Colonoscopy surveillance of individuals at risk of familial colorectal cancer

Guidelines for the management of hereditary colorectal cancer from the British Society of Gastroenterology (BSG)/Association of Coloproctology of Great Britain and Ireland (ACPGBI)/United Kingdom Cancer Genetics Group (UKCGG)

Heritable factors account for approximately 35% of colorectal cancer (CRC) risk, and almost 30% of the population in the UK have a family history of CRC. The quantification of an individual's lifetime risk of gastrointestinal cancer may incorporate clinical and molecular data, and depends on accurate phenotypic assessment and genetic diagnosis. In turn this may facilitate targeted risk-reducing interventions, including endoscopic surveillance, preventative surgery and chemoprophylaxis, which provide opportunities for cancer prevention. This guideline is an update from the 2010 British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland (BSG/ACPGBI) guidelines for colorectal screening and surveillance in moderate and high-risk groups; however, this guideline is concerned specifically with people who have increased lifetime risk of CRC due to hereditary factors, including those with Lynch syndrome, polyposis or a family history of CRC. On this occasion we invited the UK Cancer Genetics Group (UKCGG), a subgroup within the British Society of Genetic Medicine (BSGM), as a partner to BSG and ACPGBI in the multidisciplinary guideline development process. We also invited external review through the Delphi process by members of the public as well as the steering committees of the European Hereditary Tumour Group (EHTG) and the European Society of Gastrointestinal Endoscopy (ESGE). A systematic review of 10 189 publications was undertaken to develop 67 evidence and expert opinion-based recommendations for the management of hereditary CRC risk. Ten research recommendations are also prioritised to inform clinical management of people at hereditary CRC risk.

Decentralized colonoscopic surveillance with high patient compliance prevents hereditary and familial colorectal cancer

Although colonoscopic surveillance is recommended both for individuals with known hereditary colorectal cancer (HCRC) syndromes and those with a more moderate familial colorectal cancer (FCRC) history, the evidence for the benefits of surveillance is limited and surveillance practices vary. This study evaluates the preventive effect for individuals with a family history of CRC of decentralized colonoscopic surveillance with the guidance of a cancer prevention clinic. We performed a population based prospective study of 261 patients with HCRC or FCRC, recorded in the colonoscopic surveillance registry at the Cancer genetics clinic, University Hospital of Umeå, Sweden. Colonoscopic surveillance was conducted every second (HCRC) or fifth (FCRC) year at local hospitals in Northern Sweden. Main outcome measures were findings of high-risk adenomas (HRA) or CRC, and patient compliance to surveillance. Estimations of the expected numbers of CRC without surveillance were made. During a total of 1256 person years of follow-up, one case of CRC was found. The expected numbers of cancers in the absence of surveillance was between 9.5 and 10.5, resulting in a standardized incidence ratio, observed versus expected cases of CRC, between 0.10 (CI 95 % 0.0012-0.5299) and 0.11 (CI 95 % 0.0014-0.5857). No CRC mortality was reported, but three patients needed surgical intervention. HRA were found in 5.9 % (14/237) of the initial and in 3.4 % (12/356) of the follow-up colonoscopies. Patient compliance to the surveillance program was 90 % as 597 of the planned 662 colonoscopies were performed. The study concludes that colonoscopic surveillance with high patient compliance to the program is effective in preventing CRC when using a decentralized method for colonoscopy surveillance with the guidance of a cancer prevention clinic.

Risk of Advanced Neoplasia in First-Degree Relatives with Colorectal Cancer: A Large Multicenter Cross-Sectional Study

BACKGROUND

First-degree relatives (FDR) of patients with colorectal cancer have a higher risk of developing colorectal cancer than the general population. For this reason, screening guidelines recommend colonoscopy every 5 or 10 y, starting at the age of 40, depending on whether colorectal cancer in the index-case is diagnosed at <60 or ≥60 y, respectively. However, studies on the risk of neoplastic lesions are inconclusive. The aim of this study was to determine the risk of advanced neoplasia (three or more non-advanced adenomas, advanced adenoma, or invasive cancer) in FDR of patients with colorectal cancer compared to average-risk individuals (i.e., asymptomatic adults 50 to 69 y of age with no family history of colorectal cancer).

METHODS AND FINDINGS

This cross-sectional analysis includes data from 8,498 individuals undergoing their first lifetime screening colonoscopy between 2006 and 2012 at six Spanish tertiary hospitals. Of these individuals, 3,015 were defined as asymptomatic FDR of patients with colorectal cancer ("familial-risk group") and 3,038 as asymptomatic with average-risk for colorectal cancer ("average-risk group"). The familial-risk group was stratified as one FDR, with one family member diagnosed with colorectal cancer at ≥60 y (n = 1,884) or at <60 y (n = 831), and as two FDR, with two family members diagnosed with colorectal cancer at any age (n = 300). Multiple logistic regression analysis was used for between-group comparisons after adjusting for potential confounders (age, gender, and center). Compared with the average-risk group, advanced neoplasia was significantly more prevalent in individuals having two FDR with colorectal cancer (odds ratio [OR] 1.90; 95% confidence interval [CI] 1.36-2.66, p < 0.001), but not in those having one FDR with colorectal cancer diagnosed at ≥60 y (OR 1.03; 95% CI 0.83-1.27, p = 0.77) and <60 y (OR 1.19; 95% CI 0.90-1.58, p = 0.20). After the age of 50 y, men developed advanced neoplasia over two times more frequently than women and advanced neoplasia appeared at least ten y earlier. Fewer colonoscopies by 2-fold were required to detect one advanced neoplasia in men than in women. Major limitations of this study were first that although average-risk individuals were consecutively included in a randomized control trial, this was not the case for all individuals in the familial-risk cohort; and second, the difference in age between the average-risk and familial-risk cohorts.

CONCLUSIONS

Individuals having two FDR with colorectal cancer showed an increased risk of advanced neoplasia compared to those with average-risk for colorectal cancer. Men had over 2-fold higher risk of advanced neoplasia than women, independent of family history. These data suggest that screening colonoscopy guidelines should be revised in the familial-risk population.

Colorectal cancer screening in the familial risk population: Is colonoscopy still the strategy of choice?

First-degree relatives of patients with colorectal cancer (CRC) are at high risk of this disease. For this reason, medical organizations and clinical guidelines recommend more intensive screening and surveillance for such first-degree relatives than for the average-risk population. Colonoscopy has been the cornerstone of CRC screening in this setting. Although colonoscopy is the most sensitive technique for the detection of neoplastic lesions (especially non-advanced adenomas), its role is less clear for CRC. In addition, screening colonoscopy has several limitations that may affect the success of a screening campaign, such as poor participant acceptance, the need for skilled endoscopists, participant access to screening colonoscopy, overburdened endoscopy units, potential complications, and procedure-related costs. In addition, recent evidence has cast doubt on the advantage of colonoscopy over other strategies for the detection of advanced neoplastic lesions. Despite being less sensitive in general, other screening methods frequently recommended in the average-risk population may be more acceptable and thus help increase CRC screening uptake. This review discusses recent evidence on the risk of CRC in first-degree relatives, the advantages and disadvantages of each screening technique, participation rates depending on the technique, patient preferences, and barriers to screening.

Ideal colonoscopic surveillance intervals to reduce incidence of advanced adenoma and colorectal cancer

BACKGROUND AND AIMS

There is limited information about the interplay between multiple risk factors contributing to the risk of advanced neoplasia. We determined the actual risk for advanced neoplasia in relation to lapsed time between colonoscopies in people enrolled in a structured surveillance program. This risk information can be used to guide the selection of optimal surveillance intervals.

METHODS

Patients were recruited into programs at two major tertiary hospitals, with a personal or family history of advanced neoplasia. Five thousand one hundred forty-one patients had an index and one or more surveillance colonoscopies. Fifty-one percent had a family history of colorectal neoplasia while the remainder had a personal history.

RESULTS

Patients with an immediately prior colonoscopy result (prior result) of advanced adenoma had a risk for advanced neoplasia 7.1 times greater than those with a normal prior result. Cancer as a prior result did not confer a greater risk than either a hyperplastic polyp or a nonadvanced adenoma. Being female reduced risk, age increased risk. Only a family history of a first-degree relative diagnosed under 55, or definite or suspected hereditary nonpolyposis colorectal cancer (HNPCC) conferred an increased risk over a personal history of advanced neoplasia.

CONCLUSIONS

Most family history categories did not confer excess risk above personal history of advanced neoplasia. A prior cancer poses less of a risk than a prior advanced adenoma. Based on our models, a person with an advanced adenoma should be scheduled for colonoscopy at 3 years, corresponding to a 15% risk of advanced neoplasia for a male aged under 56. Guidelines should be updated that uses a 15% risk as a benchmark for calculating surveillance intervals.

Screening participation for people at increased risk of colorectal cancer due to family history: a systematic review and meta-analysis

We conducted a systematic review and a meta-analysis of observational studies to identify and summarise the level of colorectal cancer (CRC) screening participation for people at increased risk due to family history of the disease. Medline, Cinhal, Embase and PsychInfo databases were comprehensively searched between January 1995 and May 2012 to identify relevant articles. To be included, studies had to report on screening for people who had at least one first-degree relative with CRC and no previous personal diagnosis of the disease. Pooled screening participation levels were calculated for each screening modality. Seventeen studies, accounting for a total of 13,269 subjects with a family history of CRC met the inclusion criteria. Seven studies, including a total of 6,901 subjects had a pooled faecal occult blood testing screening participation (at least once) of 25 % (95 % CI 12-38). Five studies including a total of 5,091 subjects had a pooled sigmoidoscopy-based screening participation (at least once) of 16 % (95 % CI 7-27). Seven studies including a total of 9,965 subjects had pooled participation colonoscopy-based screening (at least once) of 40 % (95 % CI 26-54). There was a significant level of screening heterogeneity between studies. This review identified a substantial underuse of CRC screening for people at increased risk of developing the disease. It highlights the potential opportunity that exists for increasing screening participation among this segment of the population and the need to adjust the current CRC screening policies towards that objective.

22-year longitudinal study of repetitive colonoscopy in patients with a family history of colorectal cancer

INTRODUCTION

We report the outcomes of a long-term surveillance programme for individuals with a family history of colorectal cancer.

METHODS

The details of patients undergoing a colonoscopy having been referred on the basis of family history of colorectal cancer were entered prospectively into a database. Further colonoscopy was arranged on the basis of the findings. The outcomes assessed included incidence of cancer and adenoma identification at initial and subsequent colonoscopy.

RESULTS

The records of 2,293 patients (917 men; median patient age: 51 years) were entered over 22 years, giving data on 3,982 colonoscopies. Eight adverse events (0.2%) were recorded. Twenty-seven cancers were found at first colonoscopy and thirteen developed during the follow-up period. There were significantly more cancers identified in those with more than one first-degree relative with cancer than in other groups (p=0.01). The number of adenomas identified at subsequent surveillance colonoscopies remained constant with between 9.3% and 12.0% of patients having adenomas that were removed. Two-thirds (68%) of patients with cancer and three-quarters (77%) with adenomas fell outside the British Society of Gastroenterology (BSG) 2006 guidelines.

CONCLUSIONS

Repeated colonoscopy continues to yield significant pathology including new cancers. These continue to occur despite removal of adenomas at prior colonoscopies. The majority of patients with cancers and adenomas fell outside the BSG 2006 guidelines; more would have fallen outside the 2010 guidelines.

22-year longitudinal study of repetitive colonoscopy in patients with a family history of colorectal cancer

Introduction

We report the outcomes of a long-term surveillance programme for individuals with a family history of colorectal cancer.

Methods

The details of patients undergoing a colonoscopy having been referred on the basis of family history of colorectal cancer were entered prospectively into a database. Further colonoscopy was arranged on the basis of the findings. The outcomes assessed included incidence of cancer and adenoma identification at initial and subsequent colonoscopy.

Results

The records of 2,293 patients (917 men; median patient age: 51 years) were entered over 22 years, giving data on 3,982 colonoscopies. Eight adverse events (0.2%) were recorded. Twenty-seven cancers were found at first colonoscopy and thirteen developed during the follow-up period. There were significantly more cancers identified in those with more than one first-degree relative with cancer than in other groups (p=0.01). The number of adenomas identified at subsequent surveillance colonoscopies remained constant with between 9.3% and 12.0% of patients having adenomas that were removed. Two-thirds (68%) of patients with cancer and three-quarters (77%) with adenomas fell outside the British Society of Gastroenterology (BSG) 2006 guidelines.

Conclusions

Repeated colonoscopy continues to yield significant pathology including new cancers. These continue to occur despite removal of adenomas at prior colonoscopies. The majority of patients with cancers and adenomas fell outside the BSG 2006 guidelines; more would have fallen outside the 2010 guidelines.

Colorectal cancer screening in patients at moderately increased risk due to family history

Patients with a positive family history have an increased risk of colorectal cancer (CRC) and, in many countries, more intensive screening regimens, sometimes involving the use of colonoscopy as opposed to sigmoidoscopy or fecal occult blood testing, are recommended. This review discusses current screening guidelines in the United States and other countries, data on the magnitude of CRC risk in the presence of a family history and the efficacy of recommended screening programs, as well as ancillary issues such as compliance, cost-effectiveness and accuracy of family history ascertainment. We focus on the relatively common “sporadic” family histories of CRC, which typically imparts a mild to moderate elevation in the risk for CRC development in the proband. Defined familial syndromes associated with extremely high risks of CRC, such as hereditary non-polyposis colorectal syndrome or familial adenomatous polyposis, require specialized management approaches and are beyond the scope of this article. We will also not discuss colonoscopic surveillance in patients with a personal history of adenomas or CRC.

Familial risk of colorectal cancer in subjects attending an organised screening programme

BACKGROUND

First degree relatives of colorectal cancer patients are at increased risk for the same disease.

AIMS

To evaluate the prevalence of familial risk and its association with the occurrence of pathological significant lesions in subjects with positive faecal occult blood testing leading to colonoscopy.

METHODS

Faecal occult blood testing is offered biennially to subjects aged 50-70. Subjects with a positive faecal test are invited to undergo colonoscopy. Familial history for colorectal cancer in subjects undergoing colonoscopy was routinely recorded.

RESULTS

From 1995 to 2009, 4833 screenees with positive faecal occult blood test undergoing colonoscopy were enrolled. Twelve percent reported a positive first degree family history. Multivariate analysis evidenced that the probability of detecting pathological significant lesions was statistically associated with age, gender, type of test, repeated or first screening, and having at least 1 first degree relative with colorectal cancer.

CONCLUSIONS

Subjects attending colonoscopy reporting a positive first degree family history are at increased risk for pathologically significant lesions.

A decision-analytic evaluation of the cost-effectiveness of family history-based colorectal cancer screening programs

OBJECTIVES

The aim of this study was to determine the cost-effectiveness of family history screening (FHS) for colorectal cancer (CRC) susceptibility at age 40 with early screening of those with increased risk.

METHODS

The cost-effectiveness of several family history-based screening programs was estimated with a validated microsimulation model, using data from the SEER cancer registry, life tables, medicare records, and published data. Familial cancer syndromes were excluded. Screening programs evaluated included (i) colonoscopy screening every 10 years starting at age 50 (no family history assessment); (ii) colonoscopy every 10 years from age 40 for persons with a family history; (iii) colonoscopy every 5 years from age 50 for those with a family history; and (iv) colonoscopy every 5 years from age 40 for persons with a family history. In each FHS scenario, persons without a family history are screened with colonoscopy at age 50, then every 10 years to age 80.

RESULTS

Compared with colonoscopy screening of all persons from age 50, the cost-effectiveness of the family history-based screening programs varied from $18,000-$51,000 per life year (LY) gained. Screening family history cases every 5 years from age 40 is more cost-effective than screening every 10 years from age 40. Reducing screening frequency for those without a family history lowers program expenditures substantially at a modest loss of LYs. The results are sensitive to the CRC risk difference between positive and negative family histories.

CONCLUSIONS

The cost-effectiveness of CRC FHS guidelines varies widely. Economic issues should be considered before implementing family history-directed screening programs.

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.

Clinicopathological characteristics of colorectal cancer with family history: an evaluation of family history as a predictive factor for microsatellite instability

To determine whether family history of cancer may be a risk factor for the mutator phenotype in colorectal cancer, we recruited 143 consecutive colorectal cancer patients with a family history of accompanying cancers not meeting the Amsterdam criteria. Microsatellite instability (MSI) at 5 markers, hMLH1-promoter methylation, and expression of mismatch repair (MMR) proteins (hMLH1, hMSH2, hMSH6, hMPS1, and hPMS2) were determined. Among the relatives of familial colorectal cancer patients, colorectal cancer was the most common tumor type. Of the proband colorectal cancers, 26 (18.2%) showed high-level MSI (MSI-H); 47 additional tumors with mutator phenotype (32.9%) were identified by hMLH1-promoter methylation and/or loss of MMR protein expression. Mutator phenotype was associated with right-sided colon cancer and the type of accompanying cancer. Family history, which was differentially quantified according to the degree of relatives and the type of accompanying cancers, effectively discriminated MSI-H from microsatellite stable (MSS) and low-level microsatellite instability (MSI-L) and mutator phenotypes. Our findings indicate that familial colorectal cancer may be associated with multiple occurrences of colorectal or accompanying cancers and that family history could be correlated with microsatellite instability.

The impact of new screening protocol on individuals at increased risk of colorectal cancer

OBJECTIVE

Screening colonoscopy has been shown to reduce mortality and cancer stage in hereditary nonpolyposis colorectal cancer (HNPCC) individuals. However, the benefit of screening in intermediate risk groups is unknown. The most recent national guidelines have recommended a reduction of screening frequency for the intermediate risk group. Therefore, this study aims to compare the results of colonoscopic screening in HNPCC and intermediate risk groups and assess the effect of the most recent screening protocol recommendations.

METHOD

A total of 244 individuals; 108 from HNPCC families (28 mismatch repair gene carriers) and 136 from intermediate risk families were referred for regular colonoscopic screening by the Regional Genetics Service. Findings from 417 colonoscopies performed between 1992 and 2003 were evaluated.

RESULTS

A total of three cancers, 39 adenomas and 41 hyperplastic polyps were found in the HNPCC group compared with one cancer, 22 adenomas and 19 hyperplasic polyps in the intermediate risk group. If the recent screening guidelines for the intermediate group were applied, then 89 (44%) fewer colonoscopies would have been performed. Although no cancers would have been missed, six adenomas (mean size = 5.7 mm, range 2-10 mm) with two graded as severely dysplasic and six hyperplastic polyps would not have been detected.

CONCLUSION

The detection rate and distribution of adenomas were similar in both groups. If the new colonoscopic screening recommendations for the intermediate risk group had been applied, a small number of significant lesions would have been missed.

Gynecological tumors revealing hereditary nonpolyposis colorectal cancer: analysis of a large Lebanese pedigree

The objective of this study was to evaluate the aggregation of colorectal cancer (CRC) and hereditary nonpolyposis colorectal cancer (HNPCC)-related extracolonic cancers in an extended Lebanese family with HNPCC. This was a pedigree analysis and a prospective follow-up over an 8-year period. The causative germ line mutation was detected using denaturing high-performance liquid chromatography, polymerase chain reaction (PCR) of short fluorescent fragments, and direct DNA sequencing of purified PCR products. The penetrance of CRC is high and accounts for approximately two thirds of risk carriers with an early age of onset (21 years). The extracolonic cancer spectrum includes ovary, endometrium, small bowel, skin, and brain, with an age of onset as early as 30 years. The causative mismatch repair gene mutation is an MSH2 point mutation involving the splice donor site of intron 3 (G-->A). Scrutinized in genomic DNA from 35 consented members, it was found in 18 of them and cosegregates with the cancer phenotype in the family. Early-onset ovarian and endometrial carcinomas may reveal HNPCC families in the Middle Eastern region, with MSH2 germ line mutation. We propose a biannual screening program, starting around the age of 20-25 years, pending additional data on this topic.

Systemic analysis of the differential gene expression profile in a colonic adenoma-normal SSH library

BACKGROUND

The discovery of differentially expressed genes of colonic adenoma minus normal mucosa enables the understanding of early molecular events in colorectal carcinogenesis. In our previous study, we have developed an adenoma minus normal mucosa suppression subtractive hybridization (SSH) library and identified 109 differentially expressed clones.

METHODS

An in-house EST pipeline and the Gene Ontology web-based tool () were used to analyze these clones. Realtime quantitative RT-PCR (Q-PCR) was applied to detect the expression of 14-3-3 zeta, REG4 and 6 ribosomal protein genes (RPS2, RPS12, RPS27A, RPL5, RPL7a and RPL10a) in 14 adenomas (8 with concurrent cancers) and 44 colorectal adenocarcinomas with paired normal mucosa.

RESULTS

Sixty-two candidate genes were obtained from this library. Bioinformatics analysis indicated that both ribosomal protein genes and immune-related genes were enriched. REG4 was significantly upregulated in colorectal adenomas (medium fold: 1.676, p<0.05, Wilcoxon test) and 14-3-3 zeta in cancers (medium fold: 1.202, p<0.01, Wilcoxon test), as compared with those of paired normal mucosa. However, all ribosomal protein genes were not significantly overexpressed in colorectal adenomas or cancers.

CONCLUSIONS

A differential gene expression profile in A-N SSH library may be helpful in understanding the molecular mechanism of colorectal cancer initiation and progression. REG4 and 14-3-3 zeta may be potential biomarkers for early colorectal cancer detection.

Surveillance colonoscopy in individuals at risk for hereditary nonpolyposis colorectal cancer: an evidence-based review

PURPOSE

Surveillance colonoscopy plays an important role in the management of asymptomatic patients known to carry and suspected of carrying hereditary nonpolyposis colorectal cancer gene mutations. Although the shortest interval between surveillance examinations may seem to offer the most benefit to patients, excessive use of this procedure may have unwanted consequences. This study was designed to evaluate the evidence and make recommendations regarding the optimal frequency of surveillance colonoscopy and the age at which to initiate surveillance based on the best available evidence.

METHODS

MEDLINE was searched for all articles assessing surveillance colonoscopy from 1966 to 2004 by using the MESH terms "hereditary nonpolyposis colorectal cancer" and "screening." The evidence was systematically reviewed and a critical appraisal of the evidence was performed.

RESULTS

There are no randomized, controlled, clinical trials examining the frequency of surveillance colonoscopy in hereditary nonpolyposis colorectal cancer. Three cohort studies were identified for review. There is one cohort study of good quality that provides evidence that surveillance colonoscopy every three years in patients with hereditary nonpolyposis colorectal cancer reduces the risk of developing colorectal cancer and the risk of death. The two remaining cohort studies provide poor evidence on which to make a recommendation.

CONCLUSIONS

The best available evidence supports surveillance with complete colonoscopy to the cecum every three years in patients with hereditary nonpolyposis colorectal cancer (B recommendation). There is no evidence to support or refute more frequent screening. Further research is required to examine the potential harms and benefits of more frequent screening. However, given the potential for rapid progression from adenoma to carcinoma and missing lesions at colonoscopy, there is consensus that screening more frequently than every three years is required.

Is colonoscopy sufficient for colorectal cancer surveillance in all HNPCC patients?

A 34-year-old male with hereditary non-polyposis colon cancer with a mutation in hMSH2 line is reported. Despite regular colonoscopic follow-up, he developed cecal cancer involving the extraluminal area. Due to sub-occlusive symptoms, the patient was submitted to further colonoscopy, however with no clear evidence of neoplasia. Thin slice multiplanar reconstruction computed tomography CT scan performed thereafter revealed a transmural mass 2.5 cm in size localized near the cecal valve. Discussion is made on the reliability of colonoscopic examinations as well as the need for further investigations in the follow-up of patients at very high risk of right-sided colon cancer, such as male hMSH2 carrier affected by hereditary non-polyposis colon cancer.

Prevention of colorectal cancer by colonoscopic surveillance in individuals with a family history of colorectal cancer: 16 year, prospective, follow-up study

OBJECTIVE

To determine to what extent individuals with various family histories of colorectal cancer (from one to three or more affected first degree relatives) benefit from colonoscopic surveillance.

DESIGN

Prospective, observational study of high risk families, followed up over 16 years.

SETTING

Tertiary referral family cancer clinic in London.

PARTICIPANTS

1678 individuals from families registered with the clinic. Individuals were classified according to the strength of their family history: hereditary non-polyposis colorectal cancer (if they fulfilled the Amsterdam criteria), and one, two, or three affected first degree relatives (moderate risk).

INTERVENTIONS

Colonoscopy was initially offered at five year intervals or three year intervals if an adenoma was detected.

MAIN OUTCOME MEASURES

The incidence of adenomas with high risk pathological features or cancer. This was analysed by age, the extent of the family history, and findings on previous colonoscopies. The cohort was flagged for cancer and death. Incidence of colorectal cancer and mortality during over 15,000 person years of follow-up were compared with those expected in the absence of surveillance.

RESULTS

High risk adenomas and cancer were most common in families with hereditary non-polyposis colorectal cancer (on initial colonoscopy 5.7% and 0.9%, respectively). In the families with moderate risk, these findings were particularly uncommon under age 45 (1.1% and 0%) and on follow-up colonoscopy if advanced neoplasia was absent initially (1.7% and 0.1%). The incidence of colorectal cancer was substantially lower-80% in families with moderate risk (P = 0.00004), and 43% in families with hereditary non-polyposis colorectal cancer (P = 0.06)-than the expected incidence in the absence of surveillance when the family history was taken into account.

CONCLUSIONS

Colonoscopic surveillance reduces the risk of colorectal cancer in people with a strong family history. This study confirms that members of families with hereditary non-polyposis colorectal cancer require surveillance with short intervals. Individuals with a lesser family history may not require surveillance under age 45, and if advanced neoplasia is absent on initial colonoscopy, surveillance intervals may be lengthened. This would reduce the demand for colonoscopic surveillance.

A scoring system for the strength of a family history of colorectal cancer

BACKGROUND

Family history of colorectal cancer is associated with an increased risk for the disease, although there are many combinations of family history that are hard to correlate with risk status. A scoring system for family history of colorectal cancer was designed to make risk more readily quantifiable.

METHODS

A colonoscopy database was used to test the following points system: each first-degree relative with colorectal cancer = 3 points; each second-degree relative with colorectal cancer = 1 point. Families with one or more first-degree relative affected under 50 years of age = an extra 3 points. Families with one or more second-degree relative affected under 50 years of age = an extra 1 point. Families with multiple relatives on the same side of the family = an extra 3 points (first-degree relatives), 1 point (second-degree relatives), or 2 points (first-degree and second-degree relatives). Points were added and categories defined as follows: low risk, 1 to 4 points; medium risk, 5 to 7 points; high risk, 8 to 10 points; very high risk, >10 points. A control group of average-risk patients having screening colonoscopy was used. Categories were compared in number of adenomas, hyperplastic polyps, and cancers.

RESULTS

The records of 992 patients were used to test the system. Mean adenomas per patient per group were 0.4 for controls, 1.0 for low risk, 1.0 for medium risk, 1.7 for high risk, and 1.7 for very high risk. Cancers per group were 2 of 196 for controls, 8 of 513 for low risk, 3 of 171 for medium risk, 3 of 84 for high risk, and 1 of 28 for very high risk. The score categories were combined to produce revised risk levels of low (score 1 to 7) and high (>7). Average adenomas per patient in the revised categories were 0.4 (control), 1.0 (low risk), and 1.7 (high risk). The odds ratio of having one to two adenomas was 1.73 (1.19-2.50, 95% confidence limits) in the low-risk group and 2.39 (1.41-4.01) in the high-risk group. Odds ratios for having three or more adenomas were 5.70 (2.44-13.32) in the low-risk group and 10.35 (3.97-26.97) in the high-risk group.

CONCLUSION

In the two-category system proposed here of quantifying familial risk of colorectal cancer, patients having less than 8 points were at low risk and those with 8 or more were at high risk. Surveillance and chemoprevention protocols can be designed through use of these risk categories. A scoring system for family history of colorectal cancer can make risk assessment easier and facilitate both collaborative studies and patient triage into appropriate screening programs.

Colorectal cancer and theCHEK2 1100delC mutation

The CHEK2 1100delC mutation was recently identified as a low-penetrance breast cancer susceptibility allele. The mutation occurred more frequently in families with clustering of breast and colorectal cancers (CRCs) than in families with clustering of breast cancer only. Hence, the 1100delC mutation could also be a low-penetrance CRC susceptibility allele. To test this hypothesis, we examined the mutation in 629 unselected CRC cases, 230 controls, and 105 selected CRCs diagnosed in patients before age 50. The mutation was observed in 1.6% of unselected patients and in 0.3% of controls (Not significant (NS)). After stratifying unselected patients according to defined genetic risk (on the basis of age at diagnosis and family history of colorectal and endometrial cancer), the highest frequency was observed in high-risk patients (12.5%), followed by moderate-risk patients (3.3%), and was lowest in low-risk patients (1.0%, P(trend) 0.014). In selected patients, 1.6% carried the mutation (NS). Subgroup analyses for tumor localization, gender, and age at diagnosis did not reveal an association with the 1100delC genotype. In addition, a pooled analysis, combining data of one published study in unselected CRC cases and our study, also did not reveal an association. In conclusion, the frequency of the 1100delC genotype was neither significantly increased in unselected CRC patients nor in selected CRC patients diagnosed before age 50. However, after stratifying unselected CRC patients according to defined genetic risk, a significant trend of increasing frequency was observed. Together, the results are consistent with a low-penetrance effect (OR 1.5-2.0) of the CHEK2 1100delC on CRC risk. Large case-control studies are required to clarify the exact role of the CHEK2 1100delC mutation in CRC.