Relationship between age and site of colorectal cancer based on colonoscopy findings

Advanced age alone should not preclude surveillance colonoscopy in the octogenarian and older population

BACKGROUND

Although the risk of colorectal cancer increases with advancing age, there remains a lack of guidelines for surveillance colonoscopy in the octogenarian and older population. Our objective is to document the diagnostic yield of surveillance colonoscopies, and to analyze adenoma characteristics, complications, and short-term survival in asymptomatic octogenarian and older patients undergoing adenoma surveillance colonoscopy.

METHODS

Surveillance colonoscopies performed at a tertiary level hospital colorectal surgery department between January 2010 and September 2018 were queried from a prospectively maintained institutional colonoscopy database. Patients 80 years old or older undergoing routine surveillance colonoscopy after having had an adenoma or advanced adenoma diagnosed on a prior exam were included in the study.

RESULTS

604 patients were included in the study with a median age of 82 and 43% were female. Median follow-up was 52 months (range 2-110), with 511(85%) patients alive at their last available follow-up. Overall, 292 patients had at least one had adenomatous lesion and 105 (17.4%) patients had advanced adenomas. Increasing age was not associated with increased rate of sessile serrated lesions (p = 0.2) however, there was an association between increasing age and advanced adenoma rates (p = 0.01). Advanced adenomas were more commonly found to be right-sided (p = 0.02). Four asymptomatic patients were diagnosed with cancer at surveillance (0.6%).

CONCLUSIONS

Patients 80 years of age or older with a previous history of colorectal adenoma(s) may have a high risk of future advanced lesions and can be considered to undergo surveillance colonoscopy.

Colonoscopy Versus Fecal Immunochemical Test for Reducing Colorectal Cancer Risk: A Population-Based Case-Control Study

INTRODUCTION

Use of colonoscopy or the fecal immunochemical test (FIT) for colorectal cancer (CRC) prevention is supported by previous studies. However, there is little specific evidence regarding comparative effectiveness of colonoscopy or FIT for reducing CRC risk. In this study, we compared the association of CRC risk with colonoscopy and FIT using a nationwide database.

METHODS

This population-based case-control study used colonoscopy and FIT claims data from the Korean National Health Insurance System from 2002 to 2013. Data were analyzed from 61,221 patients with newly diagnosed CRC (case group) and 306,099 individuals without CRC (control group). Multivariable logistic regression models were used to evaluate the association between CRC and colonoscopy or FIT.

RESULTS

Colonoscopy was associated with a reduced subsequent CRC risk (adjusted odds ratio [OR] 0.29). Stronger associations were found between colonoscopy and distal CRC, compared with proximal CRC (0.24 vs 0.47). In an analysis stratified by sex, the association was weaker in female subjects compared with male subjects (0.33 vs 0.27). Any FIT exposure was associated with CRC risk with an OR of 0.74; this association was stronger for distal cancer. As the frequency of cumulative FIT assessments increased (from 1 to ≥5), the OR of FIT exposure for CRC gradually decreased from 0.81 to 0.45.

DISCUSSION

The association of colonoscopy or FIT with reduced CRC risk was stronger for distal CRC than for proximal CRC. FIT showed less CRC risk reduction than colonoscopy. However, as the frequency of cumulative FIT assessments increased, the association with CRC prevention became stronger.

The efficacy and safety of colonoscopy in nonagenarians: A multicenter study

INTRODUCTION

The number of colonoscopy (CS) for the elderly is increasing. There are only a few reports focusing on CS among the very elderly aged ≥ 90-y. We aimed to analyze the efficacy of CS and of colorectal cancer (CRC) for patients aged ≥ 90-y.

METHODS

We retrospectively analyzed consecutive patients aged ≥ 90-y receiving CS at eight institutions from October 2016 to September 2017. Bowel preparation, complications, and endoscopic diagnosis were analyzed. The non-elderly group aged between 50-y and 64-y and elderly group aged between 65-y and 79-y were compared to very-elderly group aged ≥ 90-y. Through propensity score matching of sex and CS indications (symptomatic or asymptomatic), the number of CRC and the treatment in each group were analyzed.

RESULTS

We analyzed 125 patients receiving 154 colonoscopies (0.9%) in the very-elderly group from among 16,968 cases. Among 92 cases who received bowel-cleansing solution, good preparations were achieved in 94.5%. The rate of CS-related complications was 1.3% (2/154). The rate of CRC in the very-elderly group was 27.2% (34/125), higher than the non-elderly group (7.2%, 9/125, p < 0.01) and elderly group (8.8%, 11/125, p < 0.01). Therapeutic interventions for CRC in the very-elderly group were performed in 73.5% (24/34) patients. The mean survival of 12 patients with CRC resection was 788 days.

CONCLUSIONS

CS could be performed safely for the very elderly aged ≥ 90-y with careful considerations. CRC was confirmed to be more frequent in this group with over 70% of patients receiving appropriate therapeutic intervention.

Polyp Detection Rate Correlates Strongly with Adenoma Detection Rate in Trainee Endoscopists

BACKGROUND

The adenoma detection rate (ADR) is a widely accepted quality benchmark for screening colonoscopy but can be burdensome to calculate. Previous studies have shown good correlation between polyp detection rate (PDR) and ADR, but this has not been validated in trainees. Additionally, the correlation between PDR and detection rates for sessile serrated polyps (SSPDR) and advanced neoplasia (ANDR) is not well studied.

AIMS

We investigated the relationship between PDR and ADR, SSPDR, and ANDR in trainees.

METHODS

We examined 1600 outpatient colonoscopies performed by 24 trainees at a VA hospital from 2014 to 2017. Variables collected included patient demographics, year of fellowship, colonoscopy indication, and endoscopic and histologic findings. We calculated the overall ratios of PDR to ADR, SSPDR, and ANDR to assess the correlation between measured and calculated ADR, SSPDR, and ANDR, which is equivalent to the correlation between PDR and measured ADR, SSPDR, and ANDR.

RESULTS

The overall PDR, ADR, SSPDR, and ANDR were 72%, 52%, 2%, and 14%. PDR (48%) was highest in the left colon, while ADR (32%) and ANDR (7%) were highest in the right colon (p < 0.001 for all). The overall ADR/PDR, SSPDR/PDR, and ANDR/PDR ratios were 0.73, 0.03, and 0.20. Correlation between PDR and ADR was highly positive overall (r = 0.87, p < 0.0001) and stronger in the right (r = 0.91) and transverse (r = 0.94) colon than the left colon (r = 0.80). Correlation between PDR and overall SSPDR and ANDR were not statistically significant.

CONCLUSIONS

PDR can serve as a surrogate measure of ADR to monitor colonoscopy quality in gastroenterology fellowship.

Cross-national analysis about the difference of histopathological management in Tis and T1 colorectal cancer between Japan and Korea

OBJECTIVES

There are differences in each country with regards to histopathological managements of colorectal cancer (CRC), such as definition of Tis and lymphatic and venous invasion. In this study, we compared Tis and T1 CRC in Japan and Korea.

METHODS

We retrospectively compared various clinical characteristics of consecutive patients who had Tis and T1 CRCs and who were newly diagnosed between 2010 and 2014 at the Kyoto Prefectural University of Medicine (Japan) and the Konkuk University (Korea).

RESULTS

Three hundred and sixty-five cases of T1 cancer and 510 cases of Tis cancer from 726 Japanese and 149 Korean patients were included. The rate of Tis in Japan was higher than in Korea (59.8% vs. 51.0%, P = 0.047), according to the difference of definition of Tis. In the analyses of 365 T1 CRCs, median age was higher in Japan than Korea (67.8 ± 10.6 vs. 62.2 ± 10.1, P < 0.001). Right-sided lesions were more frequent in Japan than they were in Korea (38.7% vs. 22.2%, P < 0.001). The rates of venous and lymphatic invasion were higher in Japan than they were in Korea (venous: 18.6% vs. 1.4%, P < 0.001, lymphatic: 25.3% vs. 13.7%, P = 0.042), according to the different methods of immunohistochemical examinations used (Japan: E-HE and D2-40, Korea: ERG).

CONCLUSIONS

Our study of T1 CRC showed that there were differences between Japan and Korea in tumor location, elderly incidence, and histopathological lymphatic and venous invasion. Additionally, rates of Tis were different between the two countries. In this international study for CRC, it is considered that we have to pay attention regarding the difference of histopathological definition and method in each country.

Prospective diagnostic study on the use of narrow-band imaging on suspicious lesions during colonoscopy examination

INTRODUCTION

Colonoscopy is the gold standard to detect colorectal neoplasm. Narrow-band imaging (NBI) has a good diagnostic accuracy to differentiate between neoplastic and non-neoplastic colorectal lesions. This study explores the diagnostic validity of NBI colonoscopy as well as its associated factors related to neoplastic and non-neoplastic colorectal lesions.

METHODS

This study enrolled 100 patients in a single-center tertiary teaching hospital. Patients presented for screening colonoscopy, and those with suspicious colorectal lesions were included in this study. During colonoscopy, the most suspicious lesion in each patient was analyzed using the NBI system based on Sano's classification. Each lesion was biopsied for histopathological analysis, the gold standard. Endoscopic images were captured electronically. The sensitivity, specificity, and diagnostic accuracy of NBI colonoscopy were assessed. Other associated factors related to neoplastic and non-neoplastic lesions were analyzed accordingly.

RESULTS

The sensitivity and specificity of the NBI were 88.2% and 71.9%, respectively. The area under the receiver-operator curve was 0.801, indicating that NBI has a good ability to differentiate between disease and non-disease. There are significant associations between histopathological examination outcomes and both presenting symptoms, especially weight loss, and lesion site, even after other variables were controlled (P < 0.05).

CONCLUSION

The NBI system in colonoscopy was capable of distinguishing neoplastic from non-neoplastic colorectal lesions. It indicates an acceptable level of agreement with histopathology, the gold standard. However, the role of NBI in screening and surveillance in Malaysia still needs further evaluation and exploration.

Polyp detection rate and pathological features in patients undergoing a comprehensive colonoscopy screening

AIM

To identify the prevalence, and clinical and pathologic characteristic of colonic polyps among Iranian patients undergoing a comprehensive colonoscopy, and determine the polyp detection rate (PDR) and adenoma detection rate (ADR).

METHODS

In this cross-sectional study, demographics and epidemiologic characteristics of 531 persons who underwent colonoscopies between 2014 and 2015 at Mehrad gastrointestinal clinic were determined. Demographics, indication for colonoscopy, colonoscopy findings, number of polyps, and histopathological characteristics of the polyps were examined for each person.

RESULTS

Our sample included 295 (55.6%) women and 236 (44.4%) men, with a mean age of 50.25 ± 14.89 years. Overall PDR was 23.5% (125/531). ADR and colorectal cancer detection rate in this study were 12.8% and 1.5%, respectively. Polyps were detected more significantly frequently in men than in women (52.8% vs 47.2%, P < 0.05). Polyps can be seen in most patients after the age of 50. The average age of patients with cancer was significantly higher than that of patients with polyps (61.3 years vs 56.4 years, P < 0.05). The majority of the polyps were adenomatous. More than 50% of the polyps were found in the rectosigmoid part of the colon.

CONCLUSION

The prevalence of polyps and adenomas in this study is less than that reported in the Western populations. In our patients, distal colon is more susceptible to developing polyps and cancer than proximal colon.

Comparison of biomarker expression between proximal and distal colorectal adenomas: The Tennessee-Indiana Adenoma Recurrence Study

It is unclear if proximal and distal traditional adenomas present with differences in molecular events which contribute to cancer heterogeneity by tumor anatomical subsite. Participants from a colonoscopy-based study (n = 380) were divided into subgroups based on the location of their most advanced adenoma: proximal, distal, or "equivalent both sides." Eight biomarkers in the most advanced adenomas were evaluated by immunohistochemistry (Ki-67, COX-2, TGFβRII, EGFR, β-catenin, cyclin D1, c-Myc) or TUNEL (apoptosis). After an adjustment for pathological features, there were no significant differences between proximal and distal adenomas for any biomarker. Conversely, expression levels did vary by other features, such as their size, villous component, and synchronousness. Large adenomas had higher expression levels of Ki-67(P < 0.001), TGFβRII (P < 0.0001), c-Myc (P < 0.001), and cyclin D1 (P < 0.001) in comparison to small adenomas, and tubulovillous/villous adenomas also were more likely to have similar higher expression levels in comparison to tubular adenomas. Adenoma location is not a major determinant of the expression of these biomarkers outside of other pathological features. This study suggests similarly important roles of Wnt/β-catenin and TGF-β pathways in carcinogenesis in both the proximal and distal colorectum. © 2016 Wiley Periodicals, Inc.

Association Between Colorectal Cancer and Atherosclerotic Diseases: A Study Using a National Inpatient Database in Japan

BACKGROUND

Both colorectal neoplasms and atherosclerosis can be induced by common visceral fat accumulation. However, the association between these diseases at the advanced stage, colorectal cancer and cardiovascular/cerebrovascular diseases, has not been elucidated.

AIMS

This study aimed to investigate the association between colorectal cancer and vascular diseases in relation to obesity and metabolic disorders, using a nationwide database of hospitalized patients in Japan. We used non-cardiac gastric cancer patients as a reference, because they were considered to be neutral for obesity or metabolic disorders.

METHODS

We identified 54,591 patients with colorectal cancer and 19,565 patients with gastric cancer from the Diagnosis Procedure Combination database. The data collected included: sex; age; body mass index (BMI); smoking status; comorbidity; and medication data, comprising hypertension, diabetes, hyperlipidemia, coronary artery disease, and stroke. We compared these data in a cross-sectional setting by multivariate analyses.

RESULTS

Multivariate logistic regression analyses showed that female sex, increased BMI, hypertension [odds ratio (OR) 1.11; 95 % confidence interval (CI) 1.07-1.15; P < 0.0001], and diabetes (OR 1.17; 95 % CI 1.12-1.23; P < 0.0001) were more associated with colorectal cancer than with gastric cancer. Smoking, aspirin use (OR 0.85; 95 % CI 0.79-0.92; P < 0.0001), and coronary artery disease (OR 0.90; 95 % CI 0.86-0.95; P = 0.0001) were inversely associated with colorectal cancer.

CONCLUSIONS

Obesity and metabolic disorders were more associated with colorectal cancer than with non-cardiac gastric cancer, while coronary artery disease (CAD) was inversely associated. Some mechanisms involving separate populations of colorectal cancer and CAD under visceral fat accumulation might be suggested.

Decreased CK1δ expression predicts prolonged survival in colorectal cancer patients

Cancers arising from the large intestine or rectum are called colorectal cancer (CRC) and represent the fourth leading cause of cancer-related death worldwide. Since casein kinase 1 (CK1) isoforms are involved in many cellular processes and have been reported to be deregulated in various tumor entities, CK1 has become an interesting drug target. In this study, we examined the potential of CK1δ expression levels in tumor tissue of CRC patients as a prognostic biomarker. We show by quantitative RNA expression analyses that decreased CK1δ expression levels in tumor tissue predict prolonged survival rates. Random sampling of CK1δ stained tumor tissue indicates that CK1δ gene expression corresponds with CK1δ protein expression. Especially in low grade (grade 1, grade 2) and in UICC II/III classified tumors decreased CK1δ RNA levels correlate with significantly improved survival rates when the tumor was located in the right colon. We furthermore found gender-specific differences within these subgroups, revealing most significant increase in overall survival rates in male patients with tumors in right colon expressing low levels of CK1δ RNA. Results become even clearer, when only male patients over 50 years were considered. Together, these findings support the assumption that CK1δ might be a prognostic biomarker for CRC thereby providing an interesting drug target for the development of new therapy concepts.

Is there a proximal shift in the distribution of colorectal adenomas?

INTRODUCTION

Several studies have shown a proximal shift of colorectal cancer (CRC) during the last decades. However, few have analyzed the changing distribution of adenomas over time.

AIM

The aim of this study was to compare the site and the characteristics of colorectal adenomas, in a single center, during two periods.

METHODS

We conducted a retrospective, observational study in a single hospital of adenomas removed during a total colonoscopy in two one-year periods: 2003 (period 1) and 2012 (period 2). Patients with inflammatory bowel disease, familial adenomatous polyposis, hereditary non-polyposis colorectal cancer syndrome, or history of CRC were excluded from the study. The χ(2) statistical test was performed. P values less than 0.05 were considered statistically significant.

RESULTS

During the two considered periods, a total of 864 adenomas from 2394 complete colonoscopies were analyzed: 333 adenomas from 998 colonoscopies during period 1 and 531 adenomas from 1396 colonoscopies during period 2. There was a significant increase in the proportion of adenomatous polyps in the proximal colon from period 1 to 2 (30.6% to 38.8% (p = 0.015)). Comparing the advanced features of adenomas between the two periods, it was noted that in period 2, the number of adenomas with size ≥1 cm (p = 0.001), high-grade dysplasia (p = 0.001), and villous features (p < 0.0001) had a significant increase compared to period 1.

CONCLUSION

Incidence of adenomatous polyps in the proximal colon as well as adenomas with advanced features has increased in the last years. This finding may have important implications regarding methods of CRC screening.

Influence of patient age and colorectal polyp size on histopathology findings

Background

Colorectal cancer is a major cause of morbidity and mortality and can arise through the adenoma-carcinoma sequence. Colonoscopy is considered the method of choice for population-wide cancer screening.

Aim

To assess the characteristics of endoscopically resected polyps in a consecutive series of patients who underwent colonoscopy at a university hospital and compare histopathology findings according to patient age and polyp size.

Methods

Retrospective, cross-sectional of 1950 colonoscopy reports from consecutively examined patients. The sample was restricted to reports that mentioned colorectal polyps. A chart review was carried out for collection of demographic data and histopathology results. Data were compared for polyps sized ≤0.5 cm and ≥0.6 cm and then for polyps sized ≤1.0 cm and ≥1.1 cm. Finally, all polyps resected from patients aged 49 years or younger were compared with those resected from patients aged 50 years or older.

Results

A total of 272 colorectal polyps were resected in 224 of the 1950 colonoscopies included in the sample (11.5%). Polyps >1 cm tended to be pedunculated (p=0.000) and were more likely to exhibit an adenomatous component (p=0.001), a villous component (p=0.000), and dysplasia (p=0.003). These findings held true when the size cutoff was set at 0.5 cm. Patients aged 50 years or older were more likely to have sessile polyps (p=0.023) and polyps located in the proximal colon (p=0.009). There were no significant differences between groups in histopathology or presence of dysplasia.

Conclusion

Polyp size is associated with presence of adenomas, a villous component, and dysplasia, whereas patient age is more frequently associated with sessile polyps in the proximal colon.

Age and site of Colonic Neoplastic Lesions: Implications of screening in South Asia

Objective : To evaluate the Age of patients and the site of Colonic Neoplastic Lesions (CNL) and to determine the appropriate screening strategy for Colorectal Carcinoma (CRC) (sigmoidoscopy versus colonoscopy) in our population. Methods : This is a cross sectional study. Data of all patients more than 16 years of age who underwent full colonoscopic examination at the Aga Khan University hospital between January 2011 till December 2013 and were diagnosed to have CRC or advanced adenomas (defined as polyp more than 1 cm and/or having villous morphology on histology) was recorded. Lesions found distal to the splenic flexure were characterized as distal lesions and while lesions found between the splenic flexure and the cecum were characterized as proximal lesions.

RESULTS

During the study period colonic neoplastic lesions were found in 217 patients; 186 (85.7%) patients had CRC and 31(14.3%) patients had advanced adenomatous polyps. Mean age was 55.8±14 years and amongst them 72 (33.2%) patients were less than 50 years of age while 145 (66.8%) were more than 50 years. In 144 (66.4%) patients lesions were located in the distal colon, 65 (30%) had lesions in the proximal colon while in 8 (3.7%) patients the neoplastic lesions were found both in the proximal and distal colon. The predominant symptoms were bleeding per rectum in 39.6% of patients followed by weight loss in 31.8% of patients. Only 3 patients had familial syndromes with multiple polyps. When patients younger than 50 years of age were compared with patients more than 50 years there was no statistically significant difference between the site of neoplastic lesion as well as the presenting symptoms. (p value 0.85).

CONCLUSION

Colonic Neoplastic Lesions presented at younger age in our study population and one third of the lesions were found in the right sided colon. Hence screening for CNLs should be implied at an earlier age preferably with colonoscopy. More population based data is required to further validate our results.

Pulse-wave velocity, the ankle-brachial index, and the visceral fat area are highly associated with colorectal adenoma

BACKGROUND

Although both colorectal neoplasms and atherosclerosis may be induced by visceral fat accumulation, no association between these factors has yet been elucidated.

METHODS

Among Japanese participants in our colonoscopic screening and annual surveillance programs, asymptomatic subjects were investigated. Visceral fat area was measured by computed tomography, and the ankle-brachial index and pulse-wave velocity (markers of systemic atherosclerosis) were also estimated. Colorectal findings during screening were investigated in association with these parameters.

RESULTS

Nine hundred and seven subjects (males: 71.9%; mean age: 57.3±8.7 years) were enrolled. Colorectal adenomas were identified during colorectal screening of 407 subjects (44.9%). The prevalence of all colorectal adenoma and advanced neoplasia increased with an elevated pulse-wave velocity from 32.2% (advanced neoplasia, 2.6) to 62.1% (8.4%) in higher quartiles (p<0.001 and p=0.003). The risk of advanced neoplasia was higher in subjects with an abnormal ankle-brachial index (33% vs. 4.6%, p<0.001). Upon multivariate analysis, visceral fat area and pulse-wave velocity were associated with all adenoma, and the ankle-brachial index with advanced neoplasia.

CONCLUSIONS

The risk of colorectal adenoma was strongly associated with visceral fat area and markers of atherosclerosis. Colorectal adenoma and atherosclerosis may share a common pathogenesis and the same populations are at high-risk.

Proximal shift of colorectal cancer along with aging

INTRODUCTION

Although several reports have documented the increased incidence of right-sided colorectal cancer (CRC) in the elderly, especially in women, the gender-specific, age-related changes in the characteristics of CRCs, especially related to the cancer localization, have not been fully investigated. This study evaluated the age-related changes in the clinicopathologic features of CRCs, according to the gender.

MATERIALS AND METHODS

A total of 1059 consecutive patients with CRCs who were admitted to the authors' surgical department between February 2005 and June 2012 were retrospectively reviewed. The patients were divided into male (n = 632) and female (n = 427) groups and then according to the age group, and the correlation between the age group and the other clinicopathologic features was analyzed by univariate and multivariate analysis.

RESULTS

The number of concomitant adenomas found was significantly increased along with increasing age in men, and the presence of concomitant adenoma was the only independent age-related factor of male CRC in the multivariate analysis (P = .0044). In contrast, in women, the location of the CRC progressively shifted to the right side (proximal colon) with increasing age, and the presence of right-sided CRC was the only independent factor of female CRC in the multivariate analysis (P < .0001).

CONCLUSION

There was a significant gender-specific difference in the age-related changes in the characteristics of CRC. Increasing the number of concomitant adenomas and the shift of CRC localization to the proximal colon were the gender-specific characteristics of male and female CRC, respectively.

Acute large bowel obstruction secondary to stage 4 colonic carcinoma in an elderly man with severe aortic stenosis: a therapeutic challenge

Colonic adenocarcinoma is a common gastrointestinal malignancy affecting the elderly, and has a multifactorial aetiology. Depending on the individual circumstances, surgical resection is the treatment of choice for colon cancer even for oligometastasis. Metastatic evidence as well as presence of comorbidities, particularly in the elderly, make surgical management difficult and often present a clinical challenge for clinicians. This is a case report exploring the treatment options for an 80-year-old male patient presenting with acute large bowel obstruction secondary to colonic adenocarcinoma with disseminated metastases and severe aortic stenosis.

Is proliferative colonic disease presentation changing?

AIM: To compare the site, age and gender of cases of colorectal cancer (CRC) and polyps in a single referral center in Rome, Italy, during two periods.

METHODS: CRC data were collected from surgery/pathology registers, and polyp data from colonoscopy reports. Patients who met the criteria for familial adenomatous polyposis, hereditary non-polyposis colorectal cancer syndrome or inflammatory bowel disease were excluded from the study. Overlap of patients between the two groups (cancers and polyps) was carefully avoided. The χ² statistical test and a regression analysis were performed.

RESULTS: Data from a total of 768 patients (352 and 416 patients, respectively, in periods A and B) who underwent surgery for cancer were collected. During the same time periods, a total of 1693 polyps were analyzed from 978 patients with complete colonoscopies (428 polyps from 273 patients during period A and 1265 polyps from 705 patients during period B). A proximal shift in cancer occurred during the latter years for both sexes, but particularly in males. Proximal cancer increased > 3-fold in period B compared to period A in males [odds ratio (OR) 3.31, 95%CI: 2.00-5.47; P < 0.0001). A similar proximal shift was observed for polyps, particularly in males (OR 1.87, 95%CI: 1.23-2.87; P < 0.0038), but also in females (OR 1.62, 95%CI: 0.96-2.73; P < 0.07).

CONCLUSION: The prevalence of proximal proliferative colonic lesions seems to have increased over the last decade, particularly in males.

Changing epidemiology of colorectal cancer makes screening sigmoidoscopy less useful for identifying carriers of colorectal neoplasms

BACKGROUND

There is renewed interest in flexible sigmoidoscopy (FS) colorectal cancer (CRC) screening following trials showing significantly reduced CRC incidence and mortality.

AIMS

To evaluate the potential usefulness of FS screening in our population.

METHODS

We examined rectosigmoid (RS) cancer epidemiology in our Jewish population using Israel National Cancer Registry data, computed by CRC site, age groups, and gender. We also reviewed endoscopy-screening publications for prevalence of RS and proximal advanced adenomas (AAP) and having both or either.

RESULTS

During 1980-2008, there were 64,559 CRCs registered; 31.6 % were RS cancer which has now decreased to 29 % of men's and 26 % of women's CRC (both P < 0.01). In <50 year olds, RS cancer occurred in 42 % of males' and 35 % of females' CRC, and in the last 2 decades this ratio is unchanged. In 50-74 year olds, RS cancer decreased to stable levels of 32 % of males' and 29 % females' CRC (both P < 0.01). In ≥75 year olds, RS cancer progressively decreased to 24 % of males' and 22 % females' CRC (both P < 0.001). From endoscopy screening reports in 40-79 year olds, RS AAPs occurred in 2.0-5.8 %, being least in women, most in men, and not increased with aging. Some 50-57 % of screenees had both RS and proximal AAPs, least when aged 40-49 years at 25 %, women were 35 %, and with aging 40 %, but most in men at 70 %.

CONCLUSIONS

With the changing CRC epidemiology, having fewer RS neoplasms but more proximal cancer, the effectiveness of FS screening for identifying significant neoplasms decreases with screenees' age and especially in females. These make FS screening less suitable for our aging and increasingly female population.

Clinicopathological features of serrated adenocarcinoma defined by Mäkinen in dukes' B colorectal carcinoma

OBJECTIVE

Serrated adenocarcinoma (SAC), proposed as a new pathologic type, arises predominantly in the right side of the colon and has a poorer prognosis than conventional colorectal carcinoma. The prognosis of colorectal carcinoma is variable in Dukes' B, so the aim of this study was to determine whether or not SAC has a poor prognosis in Dukes' B.

METHODS

The study group comprised 64 patients who underwent surgery for colorectal carcinoma. We undertook a statistical analysis of the association of SAC and non-SAC with sex, age, histologic type, depth of tumor, location of tumor, venous invasion and lymphatic invasion.

RESULTS

SACs were encountered in 17.5% of cases (n = 11). SAC had a less favorable 5-year survival than non-SAC (p = 0.0396 log-rank, Kaplan-Meier). The factors that achieved statistical significance in the univariate analysis were subsequently included in a multivariate analysis and we found that SAC was an independent factor (p = 0.027).

CONCLUSIONS

SAC has a poor prognosis and is not affected by other factors confirming that SAC is an independently less favorable prognostic factor.

Colorectal cancers not detected by screening flexible sigmoidoscopy in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

BACKGROUND AND OBJECTIVE

Diagnosis of colorectal cancer after negative findings on endoscopic evaluation raises concern about the effectiveness of endoscopic screening. We contrast screening-detected cancers with cancers not detected by screening among participants assigned to flexible sigmoidoscopy (FSG) in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial to determine the reasons for the lack of detection of prevalent lesions.

DESIGN

Cancers detected within 1 year of a screening FSG with abnormal findings were classified as screening detected. All other cancers were categorized, based on cancer stage and years until detection, as either not detectable or prevalent but not detected at the time of screening.

SETTING/PATIENTS

A total of 77,447 subjects in the multicenter PLCO trial.

MAIN OUTCOME MEASUREMENTS

A total of 977 colorectal cancers were diagnosed with a mean follow-up of 11.5 years.

RESULTS

A total of 243 (24.9%) cancers were screening detected, 470 (48.1%) were not detectable at screening, and 264 (27.0%) were considered prevalent but not detected. Among prevalent nondetected lesions, 35.6% (n = 94) were attributed to problems in patient compliance (58 never screened, 34 delayed colonoscopy follow-up, and 2 inadequate bowel preparation), 43.9% (n = 116) were attributable to a limitation in the FSG procedure (97 beyond the reach of the sigmoidoscope and 19 inadequate depth of insertion on FSG), and 20.5% (n = 54) were caused by endoscopist limitation (33 missed on FSG, 21 missed at initial colonoscopy) (P < .0001). Had colonoscopy instead of FSG been used for screening, an additional 15.6% and as many as 19.0% of cancers may have been screening-detected.

LIMITATIONS

These estimates are reasonable approximations, but biological variability precludes precise determinations.

CONCLUSIONS

Prevalent nondetected cancers were more often attributable to problems with patient compliance or limitations in the FSG procedure than to missed lesions. Colonoscopy instead of FSG could have moderately increased the detection of cancer via screening.

Trends in colorectal cancer incidence by anatomic site and disease stage in the United States from 1976 to 2005

OBJECTIVE

The objectives of the current study were to examine the trends in incidence rates of subsite-specific colorectal cancer at all stages in a large US population and to explore the impact of age and sex on colorectal cancer incidence.

METHODS

Data were obtained from the Surveillance, Epidemiology, and End Results (SEER) 9 registries. Colorectal cancer incidence was divided into 3 anatomic subsite groupings: proximal colon, distal colon, and rectum. Incidence rates and relative risk were calculated using the SEER*Stat software provided by the National Cancer Institute.

RESULTS

From 1976 to 2005, age-adjusted incidence of proximal colon, distal colon, and rectal cancers per 100,000 population have steadily decreased from 22.5, 18.8, and 19.2 to 21.1, 11.7, and 13.6, respectively, contributing to the overall decline in the incidence of colorectal cancer from 60.5 to 46.4. Distal colon cancer had the greatest incidence decline (-37.79%), whereas the most minimal change in the incidence rates occurred for proximal colon cancer (-6.37%) because of increased incidence rates of ascending colon (24.8%) and hepatic flexure (21.3%) over 30 years. The steadily increased proportion of proximal colorectal cancer subsites was observed in both men and women starting at age 50 although women experienced a greater increase than did men.

CONCLUSIONS

Overall incidence rate of colorectal cancer decreased over the past 3 decades. The percent of ascending colon and hepatic flexure cancers diagnosed at early stages (localized and regional) increased. The finding on sex difference over years suggests that great attention should be paid in the future studies to male and female disparities.

Epidemiological and clinical characteristics of colorectal cancer in Huidong District, Guangdong Province, over the past 10 years

AIM: To analyze the epidemiological and clinical characteristics of colorectal cancer in Huidong District, Guangdong Province, over the past 10 years.

METHODS: Data were collected from all consecutive patients receiving colonoscopy at our hospital during the past 10 years. The epidemiological data, clinical presentations, endoscopic findings, and pathohistological characteristics of patients with colorectal cancer were reviewed and analyzed retrospectively.

RESULTS: A total of 10 532 patients received colonoscopy from 2001 to 2010, and of them 853 cases of colorectal cancer were identified by histological assessment. The detection rate of colorectal cancer rose from 8.0% in the first 5-year period to 8.2% in the second five-year period. The median age of patients with colorectal cancer in the second five-year period was older than that in the first five-year period (65 years vs 59 years). The rectum is the most frequent site for colorectal cancer (55.0%), while hematochezia is the most common symptom (56.0%). The detection rate of right-sided colonic cancer in the second five-year period was significantly higher than that in the first five-year period (19.2% vs 15.1%, P < 0.05). Histologically, adenocarcinoma was the most frequent histological subtype (65.5%).

CONCLUSION: The onset age of patients with colorectal cancer is becoming older in Huidong District, Guangdong Province. The rectum remains the most frequent site for colorectal cancer. The shift in site of colonic cancer toward the right has occurred.

EGFR(s) in aging and carcinogenesis of the gastrointestinal tract

Cells of the gastrointestinal (GI) mucosa are subject to a constant process of renewal which, in normal adults, reflects a balance between the rates of cell production and cell loss. Detailed knowledge of these events is, therefore, essential for a better understanding of the normal aging processes as well as many GI diseases, particularly malignancy, that represent disorders of tissue growth. In general, many GI dysfunctions, including malignancy, increase with advancing age, and aging itself is associated with alterations in structural and functional integrity of the GI tract. Although the regulatory mechanisms for age-related increase in the incidence of GI-cancers are yet to be fully delineated, recent evidence suggests a role for epidermal growth family receptors and its family members {referred to as EGFR(s)} in the development and progression of carcinogenesis during aging. The present communication discusses the involvement of EGFR(s) in regulating events of GI cancers during advancing age and summarizes the current available therapeutics targeting these receptors. The current review also describes the effectiveness of ErbB inhibitors as well as combination therapies. Additionally, the involvement of GI stem cells in the development of the age-related rise in GI cancers is emphasized.

A shift from distal to proximal neoplasia in the colon: a decade of polyps and CRC in Italy

Background

In the last years a trend towards proximalization of colorectal carcinomas (CRC) has been reported. This study aims to evaluate the distribution of CRC and adenomatous polyps (ADP) to establish the presence of proximalization and to assess the potential predictors.

Methods

We retrieved histology reports of colonic specimens excised during colonoscopy, considering the exams performed between 1997 and 2006 at Cuneo Hospital, Italy. We compared the proportion of proximal lesions in the period 1997-2001 and in the period 2002-2006.

Results

Neoplastic lesions were detected in 3087 people. Proximal CRC moved from 25.9% (1997-2001) to 30.0% (2002-2006). Adjusting for sex and age, the difference was not significant (OR 1.23; 95% CI: 0,95-1,58). The proximal ADP proportion increased from 19.2% (1997-2001) to 26.0% (2002-2006) (OR: 1.43; 95% CI: 1.17-1.89). The corresponding figures for advanced proximal ADP were 6.6% and 9.5% (OR: 1.48; 95% CI: 1.02-2.17). Adjusting for gender, age, diagnostic period, symptoms and number of polyps the prevalence of proximal advanced ADP was increased among people ≥ 70 years compared to those aged 55-69 years (OR 1.49; 95% CI: 1.032.16). The main predictor of proximal advanced neoplasia was the number of polyps detected per exam (> 1 polyp versus 1 polyp: considering all ADP: OR 2.16; 95% CI: 1.59-2.93; considering advanced ADP OR 1.63; 95% CI: 1.08-2.46). Adjusting for these factors, the difference between the two periods was no longer significant.

Conclusions

CRC do not proximalize while a trend towards a proximal shift in adenomas was observed among people ≥ 70 years.

Adenomatous colorectal polyps in patients referred for colonoscopy in a regional hospital in Kuwait

BACKGROUND/AIM

Adenomatous colorectal polyps (ACPs) are known to be the precursor lesions for colorectal cancer. The aim of the study was to determine the prevalence, endoscopic and pathological features of ACPs in patients referred for colonoscopy.

PATIENTS AND METHODS

The endoscopic and histological reports of adult patients who underwent complete colonoscopy in the gastroenterology unit of a regional Kuwaiti hospital between January 2008 and December 2008 were retrospectively studied. The specimens of polyps were reviewed by an experienced pathologist who was blinded to the clinical or endoscopic information. Non-neoplastic polyps were not included in the analysis.

RESULTS

Of 530 eligible patients (mean age, 45 years; male-female ratio, 2:1), 54 (10%) had 103 ACPs. Of the patients with ACPs (mean age, 57 years), 43 (80%) were males and 36 (67%) were Kuwaitis. Histopathological examination of the most significant polyp in each patient revealed that 40 (74%) polyps were tubular adenomas (TAs); 11 (20%), tubulovillous (TV) adenomas; and 3 (6%), villous adenomas. High-grade dysplasia was noticed in 4 (10%) adenomas. Fifteen (2.8%) of the 530 patients had advanced ACPs. Logistic regression analysis of some variables and their association with ACPs found that age (P < 0.001; OR, 1.9; CI, 1.5-2.3), history of adenoma (P=0.001; OR, 6.4; CI, .2.1-19.4) and being Kuwaitis (P=0.029; OR, 2.1; CI, 1.1-4.1) to be independently associated with ACPs.

CONCLUSION

The most common histological type of ACPs was tubular adenoma. Advancing age, being Kuwaiti nationals and prior removal of ACPs were significantly associated with the occurrence of ACPs.

Colorectal cancer in Guangdong Province of China: A demographic and anatomic survey

AIM: To determine the basic demographic features of colorectal cancer (CRC) in five hospitals located in four different areas of Guangdong Province, China.

METHODS: A review of patient records from 1986 to 2006 from five hospitals was conducted. Patient data was obtained, including age, gender, location of lesions, staging and histological type of CRC. The Chi-square test was used to assess differences in rates and a significance level of 0.05 was used. Univariate comparisons were made via Fisher’s exact tests.

RESULTS: Analysis was carried out on 8172 CRC patents, 6.1% (499/8172) of the patients were aged ≤ 30 years. The peak incidence was between the ages 61-70 years (27.8%). The mean age at CRC diagnosis increased from 52 years (1986-1988) to 60 years (2004-2006) and the proportion of young CRC patients decreased from 8.0% to 5.9% over the same period. Of 8172 lesions, 4434 (54.3%) were located in rectum and 3738 (45.7%) in colon. The incidence of rectal cancer decreased significantly from 59.4% (1989-1991) to 51.8% (2004-2006) and right sided colon cancer increased from 40.6% to 48.2%. The mean age, anatomic distribution, histological type and differentiation degree were significantly different among the four geographical areas (P < 0.05).

CONCLUSION: The hospitalization rate for CRC has increased in Guangdong in recent years. The characteristics of CRC from the five hospitals located in the four different areas of Guangdong Province are also different. Further studies are needed to assess more recent trend in the incidence and prevalence of CRC as well as the respective roles of genetic and environmental factors in CRC.

Changes on the disease pattern of primary colorectal cancers in Southern China: a retrospective study of 20 years

PURPOSE

Some changes on the disease pattern of colorectal cancer (CRC) have occurred in some Asian countries recently. However, nothing is known about it in China lately. The present study is to determine whether there are any changes on the disease pattern of CRC in Southern China.

PATIENTS AND METHODS

Data were collected from all consecutive patients accepting colonoscopy in our endoscopy center during the last 20 years. The sociodemographic data, clinical presentations, endoscopic descriptions, and histological subtypes of patients confirmed as CRC by pathology were analyzed retrospectively.

RESULTS

A total of 37,578 patients accepted colonoscopy from 1987 to 2006, in which 2,876 patients were diagnosed as CRC. The median age of patients in the 2nd decade (1997-2006; 62 years) was getting older than the 1st decade (1987-1996; 58 years; P = 0.043). Hematochezia was the most frequent symptom (55.8%), while rectum was the most common site distribution of CRC (51.0%). The incidence of right-sided colonic cancers in the 2nd decade (21.0%) was higher than the 1st decade (17.3%; P = 0.0314). Histologically, adenocarcinoma was the most common (92.4%), of which moderately differentiated tumors were more frequent (67.7%). CRCs with high-grade malignancy were more likely to occur in the 1st decade (P < 0.0001).

CONCLUSIONS

Rectum remains the most common site of CRC in southern China. But a rightward shift in the site distribution has occurred and patients are getting older. Tumors with high-grade malignancy have the tendency to decrease.

Cholelithiasis is a risk factor for colorectal adenoma

OBJECTIVES

Postcholecystectomy patients show moderate risk of colorectal cancer. However, few studies have investigated the relationship between cholelithiasis and colorectal adenoma. We examined this possibility through a combination of colonoscopy and ultrasonography in asymptomatic Japanese.

METHODS

We reviewed a subgroup of subjects drawn from a prospective annual colonoscopy screening survey. Subjects who underwent both ultrasonography and colonoscopy, and completed a questionnaire regarding lifestyle habits were entered. We investigated whether subjects with cholelithiasis or a previous cholecystectomy showed an increased risk of colorectal adenoma, as compared with subjects with normal gallbladders.

RESULTS

Data of 4,458 subjects (men 3,053, women 1,405, mean age +/- SD 46.1 +/- 8.62 yr) were analyzed. Cholelithiasis was detected in 206 subjects, 4,189 subjects had normal gallbladders, and 63 subjects had cholecystectomies. The prevalence of colorectal adenoma was 29.6% (61/206) in subjects with cholelithiasis, which was significantly higher when compared with normal subjects, with a prevalence of 17.7% (741/4,189, P < 0.001). In cholecystectomy patients, only 15.9% (10/63) developed colorectal adenomas, which was not significantly different from the control group. In a multivariate analysis controlling for sex, age, family history of colorectal cancer, alcohol, smoking, and body mass index, cholelithiasis was shown to be an independent risk factor for colorectal adenoma (adjusted OR 1.57, 95% CI 1.14-2.18). Cholelithiasis was strongly associated with multiple (> or = 3 lesions, adjusted OR 2.39, 95% CI 1.21-4.72) and left-sided colorectal adenomas (adjusted OR 1.82, 95% CI 1.28-2.59).

CONCLUSIONS

Cholelithiasis is a risk factor for colorectal adenoma.

Differences between right- and left-sided colon cancer in patient characteristics, cancer morphology and histology

BACKGROUND AND AIM

Recently, the clinical and biological differences between right- and left-sided colon cancers have been widely debated. However, close analyses of these clinical differences, based on large-scale studies, have been scarcely reported.

METHODS

A total of 3552 consecutive Japanese colorectal cancer cases were examined and the clinical differences between right- and left-sided colon cancer cases were investigated.

RESULTS

The proportion of right-sided colon cancer was relatively high in patients aged less than 40 years (33%) and more than 80 years (43%). The proportion of right-sided colon cancer in patients aged 40-59 years was relatively low (male 22% and female 29%). In male patients the proportion increased in the 70-79 years age group (30%), while in female patients the proportion increased in the 60-69 years age group (39%). Right-sided colon cancer was more likely to be detected at an advanced stage (T1 stage; left 22%, right 15%) (P < 0.01) with severe symptoms. Polypoid-type early cancer was dominant in the left colon (left 59%; right 40%) (P < 0.01), while the proportion of flat-type early cancer in the right colon was significantly higher than that in the left colon (left 25%; right 44%) (P < 0.01).

CONCLUSIONS

Specific age distribution of right-sided colon cancer was observed and the difference between male and female patients was highlighted. Other clinical features also differed between right- and left-sided colon cancer, suggesting that different mechanisms may be at work during right and left colon carcinogenesis.

Right-side shift of metachronous colorectal adenomas after polypectomy

OBJECTIVE

In our previous study, we showed that the development of adenomas in the right-side colon increased with aging in subjects with no colorectal neoplasms. The aim of the present study was to investigate the location of metachronous colorectal adenomas after endoscopic polypectomy.

MATERIAL AND METHODS

The records of a colonoscopic follow-up study on 2900 subjects after polypectomy were analyzed. The location was classified as the right-side colon and left-side colon at the splenic flexure. Subjects were classified into three groups according to distribution of adenomas at the initial two colonoscopies: those with adenomas located only in the left side (LL), adenomas in both the left side and right side (LR), and adenomas only in the right side (RR). Distribution of initial and metachronous adenomas was evaluated according to age.

RESULTS

The annual incidence rates of colorectal adenomas in the left-side colon were estimated to be 8.56%, 11.2%, and 5.71% in the LL, LR, and RR groups, respectively. The rates in the right side were 5.91%, 15.5%, and 9.38%, respectively. The incidence rates in the left side in the age groups <40, 40-49, 50-59, and > or =60 years were 6.93%, 8.08%, 8.33%, and 8.48%/year, respectively. Those in the right side were 4.91%, 7.27%, 9.86%, and 12.41%/year, respectively.

CONCLUSIONS

Although there may be individual predilection for right-side or left-side location of colorectal adenomas, aging tends to increase the number of adenomas in the right-side colon, while only modestly affecting those in the left-side colon.

Age and distal colonic findings determine the yield of advanced proximal neoplasia in Chinese patients with rectal bleeding

BACKGROUND AND AIMS

Few data were available on the optimal diagnostic strategy for Chinese patients with hematochezia. We aimed to evaluate the impact of age and distal colonic findings on the yield of diagnostic strategies in young Chinese patients with hematochezia.

METHODS

Consecutive outpatients aged less than 50 years were analyzed using a hypothesized mixed diagnostic strategy to determine the optimal cut-off age for the use of sigmoidoscopy and colonoscopy. The efficacy and cost of the diagnostic strategy and the number of colonoscopies needed to detect one advanced proximal neoplasm (APN) using different cut-off ages were assessed.

RESULTS

In the hypothesized mixed diagnostic strategy for young patients, the sensitivities for the detection of APN were 100%, 92% and 75% if the cut-off ages were 30, 35 and 40 years, respectively. The cost needed to detect one APN would be $US 3155, $US 3179 and $US 3497 if the cut-off ages were 30, 35 and 40 years, respectively. Colonoscopy would be performed in 84%, 69% and 51% of patients if the cut-off ages were 30, 35 and 40 years, respectively.

CONCLUSION

Colonoscopy should be considered for Chinese patients with rectal bleeding who are aged > or =35 years or those aged <35 years who have adenoma in the distal colon.

Sensitivity of immunochemical fecal occult blood test to small colorectal adenomas

BACKGROUND

Although the immunochemical fecal occult blood test (FOBT) is reportedly more sensitive to large adenomas or colorectal cancer (CRC) than the guaiac-based FOBT, the sensitivity of the immunochemical FOBT to small adenomas has scarcely been reported. Previous reports have indicated that the guaiac-based FOBT can detect small adenomas only by serendipity.

OBJECTIVES

To investigate the sensitivity of immunochemical FOBT to small adenomas using a large-scale cohort.

METHODS

We analyzed 21,805 consecutively enrolled asymptomatic persons who underwent colonoscopy and immunochemical FOBT.

RESULTS

The sensitivity to adenomas </=9 mm was significantly higher than the false-positive rate as revealed by analysis of all eligible subjects (7.0%vs 4.5%, P < 0.001). In men, the sensitivity was superior to the false-positive rate and increased with age (<50 yr 6.1% and >60 yr 11.3%). On the other hand, the sensitivity in women was not significantly different from the false-positive rate in any generation (5.1%vs 4.7% for all eligible women, P= 0.72).

CONCLUSIONS

Immunochemical FOBT detected a small percentage of small adenomas in men at a rate that is significantly higher than the false-positive rate. Studies comparing the guaiac and immunochemical FOBTs using the end point of CRC-related death are expected.

Screening for colorectal cancer in average-risk Chinese population using a mixed strategy with sigmoidoscopy and colonoscopy

PURPOSE

The Chinese population has been shown to have more distal colonic neoplasm and a higher sensitivity of sigmoidoscopic screening strategy for detecting advanced neoplasm compared with Western populations. This study was designed to evaluate the efficacy of the mixed screening strategy with sigmoidoscopy and colonoscopy in the average-risk Chinese population.

METHODS

Consecutive average-risk adults aged >/=50 years who underwent colonoscopy as part of a health checkup were enrolled. Data were analyzed in a hypothetical graded screening strategy using colonoscopy on patients older than a certain cutoff age or those with distal sentinel polyps. The sensitivity in detecting advanced colonic neoplasm and advanced proximal neoplasm as well as the number of colonoscopies reduced were assessed.

RESULTS

Of the 2,106 persons eligible for analysis, 1,193 (56.6 percent) were males and 913 (43.4 percent) were females. If the cutoff ages were 55, 60, and 65 years, and adenoma detected in the distal colon was the indication for subsequent colonoscopy, the detection rate for 1) advanced colonic neoplasm in the entire colon would be 94, 93.1, and 83.6 percent, respectively, and 2) advanced proximal neoplasm would be 84.8, 82.6, and 58.7 percent, respectively. The number of colonoscopic procedures could be reduced by 28, 48, and 65 percent if the cutoff ages were 55, 60, and 65 years, respectively.

CONCLUSIONS

The mixed screening strategy using a cutoff age at 60 years and distal adenoma as the sentinel lesion is an effective screening program in the average-risk Chinese population.

Analysis on clinicopathological characteristics and prognosis of 576 patients with primary colorectal cancer

AIM: To analyze the clinicopathological characteristics of primary colorectal cancer and explore the influencing factors on the prognosis of patients.

METHODS: The clinical data of 576 patients with colorectal cancer diagnosed by colonoscopy during the past five years in the second affiliated hospital of Sun Yat-Sen University were analyzed retrospectively.

RESULTS: The occurrence rate of colorectal cancer was not significantly different between patients of different ages. The frequency of abdominal pain (χ² = 7.20, P < 0.05), the proportion of mucinous adenocarcinoma (χ² = 43.71, P < 0.05) and the rate of lymph node metastasis (χ² = 4.47, P < 0.05) in adolescent group were significantly higher than those in the mid-aged and aged one. The number of thin individuals was markedly higher in the aged group than that in the adolescent and mid-aged group (χ² = 9.64, P < 0.05). High differentiation was also observed in the aged patients (χ² = 8.06, P < 0.05). The overall 5-year survival rate was 61.79% (43.64%, 87.16% and 53.79% in the adolescent, mid-aged, and aged patients, respectively). The prognosis of colorectal cancer was associated with the age, tumor cell differentiation, lymph node metastasis, Dukes stages and the radical operation.

CONCLUSION: The frequency of abdominal pain, the malignant degree and the proportion of lymph node metastasis are the highest in the young patients. Age and Dukes staging are the independent factors correlated with the prognosis.

Changing sites of colorectal cancer in the Israeli Jewish ethnic populations and its clinical implications

Countries at risk for colorectal cancer noted an increase in right-sided colorectal cancer. We examined this in the Israeli Jewish populations. Israel Cancer Registry data, 1982-2001, were computed by sex, age, ethnic group and colorectal cancer site: 'rectal cancer' included the recto-sigmoid junction, 'right-sided' colorectal cancer included proximal colon up to and including the splenic flexure. In both sexes, colorectal cancer trends increased significantly owing to colonic cancer (P<0.01) whereas rectal cancer decreased (P<0.01). Left and right colorectal cancer trends decreased in Israel born people (P<0.01), but in Asia-Africa born people increases were seen at both sites in the male (P=0.02 and 0.06, respectively) and female (P=0.03 and 0.01, respectively) population. In those > or =65 years old, right colorectal cancer trends increased in all men (P=0.05) and women (P=0.01). On comparing data from 1982-1986 with that from 1997-2001 right colorectal cancer showed an increase in both sexes (P<0.01): to 32.7% of male colorectal cancer and 57.6% of female colorectal cancer. In the period 1997-2001, the total male population > or =65 years had increased relatively by 7.5% (P<0.01), and women by 22.6% (P<0.01) and the proportion of right colorectal cancer in > or =65 years olds increased relatively by 10.9% in the male population, and 18.2% in the female population, with one-third of this increase occurring in Russian immigrants arriving after 1990. In conclusion, there is a trend for right colorectal cancer in Jews aged > or =65 years. The proportion and amount of colorectal cancer increased most significantly in older women, which was partially explained by their increasing numbers and by colorectal cancer occurring in recent immigrants from Russia, who were at high-risk for colorectal cancer. These results should influence colorectal cancer screening and diagnostic methodologies used.

The Malignant Potential of Freshly Developed Colorectal Polyps According to Age

BACKGROUND

Although malignant colorectal neoplasms are found more frequently in older population, polyps found at one-time colonoscopy may be a mixture of lesions that developed at various earlier ages. Newly developed adenomas found at the follow-up colonoscopies will reflect the exact relation between malignant potential and the age of development of colorectal polyps.

METHODS

The results of 44,065 follow-up colonoscopies on 11,912 subjects were analyzed. The proportion of invasive cancer or high-grade dysplasia among all neoplasms, "proportion of malignancy," was evaluated in relation to age groups (young: <50 years old; middle: 50-59 years old; and old: >or=60 years old).

RESULTS

At the follow-up colonoscopies, a total of 8,271 newly developed neoplasms were found, of which 41 (0.50%) lesions were malignant. The proportion of malignancy was 0.35%, 0.31%, and 1.07% in the young, middle, and old age groups, respectively (P(trend) = 0.002). This trend remained significant when stratified by the size of polyps. The proportion of malignancy was higher on the left-side colon than on the right-side colon, except in the old age group, where it was similar on either side. The proportion of malignancy at the follow-ups was not associated with the lesions found at the initial colonoscopies.

CONCLUSIONS

The development of malignant lesions in small sizes increased on the colon or rectum at older ages.

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 (< or =5 mm), small adenoma (6-9 mm), advanced adenoma (> or =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.

Clinicopathological features of nonpolypoid colorectal tumors as viewed from the patients' background

BACKGROUND

This study was performed to characterize the clinicopathological features of colorectal tumors with flat-, depressed-, or protruded-type morphology (hereafter referred to simply as flat, depressed, or protruded lesions).

METHODS

There are two major types of colorectal tumor: polypoid (protruded) and nonpolypoid (flat and depressed). A total of 130 lesions from 130 patients with colorectal submucosal invasive cancer were classified into three groups according to their macromorphology seen during endoscopy: flat (laterally spreading) and depressed nonpolypoid tumors and protruded polypoid tumors. The following factors in the patients' background were evaluated: indication for colonoscopy, age, and family history of colorectal cancer in first-degree relatives (i.e., parents, siblings, children). We also compared the following characteristics of the tumors: size, location, depth of submucosal invasion, vascular invasion, and frequency of synchronous and metachronous tumor lesions.

RESULTS

The incidence of abnormal findings on follow-up studies after polypectomy as an indication for colonoscopy was significantly higher among patients with flat lesions (4/24, 16.7%) and depressed lesions (3/22, 13.6%) than among those with protruded lesions (1/84, 1.2%) (P < 0.01, P < 0.01). Patients with flat lesions (65.8 +/- 7.6 years old) were significantly older than those with protruded lesions (P < 0.05). The patients with flat tumors had a significantly higher rate of a family history of colorectal cancer (6/24, 25.0%) than patients with protruded or depressed lesions (P < 0.01, P < 0.05). The protruded lesions were significantly larger than the depressed lesions (size 13.3 +/- 6.7 mm) (P < 0.05), and the flat lesions (24.1 +/- 10.1 mm) were significantly larger than either the protruded or depressed lesions (P < 0.01, P < 0.01). Seventy-five percent (18/24) of the flat lesions were located in the right colon, and this proportion was significantly higher than that among the protruded or depressed lesions (P < 0.01, P < 0.01). The mean +/- SD depth of submucosal invasion was 1218 +/- 1034 microm in the flat lesions, 2392 +/- 1869 microm in the depressed lesions, and 2761 +/- 1929 microm in the protruded lesions, representing a significant difference (P < 0.05, P < 0.0001). Of the 24 patients with flat lesions, 9 (37.5%) showed vascular invasion; this proportion was significantly lower than that among patients with the depressed or protruded lesions (P < 0.01, P < 0.01). Patients with depressed lesions tended to have higher incidence of synchronous and metachronous malignant polyps than those with protruded or flat lesions.

CONCLUSION

It is important to examine the morphology of colorectal tumors when diagnosing them and planning the treatment strategy, including follow-up, after resection of nonpolypoid tumors. It is useful to know the patient's family history so nonpolypoid tumors can be accurately diagnosed.

Right-side shift of colorectal adenomas with aging

BACKGROUND

Although it is known that right-side colon cancers increase with aging, the location of adenomas according to age has been controversial. Adenomas found at initial colonoscopies may be a mixture of polyps that arose at various earlier ages.

OBJECTIVES

To elucidate the relationship between location and age at which adenomas actually developed.

DESIGN

Prospective cohort study.

SETTING

A large-scale health appraisal institution in Japan.

PATIENTS

A total of 23,444 consecutive, asymptomatic Japanese who underwent total colonoscopy at their annual medical health check-up.

INTERVENTIONS

We analyzed newly developed adenomas after confirmation of the absence of colorectal neoplasms by two serial total colonoscopies.

MAIN OUTCOME MEASUREMENTS

The results of follow-up colonoscopies in 6304 subjects with no colorectal neoplasms at 2 initial colonoscopies were analyzed. The locations were separated into right-side colon and left-side colon from the splenic flexure. The locations of new adenomas found for the first time during the follow-up term were analyzed.

RESULTS

A total of 1472 subjects developed new colorectal adenomas. In 1255 cases with single adenomas, the ratios of number of cases with right-side lesions to that with left-side lesions at the ages of <40 years, 40 to 49 years, 50 to 59 years, 60 to 69 years, and > or =70 years were 1.18, 1.00, 1.29, 1.31, and 1.89, respectively. In 217 cases with multiple adenomas found concurrently, the percentage of cases with adenomas only on the right side at the ages of <40 years, 40 to 49 years, 50 to 59 years, 60 to 69 years, and > or =70 years were 0%, 25%, 34%, 37%, and 63%, respectively.

LIMITATIONS

Small lesions might have been missed even by 2 serial colonoscopies.

CONCLUSIONS

Adenomas on the right-side colon increased with aging.

Ultrathin colonoscope with a diameter of 9.8 mm for total colonoscopy

BACKGROUND

The pediatric colonoscope is superior to the standard colonoscope in some patients with a fixed, angulated colon. A colonoscope thinner than the pediatric one is thought to outperform even the pediatric colonoscope in such cases. This study was conducted to assess the efficacy of an ultrathin colonoscope, 9.8 mm in diameter, comparing it with pediatric and standard colonoscopes.

METHODS

Three types of colonoscopes were used: ultrathin, pediatric, and standard. A total of 287 consecutive patients were assigned to three groups: ultrathin (n=94), pediatric (n=98), and standard (n=95). First assessment was the ratio of cecal intubation and the reasons for unsuccessful colonoscopy. The second was the time to cecal intubation.

RESULTS

Cecal intubation rates were not different among three groups (96% in each). The main reasons for failed colonoscopy were looping in the ultrathin group, and angulation or stricture in the pediatric and standard groups. Mean time to the cecum was slightly longer in the ultrathin group (6.5 minutes) than the pediatric group (5.6 minutes) and standard group (6.1 minutes), but there were no significant differences among three groups.

CONCLUSION

Colonoscopy with the ultrathin colonoscope was as successful as with the pediatric and standard colonoscopes. The advantage of the ultrathin colonoscope might be notable in cases with stricture or severe angulation.

The changing distribution and survival of colorectal carcinoma: an epidemiological study in an area of northern Italy

OBJECTIVE

This study analyses the inter-relations of anatomical tumour location, gender, age and incidence rates for colorectal cancer from 1978 to 1999 in an area of northern Italy: the Parma district.

METHODS

Data were obtained from the Parma Cancer Registry. Age-adjusted incidence rates were analysed by gender, age and colorectal cancer subsites. In addition, 5 year observed survival rates were determined.

RESULTS

In the Parma area, the incidence of colorectal cancer is rising. We have observed a true increase in the rate of the age standardized incidence of right colon cancer, linked to an increased incidence of left colon cancer, while the incidence of rectal cancer has remained constant. The frequency of right-sided colon cancer was higher in aged patients, and in women. Age-standardized relative survival of patients after diagnosis of colorectal cancer between 1992 and 1996 was found to be significantly higher than age-standardized relative survival after diagnosis between 1978 and 1982.

CONCLUSIONS

In the Parma area there has been an increased incidence of right colon cancer, linked to an increased incidence of left colon cancer, while the incidence of rectal cancer has remained constant. We feel that this shift, whatever the reason for it, has important implications for the choice of screening techniques.

Rectosigmoid findings are not associated with proximal colon cancer: Analysis of 6196 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 6196 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.

A prospective study of the frequency and the topographical distribution of colon neoplasia in asymptomatic average-risk Chinese adults as determined by colonoscopic screening

BACKGROUND

The goal of this study was to determine the frequency of colorectal neoplasia in an asymptomatic Taiwanese population and the topographic distribution of lesions relative to age and gender.

METHODS

Colonoscopy was performed in 1846 consecutive asymptomatic adults undergoing a health evaluation in 2003. Neoplastic lesions were considered advanced if they exceeded 10 mm in size, had a villous component, or contained moderately or severely dysplastic tissue or invasive cancer. Lesions at and proximal to the splenic flexure were considered proximal in location; those distal to the splenic flexure were classified as distal in location.

RESULTS

Of 1741 (94.3%) patients (1041 men, 700 women; mean 52.5 years) enrolled, 1708 (98.1%) underwent total colonoscopy. Of these patients, 263 (15.4%) had colorectal neoplasia; 51 (3.0%) had advanced lesions. A total of 331 lesions were detected; 125 (37.8%) were proximal in location. Two thirds of patients with proximal advanced lesions (66.7%, 10/15) had no distal lesion. The proportion of patients with proximal or proximal plus distal lesions increased with age ( p = 0.027).

CONCLUSIONS

Colonoscopy is an effective primary screening modality for colorectal neoplasia in asymptomatic Chinese patients. Many lesions would be missed, especially in the elderly, if only sigmoidoscopy was used for initial screening.

Flat-type early colorectal cancer preferentially develops in right-sided colon in older patients

BACKGROUND

Flat-type colorectal cancer is frequently reported in Japan and Europe, but its clinical features remain obscure. Thus, we investigated the clinical features of flat-type early colorectal cancer with respect to tumor location and patient age and compared them with those of polypoid-type early and advanced cancer.

METHODS

Between January 1999 and June 2001, total colonoscopy was performed in 6,178 patients (mean age, 61 years; 4,290 males and 1,888 females). Of these patients, 402 patients with 429 colorectal cancers were found: 202 at advanced stage (invading beyond muscularis propria) and 227 at early stage (carcinoma in situ or invading within submucosa). Early-stage cancer was classified into two macroscopic subgroups: flat-type and polypoid-type.

RESULTS

Out of 227 early cancers, 44 were flat type and 183 were polypoid. Flat-type early cancer was more frequently located in the right colon (57 percent, 25/44) than polypoid-type cancer (19 percent, 35/183; P < 0.001). Adenomatous component in flat-type early cancer was less frequent than in polypoid-type cancer (23 percent vs. 92 percent, P < 0.001). The proportion of right-sided colon in flat-type early cancer increased with age (33 percent in patients < or = 59 years, 50 percent in patients between 60 and 69 years, and 72 percent in patients > or = 70 years), whereas polypoid-type early cancer showed minimal change (16 percent, 18 percent, and 25 percent, respectively). An increase in the proportion of right-sided colon with age was also found in advanced cancer (20 percent, 38 percent, and 52 percent, respectively).

CONCLUSION

The incidence of flat-type early cancer in right-sided colon increased with age, similar to the pattern of advanced cancer. This suggests that flat-type early cancer may be a precursor of advanced cancer in the right colon, especially in older people.