PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Colorectal Neoplasms”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2001

Genetic pathways in the evolution of morphologically distinct colorectal neoplasms.

Colorectal adenomas can be morphologically classified as exophytic or flat. Polypoid cancers and cancers arising de novo (ie., without any adenomatous component) might be the results of genetic progression from exophytic and flat adenomas, respectively. In this study, we examined 94 morphologically distinct neoplastic specimens for mutations in K-RAS and analyzed 10 microsatellite loci tightly linked to the tumor suppressor genes APC, p53, DCC/SMAD4, hMSH2, and hMLH1. K-RAS mutations were significantly associated with exophytic adenomas [11 of 21 (52%)] compared to flat adenomas [2 of 13(15%), P < 0.03] and polypoid cancers [17 of 25 (68%)] compared to cancers arising de novo [7 of 25 (28%), P < 0.01]. Two polypoid cancer cases demonstrated three and four different K-RAS mutations, respectively, suggesting multiple areas of clonal expansion. Cancers arising de novo were significantly associated with loss of heterozygosity (LOH) at chromosome 3p compared to pol ypoid cancers [6 of 18(33%) versus 1 of 20(5%), P < 0.03], whereas the prevalence of LOH at chromosomes 2p, 5q, 17p, and 18q and microsatellite instability were not different between the groups. For all cancers, LOH at chromosomes 17p and 18q occurred in 47 and 51%, respectively. However, LOH at 17p and 18q occurred in 0 and 16% of benign lesions, respectively, suggesting their role in malignant transformation. There was no difference in LOH at chromosomes 17p and 18q between exophytic and flat lesions. These findings suggest that (a) mutant K-RAS is associated with the exophytic growth of colonic neoplasms, and that (b) some colorectal cancers arising de novo lose chromosome 3p during their evolution, which is not seen in polypoid cancers. Half of all cancers lose chromosomes 17p and 18q at or near the malignant transition of benign lesions as reported previously, irrespective of morphology. There may be more than one genetic avenue for colorectal cancer formation, and this correlates with the morphological characteristics.

Adenoma↗
PubMed2003

Clinical indications of patients with colorectal neoplasm who underwent colonoscopy at King Chulalongkorn Memorial Hospital (presentations of colorectal neoplasm from colonoscopy database).

Even though colorectal cancer in Thailand is not the number one leading cause of death, the incidence of this malignancy is not ignorable. Unfortunately, the majority of patients are diagnosed at a very late stage because of no screening protocol for a high risk group. The authors retrospectively reviewed clinical presentations of patients with colorectal neoplasm who underwent colonoscopy at King Chulalongkorn Memorial Hospital during the two-year period from September 2000 to December 2002. There were 107 patients with colorectal polyps and 48 patients with colorectal cancer. According to frequency of indications: anemia, bowel habit change, and abnormal radiography were presented in patients with colorectal polyps and cancers. There were more right sided colorectal polyps than rectosigmoid polyps. In addition, rectosigmoid cancer was detected less often than right sided colonic cancer. Half of the patients with rectosigmoid cancer presented with hematochezia compared to right sided colonic cancer. Total colonic examination is required if a colonic neoplasm is suspected.

Adult↗
PubMed2004

Synchronous colorectal neoplasms in patients with colorectal cancer: predisposing individual and familial factors.

PURPOSE: Patients with colorectal cancer have an increased risk for developing synchronous and metachronous neoplasms. However, besides those cases with inherited disorders predisposing to tumor multicentricity, it is unknown which patients are prone to this condition. This study was designed to identify individual and familial characteristics associated with the development of synchronous colorectal neoplasms in patients with colorectal cancer. METHODS: During a one-year period, all patients with colorectal cancer attended in 25 Spanish hospitals were included. Exclusion criteria were colorectal cancer developed in the context of familial adenomatous polyposis or inflammatory bowel disease, refusal to participate in the study, incomplete family history, and inadequate examination of the colon and rectum. In addition to demographic, clinical, pathology, molecular (microsatellite instability status), and familial characteristics, presence of synchronous colorectal neoplasms (adenoma or carcinoma) were analyzed. RESULTS: A total of 1,522 patients were included in the study. Synchronous colorectal neoplasms were documented in 505 patients (33.2 percent): adenoma (n = 411), carcinoma (n = 27), or both (n = 67). Development of these lesions was associated with male gender (odds ratio, 1.94; 95 percent confidence interval, 1.43-2.65), personal history of colorectal adenoma (odds ratio, 3.39; 95 percent confidence interval, 1.58-7.31), proximal location of primary tumor (odds ratio, 1.40; 95 percent confidence interval, 1.02-1.94), tumor TNM Stage II (odds ratio, 1.31; 95 percent confidence interval, 1.15-4.66), mucinous carcinoma (odds ratio, 1.89; 95 percent confidence interval, 1.19-2.99), and family history of gastric cancer (odds ratio, 2.03; 95 percent confidence interval, 1.17-3.52). CONCLUSIONS: Based on individual and familial characteristics associated with synchronous colorectal neoplasms, it has been possible to identify a subgroup of patients with colorectal cancer prone to tumor multicentricity with potential implications on the delineation of preventive strategies.

Adenocarcinoma↗
PubMed1998

Loss of p21WAF1/Cip1 protein expression accompanies progression of sporadic colorectal neoplasms but not hereditary nonpolyposis colorectal cancers.

p21 (p21WAF1/Cip1), a cyclin-dependent kinase inhibitor, induces G1 arrest and can inhibit the activity of the proliferating cell nuclear antigen (PCNA). We analyzed p21 expression during colorectal tumorigenesis, its association with its transcriptional regulator p53, and its relationship to rates of cell proliferation and apoptosis. p21 and p53 protein expression were examined in sporadic tumors and hereditary nonpolyposis colorectal cancers (HNPCCs) by immunohistochemistry (IHC) and immunoblotting. Apoptosis was examined using a DNA nick end-labeling assay, and cell proliferation was examined by PCNA staining. In normal colorectal epithelia, nuclear p21 staining was uniformly detected in crypt cells of the superficial compartment (upper one-third) that stained negatively for PCNA. p21 and PCNA expression were, therefore, mutually exclusive. In sporadic cases, a decrease in the frequency of p21 expression accompanied adenoma development and progression to carcinoma. Specifically, p21 was detected in 12 of 16 (75%) adenomas and 10 of 32 (31%) carcinomas. In contrast to sporadic cases, HNPCCs with known mutations in DNA mismatch repair genes expressed p21 in 12 of 15 (80%) carcinomas. An inverse relationship between p21 and p53 was observed wherein mutant p53 proteins were detected in 4 of 15 (27%) HNPCCs versus 22 of 32 (69%) sporadic carcinomas. Although p21+ carcinoma cells were generally negative for p53, IHC revealed that some carcinoma cells expressed both p21 and p53 proteins. Furthermore, p53-mutated SW480 colon carcinoma cells were found to coexpress p21 and p53, suggesting that p21 can also be activated by a p53-independent mechanism. No association was found between p21 or PCNA and apoptotic labeling indices in adenomas or carcinomas. In conclusion, a decrease in p21 expression accompanies neoplastic progression in sporadic cases but not in HNPCCs. This finding appears related to p53 status in that the frequency of p53 expression was significantly reduced in HNPCCs compared to sporadic cases, suggesting a difference in their molecular pathways of tumorigenesis.

Colorectal Neoplasms↗
PubMedDate not supplied

Steroid receptor pattern of human colorectal neoplasms.

Twenty-four colorectal carcinomas were assayed for estrogen and progestin receptors by sucrose gradient centrifugation. Most biopsies were either completely estrogen receptor negative or displayed low titers of specific estrogen binding. Only three tumors demonstrated moderate estrogen binding activity (10-18 fmol/mg cytosol protein). In four tumors specific progestin binding exceeded 20 fmol/mg protein. Only a minor subset of the binders sedimented at 8S. Twenty-one colorectal tumors examined for the presence of glucocorticoid receptors were found to be receptor positive, without exception. Biopsies from normal colorectal mucosa displayed minute quantities of specific 8S estrogen and progestin binding, but significant titers of specific glucocorticoid binding. Our findings support the hypothesis that estrogens and progestins are unlikely to play a major role in endocrine control of colorectal neoplasms. The role of glucocorticoids in growth control of colorectal neoplasms remains to be defined.

Aged↗
PubMed2001

Recurrence and malignancy rates in a benign colorectal neoplasm patient cohort: results of a 5-year analysis in a managed care environment.

OBJECTIVE: To estimate the apparent recurrence rates of benign neoplasms and the development of malignant colorectal neoplasms over a 5-yr period in a high risk managed care population. METHODS: Using the CPT and ICD-9 CM codes, a cohort of subjects with benign neoplasms were identified with a colonoscopy in 1992 from a longitudinal claims database (MarketScan). Three groups of subjects (benign neoplasms with polypectomy, benign neoplasms without polypectomy, and no neoplasms) were evaluated. Five-year recurrence rates of benign or new malignant colorectal neoplasms were determined for the baseline benign neoplasms with polypectomy and no neoplasm groups. For the benign neoplasm without polypectomy, only rates for malignancy were evaluated. RESULTS: Of 16,293 subjects at baseline, 39.50% were diagnosed with benign and 5.50% with malignant neoplasms. The 5-yr cumulative incidence of benign neoplasms in subjects without an index neoplasm (n = 8,967) was 7.92% compared to the recurrence of 40.93% in subjects with a benign neoplasm and polypectomy (n = 4,046) at baseline (p < 0.001). The 5-yr cumulative incidence rates of malignant colorectal neoplasms in the no neoplasm (n = 8,967) and benign neoplasm groups (n = 6,438) were 1.81% and 2.55%, respectively (p < 0.005). A lower 5-yr malignancy rate was observed in benign neoplasm group with polypectomy (2.17%) compared to the benign neoplasm group without polypectomy (3.18%) (p < 0.05). CONCLUSION: The high recurrence rate of benign colorectal neoplasms and a higher incidence of colorectal cancer in subjects at high risk (history of benign colorectal neoplasm) highlight a healthcare opportunity for surveillance and/or interventions to reduce the morbidity associated with colorectal neoplasms.

Adult↗
PubMed1993

Dietary factors related to colorectal neoplasms.

Although the etiology of colorectal cancer is multifactorial, experimental evidence suggests a role for dietary factors in the promotion of this disease. The complex interrelations governing energy balance and the consumption of fat, fiber, and micronutrients make it difficult to define the precise role of specific dietary factors in the etiology of colorectal neoplasms. Epidemiologic studies have demonstrated a correlation between the prevalence of colorectal cancer and per capita consumption of meat and fat. Case-control studies investigating the relation between colorectal cancer and dietary fat consumption have yielded inconsistent results. Prospective studies have failed to demonstrate a relation between fat consumption and subsequent risk for colorectal cancer. There is an inverse correlation between fiber intake and the prevalence of colorectal carcinoma. A more detailed analysis of the influence of various types of dietary fiber on the subsequent risk for colorectal cancer will provide a better understanding of this relation. Fiber derived from fruits and vegetables may provide more effective protection than cereal fibers. Correlational studies have established an association between total caloric intake and the prevalence of colorectal carcinoma. The design of future studies investigating the influence of individual dietary constituents on the risk for colorectal cancer must control for variations in energy balance as a confounding variable. Recent evidence suggests that a variety of micronutrients, including calcium, vitamin D, selenium, and vitamins A, C, and E, exert an anticarcinogenic effect. Studies designed to evaluate the influence of alcohol consumption on colorectal carcinogenesis have yielded inconclusive results. The potential influence of food preparation methods on colorectal carcinogenesis requires further evaluation. There is no conclusive evidence to support any of the hypotheses proposed to explain the role of dietary factors in colorectal carcinogenesis. Intervention trials designed to monitor intermediate markers for colorectal cancer such as increased epithelial-cell proliferation rates and the development of aberrant crypt architecture provide the opportunity for testing these hypotheses in relatively short-term studies. The results from such studies can be utilized in the design of large-scale, long-term prospective studies to evaluate the influence of dietary factors on the development of colorectal neoplasms. These trials should generate the information required to develop strategies for diet modification to reduce the incidence of colorectal carcinoma.

Colorectal Neoplasms↗
PubMed1990

Hemoccult screening in detecting colorectal neoplasm: sensitivity, specificity, and predictive value. Long-term follow-up in a large group practice setting.

STUDY OBJECTIVE: To determine the sensitivity, specificity, and predictive value of Hemoccult II tests for detecting colorectal neoplasm (colorectal carcinoma or polyp or both). STUDY DESIGN: Prospective analyses of asymptomatic patients (greater than or equal to 45 years) followed for 4 years after screening with Hemoccult II testing and retrospective analyses of patients, with known colorectal carcinoma or polyps or both who had Hemoccult II testing within 2 years of diagnosis. SETTING: A large, health maintenance organization practice. MEASUREMENTS AND MAIN RESULTS: In the prospective analysis, the sensitivity of Hemoccult II was 50% for colorectal carcinoma diagnosed within 1 year of testing, 43% within 2 years, and 25% within 4 years. For polyps, sensitivity was 36% at 1 year, 28% at 2 years, and 17% at 4 years. Specificity was 99%. The predictive value of a positive test for colorectal carcinoma was 8% at 1 year, 10% at 2 years, and 11% at 4 years. On the basis of the retrospective analyses, the sensitivity of Hemoccult II for colorectal carcinoma diagnosed within 1 year of testing was 66% and was 61% within 2 years. Many of these patients had symptoms when tested. CONCLUSIONS: An asymptomatic patient age 45 or older with a positive Hemoccult II test has about a chance of 1 in 10 for having colorectal carcinoma and a 1-in-3 chance of having either a colorectal carcinoma or polyp: The same patient with a negative Hemoccult test has a 0.2% chance of having a colorectal carcinoma diagnosed within 2 years of testing and a 0.7% chance of having a polyp. Within 4 years of testing the chance increases to 0.5% for colorectal carcinoma and 1.5% for polyps. If Hemoccult II slides are the only screening method used for detecting asymptomatic colorectal neoplasms, 50% to 60% of lesions will remain undetected. Clinical interpretation of Hemoccult screening requires appreciation of its limits as well as its benefits.

Aged↗
PubMed2002

Clinical significance of depressed-type colorectal neoplasms based on growth and development.

A route of colorectal cancer development other than the adenoma-carcinoma sequence has recently become an issue due to the discovery of depressed-type early colorectal cancers. Moreover, the fact that some polyp-like cancers actually originate from depressed-type lesions has become obvious. Despite the protruding shapes of depressed-type early colorectal cancers, they probably have biological characteristics, which are different from those of the usual polyp lesions. We undertook this study to evaluate the clinical significance of depressed-type colorectal neoplasms. The authors recently experienced 87 cases of depressed-type colorectal neoplasms. Using Kudo's classification, we classified these 87 cases into three types based on their growth patterns, type IIc, type IIa + IIc, and type Is + IIc, and then analyzed these types on the basis of size, type, and submucosal invasion rate. The submucosal invasion rate of cancers of type IIa + IIc was significantly higher than that of type IIc (p < 0.05), and the rate for cancers of types IIa + IIc and Is + IIc together was significantly higher than that of type IIc (p < 0.05). However, no significant difference was found between the rates of types IIa + IIc and Is + IIc. In conclusion, the IIa + IIc and Is + IIc sub-types of depressed-type colorectal neoplasms, individually and together, have higher rates of submucosal invasion than type IIc lesions. Accordingly, type IIa + IIc and type Is + IIc must be differentiated from the usual polyps and should be managed cautiously, despite their protruding shapes.

Colorectal Neoplasms↗
PubMed2006

Depressed-type (0-IIc) colorectal neoplasm in patients with family history of first-degree relatives with colorectal cancer: A cross-sectional study.

AIM: To investigate the correlation of depressed-type (0-IIc) colorectal neoplasm and family history of first-degree relatives (FDR) with colorectal cancer (CRC). METHODS: This cross-sectional study was conducted from June 2000 to October 2002 at National Cancer Center Hospital East. Eligible patients undergoing initial total colonoscopy were surveyed regarding family history of CRC among FDR by a questionnaire prior to colonoscopic examinations. All endoscopic findings during colonoscopy were recorded and the macroscopic classification of the early stage neoplasm/cancer was classified into two types (0-IIc vs non 0-IIc). Odds ratios (OR) and 95% confidence intervals (CI) were calculated by univariate and multivariate logistic regression to estimate the association between macroscopic features and clinicopathological data including gender, age, and family history of FDR with CRC. RESULTS: The OR of an association between family history of FDR with CRC and overall early stage neoplasm adjusted by gender and age was 1.85 (95% CI: 1.31-2.61, P = 0.0004), that for non 0-IIc neoplasm was 1.71 (95% CI: 1.22-2.41, P = 0.0017) and for 0-IIc colorectal neoplasm was 2.78 (95% CI: 1.49-5.16, P = 0.0031). CONCLUSION: Our study shows a significant association between a family history of FDR with CRC and 0-IIc colorectal neoplasm. When patients with a family history of FDR with CRC undergo colonoscopy, colonoscopists should check carefully for not only polypoid, but also depressed-type (0-IIc) lesions.

Aged↗
PubMed1989

Value of a risk questionnaire in screening for colorectal neoplasm.

The value of a postal questionnaire and of Hemoccult II (Smith Klein Diagnostic Inc., Sunnyvale, California, USA) testing in screening for colorectal neoplasms was compared. In the questionnaire, the subjects were asked about previous treatment for colorectal neoplasm and rectal bleeding during the previous 6 months, specified as to type. All participants were asked to perform Hemoccult II blood testing over 3 days. Of 13,759 randomly selected subjects 9040 (66 per cent) performed the test and returned the questionnaire. Three hundred and fifty-four subjects with a positive Hemoccult II test and/or a proven previous colorectal neoplasm had a full assessment including double-contrast enema and rectosigmoidoscopy to 60 cm. Eighteen carcinomas and 61 adenomas were thus diagnosed. The population was followed for from 20 to 29 months, during which time rescreening was undertaken. An additional 34 subjects with carcinomas and 90 with adenomas were identified during this period. A significant correlation between the presence of a colorectal neoplasm and a previous history of colorectal neoplasm, a positive Hemoccult II and a previous history of bright red bleeding but not dark bleeding was found. The possibility of diagnosing a neoplasm was two, four and 19 times higher in a subject with a previous history of bleeding, a history of colorectal neoplasm, or a positive Hemoccult II respectively. Screening by faecal occult blood testing, therefore, at the moment seems to be the best and only practicable method.

Adenoma↗
PubMed2006

Screening practices of patients presenting for resection of a colorectal neoplasm.

Multiple studies demonstrate the efficacy of colorectal cancer (CRC) screening in patients over 50 years of age. However, there is a lack of consensus regarding which screening method to use, and compliance has been poor. The objective of this study was to identify the CRC screening practices at two institutions and determine the relationship between screening and pathologic stage for patients presenting with a colorectal neoplasm. This study, conducted at the University of Virginia (UVA) Health System and the Salem Veterans Affairs Medical Center (VAMC) between October 30, 2000, and September 1, 2004, included 198 patients > or = 50 years who presented for resection of a primary colorectal neoplasm. Pathologic stage and prior screening were identified retrospectively through chart review and patient response to an anonymous survey. Prior screening was demonstrated in 71 per cent of patients. Colonoscopy was the most commonly used modality. There was a higher percentage of CRC screening at VAMC compared with UVA (80% vs 62%, P < 0.0008). Patients at UVA were more likely screened with colonoscopy, whereas fecal occult blood testing (FOBT) was most common at VAMC (P < 0.0001). Prior CRC screening and cancer stage were inversely related. Ninety-one per cent of patients with benign polyps had been screened prior to diagnosis, compared with 72 per cent of patients with stage I and II cancer and 54 per cent of patients with stage III and IV cancer (P < 0.05). Of patients presenting for surgery, 71 per cent underwent CRC screening. Variability exists in the methods employed for CRC screening. CRC screening facilitates diagnosis at an early stage.

Aged↗
PubMed1996

Colorectal neoplasms detected colonoscopically in at-risk members of colorectal cancer families stratified by the demonstration of DNA microsatellite instability.

This study compared colonoscopic findings in families meeting the Amsterdam criteria (A) for hereditary non-polyposis colorectal cancer (HNPCC) but stratified according to whether the familial cancers showed DNA microsatellite instability. DNA was extracted from paired samples of normal and cancer, and microsatellite instability was analysed at up to six loci. Families were termed replication error positive (RER+) when at least 50% of tumours tested per family were positive. Of 26 families studied 17 were RER+ and 9 were RER-. Cancers in the A/RER- families showed no right-sided predilection (P < 0.001). Colonoscopies have been performed on 182 at-risk members of A/RER+ families and 60 members of A/RER- families. More of the at-risk members of A/RER-families were found to have adenomas at colonoscopy (P = 0.095), but these were smaller than those of A/RER+ families (P = 0.19). The adenoma:carcinoma ratio was twice as high in A/RER- families (13:1) as in A/RER+ families (7:1). One of the A/RER- families had hyperplastic polyposis. The others do not appear to have attenuated familial adenomatous polyposis and are similar to the adenoma families or late-onset colorectal cancer families described by others. This study illustrates the importance of molecular technology in separating HNPCC from syndromes with overlapping phenotypes.

Adenoma↗
PubMedDate not supplied

Laparoscopy-assisted surgery for colorectal neoplasm is justifiable regardless of advanced age.

BACKGROUND/AIMS: Laparoscopy-assisted surgery has been applied in patients with colorectal disease and resulted in favorable outcome compared with open surgery. However, it is not reported exclusively in terms of the curative mean in the geriatric patients with colorectal neoplasm yet. The aim of this study was to confirm the pros and cons of laparoscopy-assisted surgery for colorectal neoplasm in geriatric patients. METHODOLOGY: Seventy-four patients with colorectal neoplasm underwent laparoscopic surgery and all their charts were retrospectively reviewed. Fourteen patients were 75 years of age or older and compared with the remaining non-aged 60 patients in STUDY 1, and also compared with 46 aged patients who underwent open surgery in STUDY 2. RESULTS: In STUDY 1, the compiled total frequency of preoperative concomitant disease was significantly higher in the LAS-aged group. In STUDY 2, the mean operative time of the laparoscopic group was significantly longer than that of the open group. Mean estimated blood loss of the laparoscopic group was significantly smaller than that in the open group. Postoperative oral resumption and duration of hospital stay tended to be shorter in the laparoscopic group than in the open group. CONCLUSIONS: Laparoscopy-assisted surgery is a satisfactory treatment for colorectal neoplasm, even in geriatric patients.

Aged↗
PubMed2004

Prospective comparison of contrast enhanced CT colonography and conventional colonoscopy for detection of colorectal neoplasms in a single institutional study using second-look colonoscopy with discrepant results.

BACKGROUND: Colorectal cancer is the second leading cause of death from cancer in Western countries. Early detection by colorectal cancer screening can effectively cut its mortality rate. CT colonography represents a promising, minimally invasive alternative to conventional methods of colorectal carcinoma screening. AIMS: The purpose of this prospective single institutional study was to compare the abilities of routine clinical CT colonography and conventional colonoscopy to detect colorectal neoplasms using second-look colonoscopy to clarify discrepant results. PATIENTS AND METHODS: CT colonography was performed in 100 symptomatic patients using contrast enhanced multidetector CT followed by conventional colonoscopy on the same day. If results were discrepant, a second-look colonoscopy was performed after unblinding. CT colonographic findings were compared with those of conventional colonoscopy. RESULTS: Conventional colonoscopy found 122 colorectal neoplasms in 49 patients. The overall sensitivity of CT colonography at detecting patients with at least one polyp 6 mm or larger was 76% and its specificity was 88%. Its by-patient sensitivity for polyps 10 mm or larger was 95% and its specificity was 98%. By-polyp sensitivities were 71% for polyps 10 mm or larger, and 61% for polyps 6 mm or larger. A second-look colonoscopy was performed in 19 patients and two initial false-positive findings of CT colonography were reclassified as true-positive. For conventional colonoscopy, this produced a by-polyp sensitivity of 94% for detection of lesions 6 mm and larger. CONCLUSIONS: CT colonography had both a high by-patient sensitivity and specificity for detection of clinically important colorectal neoplasms 10 mm or larger. This suggests that CT colonography has the potential to become a valuable clinical screening method for colorectal neoplasms.

Adult↗