[Colorectal carcinoma: prevention and early detection in an asymptomatic population--prevention in patients at risk--endoscopic diagnosis, therapy and after-care of polyps and carcinomas. German Society of Digestive and Metabolic Diseases/Study Group for Gastrointestinal Oncology]

Smoking, lower gastrointestinal endoscopy, and risk for colorectal cancer

BACKGROUND

Lower gastrointestinal endoscopy can decrease colorectal cancer risk strongly through detection and removal of adenomas. Thus, we aimed to investigate whether utilization of lower gastrointestinal endoscopy modifies the effect of lifetime smoking exposure on colorectal cancer risk in a population-based case-control study.

METHODS

In this study from Southern Germany including 2,916 patients with colorectal cancer and 3,044 controls, information about lifetime smoking and other risk factors was obtained from standardized interviews. Self-reported endoscopies were validated by medical records. Multivariate logistic regression was performed to investigate associations of smoking with colorectal cancer risk after stratification by utilization of lower gastrointestinal endoscopy in the preceding 10 years.

RESULTS

Median age of patients and controls was 69 and 70 years, respectively. Former regular smoking was associated with increased colorectal cancer risk in the group with no previous endoscopy [adjusted OR, 1.50; 95% confidence interval (CI), 1.28-1.75], whereas no association was found in the group with preceding endoscopy (OR, 1.05; CI, 0.83-1.33; P for interaction <0.01). Lower gastrointestinal endoscopy did not modify the association of smoking and colorectal cancer risk among current smokers and among the more recent quitters.

CONCLUSIONS

Our results suggest that the increased risk of colorectal cancer among former regular smokers is essentially overcome by detection and removal of adenomas at lower gastrointestinal endoscopy. However, risk of colorectal cancer was increased if smoking was continued into higher adult age.

IMPACT

The strong protective effect of lower gastrointestinal endoscopy may be compromised by continued smoking. Smoking cessation may increase the efficacy of lower gastrointestinal endoscopy.

Expression of Transketolase like gene 1 (TKTL1) predicts disease-free survival in patients with locally advanced rectal cancer receiving neoadjuvant chemoradiotherapy

Background

For patients with locally advanced rectal cancer (LARC) neoadjuvant chemoradiotherapy is recommended as standard therapy. So far, no predictive or prognostic molecular factors for patients undergoing multimodal treatment are established. Increased angiogenesis and altered tumour metabolism as adaption to hypoxic conditions in cancers play an important role in tumour progression and metastasis. Enhanced expression of Vascular-endothelial-growth-factor-receptor (VEGF-R) and Transketolase-like-1 (TKTL1) are related to hypoxic conditions in tumours. In search for potential prognostic molecular markers we investigated the expression of VEGFR-1, VEGFR-2 and TKTL1 in patients with LARC treated with neoadjuvant chemoradiotherapy and cetuximab.

Methods

Tumour and corresponding normal tissue from pre-therapeutic biopsies of 33 patients (m: 23, f: 10; median age: 61 years) with LARC treated in phase-I and II trials with neoadjuvant chemoradiotherapy (cetuximab, irinotecan, capecitabine in combination with radiotherapy) were analysed by quantitative PCR.

Results

Significantly higher expression of VEGFR-1/2 was found in tumour tissue in pre-treatment biopsies as well as in resected specimen after neoadjuvant chemoradiotherapy compared to corresponding normal tissue. High TKTL1 expression significantly correlated with disease free survival. None of the markers had influence on early response parameters such as tumour regression grading. There was no correlation of gene expression between the investigated markers.

Conclusion

High TKTL-1 expression correlates with poor prognosis in terms of 3 year disease-free survival in patients with LARC treated with intensified neoadjuvant chemoradiotherapy and may therefore serve as a molecular prognostic marker which should be further evaluated in randomised clinical trials.

The relevance of unrelated costs internal and external to the healthcare sector to the outcome of a cost-comparison analysis of secondary prevention: the case of general colorectal cancer screening in the German population

The potential of secondary prevention measures, such as cancer screening, to produce cost savings in the healthcare sector is a controversial issue in healthcare economics. Potential savings are calculated by comparing treatment costs with the cost of a prevention program. When survivors' subsequent unrelated health care costs are included in the calculation, however, the overall cost of disease prevention rises. What have not been studied to date are the secondary effects of fatal disease prevention measures on social security systems. From the perspective of a policy maker responsible for a social security system budget, it is not only future healthcare costs that are relevant for budgeting, but also changes in the contributions to, and expenditures from, statutory pension insurance and health insurance systems. An examination of the effect of longer life expectancies on these insurance systems can be justified by the fact that European social security systems are regulated by the state, and there is no clear separation between the financing of individual insurance systems due to cross-subsidisation. This paper looks at how the results of cost-comparison analyses vary depending on the inclusion or exclusion of future healthcare and non-healthcare costs, using the example of colorectal cancer screening in the German general population. In contrast to previous studies, not only are future unrelated medical costs considered, but also the effects on the social security system. If a German colorectal cancer screening program were implemented, and unrelated future medical care were excluded from the cost-benefit analysis, savings of up to 548 million euros per year would be expected. The screening program would, at the same time, generate costs in the healthcare sector as well as in the social security system of 2,037 million euros per year. Because the amount of future contributions and expenditures in the social security system depends on the age and gender of the recipients of the screening program (i.e. survivors of a typically fatal condition), the impact of age and gender on the results of a cost-comparison analysis of colorectal cancer screening are presented and discussed. Our study shows that colorectal cancer screening generates individual cost savings in the social security system up to a life expectancy of 60 years. Beyond that age, the balance between a recipient's social security contributions and insurance system expenditure is negative. The paper clarifies the relevance of healthcare costs not related to the prevented disease to the economic evaluation of prevention programs, particularly in the case of fatal diseases such as colorectal cancer. The results of the study imply that, from an economic perspective, the participation of at-risk individuals in disease prevention programs should be promoted.

[Hereditary colorectal cancer]

One of the main challenges in the clinical management of familial colorectal cancer (CRC) remains the overlap of syndromes with different underlying genetic causes and the differentiated risk management of colorectal and associated malignancies. The Lynch syndrome (hereditary non-polyposis colorectal cancer, HNPCC) is characterized by the development of colorectal, endometrial, gastric and other cancers and is caused by a mutation in one of the mismatch repair (MMR) genes. Microsatellite instability (MSI) and/or immunohistochemistry (IHC) are important prognostic factors and may predict the response to chemotherapy. Familial adenomatous polyposis (FAP) may be seen as a counterpart to Lynch syndrome, responsible for <1% of all CRC cases. Recently the MUTYH gene has been identified as a further polyposis gene. The associated disorder has been termed MYH-associated polyposis (MAP) and displays an autosomal recessive pattern of inheritance. For clinical management, distinguishing between Lynch syndrome, attenuated FAP and MAP is important for risk assessment, surveillance recommendations and indication for prophylactic surgery.

Importance of postpolypectomy surveillance and postpolypectomy compliance to follow-up screening--review of literature

INTRODUCTION

Approximately 150,000 people are diagnosed with colorectal cancer each year and 56,000 may die from it annually in the United States. Colorectal cancer is the second leading cause of cancer deaths in the USA and yet, when diagnosed at an early stage, it is one of the most preventable cancers. According to the US Preventive Services Task Force, initial screening for colorectal cancer is recommended in people above 50 years of age with average risk and earlier in people with a strong family history and other risk factors. Adenomatous polyps are considered as precursors of colorectal cancer. Removal of polyps and postpolypectomy surveillance reduces the overall mortality from colorectal cancer.

DISCUSSION

According to updated guidelines in 2006, a 3-year-follow-up colonoscopy is recommended in patients with adenomatous polyps>or=1 cm. An important factor in the surveillance and prevention of colorectal cancer in postpolypectomy patients is compliance with follow-up colonoscopy. In the present article, we provide an overview of the importance of postpolypectomy surveillance and summarize the compliance data for postpolypectomy surveillance. Compliance to postpolypectomy surveillance varies from one study to another and it should be expected that the compliance with follow-up would be low outside of clinical trials. Some measures that can improve patient compliance include patient education regarding a need of follow-up screening, reminder letters, and alerts in patient's charts.

CONCLUSION

In conclusion, effective surveillance screening with good patient compliance in postpolypectomy patients will contribute significantly in reducing colon cancer morbidity and mortality.

Appropriateness of colonoscopy in the era of colorectal cancer screening: a prospective, multicenter study in a private-practice setting (Berlin Colonoscopy Project 1, BECOP 1)

PURPOSE

The introduction of reimbursement for screening colonoscopy in Germany more than one year ago raised concerns that the consequent workload might lead to underuse of diagnostic colonoscopy for symptomatic patients. Available appropriateness criteria for diagnostic colonoscopy have been rarely tested in a realistic outpatient setting. This study was designed to test current appropriateness criteria for diagnostic colonoscopy to better select patients and potentially provide more capacity for screening cases. Secondary goals were yield and quality control in both the diagnostic and screening cases.

METHODS

A prospective study was initiated in 39 private-practice offices to collect data on consecutive colonoscopies conducted during a 6-day study period. A detailed questionnaire was developed to define indications and symptoms, and all findings at colonoscopy were recorded. Colonoscopies were further analyzed and stratified into a screening and a diagnostic group. In the diagnostic group, indications were assessed according to the current guidelines for appropriateness (American Society for Gastrointestinal Endoscopy, European Panel for the Appropriateness of Gastrointestinal Endoscopy), and the results were correlated with the percentage of relevant findings (tumors, inflammatory conditions).

RESULTS

During the study period, 1,397 colonoscopies (57 percent screening, 43 percent diagnostic) were analyzed (male/female ratio = 39/61 percent; mean age, 61 years). Fourteen percent and 37 percent, respectively, of the 605 diagnostic colonoscopies were regarded as inappropriate relative to the criteria of the American Society for Gastrointestinal Endoscopy and the European Panel for the Appropriateness of Gastrointestinal Endoscopy. However, the percentage of relevant inflammatory and neoplastic findings (polyps, cancer, inflammatory bowel disease, benign strictures) was only 5 to 10 percent higher in the appropriate group than in the inappropriate group. On the basis of these data, a hypothetical model for selecting appropriate indications was developed: if patients older than aged 50 years with pain, bleeding, and diarrhea, but not constipation, are regarded as having an appropriate indication, such an approach would save 20 percent of colonoscopies in these main indication groups (bleeding, pain, diarrhea, constipation), with a hypothetical miss rate for relevant findings (as defined above) of 5 percent.

CONCLUSIONS

Currently used appropriateness criteria for diagnostic colonoscopy increase the yield of relevant findings but lead to a miss rate for relevant findings in the range of 10 to 15 percent. Simple selection criteria based on age and symptoms could be more suitable and should be tested in a larger group of patients.

Non-compliance in surveillance for patients with previous resection of large (≥ 1 cm) colorectal adenomas

AIM: To assess the extent and reasons of non-compliance in surveillance for patients undergoing polypectomy of large (≥ 1 cm) colorectal adenomas.

METHODS: Between 1995 and 2002, colorectal adenomas ≥ 1 cm were diagnosed in 210 patients and subsequently documented at the Erlangen Registry of Colorectal Polyps. One hundred and fifty-eight patients (75.2%) could be contacted by telephone and agreed to be interviewed. Additionally, records were obtained from the treating physicians.

RESULTS: Fifty-four out of 158 patients (34.2%) neglected any surveillance. Reasons for non-compliance included lack of knowledge concerning surveillance intervals (45.8%), no symptoms (29.2%), fear of examination (18.8%) or old age/severe illness (6.3%). In a multivariate analysis, the factors including female gender (P = 0.036) and age > 62 years (P = 0.016) proved to be significantly associated with non-compliance in surveillance.

CONCLUSION: Efforts to increase compliance in surveillance are of utmost importance. This applies particularly to women’s compliance. Effective strategies for avoiding metachronous colorectal adenoma and cancer should focus on both the improvement in awareness and knowledge of patients and information about physicians for surveillance.

Cost-benefit analysis of screening colonoscopy in 40- to 50-year-old first-degree relatives of patients with colorectal cancer

BACKGROUND AND AIMS

As shown previously, 40- to 50-year-old first-degree relatives of patients with colorectal cancer (CRC) have significantly more colorectal adenomas than controls of the same age. Screening colonoscopy of these persons at risk between 40 and 50 years might be cost beneficial.

METHODS

We prepared a detailed cost-benefit analysis of screening colonoscopy and possible repeat endoscopies according to current expenditures for endoscopic procedures in Germany. Since screening colonoscopy is generally offered and reimbursed from 55 years on in Germany, we analysed the period between 45 and 55 years, taking an annual interest rate of 5% into account. Costs were analysed based on the results of a former study [11] depending on various participation rates in a general screening programme.

FINDINGS

Based on the available 1994 figure of about 20,000 euros for diagnosis and treatment of one cancer case, screening colonoscopy is cost beneficial when participation is high. Under a more realistic assumption of currently about 40,000 euros per cancer case, screening colonoscopy is cost beneficial in any case.

INTERPRETATION

Our data support that systematic screening colonoscopy in first-degree relatives of patients with CRC by the age of 45 years most likely demonstrates an economic benefit.

Occult endometrial cancer and decision making for prophylactic hysterectomy in hereditary nonpolyposis colorectal cancer patients

BACKGROUND AND OBJECTIVE

Hereditary nonpolyposis colorectal cancer (HNPCC) is the most frequent form of hereditary colorectal cancer. In addition to the high lifetime risk for colorectal cancer in mutation carriers, there is also a remarkably increased risk for endometrial cancer (EC).

METHODS

In this retrospective study, clinical and molecular approach to the individual decision making as to whether or not to perform a prophylactic hysterectomy in a subset of HNPCC patients is discussed. 147 female patients meeting at least one criterion of the Bethesda guidelines were included in this analysis between 1995 and 2003. After clinical and genetic counseling, patients gave informed written consent and microsatellite analysis, immunohistochemistry and sequencing of the mismatch repair genes MLH1, MSH2 and MSH6 was performed.

RESULTS

11 of the analyzed patients had a personal history of EC and had undergone previous hysterectomy at ages 26 to 62 years. Prophylactic hysterectomy with oophorectomy was considered in postmenopausal women meeting the Amsterdam criteria and/or carrying a disease causing mismatch repair gene mutation who were operated on because of diagnosed colorectal cancer in our center for hereditary cancer. This procedure was performed in 4 patients. None of them had shown any symptoms of a gynecologic malignancy. Preoperative gynecological examination showed no evidence for EC or ovarian cancer in these patients. Postoperative histological examination showed EC stage T1b N0 M0 in 2 patients.

CONCLUSIONS

Since the efficiency of gynecological surveillance is uncertain, prophylactic hysterectomy could be an option for a subset of HNPCC patients and mutation carriers.

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

BACKGROUND AND AIMS

Persons with a familial risk of colorectal cancer (CRC) account for about 25% of all CRC cases. The adenoma prevalence in relatives of CRC patients 50-60 years of age is 17-34%; data on younger individuals are scarce. Our aim was to prospectively define the adenoma prevalence in 40- to 50-year-old first-degree relatives of CRC patients compared to controls.

PATIENTS AND METHODS

CRC patients were identified via the regional cancer registry, and their 40- to 50-year-old first-degree relatives (risk group) were invited for screening colonoscopy. Additional probands and controls of the same age were recruited by newspaper articles and radio or television broadcastings. Using high-resolution video colonoscopy, each detected polyp was removed and histopathologically assessed. Each participant completed demographic and epidemiological questionnaires.

RESULTS

Of 228 subjects in the risk group 36.4% had polypoid lesions compared to 20.9% of 220 controls (p<0.001). Forty-three (18.9%) subjects in the risk group had adenomas compared to 18 (8.2%) in the control group (p=0.001). High-risk adenomas (>10 mm and/or of villous type) were found in 12 persons in the risk group compared to 5 controls (not significant). In the risk group most lesions (52%) were located proximal to the sigmoid colon compared to 29% in controls.

CONCLUSIONS

Subjects between 40-50 years with first-degree relatives with CRC demonstrate a significantly higher prevalence of adenomas than controls, with a tendency towards a more proximal location. These data support a screening colonoscopy in persons with familial risk already between 40 and 50 years.

Feasibility and diagnostic utility of video capsule endoscopy for the detection of small bowel polyps in patients with hereditary polyposis syndromes

OBJECTIVES

At present, surveillance of premalignant small bowel polyps in hereditary polyposis syndromes has a number of limitations. Capsule endoscopy (CE) is a promising new method to endoscopically assess the entire length of the small bowel.

METHODS

We prospectively examined 40 patients with hereditary polyposis syndromes (29 familial adenomatous polyposis (FAP), 11 Peutz-Jeghers syndrome (PJS)). Results were compared with push-enteroscopy (PE) results in FAP and with esophagogastroduodenoscopy, PE, (MR)-enteroclysis, and surgical specimen in PJS patients.

RESULTS

A total of 76% of the patients with FAP with duodenal adenomas (n = 21) had additional adenomas in the proximal jejunum that could be detected by CE and PE. Moreover, 24% of these FAP patients had further polyps in the distal jejunum or ileum that could only be detected by CE. In contrast, in FAP patients without duodenal polyps (n = 8), jejunal or ileal polyps occurred rarely (12%). CE detected polyps in 10 of 11 patients with PJS, a rate superior to all other reference procedures employed. Importantly, the findings of CE had immediate impact on further clinical management in all PJS patients.

CONCLUSIONS

Our results suggest that CE may be of clinical value in selected patients with FAP, whereas in PJS, CE could be used as first line surveillance procedure.

Detection of colorectal polyps by multislice CT colonography with ultra-low-dose technique: comparison with high-resolution videocolonoscopy

BACKGROUND

This prospective study compared multislice CT colonography with ultra-low-dose technique to high-resolution videocolonoscopy as the standard for detection of colorectal cancer and polyps.

METHODS

After standard bowel preparation, 115 patients underwent multislice CT colonography with an ultra-low-dose multislice CT colonography protocol immediately before videocolonoscopy. After noise reduction by using a mathematical algorithm, ultra-low-dose multislice CT colonographic images were analyzed in blinded fashion, and the results were compared with the results of high-resolution videocolonoscopy.

RESULTS

A total of 150 lesions were detected by high-resolution videocolonoscopy in 115 patients. For ultra-low-dose multislice CT colonography, sensitivities for detection of polyps less than 5 mm in size, 5 to 10 mm, and greater than 10 mm in diameter were 76%, 91%, and 100%, respectively. Although the sensitivity for detection of flat lesions was only 50%, the sensitivity and the specificity for detection of polyps 5 mm or greater in size were 94% and 84%, respectively. For adenomatous lesions greater than 5 mm in size, sensitivity was 94% and specificity was 92%. The overall specificity was 79%. The calculated effective radiation dose ranged between 0.75 and 1.25 mSv.

CONCLUSIONS

Compared with high-resolution videocolonoscopy, ultra-low-dose multislice CT colonography has excellent sensitivity and specificity for detection of colorectal lesions 5 mm or greater in size, and the radiation exposure is relatively low. However, before this technique can be generally recommended for colorectal screening, further improvement in the detection of flat and extremely small lesions must be achieved.

[The importance of rectoscopy and colonoscopy in Internal Medicine]

The endoscopic examination of the large intestine can be considered today a routine examination in internal medicine. Since the introduction of flexible videoendoscopy, evaluating diseases in the distal colon using rectoscopy has become less important. Anoproctoscopy is an obligatory component for a complete colon diagnostic after a flexible ileo-colonoscopy has been performed. Colonoscopy has improved significantly the diagnosis and therapy of diseases in the large intestine since it has been introduced more than 30 years ago. By introducing modern videocolonoscopy in addition to other instruments, there is today a broad spectrum of diagnostic and therapeutic indications available. Specifically, due to its frequency and prognostic relevance, colonoscopy has become the most powerful and important procedure in the early detection and prevention of colon cancer.

Is colonoscopic screening of a low-risk (normal) population ethically justifiable?

This report summarizes the arguments for and against colonoscopic screening of a low-risk population for colorectal cancer. The strongest argument in favor of colonoscopy is that colonoscopy rarely misses an existing colorectal neoplasia and its precursor lesions and that procedural side effects are rare. In contrast, the combination of fecal occult blood test plus sigmoidoscopy leaves 10-15% of advanced neoplasms in the proximal colon undetected. However, colonoscopy is costly and the health care systems of only few European countries refund the respective costs. In addition, there is presently not sufficient manpower available to deliver colonoscopy to the public starting at the age of 50 in a 1:10 yearly frequency. Compliance to the procedure is very low even in countries which refund screening costs. Therefore, promotion of colonoscopy as the presently most effective screening procedure depends mainly on major educational efforts within the public to increase compliance as well as on the readiness of European health care systems to cover the respective costs.

Neoadjuvant treatment with weekly high-dose 5-Fluorouracil as 24-hour infusion, folinic acid and oxaliplatin in patients with primary resectable liver metastases of colorectal cancer

PURPOSE

To evaluate the efficacy and safety of neoadjuvant treatment comprising weekly high-dose 5-fluorouracil (5-FU) as a 24-hour infusion, folinic acid (FA) and biweekly oxaliplatin (L-OHP), followed by metastatic resection in patients with primarily resectable liver metastases of colorectal cancer (CRC).

PATIENTS AND METHODS

20 patients with primarily resectable liver metastases of CRC were enrolled in a prospective phase II study. On an outpatient basis, the patients received a treatment regimen comprising biweekly 85 mg/m(2) L-OHP in the form of a 2-hour intravenous infusion and 500 mg/m(2) FA as a 1- to 2-hour intravenous infusion, followed by 2,600 mg/m(2 ) 5-FU administered as a 24-hour intravenous infusion once weekly. A single treatment cycle comprised one infusion per week during a period of 6 weeks followed by a 2-week rest. Two cycles were administered, with a third being added when the treatment was well tolerated. Thereafter, curative resection of the liver metastases was attempted, and the patients were followed up.

RESULTS

After neoadjuvant therapy, 2 of the original 20 patients showed complete remission (CR; 10%) and 18 patients partial remission (PR; 90%). As the main symptom of toxicity, diarrhea (CTC toxicity grade 3-4) was observed in 6 patients (30%), followed by vomiting in 3 patients (15%). The curative resectability rate was 80% (16 of 20). In 9 of 18 patients (50%) undergoing surgical intervention, mild postoperative complications, mainly wound healing disturbances (n = 5), occurred. No postoperative mortality was observed. Over a median follow-up of 23 months (12-38) 6 of 16 curatively resected patients developed distant metastases and 1 patient a local pelvic recurrence. The 2-year disease-free survival rate was 52% and the 2-year cancer-related survival rate 80%.

CONCLUSION

The neoadjuvant treatment with weekly high-dose 5-FU in the form of a 24-hour infusion combined with FA and L-OHP is very effective and well tolerated. Surgical morbidity does not appear to be increased by the neoadjuvant treatment.

Preventive surgery for colon cancer in familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer syndrome

BACKGROUND

A better understanding of the molecular basis of hereditary colorectal cancer syndromes such as hereditary nonpolyposis colorectal cancer syndrome (HNPCC) and familial adenomatous polyposis (FAP) has profound consequences for both the diagnosis and (prophylactic) treatment of (pre)malignant neoplastic lesions.

DISCUSSION

Sequence analysis of the underlying genes for these conditions and the detection of disease-causing genetic alterations in an index patient enable predictive testing for individuals at risk within an affected family. However, the clinical implications of predictive molecular testing depend on the overall penetrance and variability in the expression of pathogenic mutations. The extent of these parameters differs considerably among the various known hereditary colorectal cancer syndromes. Hence the integration of genetic information into the daily surgical practice remains challenging.

CONCLUSIONS

This review provides an update on the indications for family assessment, purpose and limitations of the genetic testing and resulting recommendations for prophylactic surgery in FAP and HNPCC.

Microsatellite alterations in free-circulating serum DNA in patients with ulcerative colitis

BACKGROUND/AIMS

The aim of this study was to find out whether there is free-circulating DNA in the serum of patients with ulcerative colitis and whether it is possible to establish a panel of genetic alterations which might be useful markers for diagnostic purposes, staging, or follow up.

METHODS

A set of 11 microsatellite markers located on different chromosomes were analyzed in a group of 59 patients with ulcerative colitis. Radiolabeled PCR products from serum and white blood cell DNA were analyzed by autoradiography and correlated with the clinical data from these patients.

RESULTS

Seven of 59 patients showed one or more microsatellite alteration(s) in their serum DNA. Six patients had an alteration in one marker, and two patients had changes in 4 markers, respectively. There was no correlation between the frequency of microsatellite alterations and the clinical data.

CONCLUSION

From the panel of 11 microsatellite markers used for these studies, 6 of them seem to be well suited for the detection of ulcerative colitis-associated alterations in free circulating serum DNA. In order to increase the specificity of this assay, it is necessary to increase the number of patients to be analyzed and to use a different set of markers.

Colonic cancer and polyps

Colorectal cancer (CRC) is one of the best studied cancers. It is easily accessible and develops slowly over several years from premalignant lesions (adenomatous polyps) to invasive cancers. The key molecular events in this sequence have been characterized. Different screening strategies have proven to be effective in lowering both the mortality and the incidence of CRC. Nevertheless, CRC is still the second leading cause of cancer-related deaths for both men and women in the USA and other Western countries. An estimated 130 000 new cases and more than 50 000 deaths have been diagnosed in the USA in 2000. Surgical resection remains the only curative treatment, and the likelihood of cure is greater when the disease is detected at an early stage. Hereditary non-polyposis colorectal cancer (HNPCC) and the different polyposis syndromes such as familial adenomatous polyposis (FAP) or Peutz-Jeghers disease are rare causes of CRC but have been a major focus of research in past years, helping with the understanding of the molecular events in carcinogenesis. This review summarizes our current knowledge of the pathogenesis and management of colorectal polyps and polyposis syndromes as well as sporadic CRC.