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At least 649 records · Page 36Linked to original sources
PubMed2002

Analysis of minichromosome maintenance proteins as a novel method for detection of colorectal cancer in stool.

Colorectal cancer is a common disease, and more reliable screening methods are needed for early detection. We aim to develop a non-invasive, stool-based assay that can identify colorectal cancer by detection of minichromosome maintenance protein 2 (MCM2) expression in colonocytes retrieved from the faecal surface. We devised a cell line model to investigate methods and conditions for optimum colonocyte retrieval. In our clinical evaluation study, MCM2-positive cells were retrieved from 37 of 40 patients with symptomatic colorectal cancer, but from none of 25 healthy control individuals. These results suggest that immunocytochemical analysis of retrieved colonocytes might enable accurate detection of colorectal cancer in stool.

Adenocarcinoma↗
PubMed2004

A randomized trial of direct mailing of fecal occult blood tests to increase colorectal cancer screening.

BACKGROUND: Although colorectal cancer screening by using a fecal occult blood test (FOBT), flexible sigmoidoscopy, colonoscopy, or barium enema x-ray reduces the incidence of and death from colorectal cancer, the rate of colorectal cancer screening in the general population is low. We conducted a randomized trial consisting of direct mailing of FOBT kits to increase colorectal cancer screening among residents of Wright County, Minnesota, a community in which colorectal cancer screening was promoted. METHODS: At baseline, we mailed a questionnaire about colorectal cancer screening to a random sample of Wright County residents aged 50 years or older who were randomly selected from the Minnesota State Driver's License and Identification Card database (estimated N = 1451). The sample was randomly allocated into three equal subgroups: one group (control) received only the questionnaire, one group received FOBT kits by direct mail with reminders, and one group received FOBT kits by direct mail without reminders. Study participants were sent a follow-up questionnaire 1 year after baseline. We used the responses to the questionnaires to estimate the 1-year change in self-reported screening rates in each group and the differences in the changes among the groups, along with the associated bootstrap 95% confidence intervals (CIs). RESULTS: At baseline, the estimated response rate was 86.5%, self-reported adherence to FOBT guidelines was 21.5%, and overall adherence to any colorectal cancer screening test guidelines was 55.8%. The 1-year rate changes in absolute percentage for self-reported adherence to FOBT use were 1.5% (95% CI = -2.9% to 5.9%) for the control group, 16.9% (95% CI = 11.5% to 22.3%) for the direct-mail-FOBT-with-no-reminders group, and 23.2% (95% CI = 17.2% to 29.3%) for the direct-mail-FOBT-with-reminders group. The 1-year rate changes for self-reported adherence to any colorectal cancer screening test were 7.8% (95% CI = 3.2% to 12.0%) for the control group, 13.2% (95% CI = 8.4% to 18.2%) for the direct-mail-FOBT-with-no-reminders group, and 14.1% (95% CI = 9.1% to 19.1%) for the direct-mail-FOBT-with-reminders group. CONCLUSION: Direct mailing of FOBT kits combined with follow-up reminders promotes more rapid increases in the use of FOBT and nearly doubles the increase in overall rate of adherence to colorectal cancer screening guidelines in a general population compared with a community-wide screening promotion and awareness campaign.

Aged↗
PubMed2003

Genetic alterations and MSI status in primary, synchronous, and metachronous tumors in a family with hereditary nonpolyposis colorectal cancer (HNPCC).

In colorectal cancer, different levels of microsatellite instability (MSI) have been described: high-frequency MSI, low-frequency MSI, and stable microsatellites. MSI-H characterizes a unique clinical and pathologic phenotype known as hereditary nonpolyposis colorectal cancer syndrome (HNPCC). In this case, an increased incidence of synchronous and metachronous tumors has been reported, but there are few reports with standardized criteria of MSI in HNPCC-associated tumors. The authors attempted to establish whether tumors of the HNPCC spectrum with different levels of MSI could predict the development of metachronous carcinomas. We have examined the levels of MSI at loci frequently affected in colorectal cancers in primary, synchronous, and metachronous tumors in a family that fulfils the Amsterdam criteria for HNPCC. This family presents colorectal cancers, HNPCC-extracolonic tumors (endometrial and ureter), and tumors (breast and bladder) not described in the HNPCC spectrum. The tumors exhibited MSI-H, irrespective of their location and regardless whether they were primary, synchronous, or metachronous, with the only exception of both endometrial tumors that showed low-frequency MSI tumors (MSI-L). Our results suggest that not only colorectal tumors with MSI-H result in a potential marker for the determination of high-risk individuals for metachronous and synchronous tumors, but also MSI-L endometrial tumors might be considered as indicative of high-risk individuals.

Adult↗
PubMed1995

Randomized phase III study of 5-fluorouracil plus high dose folinic acid versus 5-fluorouracil plus folinic acid plus methyl-lomustine for patients with advanced colorectal cancer.

BACKGROUND: Metastatic colorectal cancer is generally incurable. The most active regimen available, 5-fluorouracil (5-FU) and folinic acid (Leucovorin), produces response rates of approximately 25% to 30%. Methyl-lomustine is a nitrosourea with modest activity against colorectal cancer. A randomized trial was undertaken to evaluate the impact the addition of methyl-lomustine would have on response, duration of survival, and survival rates in patients with advanced colorectal cancer. METHODS: The methyl-lomustine/5-FU/Leucovorin (MFL) regimen consisted of methyl-lomustine (110 mg/m2), administered on Day 1 of each 8-week cycle with six weekly boluses of 5-FU (600 mg/m2), and Leucovorin (500 mg/m2). The FL treatment arm consisted of the administration of 5-FU and Leucovorin as described above. Patients were evaluated for response and toxicity after each 8-week cycle. RESULTS: Of 319 patients included in this trial, 297 (93.1%) had disease evaluable for response and toxicity: 145 received MFL, and 152 received FL. In this trial, 526 courses of MFL and 529 courses of FL were administered. Methyl-lomustine/5-FU/Leucovorin treatment resulted in 4 complete and 30 partial responses (response rate, 21.9%), and FL treatment resulted in 9 complete and 33 partial responses (response rate, 26.4%). There was no significant difference in median survival duration between patients in the two arms (MFL = 48 weeks, FL = 51 weeks). However, MFL was significantly more toxic with greater myelosuppression than was FL (Grade 3-4 neutropenia: MFL = 56 patients, FL = 27 patients, P < 0.001; Grade 3-4 thrombocytopenia: MFL = 49 patients, FL = 2 patients, P < 0.001; Grade 3-4 anemia: MFL = 15 patients, FL = 6 patients, P < 0.001; and more prolonged median duration of granulocytopenia: MFL = 9 days, FL = 7 days, P < 0.001; and thrombocytopenia: MFL = 14 days, FL = 7.5 days, P < 0.001). CONCLUSION: Because the addition of methyl-lomustine in the MFL schedule markedly increased the toxicity of the regimen and because the FL regimen was as effective as MFL, the authors recommend that Leucovorin and 5-FU remain the treatment choice for treating patients with metastatic colorectal cancer.

Adult↗
PubMed2003

The role of hMLH3 in familial colorectal cancer.

Hereditary nonpolyposis colorectal cancer (HNPCC) is commonly associated with at least three currently known DNA mismatch repair genes: (a) hMSH2; (b) hMLH1; and (c) hMSH6. A majority of HNPCC families has identifiable mutations in hMLH1 and hMSH2. When these mutations cause an inherited risk of colorectal cancer, they are also most often associated with microsatellite instability in the tumors. Recently, hMLH3 was suggested to be causative in HNPCC. We screened 70 index patients suggestive of a genetic predisposition for germ-line mutations in hMLH3 with denaturing high-performance liquid chromatography. One frameshift mutation and 11 missense mutations were identified in 16 index patients (23%). Most families presented evidence against hMLH3 as a high risk factor in familial colorectal cancer, and most of the mutations were found in the low risk patients, suggesting hMLH3 to be a low risk gene for colorectal cancer. We demonstrate in one family that a hMLH3 mutation segregated with disease together with a missense mutation in hMSH2, which makes us hypothesize that these mutations work together in an additive manner and result in an elevated risk of colorectal tumors in the family. None of the tumors with hMLH3 mutations showed microsatellite instability, which demonstrates that hMLH3 does not make its contribution to carcinogenesis through an impaired DNA mismatch repair function.

Carrier Proteins↗
PubMed2006

Reduction in late diagnosis of colorectal cancer following introduction of a specialist colorectal surgery service.

INTRODUCTION: An audit of patients presenting with colorectal cancer to our district general hospital during a 2-year period from November 1994 found that 12.1% of cases were diagnosed later than 6 months after initial presentation to a physician. This audit was repeated for a 2-year period from December 2001, to determine whether the introduction of a specialist coloproctology surgery service had led to a reduction in late diagnosis of colorectal cancer. PATIENTS AND METHODS: Case notes were reviewed of all patients presenting with colorectal cancer between December 2001 and November 2003. Late diagnosis was defined as diagnosis of colorectal cancer more than 6 months after their first attendance to either their general practitioner or district general hospital. The results were compared with those of the previous study. RESULTS: Of a total of 218 patients presenting with colorectal cancer during the study period, 14 (6.4%; 10 men and 4 women) satisfied the criteria for late diagnosis, with the longest delay being 12.5 months. Reasons for late diagnosis were false-negative reporting of barium studies (n = 3), inaccurate tumour biopsy (n = 2), concurrent pathology causing anaemia (n = 4), inappropriate delay in definitive investigation (n = 3), and refusal of investigation by patients (n = 2). CONCLUSIONS: There has been a reduction of nearly 50% (12.1% to 6.4%) in the proportion of patients with a late diagnosis of colorectal cancer compared with our previous audit. It is suggested that an important factor in this improvement in diagnosis has been the introduction of a specialist coloproctology surgery service.

Adult↗
PubMed2006

[Prognosis of colorectal cancer and socio-economic inequalities].

It is well established that socio-economic status is a major prognostic factor for many cancers, including colorectal cancer. The aims of this review are (i) to report epidemiological data showing how socio-economic status influences colorectal cancer survival, (ii) to attempt to describe the mechanisms underlying these survival inequalities, and (iii) to assess their impact on survival of colorectal cancer.

Colorectal Neoplasms↗
PubMed1996

Colorectal cancer: the challenge.

Colorectal cancer is a common cancer and a common cause of death. The incidence varies widely and is highest in industrialised Western countries. Surgery remains the mainstay of treatment of localised tumours and, in addition, may also play a role in some patients with local recurrence and/or isolated liver or lung metastases. Chemotherapy is required to improve the results of surgery and to treat patients with disseminated disease. For more than 30 years, 5-fluorouracil (5-FU) has been the only active agent in advanced colorectal cancer with an overall response rate of less than 15%. Biomodulation of 5-FU with leucovorin has led to a substantial increase in the response rate, but only a modest benefit in survival. Improvement in palliative effects has also been observed. In adjuvant treatment after curative surgery, 5-FU with levamisole or leucovorin has shown approximately a 10% absolute increase in survival, compared with controls. Despite this progress, there is evidence that an important proportion of colorectal cancer patients remains untreated. New treatments, such as the direct and specific thymidylate synthase inhibitors (e.g. 'Tomudex'--raltitrexed, previously known as ZD1694) in first-line therapy, or CPT-11 or oxaliplatin, along with increased referral and a more consistent treatment approach could improve the outcome of patients with advanced colorectal cancer.

Antimetabolites, Antineoplastic↗
PubMed2002

Randomized adjuvant trial of tamoxifen and goserelin versus cyclophosphamide, methotrexate, and fluorouracil: evidence for the superiority of treatment with endocrine blockade in premenopausal patients with hormone-responsive breast cancer--Austrian Breast and Colorectal Cancer Study Group Trial 5.

PURPOSE: Effective adjuvant treatment modalities in premenopausal breast cancer patients today include chemotherapy, ovariectomy, and tamoxifen administration. The purpose of Austrian Breast and Colorectal Cancer Study Group Trial 5 was to compare the efficacy of a combination endocrine treatment with standard chemotherapy. PATIENTS AND METHODS: Assessable trial subjects (N = 1,034) presenting with hormone-responsive disease were randomized to receive either 3 years of goserelin plus 5 years of tamoxifen or six cycles of cyclophosphamide, methotrexate, and fluorouracil (CMF). Stratification criteria included tumor stage and grade, number of involved nodes, type of surgery, and steroid hormone receptor content. Relapse-free survival (RFS) was defined as time from randomization to first relapse, local recurrence, or contralateral incidence, and overall survival (OS) as time to date of death. RESULTS: With a 60-month median follow-up, 17.2% of patients in the endocrine group and 20.8% undergoing chemotherapy developed relapses. Local recurrences emerged in 4.7% and 8.0%, respectively. RFS and local recurrence-free survival differed significantly in favor of endocrine therapy (P =.037 and P =.015), with a similar trend observed in OS (P =.195). CONCLUSION: Overall, our data suggest that the goserelin-tamoxifen combination is significantly more effective than CMF in the adjuvant treatment of premenopausal patients with stage I and II breast cancer.

Antineoplastic Agents, Hormonal↗
PubMed1985

Leukocyte adherence inhibition (LAI) for detecting specific tumor immunity in colorectal cancer.

Immunity to colorectal cancer antigen was tested by the tube leukocyte adherence inhibition (LAI) assay, using spent medium of human carcinoma cell lines as a source of antigen. The assay was positive in 18 out of 43 patients (41%) with colorectal tumor in comparison to only 2 out of 34 (5.8%) of colorectal cancer patients clinically free of disease, and to 4 out of 150 (2.6%) healthy subjects. The frequency of positive results correlated negatively with the tumor burden, 16 out of 29 (55.1%) patients with Dukes' A, B and C being positive compared to only 2 out of 14 (14.2%) patients with Dukes' stage D disease. Addition of PGE2 enhanced the sensitivity of the assay without affecting its specificity. The number of positive assays increased from 18 to 32 (41.8% to 74.4%) in the whole group of 43 colorectal cancer patients without altering significantly the frequency of positive results in the control group. The results with all groups of patients were influenced similarly by the addition of prostaglandins, the frequency of positive assays increasing from 55.1% to 82.7% and from 14.1% to 57.1% in early and advanced disease, respectively. These results lend further support to the value of the LAI assay in diagnosis and monitoring of the immune response in human colorectal cancer.

Antigens, Neoplasm↗
PubMed1990

Screening of average-risk individuals for colorectal cancer. WHO Collaborating Centre for the Prevention of Colorectal Cancer.

Recent developments in screening, diagnosis and treatment of colon cancer could lead to a reduction in mortality from this disease. Removal of adenomas, identification of risk factors, appropriate application of accurate diagnostic tests, and aggressive anatomic-surgical resection of colon cancers may already be having a favourable impact. Screening of average-risk populations over the age of 50 also offers promise in the control of this important cancer. The disease is of sufficient magnitude to deserve detection at an early stage with better prospects of patient survival, since screening tests with moderate sensitivity and high specificity are available. Flexible sigmoidoscopy and faecal occult blood tests are sufficiently acceptable to be included in case-finding among patients who are in the health care system. The results of current controlled trials involving more than 300,000 individuals for evaluating the impact of screening on mortality from colon cancer are needed before this approach can be recommended for general public health screening of the population. Further research is required to develop better screening tests, improve patient and physician compliance, and answer more definitively critical questions on cost-effectiveness. Mathematical modelling using current and new data can be used to determine the effectiveness of screening in conjunction with recommendations for primary prevention.

Colorectal Neoplasms↗
PubMed2005

Low dose aspirin, COX-inhibition and chemoprevention of colorectal cancer.

Chemoprevention of colorectal cancer involves the long-term use of pharmacologic agents that can prevent neoplasms from developing in the large bowel. This new approach requires major funding and human investments. Among the most widely studied agents for the chemoprevention of colorectal cancer, aspirin, the NSAIDs and COX-2 inhibitors seem to be the most promising. A large number of observational epidemiological studies show that regular use of aspirin and other NSAIDs is associated with a reduction in the risk of developing both colorectal adenomas and cancer. In addition, the prodrug sulindac reduces the growth of existing polyps in familial adenomatous polyposis (FAP). However, the dose, duration of effect and length of protection seen after cessation remain to be fully established. Furthermore, in view of previous discrepancies between the results of observational studies and randomized control trials (RCTs), it is crucially important to investigate the effects of aspirin by RCTs. RCTs investigating the effect of chemopreventive agents on adenoma recurrence as an intermediate endpoint for colorectal cancer is a more feasible approach than RCTs to investigate the effect on the incidence if colorectal cancer per se. Four RCTs of the effect of aspirin on adenoma recurrence are available. Other trials are currently underway.

Adenoma↗
PubMed1999

Colorectal cancer: genetics and screening.

Colorectal cancer is a common disease in the Western world. Most, if not all, colorectal cancers develop from previously benign adenomas. There are a number of genetic abnormalities including mutations in oncogenes and tumor suppressor genes which either present as a germline, or acquired defects lead to the development of colorectal cancer. Two well-defined hereditary colorectal cancer syndromes exist, hereditary nonpolyposis colorectal cancer syndrome and familial adenomatous polyposis coli, for which genetic testing is possible and advised. Guidelines for screening for colorectal cancer in average, moderate, and high risk patients are available from the American Cancer Society and were updated in 1997. The American Society of Clinical Oncology has published guidelines for genetic testing in a variety of cancers including colorectal cancer.

Colorectal Neoplasms↗
PubMed1999

Microsatellite instability in adenomas as a marker for hereditary nonpolyposis colorectal cancer.

Hereditary nonpolyposis colorectal cancer (HNPCC) is the most common of the well-defined colorectal cancer syndromes, accounting for at least 2% of the total colorectal cancer burden and carrying a greater than 80% lifetime risk of cancer. Significant reduction in cancer morbidity and mortality can be accomplished by appropriate clinical cancer screening of HNPCC patients with mutations in mismatch repair (MMR) genes. Thus, it is desirable to identify individuals who are mutation-positive. In individuals with cancer, mutation detection can be accomplished relatively efficiently by germline mutation analysis of individuals whose cancers show microsatellite instability (MSI). This study was designed to assess the feasibility of screening colorectal adenoma patients for HNPCC in the same manner. Among 378 adenoma patients, six (1.6%) had at least one MSI adenoma. Five out of the six patients (83%) had a germline MMR gene mutation. We conclude that MSI analysis is a useful method of prescreening colorectal adenoma patients for HNPCC.

Adenoma↗
PubMed2004

Meat-related mutagens/carcinogens in the etiology of colorectal cancer.

Diets containing substantial amounts of red or preserved meats may increase the risk of various cancers, including colorectal cancer. This association may be due to a combination of factors such as the content of fat, protein, iron, and/or meat preparation (e.g., cooking or preserving methods). Red meat may be associated with colorectal cancer by contributing to N-nitroso compound (NOC) exposure. Humans can be exposed to NOCs by exogenous routes (from processed meats in particular) and by endogenous routes. Endogenous exposure to NOCs is dose-dependently related to the amount of red meat in the diet. Laboratory results have shown that meats cooked at high temperatures contain other potential mutagens in the form of heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). To investigate the role of these compounds, we have created separate databases for HCAs and PAHs, which we have used in conjunction with a validated meat-cooking food frequency questionnaire. The role of meat type, cooking methods, doneness levels, and meat-cooking mutagens has been examined in both case-control studies and prospective cohort studies, with mixed results. Here, we review the current epidemiologic knowledge of meat-related mutagens, and evaluate the types of studies that may be required in the future to clarify the association between meat consumption and colorectal cancer.

Ammonia↗