The prevalence rate and anatomic location of colorectal adenoma and cancer detected by colonoscopy in average-risk individuals aged 40-80 years

BACKGROUND: The role of screening colonoscopy for colorectal (CR) neoplasia in average-risk population, remains to be determined. OBJECTIVES: To evaluate the prevalence and anatomic location of CR adenoma and carcinoma and the morbidity of colonoscopy in individuals at average risk for CR cancer (CRC). METHODS: A retrospective prevalence study of subjects aged 40-80 yr, with no cancer-related symptoms, personal or family history of CR neoplasia, who underwent a colonoscopy. RESULTS: Enrolled were 1,177 persons; 183 aged 40-49 yr (young), 917 aged 50-75 yr, and 77 aged 76-80 yr (elderly). The prevalence of overall CR neoplasia, advanced neoplasia, and cancer was 20.9%, 6.3%, and 1.1%, respectively. In the 50-75 age group, the prevalence of overall adenoma, advanced neoplasia, and cancer was 21.3%, 6.7%, and 1.2%, respectively. Of the 206 neoplasia cases, 21-43% harbored proximal neoplasia beyond the reach of sigmoidoscopy, without distal lesions. Among the elderly, the prevalence of overall adenoma, advanced neoplasia, and cancer reached 26.0%, 14.3%, and 2.6%, respectively. In the young group, 9.8% had overall neoplasia, 1.1% had advanced adenoma, and none had CRC. Procedure-related morbidity rate was 0.1%, with no perforations, bleedings, or mortality. CONCLUSIONS: Screening colonoscopy in average-risk subjects demonstrated a considerable prevalence of CR neoplasia and proximal lesions beyond the reach of sigmoidoscopy. The morbidity rate was negligible. Primary screening colonoscopy should be considered in health programs for the average-risk population, beginning at the age of 50 yr. The significantly high rate of advanced and proximal neoplasia in the elderly, encourages the inclusion of healthy subjects aged 76-80 yr in future prospective studies.     

Prevalence of Colorectal Neoplasia Among Young African Americans and Hispanic Americans

Background

The disproportionately higher incidence of and mortality from colorectal cancer (CRC) among African Americans (AA) led the American College of Gastroenterology to recommend screening starting at age 45 in 2005.

Aim

The purpose of this study was to determine the prevalence of colorectal neoplasia among 40–49-year-old inner city AA and Hispanic Americans (HA).

Methods

We reviewed the medical records of 2,435 inner city AA and HA who underwent colonoscopy regardless of indication and compared the prevalence of colorectal neoplasia between AA and HA patients. We used logistic regression models to calculate odds ratios (OR) and 95 % confidence intervals (CI).

Results

There were 2,163 AAs and 272 HA. There were 57 % women in both groups. A total of 158 (7 %) AA and 9 (3 %) HA (P = 0.014) underwent the procedures for CRC screening. When compared to HAs, AAs had higher prevalence of any polyp (35 vs. 18 %, OR = 2.53; 95 % CI 1.82–3.52). Overall, AA had higher prevalence of colorectal neoplasia (adenoma and cancer) when compared to HAs (16 vs. 10 %; OR = 1.68; 95 % CI 1.10–2.56).

Conclusion

We observed a higher frequency of colorectal neoplasia among 40–49-year-old AAs as compared to HAs suggesting an increased susceptibility to CRC risk in this population.     

Screening colonoscopy among persons 50 to 60 years of age with and without familial risk of colorectal cancer - a prospective multicenter trial

BACKGROUND: In Germany screening colonoscopy was introduced into the National program on colorectal cancer prevention in Oktober 2002. The prevalence of neoplasia in patients with and without familiar risk was determined together with patient satisfaction with screening colonoscopy. Methods: Asymptomatic subjects from 50 to 60 years underwent screening colonoscopy and were stratified in two groups with and without familiar risk (first-degree relatives with CRC) in a multicenter trial among German gastroenterologists. Advanced neoplasia was defined as an adenoma at least 1 cm in diameter, a villous adenoma, an adenoma with high-grade dysplasia, or invasive cancer. After recovery from sedation all subjects were asked if they would agree to a control colonoscopy and the pain score was recorded on a scale from 0 to 6. Results: A total of 557 subjects (322 at average risk and 235 with familiar risk) underwent screening colonoscopy. The prevalence of advanced neoplasia in subjects without/with familiar risk was not significantly different in persons from 50 to 54 years (9 vs. 15 %) in contrast to persons from 55 to 60 years (10 vs. 22 %, p = 0.004) where the relative risk was doubled. Compared to younger patients, the prevalence of all neoplasia (including small adenomas) was significantly different only for older patients with familiar risk (44 vs. 23 %, p < 0.0001). The mean value of the pain-score was 0.76 + 1.0. Subjects examined without medication had significantly higher pain scores than subjects under medication. Colonoscopy performed under disoprivan resulted in similar pain-scores compared to midazolam at dosages > 5 mg. All patients agreed to a control colonoscopy. CONCLUSION: Screening colonoscopy is an effective and well-accepted method. The high prevalence of advanced neoplasia even in persons from 50 to 54 years suggests that screening should start at the age of 50.     

Adenoma and advanced neoplasia detection rates increase from 45 years of age

BACKGROUND Colonoscopy is considered a valid primary screening tool for colorectal cancer(CRC). The decreasing risk of CRC observed in patients undergoing colonoscopy is correlated with the adenoma detection rate(ADR). Due to the fact that screening programs usually start from the age of 50, very few data are available on the risk of adenoma between 40 and 49 years. However, the incidence of CRC is increasing in young populations and it is not uncommon in routine practice to detect adenomas or even advanced neoplasia during colonoscopy in patients under 50 years.AIM To compare the ADR and advanced neoplasia detection rate(ANDR) according to age in a large series of patients during routine colonoscopy.METHODS All consecutive patients who were scheduled for colonoscopy were included.Exclusion criteria were as follows: patients scheduled for partial colonoscopy or interventional colonoscopy(for stent insertion or stenosis dilation).Colonoscopies were performed in our unit by a team of 30 gastroenterologists in2016. We determined the ADR and ANDR in each age group in the whole population and in the population with an average risk of CRC(excluding patients with personal or family history of advanced adenoma or cancer).RESULTS6027 colonoscopies were performed in patients with a median age of 57 years(range, 15-96). The ADR and ANDR were 28.6% and 9.7%, respectively, in the whole population. When comparing patients aged 40-44(n = 382) and 45-49 years (n = 515), a strong increase in all parameters from 45 years was observed, with the ADR rising from 9.7% in patients aged 40-44 to 21.2% between 45 and 49(P 0.001) and the ANDR increasing from 3.1% in patients aged 40-44 to 6.4% in those aged 45-49 years(P 0.03). With regard to patients aged 50-54(n = 849), a statistically significant increase in the ADR and ANDR was not observed between patients aged 45-49 and those aged 50-54 years. In the population with an average risk of CRC, the ADR and ANDR were still significantly higher in patients aged 45-49 compared with those aged 40-44 years.CONCLUSION This study shows a significant two-fold increase in the ADR and ANDR in patients aged 45 years and over.     

Prevalence and risk of colorectal adenoma in asymptomatic Koreans aged 40–49 years undergoing screening colonoscopy

Background and Aim: Colorectal cancer screening is recommended for average‐risk persons beginning at age 50. However, information about the incidence and risk factors of precursor adenoma in preceding decades is limited. The aim of this study was to determine the prevalence and risk factors of colorectal adenoma in persons aged 40–49 years and to compare the data with those aged 30–39 years and 50–59 years. Methods: A cross‐sectional study of 5254 asymptomatic subjects who underwent screening colonoscopy was conducted. Data were stratified by age into three groups: 608 aged 30–39 years, 1930 aged 40–49 years, and 2716 aged 50–59 years. Results: Prevalence of overall adenomas was 10.4% in the 30–39 years age group, 22.2% in the 40–49 years age group, and 32.8% in the 50–59 years age group. Advanced adenoma was found in 0.7% of the 30–39 years age group, 2.7% of the 40–49 years age group, and 4.1% of the 50–59 years age group. In the 40–49 years age group, male sex and current smoking habits showed associations with low‐risk adenoma after multiple adjustments. Moreover, male sex (odds ratio [OR] = 1.55, 95% confidence interval [CI]: 1.02–3.23), current smoking (OR = 1.58, 95%CI: 1.06–3.50), and family history of colorectal cancer (OR = 2.54, 95%CI: 1.16–5.56) were independent predictors of advanced adenoma in this age group. Conclusions: Prevalence of adenoma in subjects aged 40–49 years was higher than in previous studies. Male sex and current smoking habits along with a family history of colorectal cancer were associated with advanced adenoma in this age group.     

Prevalence and risk of colorectal polyps among the Korean population under 50 years

Colorectal cancer is a common cancer; generally, adults aged ≥ 50 years are screened using stool occult blood tests and colonoscopy. However, colorectal adenoma and cancer have been found in patients under the aged of 50, and studies on characteristics and risk factors in young patients are lacking. We evaluated the prevalence and risk factors of colorectal adenoma and cancer in young adults aged under 50 years.We retrospectively analyzed 570 individuals aged under 50 years who underwent colonoscopy at the Haeundae Paik Hospital, Korea, from January to June 2018. Logistic regression model was used to identify the risk factors for colorectal adenoma and colorectal cancer.The prevalence of colorectal adenoma in group of 19–29 years was 3.2% (1 of 31), 30–39 years was 13.8% (30 of 217) and in the group of 40–49 years was 21.1% (68 of 322) (P = .009). In multivariable analysis, age over 45 years (adjusted odds ratio [OR], 1.941; 95% confidence interval [CI], 1.187–3.172; P = .008) and male sex (adjusted OR, 1.711; 95% CI, 1.044–2.806; P = .033) were independent risk factors for colorectal neoplasia including cancer.The prevalence of colorectal adenoma increases as the age increased in young adults under 50 years of age, especially after the age of 45 years, the risk of colorectal neoplasia increases; hence, early screening should be considered before the age of 50 years.     

Screening colonoscopy in 40- to 50-year-old first-degree relatives of patients with colorectal cancer is efficient: a controlled multicentre study

Background and aims Persons with a familial risk of colorectal cancer (CRC) account for about 25% of all CRC cases. The adenoma prevalence in relatives of CRC patients 50–60 years of age is 17–34%; data on younger individuals are scarce. Our aim was to prospectively define the adenoma prevalence in 40- to 50-year-old first-degree relatives of CRC patients compared to controls.Patients and methods CRC patients were identified via the regional cancer registry, and their 40- to 50-year-old first-degree relatives (risk group) were invited for screening colonoscopy. Additional probands and controls of the same age were recruited by newspaper articles and radio or television broadcastings. Using high-resolution video colonoscopy, each detected polyp was removed and histopathologically assessed. Each participant completed demographic and epidemiological questionnaires. Results Of 228 subjects in the risk group 36.4% had polypoid lesions compared to 20.9% of 220 controls (p<0.001). Forty-three (18.9%) subjects in the risk group had adenomas compared to 18 (8.2%) in the control group (p=0.001). High-risk adenomas (>10 mm and/or of villous type) were found in 12 persons in the risk group compared to 5 controls (not significant). In the risk group most lesions (52%) were located proximal to the sigmoid colon compared to 29% in controls.Conclusions Subjects between 40–50 years with first-degree relatives with CRC demonstrate a significantly higher prevalence of adenomas than controls, with a tendency towards a more proximal location. These data support a screening colonoscopy in persons with familial risk already between 40 and 50 years.     

The prevalence and characteristics of colorectal neoplasia in acromegaly

An increased prevalence of colorectal neoplasia has been reported in acromegalic patients, and recommendations have been made for early colonoscopic screening and regular surveillance. This assumption, however, is frequently drawn from studies using selected control populations. To clarify colonoscopic management in these patients, we undertook a 2-center prospective screening colonoscopy study in 122 acromegalics (age range, 25-82 yr). In the absence of ideal age-matched controls, we calculated prevalence rates of occult adenocarcinomas and adenomas in the general population using cumulative data in the published literature from 8 autopsy studies (model 1, n = 3,559) and 4 screening colonoscopy studies (model 2, n= 810), applying linear regression models. Of the 115 patients with complete examinations, adenocarcinomas were discovered in 3 (2.6%), and at least 1 adenoma was found in 11, giving an overall prevalence of neoplasia of 12% (14 of 115). Prevalence rates for age bands 30-40, 40-49, 50-59, 60-69, and 70+ yr were 0%, 8%, 12%, 20%, and 21%, respectively. Compared with the 2 control models, the prevalence of occult colorectal cancer was not significantly increased (acromegalics vs. models 1 and 2, 2.6% vs. 2.3% and 0.9%), nor was there an increase in the prevalence of adenomas in any age band. Pathological characteristics showed some differences, in that adenomas in acromegalics tended to be right sided (68% vs. 57% and 56%), larger (for > or =10 mm, 27% vs. 13% and 9%), and of advanced histology (for tubulovillous, 27% vs. 4% and 22%). No associations were found between the presence of colonic neoplasia and the duration of disease, total GH exposure, cure status, and serum insulin-like growth factor I. This study has failed to demonstrate an increased prevalence of neoplasia in acromegalic patients compared with the expected prevalence in the general population and questions the need for an aggressive colonoscopic screening policy.     

Colonoscopy screening in the elderly: when to stop?

OBJECTIVES: The age to begin colorectal cancer (CRC) screening is based on the risk of neoplasia and is published in screening guidelines. The age to stop screening is unknown but should be based, in part, on the same principle. The purpose of this study was to establish whether the prevalence of neoplasia detected by colonoscopy diminished with advancing age, to warrant ceasing colonoscopic screening. METHODS: The endoscopic and pathology reports of all asymptomatic subjects undergoing colonoscopy for the purpose of CRC screening or an evaluation of abdominal pain or change in bowel habits between 1997 and 2000 were reviewed. A multivariate logistic regression analysis was used to assess the effect of age, gender, and indication for examination on the prevalence of neoplasia, as well as on having more than two adenomas, advanced adenomas (tubulovillous, villous, severe dysplasia, or size > or = 1 cm), and invasive cancers. RESULTS: A total of 915 patients were included. Of these, 50% were male, with a mean age of 65 yr (range 50-100). Neoplasia peaked in the seventh decade, with a fall thereafter (p = 0.009). Numerous adenomas, advanced adenomas, and invasive cancers increased with age. The yield for overall neoplasia, advanced adenomas, and more than two adenomas was higher in the screening group than in the symptomatic group. More invasive cancers were found in the symptomatic group compared with the asymptomatic group, but this did not achieve statistical significance (4 vs 1, p = 0.44). CONCLUSIONS: The prevalence of advanced neoplasia continues to increase with age. Subjects undergoing colonoscopy for screening had a greater risk for neoplasia than did subjects with symptoms. There is no decline in yield of advanced neoplasia to justify stopping screening colonoscopy in the elderly.     

Colonoscopy surveillance of individuals at risk of familial colorectal cancer

BACKGROUND: Individuals with first degree relatives affected with colorectal cancer (CRC) at a young age, or more than one relative affected but who do not fulfil the Amsterdam criteria for a diagnosis of hereditary non-polyposis colon cancer (HNPCC), are believed to be at an increased risk of CRC. However, there is a paucity of prospective data on the potential benefit of colonoscopic surveillance in such groups categorised by empiric family history criteria. We report a prospective study of 448 individuals seeking counselling about their perceived family history of CRC. PATIENTS AND METHODS: Following pedigree tracing, verification, and risk assignment by genetic counsellors, colonoscopy was undertaken for those at a moderate or high risk (HNPCC). Those classified as low risk were reassured and discharged without surveillance. Here we report our findings at the prevalence screen in the 176 patients of the 448 assessed who underwent colonoscopy. RESULTS: Fifty three individuals had a family history that met Amsterdam criteria (median age 43 years) and 123 individuals were classed as moderate risk (median age 43 years). No cancers were detected at colonoscopy in any group. Four individuals (8% (95% confidence limits (CL) 0.4-15%)) in the high risk group had an adenoma detected at a median age of 46 years and all four were less than 50 years of age. Five (4% (95% CL 0.6- 8%)) of the moderate risk individuals had an adenoma at a median age of 54 years, two of whom were less than 50 years of age. CONCLUSIONS: These findings indicate that the prevalence of significant neoplasia in groups defined by family history is low, particularly in younger age groups. These prospective data call into question the value of colonoscopy before the age of 50 years in moderate risk individuals.     

Asia Pacific consensus recommendations for colorectal cancer screening

Colorectal cancer (CRC) is rapidly increasing in Asia, but screening guidelines are lacking. Through reviewing the literature and regional data, and using the modified Delphi process, the Asia Pacific Working Group on Colorectal Cancer and international experts launch consensus recommendations aiming to improve the awareness of healthcare providers of the changing epidemiology and screening tests available. The incidence, anatomical distribution and mortality of CRC among Asian populations are not different compared with Western countries. There is a trend of proximal migration of colonic polyps. Flat or depressed lesions are not uncommon. Screening for CRC should be started at the age of 50 years. Male gender, smoking, obesity and family history are risk factors for colorectal neoplasia. Faecal occult blood test (FOBT, guaiac-based and immunochemical tests), flexible sigmoidoscopy and colonoscopy are recommended for CRC screening. Double-contrast barium enema and CT colonography are not preferred. In resource-limited countries, FOBT is the first choice for CRC screening. Polyps 5-9 mm in diameter should be removed endoscopically and, following a negative colonoscopy, a repeat examination should be performed in 10 years. Screening for CRC should be a national health priority in most Asian countries. Studies on barriers to CRC screening, education for the public and engagement of primary care physicians should be undertaken. There is no consensus on whether nurses should be trained to perform endoscopic procedures for screening of colorectal neoplasia.     

Screening colonoscopy in asymptomatic average-risk African Americans

BACKGROUND: Recent data indicate that colorectal cancer incidence and mortality in white Americans have been declining since 1985 at a rate of 2% to 3% per year. In African Americans, however, mortality from colorectal cancer appears to be increasing. We sought to evaluate the prevalence of colonic neoplasia in asymptomatic African Americans. METHODS: We performed a cross-sectional colonoscopy screening study to determine the prevalence of colonic neoplasia in asymptomatic African Americans older than 50 years of age. RESULTS: One hundred sixty-six subjects were evaluated for the study of whom 121 (69 women) were deemed to be asymptomatic average-risk persons and completed colonoscopy. Forty-two individuals (35%) had a total of 72 adenomas (67 tubular and 5 tubulovillous); 47 (65.3%) of these were proximal to the splenic flexure. Three subjects had an adenoma 1 cm or greater in diameter and none had severe dysplasia. CONCLUSIONS: The overall prevalence of adenomas in asymptomatic average-risk African Americans was comparable to that of previously described populations. The predominance of right-sided adenomas in this study confirms previous findings and is an area requiring further study. Until this issue is resolved, we suggest the use of colonoscopy rather than sigmoidoscopy for screening for colorectal neoplasia in asymptomatic, average-risk African Americans.     

Cost-utility of one-time colonoscopic screening for colorectal cancer at various ages

OBJECTIVE: One-time colonoscopy has been recommended as a possible colorectal cancer (CRC) screening strategy. Because the incidence of colorectal neoplasia increases with age, the effectiveness and cost of this strategy depend on the age at which screening occurs. The purpose of this study was to investigate the age-dependent cost-utility of one-time colonoscopic screening. METHODS: We constructed a computer simulation model of the natural history of colorectal neoplasia. This model was used to compare the cost-utility of no screening and age-based strategies employing one-time colonoscopic screening (age ranges evaluated: 45-49, 50-54, 55-59, and 60-64 yr). RESULTS: We determined that one-time colonoscopic screening in men age <60 yr and in women age <65 yr dominates never screening and screening at older ages. For both sexes, one-time colonoscopic screening between 50 and 54 yr of age is associated with a marginal cost-utility of less than $10,000 per additional quality-adjusted life-year compared to screening between 55 and 60 yr of age. One-time colonoscopic screening between 45 and 49 yr of age is either dominated (women) or associated with a marginal cost-utility of $69,000/per quality-adjusted life-year (men) compared to screening between 50 and 54 yr of age. The marginal cost-utility of one-time colonoscopic screening is relatively insensitive to plausible changes in the cost of colonoscopy, the cost of CRC treatment, the sensitivity of colonoscopy for colorectal neoplasia, the utility values representing the morbidity associated with the CRC-related health states, and the discount rate. CONCLUSIONS: One-time colonoscopic screening between 50 and 54 yr of age is cost-effective compared to no screening and screening at older ages in both men and women. Screening in men between 45 and 49 yr of age may be cost-effective compared to screening between 50 and 54 yr of age depending on societal willingness to pay.     

Distribution trends of colorectal adenoma and cancer: a colonoscopy database analysis of 11,025 Chinese patients

Background and Aim: A left‐to‐right shift of colorectal cancer (CRC) has been reported in Western studies. However, few Asian studies have investigated the anatomic distribution of colorectal adenoma and CRC. We aimed to describe the time trends in the distribution of colorectal adenoma and CRC in a Chinese population. Methods: A colonoscopy database was reviewed, and all consecutive patients with lower gastrointestinal symptoms who underwent colonoscopy from 1998 to 2009 were identified. Data, including patients' sex, age, symptoms, and the number and anatomic locations of colorectal adenoma and CRC, were documented. Results: A total of 11 025 patients were included in the final analysis; 1012 and 363 patients were diagnosed with colorectal adenoma and CRC, respectively. Overall, there were more distal than proximal adenomas (54.4% vs 37.9%), and the proportion of proximal adenomas remained stable from 1998–2006 to 2007–2009 (38.2% vs 37.6%). Similarly, there were more distal than proximal CRC (56.5% vs 42.4%), and the proportion of proximal CRC declined from 45.8% in 1998–2006 to 38.4% in 2007–2009. Colorectal adenoma and CRC were equally distributed among both sexes. For elderly patients (> 50 years), there was a non‐significant trend towards more proximal adenoma and CRC. Conclusions: The present study suggests no distal‐to‐proximal shift of colorectal adenoma and CRC among the Chinese population in Shanghai over the past 12 years. The distribution pattern of colorectal adenoma and CRC of Chinese patients is different from that of Western patients, who had more colorectal lesions located in the distal part.     

Colonoscopic screening examination of relatives of patients with colorectal cancer. I. A comparison with an endoscopically screened normal population.

First-degree relatives (n = 206) of patients operated on for colorectal cancer (CRC) (n = 181) were offered a colonoscopic screening examination; 169 relatives (82%) attended. The findings were compared with those in a normal population sample with no CRC in first-degree relatives (n = 308), aged 50-59 years, who had been screened by means of flexible sigmoidoscopy. Three carcinomas and 176 polyps were found in 56 of 95 male relatives (57%) and 34 of 74 female relatives (46%). The adenoma prevalence rate was 37 (39%) and 26 (35%) for male and female relatives, respectively. In the 50- to 59-year age group, the adenoma prevalence rates for both sexes collectively and for women separately were significantly higher among relatives than among the population without CRC relatives. Hyperplastic polyps were larger, whereas adenomas were similar in size among relatives compared with the normal population. Colonoscopy may be a suitable method of choice for screening first-degree relatives of patients with CRC.     

Risk of colorectal adenoma in liver transplant recipients compared to immunocompetent control population undergoing routine screening colonoscopy

BACKGROUND: Immunosuppression following solid organ transplantation has been associated with a higher prevalence of cancers including colon cancer. However, the risk of colorectal adenoma following liver transplantation is unknown. The objective of this pilot study is to determine whether the prevalence of colorectal adenoma is increased in liver transplant recipients. METHODS: In this retrospective study, 25 patients who had liver transplantation at our institution between 1994 to 1997 and who underwent routine posttransplantation colonoscopy were compared with 50 controls who were undergoing routine screening colonoscopy. Transplant recipients who were younger than 45 years, survived less than 3 years following liver transplant, with history of inflammatory bowel disease, or prior history of colonic adenoma or cancer were excluded from the study. In both groups, colonoscopic diagnosis of polyp was confirmed by pathologic diagnosis of adenoma on biopsy. RESULTS: 25 (12M/13F, mean age 53 +/- 7 years) liver transplant recipients were compared with 50 controls (19M/31F, mean age of 59 +/- 7 years). In transplant recipients, colonoscopy was performed 41 +/- 19 months after liver transplantation. Seven (28%) liver transplant recipients (5M, 2F) and 4 (8%) controls (3F, 1M) were found to have adenomatous polyp (OR 4.5, 95% CI 1-21.2, P = 0.049). Malignant polyps were not detected in both groups. CONCLUSION: Liver transplant recipients appear to have an increased risk for developing colorectal adenoma. Early screening colonoscopy is warranted for this group of patients.     

Diagnostic yield of upper endoscopy in Asian patients presenting with dyspepsia

BACKGROUND: Colorectal cancer occurs more frequently in older people. Because the population of aged persons is increasing, a better understanding of the characteristics of colorectal cancer with respect to age would be useful. The purpose of this study was to determine whether there is any relationship between the site of colorectal adenoma and adenocarcinoma in the colon and age. METHODS: Colonoscopy was performed (September 1995 to December 1998) on 2942 consecutive patients (1907 men, 1035 women; mean age 61 years, range 11 to 95 years) with no history of colorectal adenoma, adenocarcinoma, or inflammatory bowel disease. The occurrence of colorectal neoplasia, histologically proven as adenoma or adenocarcinoma, was analyzed for a possible association between site in the colon and patient age. RESULTS: Adenocarcinoma was found in 191 patients (196 lesions). The proportion of patients with right-sided colonic adenocarcinoma increased with patient age: < 50 years, 15% (2/13); 50 to 59 years, 21% (8/39); 60 to 69 years, 32% (18/57); 70 to 79 years, 42% (25/49); > or =80 years, 57% (16/28). The proportion of patients with right-sided adenoma did not significantly differ among age groups: < 50 years, 40% (98/246); 50 to 59 years, 41% (280/678); 60 to 69 years, 46% (459/1001); 70 to 79 years, 53% (270/508); and > or =80 years, 57% (87/152). CONCLUSION: The frequency of right-sided colon cancer increases with patient age. Hence, colonoscopy may be indicated in the elderly for colorectal cancer screening. Over half of colon carcinomas may be missed if sigmoidoscopy alone is used for screening.     

Distribution of colon neoplasia in Chinese patients: implications for endoscopic screening strategies

OBJECTIVES: Our aim was to measure the prevalence and distribution of colonic neoplasia in Chinese adults, and to estimate the sensitivity of sigmoidoscopic screening strategies for detecting those with advanced neoplasia. METHODS: Asymptomatic, average-risk Chinese adults aged 50 years or older underwent screening colonoscopy. The prevalence and distribution of colonic neoplasia and advanced neoplasia (defined as an adenoma >or=10 mm or with villous, high-grade dysplastic, or malignant features) were reviewed retrospectively and the outcomes of various sigmoidoscopic screening strategies estimated. RESULTS: Of 1,382 individuals (833 men, 549 women; mean age 58.8 years) included, 243 (18%) had colorectal neoplasia and 72 (5.2%) had advanced neoplasia. Neoplasia prevalence was significantly higher in male and older patients. No significant differences were observed in neoplasia distribution between men and women. Overall, 24 patients had advanced neoplasia in the proximal colon, of whom four had synchronous distal neoplasia. The estimated sensitivity for detecting patients with advanced neoplasia was 72% if we assumed screening sigmoidoscopy was performed, with follow-up colonoscopy for those with distal neoplasia; 165 patients would need to undergo colonoscopy. If, instead, we assumed follow-up colonoscopy was done only for patients with distal advanced neoplasia, the estimated sensitivity would decrease slightly to 71%, but the number of colonoscopies would decrease substantially to 51. CONCLUSION: In average-risk Chinese adults, screening sigmoidoscopy is estimated to detect more than two-thirds of patients with advanced neoplasia. In Chinese societies with limited health-care resources, performing colonoscopy only on patients with distal advanced neoplasia is a screening approach that optimizes the return rate on colonoscopic capacity.     

Colonoscopy surveillance for high risk polyps does not always prevent colorectal cancer

AIM To determine the frequency and risk factors for colorectal cancer(CRC) development among individuals with resected advanced adenoma(AA)/traditional serrated adenoma(TSA)/advanced sessile serrated adenoma(ASSA). METHODS Data was collected from medical records of 14663 subjects found to have AA, TSA, or ASSA at screening or surveillance colonoscopy. Patients with inflammatory bowel disease or known genetic predisposition for CRC were excluded from the study. Factors associated with CRC developing after endoscopic management of high risk polyps were calculated in 4610 such patients who had at least one surveillance colonoscopy within 10 years following the original polypectomy of the incident advanced polyp. RESULTS84/4610(1.8%) patients developed CRC at the polypectomy site within a median of 4.2 years(mean 4.89 years), and 1.2%(54/4610) developed CRC in a region distinct from the AA/TSA/ASSA resection site within a median of 5.1 years(mean 6.67 years). Approximately, 30%(25/84) of patients who developed CRC at the AA/TSA/ASSA site and 27.8%(15/54) of patients who developed CRC at another site had colonoscopy at recommended surveillance intervals. Increasing age; polyp size; male sex; right-sided location; high degree of dysplasia; higher number of polyps resected; and piecemeal removal were associated with an increased risk for CRC developmentat the same site as the index polyp. Increasing age; right-sided location; higher number of polyps resected and sessile endoscopic appearance of the index AA/TSA/ASSA were significantly associated with an increased risk for CRC development at a different site. CONCLUSION Recognition that CRC may develop following AA/TSA/ASSA removal is one step toward improving our practice efficiency and preventing a portion of CRC related morbidity and mortality.     

Screening for colorectal lesions with high-resolution video colonoscopes in a German male average-risk population at 40 to 59 years of age

BACKGROUND: Prevalence data for colorectal neoplastic lesions obtained from screening colonoscopies have recently been reported for a U. S. American and a Polish average-risk population. However, prevalence data for a German average-risk population have not been published. METHODS: From 1998 until 2003 a screening colonoscopy was offered to all male participants of a health assessment program. In a total of 618 volunteers with an average risk for colorectal cancer, polypoid lesions were identified and removed using high-resolution video colonoscopes. The histological features of the lesions were categorised according to those of the most advanced one. An advanced lesion was defined as an adenoma of at least 1 cm in diameter, a polyp with villous histological features or high-grade intraepithelial neoplasms or a cancer. Data were analysed in two groups: age 40 - 49 years (group A) and age 50 - 59 years (group B). RESULTS: In group A (age 40 - 49 years, n = 285), 133 subjects (47 %) had polypoid lesions. Histological findings revealed that 57 subjects (20 %) had non-neoplastic and 76 subjects (27 %) had neoplastic lesions. In nine cases (3.2 %) polyps were classified as advanced lesions with a maximal diameter of 35 mm. In group B (age 50 - 59, n = 333), 183 subjects (55 %) had polypoid lesions. Histological findings revealed that 64 subjects (19 %) had non-neoplastic and 119 subjects (36 %) had neoplastic lesions. Among those, 34 (10.2 %) had advanced lesions with a maximal diameter of 55 mm. In neither group was an invasive cancer detected. The difference in the prevalence of neoplastic lesions between the two age groups was statistically significant (chi (2) = 5.85). An exceptionally high rate of 27 % neoplastic lesions was detected in subjects at 40 to 49 years of age. The rate of detected lesions in the group of older subjects was 36 %. CONCLUSION: By using high-resolution endoscopes we found an unexpectedly large number of neoplastic lesions in the colon even in a relatively young average-risk population. The question whether screening colonoscopy should therefore not only aim at detecting early colorectal cancer but also at identifying and removing precursor adenomas at younger ages clearly deserves further attention.