it appear as a dark complex. Therefore, the NBI system may improve the detection of colonic neoplasias. However, no randomized, controlled trials have evaluated the efficacy of a pan-colonic NBI system in adenoma detection. We conducted a randomized, controlled trial to determine the efficacy of the pancolonic NBI system in adenoma detection. Methods. Two hundred forty-three patients were randomized, 121 to conventional colonoscopy and 122 to pan-colonic NBI system. Demographics, indication for colonoscopy, and quality of preparation were similar between groups. Results. Extubation time was not significantly different between the conventional colonoscopy and pan-colonic NBI system. The proportions of patients with at least one adenoma and those with multiple adenomas were not significantly different between groups. However, the pan-colonic NBI system significantly increased the total number of adenomas detected (P < 0.05) and the number of diminutive (<5 mm) adenomas detected (P < 0.05). The pan-colonic NBI system allowed detection of more diminutive adenomas in the distal colon than did conventional colonoscopy (P < 0.01), and more patients in the NBI group had at least one diminutive adenoma than in the control group (P < 0.05). Conclusions. The pan-colonic NBI system improves the total number of adenomas detected, including significantly more diminutive adenomas, without prolongation of extubation time. These results indicate that routine use of the NBI system for surveillance of diminutive adenomas may be recommended.     

Predictive value of morphologic characteristics in rectosigmoid adenomatous polyps for the probability of synchronous polyps or cancer in the proximal colon.

BACKGROUND/AIMS: Sigmoidoscopy is performed more frequently than colonoscopy, especially for screening purposes and searching for colorectal neoplasm. The necessity of colonoscopy in patients with an adenoma ofor=11 mm) polyps. These groups were compared regarding the presence of proximal adenoma and advanced proximal neoplasia (>10 mm adenoma and/or villous histology and/or high grade dysplasia or cancer). Polyps found in the rectum and sigmoid colon were considered as distal polyps and polyps other than these were considered as proximal polyps. RESULTS: In this study, of 1124 consecutive patients who underwent colonoscopy between April 1997 and January 2002, 184 (16%) had 258 adenomatous polyps in the rectosigmoid area. The polyps were diminutive (or=11 mm) in 33 patients. Forty-one of the patients (39%) with diminutive polyps, 20 of the patients (43%) with small polyps and 19 of the patients (57%) with large polyps had neoplasm in the proximal bowel. In these patients, advanced proximal neoplasm was found in 8 (8%), in 6 (13%) and in 11 (33%), respectively. There was no difference regarding the presence of neoplasm in the proximal colon between these groups. The rate of advanced proximal neoplasm was found to be significantly higher in the group with large polyps in the rectosigmoid area than in the groups with small and diminutive polyps (p<0.05). In 104 patients (57%) with polyp(s) in rectum and sigmoid colon, no associated polyp or cancer was encountered in the proximal colon. CONCLUSION: Colonoscopy is indicated when adenomatous polyp, regardless of size, is found on rectosigmoidoscopy performed because of symptoms.     

Predictive value of diminutive colonic adenoma trial: the PREDICT trial.

BACKGROUND & AIMS: Diminutive adenomas (1-9 mm in diameter) are frequently found during colon cancer screening with flexible sigmoidoscopy (FS). This trial assessed the predictive value of these diminutive adenomas for advanced adenomas in the proximal colon. METHODS: In a multicenter, prospective cohort trial, we matched 200 patients with normal FS and 200 patients with diminutive adenomas on FS for age and gender. All patients underwent colonoscopy. The presence of advanced adenomas (adenoma >or= 10 mm in diameter, villous adenoma, adenoma with high grade dysplasia, and colon cancer) and adenomas (any size) was recorded. Before colonoscopy, patients completed questionnaires about risk factors for adenomas. RESULTS: The prevalence of advanced adenomas in the proximal colon was similar in patients with diminutive adenomas and patients with normal FS (6% vs. 5.5%, respectively) (relative risk, 1.1; 95% confidence interval [CI], 0.5-2.6). Diminutive adenomas on FS did not accurately predict advanced adenomas in the proximal colon: sensitivity, 52% (95% CI, 32%-72%); specificity, 50% (95% CI, 49%-51%); positive predictive value, 6% (95% CI, 4%-8%); and negative predictive value, 95% (95% CI, 92%-97%). Male gender (odds ratio, 1.63; 95% CI, 1.01-2.61) was associated with an increased risk of proximal colon adenomas. CONCLUSIONS: Diminutive adenomas on sigmoidoscopy may not accurately predict advanced adenomas in the proximal colon.     

The risk of advanced neoplasia after polypectomy of one to two non-advanced adenomas less than 5 mm in size vs. normal colonoscopy

BackgroundCurrent guidelines are inconsistent regarding the follow-up of patients with 1–2 diminutive (1–5 mm) non-advanced adenomas (DNAAs).AimsTo evaluate the risk of metachronous advanced neoplasia (AN), defined as cancer or advanced adenoma (AA), among patients with either normal colonoscopy or 1–2 DNAAs.MethodsA retrospective cohort study. Cohort I included 2,347 subjects with normal colonoscopy and 483 subjects with polypectomy of 1–2 DNAAs followed by colonoscopy. Cohort II included 11,881 subjects with normal colonoscopy and 1,342 subjects with 1–2 DNAAs followed through the cancer registry.ResultsIn cohort I, the rate of AN, cancer and AA among the polypectomy group vs. normal colonoscopy was 5.0% vs. 2.5%, Hazard Ratio (HR) 2.96 (95%CI [Confidence Interval]1.86–4.78) for AN; 0.6% vs. 0.3%, HR 3.32 (95%CI 0.85–13) for cancer; 4.3% vs. 2.2% HR 2.91 (95%CI 1.75–4.86) for AA. In cohort II, cancer occurred in 0.4% of the polypectomy group and 0.2% of the normal colonoscopy group, HR 2.27 (95% CI 0.56–9.19).ConclusionCompared to subjects with normal colonoscopy, subjects with polypectomy of 1–2 DNAAs, are at increased risk for AA when followed by colonoscopy, while the risk for cancer is non-significantly increased. Our findings suggest that patients with 1–2 DNNAs should be followed more tightly than patients with normal colonoscopy.     

Risk related surveillance following colorectal polypectomy

BACKGROUND: Patients who have had a colorectal adenoma are likely to develop a metachronous adenoma and therefore need to be kept under surveillance. It is essential to avoid unnecessary examinations by tailoring the frequency of follow up examinations to individual risk. METHODS: A total of 3134 patients undergoing endoscopic removal of colorectal adenomas were prospectively recorded on the Erlangen Registry of Colorectal Polyps between 1978 and 1996. A multivariate analysis of 1159 patients on long term follow up was performed to identify risk factors determining surveillance intervals for patients with metachronous adenomas of advanced pathology-that is, adenomas >10 mm or with high grade dysplasia or invasive carcinoma. RESULTS: Univariate analysis revealed that sex, parental history of colorectal carcinoma, and characteristics of the initial findings-that is, size, multiplicity, and amount of villous structure-were significant predictors of metachronous adenomas of advanced pathology. On the basis of multivariate analysis, two risk groups were identified: (1) patients with no parental history of colorectal carcinoma with only small (< or = 10 mm) tubular adenomas at the initial clearing examination have a very low risk, and we estimated that 10% will develop advanced metachronous adenomas after 10 years; (2) the high risk group contained all other patients, 10% of whom will show metachronous adenomas of advanced pathology at follow up after only three years. CONCLUSIONS: The risk of developing metachronous adenomas with advanced pathology can be stratified for various patient and adenoma characteristics. Surveillance intervals can be scheduled for low risk (10 years) and high risk (three years) patients. Risk related follow up thus helps to avoid unnecessary examinations.     

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.     

Risk of metachronous neoplasia on surveillance colonoscopy among young and older patients after polypectomy

Background and aimsFew reports address the appropriate colonoscopy surveillance interval for individuals <50-years-old. We compared the risk of metachronous neoplasia among young (<50 years), adult (50–74 years) and older (≥75 y) age groups.MethodsThis was a single center retrospective cohort study. Eligible subjects underwent their first colonoscopy with polypectomy between 2005 and 2014 and had at least one surveillance colonoscopy 3–5 years later. Patients (N = 495) were stratified at baseline into low-risk adenoma (LRA) and advanced adenoma groups. Study outcomes were overall and high-risk neoplasia at surveillance colonoscopy.ResultsIn the baseline LRA-group (N = 201), the 5-year risk of metachronous high-risk neoplasia was 12.5%, 15.2% and 22.5% (P = 0.426) in the young, adult and older age groups, respectively. In the baseline advanced adenoma group (N = 294), the 3-year risk of metachronous high-risk neoplasia was 13.3%, 14.8% and 25.3% (P = 0.041), respectively. In multivariate analysis, the only risk factor for metachronous high-risk neoplasia was older age (OR 1.876, CI 1.087–3.238; P = 0.024).ConclusionsConsidering the comparable risk of metachronous high-risk neoplasia in young and adult patients, surveillance recommendations after polypectomy should not differ. Since this risk is higher among older people, more frequent surveillance schedule can be considered for this age group but should be individualized.     

Current standards and new developments of colorectal polyp management and resection techniques

Introduction: Colonoscopy and endoscopic removal of precancerous polyps play an important role in colorectal cancer (CRC) prevention. Improved endoscopes and quality standards have led to an increasing polyp and adenoma detection rate. Optimal polyp resection techniques and management strategies are key for an effective colonoscopy practice.

Areas covered: Strategies for how to improve diminutive polyp (polyps up to 5 mm in size) management are discussed because of their high prevalence. Systematic removal of diminutive polyps leads to increasing costs of colonoscopy practice, while the effect on colorectal cancer prevention might be negligible. Furthermore, polypectomy recommendations for mid-size and large polyps are provided. For all larger polyps larger, complete and safe resection is mandatory to avoid post colonoscopy cancers. The focus for managing such larger polyps is to use new techniques (i.e. cold snares) and to attempt complete removal and to reduce post-polypectomy complications.

Expert commentary: The resect-and-discard strategy is a promising management strategy for diminutive polyps. However, modification of this approach might be required in order to make widespread adoption feasible. Cold snare polypectomy is a promising new approach for small polyp resection. For resection of large polyps adequate treatment recommendations with regard to endoscopic mucosal resection and complication prevention are provided.     

The association between location,age and advanced colorectal adenoma characteristics: a propensity-matched analysis

Purpose: Evidence supports an association between certain colorectal adenoma characteristics and predisposition to cancer. The association between anatomical location of colorectal adenoma, age and advanced adenomas needs attention. The objective of this study was to evaluate the possible association between occurrence of sporadic advanced adenomas with location and age.

Materials and methods: A cross-sectional study using baseline data from index colonoscopy from a randomized controlled trial evaluating chemopreventive treatment against recurrence of colorectal adenomas was performed. Inclusion criteria for patients were one adenoma of >1?cm in diameter or multiple adenomas of any size, or an adenoma of any size and familial disposition for colorectal cancer. Multivariate regression and propensity score-matched analyses were used to correlate location of adenomas and age with advanced adenoma features.

Results: In this study, 2149 adenomas were removed in 1215 patients. Advanced colorectal adenomas primarily occurred in the anal part of the colon. Older age was associated with more adenomas and more oral occurrence of adenomas, as well as a higher risk of advanced adenomas. Surprisingly, specifically for the oral adenomas the risk of advanced adenoma seems to be lower for older patients compared with younger.

Conclusions: This study presents new results with regard to association between age, location of adenomas and risk of advanced adenomas. The results indicate that sigmoidoscopy for screening purposes may be obsolete, and add to the existing literature on which future guidelines for screening may be based.     

Do patients with rectosigmoid adenomas 5 mm or less in diameter need total colonoscopy?

BACKGROUND: The need for colonoscopy in the care of patients with rectosigmoid adenoma 5 mm or less in diameter is still debatable. METHODS: We estimated the prevalence of proximal adenomas among 3052 consecutive subjects undergoing total colonoscopy. Rectosigmoid adenoma was classified as diminutive (5 mm), small (6 to 10 mm), or large (>/=11 mm). Advanced proximal adenoma was 10 mm in diameter or larger, or with a villous component, severe dysplasia, or infiltrating adenocarcinoma. RESULTS: Proximal adenoma was found in 212 of 2483 patients (8.5%, 95% CI [7.5, 9.7]) without distal neoplastic polyps, 49 of 214 (22.9%, 95% CI [17.6, 29.2]) with diminutive, 44 of 174 (25.3%, 95% CI [19.1, 32.5] with small, and 70 of 181 (38.7%, 95% CI [31.6, 46.2]) with large distal adenoma. Advanced proximal adenoma was found in 49 (2.0%, 95% CI [1.5, 2.6]), 8 (3.7%, 95% CI [1.7, 7.5]), 17 (9.8%, 95% CI [6.0, 15.4]), and 29 patients (16.0%, 95% [11.2, 22.4]), respectively. In patients with distal adenoma risk for proximal lesions increased with increasing age, size, and number of distal adenomas (p = 0.01). Size of distal adenoma was the strongest predictor of the presence of proximal advanced adenoma (multivariate analyses). CONCLUSIONS: In a clinical setting, the decision to perform colonoscopy should take into account proximal lesions of clinical interest, life expectancy, costs, and risks associated with the procedure. When detection of advanced proximal adenoma is the goal, presence of distal diminutive adenoma alone might not be an indication for total colonoscopy.     

Risk of Advanced Proximal Adenoma and Cancer According to Rectosigmoid Findings in the Korean Population

Colorectal cancer is one of the leading causes of cancer death in the United States and Europe. Recently, the incidence of colorectal cancer has been increasing remarkably in Korea. To reduce the high incidence, screening of colorectal cancer in asymptomatic individuals has been advocated. Sigmoidoscopy is simpler, faster, and better tolerable than total colonoscopy, but the scope cannot reach the proximal colon segment and, therefore, may miss proximal colon cancer. In the present study, we intended to investigate the prevalence of proximal adenoma and cancer according to the findings in rectosigmoid colon and to find their risk factors. Data were collected retrospectively from 1541 consecutive patients who underwent total colonoscopy at the Department of Gastroenterology, Hanyang University, between October 2003 and December 2004. Neoplasms were classified as diminutive adenoma (≤5 mm), small adenoma (6–9 mm), advanced adenoma (≥10 mm, with villous component or high-grade dysplasia), and cancer. The sites of neoplasms were defined as rectosigmoid (rectum and sigmoid colon) and proximal (from cecum to descending colon) colon. The prevalence of advanced proximal adenoma was associated with severe rectosigmoid findings. On the other hand, the prevalence of proximal colon cancer did not show such a tendency. Among the 131 patients with proximal advanced adenoma, 66% had no neoplasm in the rectosigmoid colon. Moreover, among the 27 patients with proximal cancer, 52% had no neoplasm in the rectosigmoid colon. Multivariate logistic regression analysis revealed that age, gender, and advanced rectosigmoid adenoma were the risk factors of advanced proximal adenoma, but nothing was associated with the risk for proximal colon cancer. Advanced rectosigmoid adenoma may be the predictor of advanced proximal adenoma, especially in old males. However, nothing is related to the risk for proximal colon cancer. Therefore, colonoscopy may be more adequate for colorectal cancer screening than sigmoidoscopy in the Korean population.     

Natural history and long-term outcome of patients treated for early stage colorectal cancer

BACKGROUND:

The long-term natural history of early stage colon cancer and the outcome of long-term colonoscopic surveillance in routine specialist clinical practice after removal of the incident cancers have not been fully defined. In the present long-term evaluation up to 25 years, metachronous neoplasia, including both advanced adenomas and carcinomas, was defined.

METHODS:

All early stage colorectal cancer patients evaluated consecutively from a single clinical practice underwent follow-up colonoscopic evaluations after removal of the incident cancer and clearing of neoplastic disease. Colonoscopic surveillance was planned for two phases – initially on an annual basis for five years, followed by continued surveillance every three years up to 25 years with removal of any metachronous neoplastic lesion.

RESULTS:

A total of 128 patients (66 men and 62 women) with 129 incident early stage colorectal cancers were evaluated. Virtually all patients were symptomatic, usually with clinical evidence of blood loss. Incident early cancers were located throughout the colon, especially in the rectosigmoid, and showed no pathological evidence of nodal or other metastases. All patients evaluated during the first five years did not experience recurrent disease or have metachronous cancer detected. After five years, a total of 94 patients were evaluated up to 25 years; six of these patients were found to have seven metachronous colon cancers. All developed cancer more than seven years after removal of the incident colorectal cancer, including six asymptomatic adenocarcinomas, of which only one had evidence of single node involvement. Another patient in this cohort developed a poorly differentiated neuroendocrine carcinoma of the colon. In addition, 45% of patients had a total of 217 adenomas removed, including 11% of patients with 33 advanced adenomas. Among 14 patients with advanced adenomas, seven (50%) developed ≥1 late metachronous cancers.

CONCLUSIONS:

Following removal of an incident symptomatic early stage colorectal cancer, the risk of later metachronous neoplasia persists for an extended period more than five years after removal of the incident colorectal cancer. Moreover, risk for late metachronous cancer appears to be predicted by the presence of multiple adenomas or advanced adenomas; most metachronous cancers in this cohort were detected using colonoscopy before onset of symptoms and at an early stage.     

Osteoporosis Is Associated with an Increased Risk of Colorectal Adenoma and High-Risk Adenoma: A Retrospective,Multicenter, Cross-Sectional,Case-Control Study

Background/AimsThe protective effects of vitamin D and calcium on colorectal neoplasms are known. Bone mineral density (BMD) may be a reliable biomarker that reflects the long-term anticancer effect of vitamin D and calcium. This study aimed to evaluate the association between BMD and colorectal adenomas including high-risk adenoma.MethodsA multicenter, cross-sectional, case-control study was conducted among participants with average risk of colorectal cancer who underwent BMD and screening colonoscopy between 2015 and 2019. The main outcome was the detection of colorectal neoplasms. The variable under consideration was low BMD (osteopenia/osteoporosis). The logistic regression model included baseline demographics, components of metabolic syndrome, fatty liver disease status, and aspirin and multivitamin use.ResultsA total of 2,109 subjects were enrolled. The mean age was 52.1±10.8 years and 42.6% were male. The adenoma detection rate was 43%. Colorectal adenoma and high-risk adenoma were both more prevalent in subjects with low BMD than those with normal BMD (48.2% vs 38.8% and 12.1% vs 9.1%). In the univariate analysis, old age, male sex, smoking, metabolic components, fatty liver, and osteoporosis were significantly associated with the risk of adenoma and high-risk adenoma. In the multivariate analysis, osteoporosis was independently associated with risk of colorectal adenoma (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.11 to 2.46; p=0.014) and high-risk adenoma (OR, 1.94; 95% CI, 1.14 to 3.29; p=0.014).ConclusionsOsteoporosis is an independent risk factor of colorectal adenoma and high-risk adenoma.     

Association of Adenoma Detection Rate and Adenoma Characteristics With Colorectal Cancer Mortality After Screening Colonoscopy

Background & AimsThe adenoma detection rate (ADR) and characteristics of previously resected adenomas are associated with colorectal cancer (CRC) incidence and mortality. However, the combined effect of both factors on CRC mortality is unknown.Patients and methodsUsing data of the Austrian quality assurance program for screening colonoscopy, we evaluated the combined effect of ADR and lesion characteristics on subsequent risk for CRC mortality. We analyzed mortality rates for individuals with low-risk adenomas (1–2 adenomas <10 mm), individuals with high-risk adenomas (advanced adenomas or ≥3 adenomas), and after negative colonoscopy (negative colonoscopy or small hyperplastic polyps) performed by endoscopists with an ADR <25% compared with ≥25%. Cox regression was used to determine the association of combined risk groups with CRC mortality, adjusted for age and sex.ResultsWe evaluated 259,885 colonoscopies performed by 361 endoscopists. A total of 165 CRC-related deaths occurred during the follow-up period, up to 12.2 years. In all risk groups, CRC mortality was higher when colonoscopy was performed by an endoscopist with an ADR <25%. Compared with negative colonoscopy with an ADR ≥25%, CRC mortality was similar for individuals with low-risk adenomas irrespective of ADR (for ADR ≥25%: adjusted hazard ratio [HR], 1.22; 95% confidence interval [CI], 0.59–2.49; for ADR <25%: adjusted HR, 1.25; 95% CI, 0.64–2.43) and after negative colonoscopy with ADR <25% (adjusted HR, 1.27; 95% CI, 0.81–2.00). Individuals with high-risk adenomas were at significantly higher risk for CRC death if colonoscopy was performed by an endoscopist with an ADR <25% (adjusted HR, 2.25; 95% CI, 1.18–4.31) but not if performed by an endoscopist with an ADR ≥25% (adjusted HR, 1.35; 95% CI, 0.61–3.02).ConclusionsOur study adds important evidence for mandatory assessment and monitoring of performance quality in screening colonoscopy. High-quality colonoscopy was associated with a lower risk for CRC death, and the impact of ADR was strongest for individuals with high-risk adenomas.