Patient accuracy of reporting on hereditary non-polyposis colorectal cancer-related malignancy in family members

Modifiable Risk Factors and Risk of Colorectal and Endometrial Cancers in Lynch Syndrome: A Systematic Review and Meta-Analysis

PURPOSE

Lynch syndrome is the most common hereditary cause of colorectal and endometrial cancers. Modifiable risk factors, including obesity, physical activity, alcohol intake, and smoking, are well-established in sporadic cancers but are less studied in Lynch syndrome.

METHODS

Searches were conducted on MEDLINE, Embase, and Web of Science for cohort studies that investigated the association between modifiable risk factors and the risk of colorectal or endometrial cancer in people with Lynch syndrome. Adjusted hazard ratios (HRs) and 95% CIs for colorectal and endometrial cancers were pooled using a random effects model. The protocol was prospectively registered on PROSPERO (CRD 42022378462), and the meta-analysis was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses and Meta-Analysis of Observational Studies in Epidemiology reporting guidelines.

RESULTS

A total of 770 citations were reviewed. Eighteen studies were identified for qualitative synthesis, with seven colorectal cancer (CRC) studies eligible for meta-analysis. Obesity (HR, 2.38 [95% CI, 1.52 to 3.73]) was associated with increased CRC risk. There was no increased CRC risk associated with smoking (HR, 1.04 [95% CI, 0.82 to 1.32]) or alcohol intake (HR, 1.32 [95% CI, 0.97 to 1.81]). Type 2 diabetes mellitus (T2DM) and some dietary factors might increase risk of CRC although more studies are needed. In a qualitative synthesis of three endometrial cancer cohort studies, female hormonal risk factors and T2DM may affect the risk of endometrial cancer, but obesity was not associated with an increased risk.

CONCLUSION

Lifestyle recommendations related to weight and physical activity may also be relevant to cancer prevention for individuals with Lynch syndrome. Further high-quality prospective cohort studies, in particular, including endometrial cancer as an end point, are needed to inform evidence-based cancer prevention strategies in this high-risk population.

Low accuracy of self-reported family history of melanoma in high-risk patients

Family history of melanoma is a major melanoma risk factor. However, self-reported family histories for some cancers, including melanoma, are commonly inaccurate. We used a unique database, the Utah Population Database (UPDB), as well as the Utah Cancer Registry to determine the accuracy of self-reported family history of melanoma in a large cohort of high-risk patients. Patient charts were reviewed and compared to records in the UPDB and the UCR to confirm personal and family history of melanoma in 1780 patients enrolled in a total body photography monitoring program. Self-reported family history of melanoma in first-degree relatives had an overall sensitivity of 71%, specificity of 79%, PPV of 31%, and NPV of 95%, with decreased accuracy (PPV) for second-degree relatives. A personal history of melanoma was the only factor significantly associated with accuracy in self-reported family history of melanoma. Patient age, sex, estimated nevus count, and number of prior personal melanomas were not significant predictors. Dermatologists should educate patients on the differences between melanomas, keratinocyte carcinomas, and pre-cancers. Confirming self-reported family history of melanoma may improve risk assessment for patients undergoing screening.

Survival in familial colorectal cancer: a Danish cohort study

The monogenic Lynch syndrome (LS) is associated with better survival in colorectal cancer (CRC) patients. Whether family history of CRC affects CRC prognosis in general remains unclear. We evaluated overall mortality in a Danish cohort of CRC patients comparing patients with a family history (FHpos) to those without (FHneg) with focus on patients from non-syndromic families, thus FHpos patients were further divided into a non-syndromic group (FHNS) and a HNPCC/LS group (FHHNPCC). We included CRC patients diagnosed 1995-1998. First degree relatives were identified using Danish population registries and family history was obtained by linkage to Danish medical registries. 1- and 5-year mortality were evaluated using the Kaplan-Meier method and Cox regression, with adjustment for age, sex, cancer site, cancer stage, and comorbidity. 1196 CRC patients were included in the study, 219 FHpos patients of whom 197 were FHNS patients. 1- and 5-year adjusted Mortality Rate Ratios comparing FHpos patients to FHneg patients were 0.99 (95% CI 0.69, 1.42) and 1.07 (95% CI 0.87, 1.32), respectively. For FHNS patients, the corresponding MRRs were 1.01 (95% CI 0.69, 1.47) and 1.15 (95% CI 0.93, 1.43). For the FHHNPCC patients MRRs were 0.84 (95% CI 0.29, 2.44) and 0.66 (95% CI 0.33, 1.31), respectively. In contrast to the lower mortality in LS patients, other types of familial CRC do not seem to affect the survival after CRC diagnosis.

Review: Clinical aspects of hereditary DNA Mismatch repair gene mutations

Inherited mutations of the DNA Mismatch repair genes MLH1, MSH2, MSH6 and PMS2 can result in two hereditary tumor syndromes: the adult-onset autosomal dominant Lynch syndrome, previously referred to as Hereditary Non-Polyposis Colorectal Cancer (HNPCC) and the childhood-onset autosomal recessive Constitutional Mismatch Repair Deficiency syndrome. Both conditions are important to recognize clinically as their identification has direct consequences for clinical management and allows targeted preventive actions in mutation carriers. Lynch syndrome is one of the more common adult-onset hereditary tumor syndromes, with thousands of patients reported to date. Its tumor spectrum is well established and includes colorectal cancer, endometrial cancer and a range of other cancer types. However, surveillance for cancers other than colorectal cancer is still of uncertain value. Prophylactic surgery, especially for the uterus and its adnexa is an option in female mutation carriers. Chemoprevention of colorectal cancer with aspirin is actively being investigated in this syndrome and shows promising results. In contrast, the Constitutional Mismatch Repair Deficiency syndrome is rare, features a wide spectrum of childhood onset cancers, many of which are brain tumors with high mortality rates. Future studies are very much needed to improve the care for patients with this severe disorder.

Colon carcinoma in childhood: review of the literature with four case reports

PURPOSE

Colorectal cancer (CRC) in childhood is extremely rare, and only a few case reports exist. We hereby present four cases of childhood CRC along with a literature review.

METHODS

A retrospective review of four cases from our institute was conducted, and 15 articles from PubMed describing childhood CRC were reviewed.

CASE REPORTS

Four patients ranging in age from 11 to 14 years were treated for colon cancer between the years 2000 and 2011. The presenting symptoms varied and included abdominal pain, nausea, vomiting, diarrhea, constipation, and hematochezia, with symptom duration ranging from a few days to 4 months. No patient had a predisposing disease or syndrome. All patients underwent surgical resections, with the most prevalent histology being mucinous adenocarcinoma. Despite radical surgery followed by systemic chemotherapy, the disease progressed in all patients.

LITERATURE REVIEW

A total of 239 cases were reviewed. The youngest patient was 6 years old. The most frequent predisposing conditions were hereditary nonpolyposis colorectal cancer and familial adenomatous polyposis. Most of the patients presented advanced stage, with the most common histopathologic diagnosis being mucinous adenocarcinoma, followed by poorly differentiated adenocarcinoma and signet ring cell carcinoma. Even though most of the patients underwent aggressive treatment, the overall prognosis was poor.

CONCLUSIONS

Childhood CRC has an aggressive pathology and distinct genetic features, which result in an advanced stage at diagnosis and consequently a poor prognosis. Although the incidence is very low, every physician should be aware of CRC as a possible childhood diagnosis.

Psychological distress in newly diagnosed colorectal cancer patients following microsatellite instability testing for Lynch syndrome on the pathologist's initiative

According to the Dutch Guideline on Hereditary Colorectal Cancer published in 2008, patients with recently diagnosed colorectal cancer (CRC) should undergo microsatellite instability (MSI) testing by a pathologist immediately after tumour resection if they are younger than 50 years, or if a second CRC has been diagnosed before the age of 70 years, owing to the high risk of Lynch syndrome (MIPA). The aim of the present MIPAPS study was to investigate general distress and cancer-specific distress following MSI testing. From March 2007 to September 2009, 400 patients who had been tested for MSI after newly diagnosed CRC were recruited from 30 Dutch hospitals. Levels of general distress (SCL-90) and cancer-specific distress (IES) were assessed immediately after MSI result disclosure (T1) and 6 months later (T2). Response rates were 23/77 (30%) in the MSI-positive patients and 58/323 (18%) in the MSI-negative patients. Levels of general distress and cancer-specific distress were moderate. In the MSI-positive group, 27% of the patients had high general distress at T1 versus 18% at T2 (p = 0.5), whereas in the MSI-negative group, these percentage were 14 and 18% (p = 0.6), respectively. At T1 and T2, cancer-specific distress rates in the MSI-positive group and MSI-negative group were 39 versus 27% (p = 0.3) and 38 versus 36% (p = 1.0), respectively. High levels of general distress were correlated with female gender, low social support and high perceived cancer risk. Moderate levels of distress were observed after MSI testing, similar to those found in other patients diagnosed with CRC. Immediately after result disclosure, high cancer-specific distress was observed in 40% of the MSI-positive patients.

Lynch syndrome: clinical, pathological, and genetic insights

INTRODUCTION

Lynch syndrome as the most common hereditary colorectal cancer syndrome and the most common cause of hereditary endometrial cancer is characterized by an autosomal dominant inheritance with a penetrance of 85-90%. The molecular genetic underlying mechanism is a mutation in one of the mismatch repair genes.

METHODS

In order to identify patients with Lynch syndrome, a nuclear family history should be ascertained and matched with the Amsterdam criteria. A different approach for identification is the adherence to Bethesda criteria and subsequent testing for microsatellite instability. In patients with unstable tumors as an indicator for mismatch repair deficiency, genetic counseling and mutation analysis are warranted. For families fulfilling the Amsterdam criteria, intensified screening is recommended, even if a pathogenic mutation is not identified.

RESULTS

Individuals from families with a proven pathogenic mutation that are tested negative are at normal population risk for cancers and may be dismissed from intensified surveillance. Prophylactic surgery in high-risk individuals without neoplasia is not generally recommended. At the time of a colon primary, however, extended surgery should be discussed in the light of a high rate of metachronous cancers. The worries of impairing functional results have now been evaluated in the light of quality of life in a large international cohort. Interestingly, extended (prophylactic) surgery does not lead to inferior quality of life with equal perioperative risks.

CONCLUSIONS

Therefore, taking the risk reduction into account, extended surgery at the time of the first colon primary should at least be discussed, if not recommended. Also, prophylactic hysterectomy and bilateral oophorectomy at the time of a colorectal primary should be recommended if family planning has been completed.

Yield of routine molecular analyses in colorectal cancer patients ≤70 years to detect underlying Lynch syndrome

Although early detection of Lynch syndrome (LS) is important, a considerable proportion of patients with LS remains unrecognized. We aimed to study the yield of LS detection by routine molecular analyses in colorectal cancer (CRC) patients until 70 years of age. We prospectively included consecutive CRC patients ≤70 years. Tumour specimens were analysed for microsatellite instability (MSI), immunohistochemical mismatch-repair protein expression and MLH1-promoter methylation. Tumours were classified as either: (a) likely caused by LS; (b) sporadic microsatellite-unstable (MSI-H); or (c) microsatellite-stable (MSS). Predictors of LS were determined by multivariable logistic regression. A total of 1117 CRC patients (57% males, median age 61 years) were included. Fifty patients (4.5%, 95% CI 3.4-5.9) were likely to have LS, and 71 had a sporadic MSI-H tumour (6.4%, 95% CI 5.1-8.0). Thirty-five patients likely to have LS (70%) were aged > 50 years. A molecular profile compatible with LS was detected in 10% (15/144) of patients aged ≤50, in 4% (15/377) of those aged 51-60 and in 3% (20/596) of patients > 61 years. Compared to MSS cases, patients likely to have LS were significantly younger (OR 3.9, 95% CI 1.7-8.7) and more often had right-sided CRCs (OR 14, 95% CI 6.0-34). In conclusion, molecular screening for LS in CRC patients ≤70 years leads to identification of a molecular profile compatible with LS in 4.5% of patients, with most of them not fulfilling the age criterion (≤50 years) routinely used for LS assessment. Routine use of MSI testing may be considered in CRC patients up to the age of 70 years, with a central role for the pathologist in the selection of patients.

Frequency of extracolonic tumors in Brazilian families with Lynch syndrome: analysis of a hereditary colorectal cancer institutional registry

Lynch syndrome (LS) is caused by inherited germline mutations in mismatch repair (MMR) genes. It is one of the commonest forms of inherited predisposition to colorectal cancer (CRC), accounting for 2-5% of all CRC. LS is characterized by early age of onset, with a tendency for multiplicity and an increased risk for extra-colonic tumors at particular sites. In this study we have evaluated the frequency of extra-colonic tumors in 60 unrelated LS families fulfilling the Amsterdam criteria (ACI. ACII) from the Oncotree database of the Hereditary Colorectal Cancer Registry of the AC Camargo Hospital. All families' pedigree was extensively analyzed, varying from 2 to 6 generations with a total of 2,095 individuals evaluated. As expected, colorectal cancer was the most frequent tumor in the families (334 cases). We found 200 extracolonic tumors among all individuals with a higher ratio in women (123 cases) than men (77 cases). By far, breast cancer (32 cases) was the most frequent extracolonic manifestation in women followed by endometrial (20 cases) and uterine cervix cancer (20 cases). For man, prostate (16 cases) and stomach (12 cases) cancer were the most frequent extracolonic tumors. It is well know that establishing the diagnosis is challenging and requires knowledge and surveillance. Thus, recognition of individuals and families with hereditary predisposition to cancer according to clinical and molecular features, combined with intensive surveillance and management programs, can contribute substantially to improve results related to the diagnosis and characterization of LS.

Young age and a positive family history of colorectal cancer are complementary selection criteria for the identification of Lynch syndrome

Families at high risk for Lynch syndrome can effectively be recognised by microsatellite instability (MSI) testing. The aim of the present study is to compare the effectiveness of a MSI test for the identification of Lynch syndrome in patients selected by a pathologist mainly based on young age at diagnosis (MSI-testing-indicated-by-a-Pathologist; MIPA), with that of patients selected by a clinical geneticist mainly based on family history (MSI-testing-indicated-by-Family-History; MIFH). Patients with a Lynch syndrome associated tumour were selected using MIPA (n=362) or MIFH (n=887). Germline DNA mutation testing was performed in 171 out of 215 patients (80%) with a MSI positive tumour. MSI was tested positive in 20% of the MIPA-group group compared to 16% in the MIFH-group (P=0.291). In 91 of 171 patients with MSI positive tumours tested for germline mutations were identified as Lynch syndrome patients: 42% in the MIPA-group and 56% in the MIFH-group (P=0.066). Colorectal cancer (CRC) or endometrial cancer (EC) presenting at an age below 50 years would have led to the diagnosis of Lynch syndrome in 89% of these families (CRC below 50 years: 88% and EC below 50 years: 12%). Families detected by MIPA were characterised more often by extracolonic Lynch syndrome associated malignancies, especially EC (P<0.001). Our results indicate that recognition of Lynch syndrome by CRC or EC below 50 years is as effective as a positive family history. Families from patients selected by individual criteria more often harbour extracolonic Lynch syndrome associated malignancies.

Electronic reminders for pathologists promote recognition of patients at risk for Lynch syndrome: cluster-randomised controlled trial

We investigated success factors for the introduction of a guideline on recognition of Lynch syndrome in patients recently diagnosed with colorectal cancer (CRC) below age 50 or a second CRC below age 70. Pathologists were asked to start microsatellite instability (MSI) testing and report to surgeons with the advice to consider genetic counselling when MSI test or family history was positive. A multicentre cluster-randomised controlled trial (ClinicalTrials.gov, number NCT00141466) was performed in 12 pathology laboratories (clusters), serving 29 community hospitals. All received an introduction to the new guideline. In the intervention group, surgeons received education and tumour test result reminders; pathologists were provided with inclusion criteria cards, an electronic patient inclusion reminder system and feedback on inclusion. Two hundred sixty-six CRC patients were eligible for recognition as at risk for Lynch syndrome. The actual recognition was 18% more successful in the intervention as compared to the control arm (77% (120 of 156) compared to 59% (65 of 110)), with an adjusted odds ratio (OR) = 2.8 (95% confidence interval (CI) 1.1–7.0). The electronic reminder system for pathologists was most strongly associated with recognition of high-risk patients, OR = 4.2 (95% CI 1.7–10.1). An electronic reminder system for pathologists appeared effective for adherence to a new complex guideline and will enhance the recognition of Lynch syndrome.

Three synchronous primary carcinomas in a patient with HNPCC associated with a novel germline mutation in MLH1: Case report

Background

MLH1 is one of six known genes responsible for DNA mismatch repair (MMR), whose inactivation leads to HNPCC. It is important to develop genotype-phenotype correlations for HNPCC, as is being done for other hereditary cancer syndromes, in order to guide surveillance and treatment strategies in the future.

Case presentation

We report a 47 year-old male with hereditary nonpolyposis colorectal cancer (HNPCC) associated with a novel germline mutation in MLH1. This patient expressed a rare and severe phenotype characterized by three synchronous primary carcinomas: ascending and splenic flexure colon adenocarcinomas, and ureteral carcinoma. Ureteral neoplasms in HNPCC are most often associated with mutations in MSH2 and rarely with mutations in MLH1. The reported mutation is a two base pair insertion into exon 10 (c.866_867insCA), which results in a premature stop codon.

Conclusion

Our case demonstrates that HNPCC patients with MLH1 mutations are also at risk for ureteral neoplasms, and therefore urological surveillance is essential. This case adds to the growing list of disease-causing MMR mutations, and contributes to the development of genotype-phenotype correlations essential for assessing individual cancer risk and tailoring of optimal surveillance strategies. Additionally, our case draws attention to limitations of the Amsterdam Criteria and the need to maintain a high index of suspicion when newly diagnosed colorectal cancer meets the Bethesda Criteria. Establishment of the diagnosis is the crucial first step in initiating appropriate surveillance for colorectal cancer and other HNPCC-associated tumors in at-risk individuals.

A review on the molecular diagnostics of Lynch syndrome: a central role for the pathology laboratory

Lynch syndrome (LS) is caused by mutations in mismatch repair genes and is characterized by a high cumulative risk for the development of mainly colorectal carcinoma and endometrial carcinoma. Early detection of LS is important since surveillance can reduce morbidity and mortality. However, the diagnosis of LS is complicated by the absence of a pre-morbid phenotype and germline mutation analysis is expensive and time consuming. Therefore it is standard practice to precede germline mutation analysis by a molecular diagnostic work-up of tumours, guided by clinical and pathological criteria, to select patients for germline mutation analysis. In this review we address these molecular analyses, the central role for the pathologist in the selection of patients for germline diagnostics of LS, as well as the molecular basis of LS.

The current state of cancer family history collection tools in primary care: a systematic review

Systematic collection of family history is a prerequisite for identifying genetic risk. This study reviewed tools applicable to the primary care assessment of family history of breast, colorectal, ovarian, and prostate cancer. MEDLINE, EMBASE, CINAHL, and Cochrane Central were searched for publications. All primary study designs were included. Characteristics of the studies, the family history collection tools, and the setting were evaluated. Of 40 eligible studies, 18 relevant family history tools were identified, with 11 developed for use in primary care. Most collected information on more than one cancer and on affected relatives used self-administered questionnaires and paper-based formats. Eleven tools had been evaluated relative to current practice, demonstrating 46-78% improvement in data recording over family history recording in patient charts and 75-100% agreement with structured genetic interviews. Few tools have been developed specifically for primary care settings. The few that have been evaluated performed well. The very limited evidence, which depends in part on extrapolation from studies in settings other than primary care, suggests that systematic tools may add significant family health information compared with current primary care practice. The effect of their use on health outcomes has not been evaluated.

Underutilization of microsatellite instability analysis in colorectal cancer patients at high risk for Lynch syndrome

OBJECTIVE

The revised Bethesda Guidelines were published to improve the efficiency of recognizing Lynch syndrome (LS) by identifying LS-related malignancies that should be analyzed for microsatellite instability (MSI). The aim of this study was to evaluate whether MSI analysis was performed in colorectal cancer patients at risk for LS according to the revised Bethesda Guidelines.

MATERIAL AND METHODS

Patients diagnosed with colorectal cancer in 11 Dutch hospitals in 2005 and 2006 were selected from a regional database. The patients were included in the study if they met any of the following criteria; 1) diagnosed with colorectal cancer <50 years, 2) a second LS-associated tumor prior to the diagnosis of colorectal cancer in 2005/2006, and 3) colorectal cancer <60 years with a tumor displaying mucinous or signet-ring differentiation or medullary growth pattern.

RESULTS

Of 1905 colorectal cancer patients, 169 met at least one of the inclusion criteria. MSI analysis had been performed in 23 (14%) of the 169 tumors. MSI status had been determined in 18 of 80 included patients aged <50 years, in 4 of 70 patients with a second LS-related tumor, and in 3 of 41 patients aged <60 years with high-risk pathology features.

CONCLUSIONS

There is marked underutilization of MSI analysis in patients at risk for LS. As a result LS might be underdiagnosed both in patients with colorectal cancer and in their relatives.

Optimizing the detection of hereditary non-polyposis colorectal cancer: An update

Hereditary non-polyposis colorectal cancer (HNPCC) is a dominant inherited disease and accounts for up to 5% of all colorectal cancer (CRC) patients. Despite the optimization of selection criteria and enhancements in molecular techniques for identifying more families with HNPCC, most cases are not recognized. Poor patient recollection of family history and inadequate family history-taking are main causative factors. We propose a new strategy for detecting HNPCC, one in which the pathologist selects patients for microsatellite instability (MSI) testing. Criteria for MSI analysis are: (1) CRC before the age of 50 years, (2) second CRC before 70 years, (3) CRC and HNPCC-associated cancer before 70 years, or (4) adenoma before 40 years. Additionally, patients with a positive MSI test and patients with a positive family history are offered referral for genetic counselling. With this strategy, at least twice the number of HNPCC patients will be identified among a population of CRC patients, and in a cost-effective, efficient and feasible way. The identification of patients with HNPCC is important because intensive surveillance can prevent death from CRC.

Hereditary colorectal cancer: screen the parents!

Hereditary nonpolyposis colorectal cancer is the most common form of hereditary colorectal cancer. Occasionally, the presentation of colorectal cancer may be at an early age when parents may be unidentified obligate carriers. The risk of colorectal cancer increases with increasing age, even in inherited disease. Therefore, it is important to screen parents of patients presenting at a young age and to obtain a complete pedigree to identify and screen those who are at risk. Two such families where the index case presented at a young age were encountered in our practice and both their mothers were found to have colorectal cancer on surveillance colonoscopy. We recommend that parents of the index cases should be screened and more detailed family pedigree obtained when patients present at a young age with colorectal cancer.

Mismatch repair protein expression in Amsterdam II criteria-positive patients in Taiwan

BACKGROUND

Hereditary non-polyposis colorectal cancer (HNPCC) is characterized genetically by germline mutations in DNA mismatch repair (MMR) genes. Immunohistochemistry (IHC) has high sensitivity and specificity for identifying MMR-deficient tumours. This study investigated the clinical presentations and frequency of HNPCC in Taiwan by combined Amsterdam II criteria (AC-II) and IHC.

METHODS

In 1995-2003, 7108 patients with primary colorectal cancer registered in Chang Gung Memorial Hospital's Colorectal Cancer Registry were screened using AC-II. Tumour specimens were analysed for MMR protein expression by IHC, and relevant clinicopathological details were documented.

RESULTS

Some 83 patients fulfilled the AC-II. Clinicopathologically, 43 patients (52 per cent) had proximal tumours, ten (12 per cent) had poorly differentiated cancers, 17 (20 per cent) had mucinous adenocarcinoma and 51 (61 per cent) had stage I-II tumours. Seventeen patients developed second primary colonic and extracolonic cancers over a mean 7.2-year follow-up. Immunohistochemically, 58 patients were MMR protein deficient. They had a significantly earlier age of onset (P < 0.001), more proximal tumour location (P = 0.002), less advanced tumour stage (P = 0.008) and more second primary cancers (P = 0.017) compared with MMR-competent patients.

CONCLUSION

These data show significant differences in clinical features between MMR protein-deficient and MMR competent subgroups.

Familial colorectal cancer referral to regional genetics department--a single centre experience

Evaluation of familial colorectal cancer referral can assist in the planning of future cancer surveillance. The aim of the study is to assess colorectal cancer referral pattern to our regional genetics service. Hospital computer records and/or department referral books were used to identify cases referred to the regional genetic service during a 10-year period (1992-2001 inclusive). All files were reviewed along with associated demographic data, risk assessments, referral details, results from mutation testing and screening recommendations. In terms of result, a total of 1100 family files were reviewed (Familial Adenomatous Polyposis families were in a separate register). The number of referrals showed a 10-fold increase over the 10 years. 171 (15.6%) of families met the Amsterdam criteria II were classified as high-risk, 589 (53.5%) families were classified as moderate-risk and 337 (31.0%) as average or low risk. 22.9% families were referred with inaccurate cancer history. Sixty-one families have been identified with mismatch repair mutations. 56.8% of referred individuals were recommended to have regular colonoscopy ranging from 18 monthly to 5 yearly depending on their risks. In conclusion, there has been a 10-fold increase in individuals with suspected hereditary bowel cancer referred to the North West Regional Genetics Service in the last ten years. Genetic assessment may reduce the number of low-risk individuals and those who were found not to be mutation carriers from having unnecessary colonoscopic screening. Thus genetic risk assessment should precede the initiation of regular endoscopic screening.

Diagnostic value of self-reported symptoms in Danish outpatients referred with symptoms consistent with colorectal cancer

OBJECTIVE

To assess the association between self-reported symptoms and a diagnosis of colorectal cancer (CRC) in symptomatic outpatients without CRC risk factors, defined by a Danish expert group.

METHOD

A cross-sectional study of patients aged 40 years and older referred by general practitioners to two Danish surgical outpatient clinics for symptoms consistent with CRC during a 16-month period. CRC was diagnosed at endoscopy and through follow up. Before their first appointment, participants completed a questionnaire about symptoms.

RESULTS

The study included 2172 patients. Of these, 122 were diagnosed with CRC (5.6%). Median age was 61 years (range: 40-97) and 44.0% were men. All symptoms had high (93.4-96.8%) negative predictive values for CRC. The highest positive predictive values (PPV) were found for dark rectal bleeding (PPV: 20.6%) and CRC was diagnosed in a first-degree relative over the age of 50 years (PPV: 11.2%). At multiple logistic regression analysis dark rectal blood was the most important predictor of CRC (OR: 7.4). Other predictors were age 60 years or older (OR: 3.0), change in frequency of bowel movements (OR: 2.5), CRC diagnosed in a first-degree relative over the age of 50 years (OR: 2.6), male gender (OR: 2.2) and mono-symptomatic fresh rectal blood (OR: 1.7).

CONCLUSION

No self-reported symptoms presented by outpatients without CRC risk factors can be used accurately to identify patients with CRC with certainty. For clinical purposes self-reported symptoms seems thus not to be a useful accurate tool to distinguish between symptomatic outpatients with and without CRC.

Cancer genetics clinics and the surgeon: a valuable role for family history screening

INTRODUCTION

This study examines how a colorectal surgeon can use a regional cancer genetics service to deal safely and efficiently, with community referrals for colorectal cancer screening on the basis of family history.

PATIENTS AND METHODS

A retrospective review of consecutive asymptomatic people with a strong family of colorectal cancer referred by the surgeon to the genetics service over a 30-month period.

RESULTS

A total of 45 people were referred by the surgeon to the cancer genetics service. Following official verification of family histories, 15 were thought to be in a low-risk category for developing colorectal cancer, 18 were moderate risk, 4 had a high-to-moderate risk and 2 satisfied the criteria for HNPCC. After official authentication, it was discovered that 20% of people had mistakenly informed the surgeon of important inaccuracies in their family history.

CONCLUSIONS

The cancer genetics service seeks to identify accurately those at increased risk of developing colorectal cancer due to their family history. It has the time, resources and expertise to verify officially a family history that cannot be properly done in a busy surgical clinic. This study shows that it can provide a valuable role for correctly identifying and counselling people who truly require screening due to their familial predisposition for colorectal cancer.

Estimated prevalence of hereditary cancers and the need for surveillance in a Norwegian county, Telemark

OBJECTIVE

The aim of the study was to estimate the prevalence of hereditary cancers and the need for surveillance in Telemark county, Norway.

MATERIAL AND METHODS

All persons attending the Norwegian Colorectal Cancer Prevention (NORCCAP) trial in Telemark were interviewed about cases of cancer in the family. Diagnoses were verified, pedigrees constructed and families classified according to preset criteria aiming at identifying hereditary cancer. Mutation analyses were performed in kindreds at risk for breast cancers when possible. Immunohistochemistry of tumors in assumed inherited colorectal cancer families was undertaken.

RESULTS

The screening examination was attended by 7,224 persons among whom 2,866 had cancer in the family. Of these, 2,479 had no suspicion of any known inherited cancer syndrome. Family information questionnaires were mailed to 387 persons and returned by 191. Sixty-four of these 191 met the clinical criteria for familial cancer by family history after verification of diagnoses. Observed prevalences for being at risk for hereditary breast and breast-ovarian cancer (HBOC) or hereditary non-polyposis colorectal cancer (HNPCC) were 2.8 per thousand and 0.77 per thousand, respectively.

CONCLUSIONS

The number of colonoscopies and mammograms obtained per year serving those who needed them was limited and reduced by clinical genetic work-up from 2,866 with a family history of cancer to 64 proven cases. Continued surveillance of an unnecessarily high number leads to unjustified cancer worry, is costly and uses up health-care facilities. Genetic work-up is a one-time job that reduces input numbers to surveillance programs, provides a starting-point for mutation testing and is economically cost beneficial if inherited cancers are prevented or cured by the health-care programs offered.

Familial risk of colon and rectal cancer in Iceland: Evidence for different etiologic factors?

The aim of this study was to characterize the familial risk of colon and rectal cancer using 2 population-based registries in Iceland, the Icelandic Cancer Registry and a genealogy database. The standardized incidence ratio (SIR) was used to estimate the risk among relatives of colorectal cancer index cases diagnosed in Iceland over a 46-year period (1955-2000). The 2,770 colorectal cancer patients had 23,272 first-degree relatives. Among first-degree relatives, there was an increased risk of both colon (SIR 1.47, 95% confidence interval (CI) 1.34-1.62) and rectal cancer (SIR 1.24, 95% CI 1.04-1.47). An increased risk of colon cancer was observed among siblings of colon cancer patients (SIR 2.03, 95% CI 1.76-2.33), whereas no such increase was observed for parents or offspring. Furthermore, the risk of rectal cancer was only increased among brothers (SIR 2.46 95% CI 1.46-3.89) of rectal cancer patients and not among their sisters (SIR 1.0 95% CI 0.40-2.06). The added risk of colon cancer among first-degree relatives was independent of site of colon cancer in the proband. Our results confirm that family history of colorectal cancer is a risk factor for the disease. However, family history has a different association with colon cancer than with rectal cancer, suggesting that the 2 cancer types may have different etiologic factors. Our results have implications for colon and rectal cancer screening programs.

Screening for an inherited susceptibility to colorectal cancer

The principal Mendelian disorders predisposing to colorectal cancer are familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). FAP is caused by mutations in the adenomatous polyposis coli (APC) gene. HNPCC is caused by a mutation in one of at least five mismatch repair genes. It is important to identify individuals with these conditions because colon cancer will occur in at least 80% and onset is earlier than in the general population. Potential benefits of identification include improved compliance with recommended surveillance, early detection of polyps, reduction in cancer mortality, and reassurance for relatives found to be negative with attendant savings in the time and expense of surveillance. For classic FAP, the large number of polyps readily identifies affected persons. For HNPCC, identification of individuals meriting DNA sequencing requires either recognition of a suspect family history or finding high microsatellite instability in a tumor. Individuals accepting the offer of genetic counseling and DNA testing often have more cancers in their family, are motivated to inform relatives, have a larger social network, and have more confidence in their coping ability. Individuals who decline are often concerned about their own or their family's emotional reaction or fear discrimination.

Genetic testing for inherited colon cancer

The genes associated with each of the inherited syndromes of colon cancer have now been identified, and genetic testing is available for diagnosis. These syndromes include familial adenomatous polyposis, hereditary nonpolyposis colorectal cancer, Peutz-Jeghers syndrome, juvenile polyposis syndrome, and, possibly, Cowden's syndrome. Clinical genetic testing approaches have been developed for each of these syndromes and are now a part of accepted clinical care. Disease-causing mutations can be found in the majority of families affected with one of the inherited syndromes, and, most importantly, once a mutation is found in an index case of the family, relatives can be tested for the presence or absence of that mutation with near 100% accuracy. Cancer screening and management in syndrome families is then based on the results of genetic testing. For the physician to order and properly interpret genetic tests, a basic understanding of the types of mutations that lead to inherited disease and the methods for detecting them is vital. These issues will be presented. Additional clinical issues somewhat unique to genetic testing include genetic counseling and informed consent for genetic testing, both of which will also be reviewed. Often the most difficult aspect of genetic testing is deciding which patients and families should undergo the testing. Furthermore, this issue is quite specific for each of the syndromes. Thus, following presentation of general principles of selection for genetic testing, a detailed approach for identifying persons who should undergo testing for each of the individual syndromes will be given, together with relevant descriptions of the syndromes. Finally, the ongoing work to discover new and possibly more common but less penetrant colon cancer susceptibility genes that cause common familial colon cancer will be presented.

A clinician's guide to hereditary colon cancer

Approximately 10% of patients diagnosed with colorectal cancer are at risk for a hereditary form of the disease. At-risk patients can be offered genetic counseling and testing to determine whether they carry a detectable mutation for such a syndrome. If so, this information provides the clinician with valuable data about the patient's risk for other cancers, and what further surveillance and risk reduction options should be incorporated into the management plan. Mutation identification within a family also makes it possible for other family members to learn if they are at risk for the same syndrome. There are many hereditary colorectal cancer syndromes, and the clinician must know what essential information should be elicited from a family history and which patients should be referred for genetic counseling and testing.

Physician assessment of family cancer history and referral for genetic evaluation in colorectal cancer patients

BACKGROUND AND AIMS

An accurate family history is an essential component of cancer risk assessment. Our aim was to determine the concordance of family history assessments made by physicians with patients' self-reports and the frequency of referral for genetic evaluation in high-risk colorectal cancer (CRC) patients.

METHODS

A self-administered family cancer history questionnaire was completed by 387 consecutive CRC patients at their first visit to a gastroenterology cancer clinic. Physician notes from the first visit were reviewed to determine the concordance of the family cancer history with patients' self-reported history. Prevalence of individuals that satisfied the Bethesda guidelines for hereditary colon cancer were compared with actual rates of referral. Regression analyses were used to determine factors associated with a comprehensive physician evaluation of family history.

RESULTS

Oncologists documented a comprehensive family history in 59% (184 of 311) of patients with a first- or second-degree relative with cancer. Young age at diagnosis and a first-degree relative with CRC were not associated with a more comprehensive family history assessment. An increasing number of cancers per family was a strong predictor of a less comprehensive family history assessment (odds ratio = 0.63; P < 0.0001). Seventy-five of 387 (19%) CRC patients met Bethesda guidelines for genetics assessment, however, only 13 of 75 (17%) were referred.

CONCLUSIONS

Increased complexity in family cancer history leads to a decrease in accuracy of family history, suggesting the need for systematic approaches to facilitate family history assessment. Familial cancer risk remains largely unrecognized and referral rates for genetic evaluation for CRC syndromes are low.

Current clinical selection strategies for identification of hereditary non-polyposis colorectal cancer families are inadequate: a meta-analysis

Present guidelines to identify hereditary non-polyposis colorectal cancer (HNPCC) families are criticized for limitations in accuracy. The Amsterdam criteria I and II (AC I and AC II) are used to predict a germline mutation in one of the mismatch repair genes. In families not fulfilling the AC I and AC II criteria, individual indications to test cancer specimens for microsatellite instability (MSI) are guided by the Bethesda Guidelines (BG). Germline mutation testing is then performed in patients who conform to the BG and show MSI. We investigated the sensitivity and specificity of AC I, AC II, and BG. A meta-analysis of studies on the value of the AC I and AC II criteria for predicting germline mutation, as well as a meta-analysis of BG for the detection of MSI was performed. For the AC I, sensitivity varied from 54 to 91% and specificity varied from 62 to 84%. For the AC II, the pooled sensitivity was 78% and specificity ranged between 46 and 68%. Post-test probabilities of a positive test result were 0.61 and 0.46 for the AC I and AC II, respectively. Post-test probabilities of a negative test result were 0.17 and 0.21 for the AC I and AC II, respectively. For the BG, the pooled sensitivity was 89% and pooled specificity was 53%. Post-test probability of a positive test result was 41%, and post-test probability of a negative test result was 9%. The sensitivity and specificity of the Amsterdam criteria for predicting a germline mutation that causes HNPCC is not sufficient. The BG are useful for the detection of MSI in a group of patients suspected of having familial colorectal cancer (CRC), but sensitivity is very low in the total group of newly diagnosed CRC patients. Therefore, a new strategy is needed for the identification of HNPCC.

Family history of colorectal cancer in a Sweden county

Hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatosis polyposis (FAP) are well-known high-risk cancer syndromes. Hereditary colorectal cancer (HCRC) with at least three relatives with colorectal cancer and a dominant pattern of inheritance but with no specifications for age at onset and two close relatives with colorectal cancer (TCR) are other forms of familial clustering known to carry an increased risk of the disease. The frequency of the total burden of familial colorectal cancer is not well known. We therefore investigated the family history of 400/411 (97%) eligible patients with recently diagnosed colorectal cancer in Västmanland county, Sweden, during a 3-year period. Records or death certificates confirmed the diagnoses of relatives. Five patients (1.2%, 95% CI 0.15-2.2) were diagnosed as having HNPCC, eight (1.9%, 95% CI 0.6-3.2) as having HCRC and thirty-four (8.3%, 95% CI 5.6-11.0) were identified as having TCR. In total, 47 patients (11.4%, 95% CI 8.3-14.5) were found to have a contributing familial background. The implication is thus that every ninth patient with colorectal cancer represents a highly or intermediately increased risk of the disease among relatives. We conclude that the low frequency of individuals identified by family history alone makes the establishment of surveillance programs feasible.

Achieving utility with family history: colorectal cancer risk

Family history of chronic disease is rapidly becoming a research tool for targeting participants at increased risk. Its current usefulness in clinical practice remains unknown. This paper details the possible utility and complications in using family history in a primary care setting, using colorectal cancer risk as the health issue. Where available, we cite data to support the issues that could arise. Where there are no studies, we invite further research. The potential of family history as a health improvement tool is still under review.

Basic concepts for genetic testing in common hereditary colorectal cancer syndromes

Approximately 5% of colorectal cancers are associated with one of the autosomal dominant hereditary cancer syndromes. The two most common familial colon cancer syndromes are familial adenomatous polyposis (FAP) and hereditary nonpolyposis colorectal cancer (HNPCC). The causative mutation can be identified in many families with these syndromes by genetic testing of an affected individual. If an affected individual tests positive for a disease-causing mutation, genetic testing of unaffected, at-risk family members can be performed to determine whether they have inherited the cancer-susceptibility mutation, and a personalized cancer surveillance strategy can be devised. Genetic testing significantly enhances cancer risk assessment in these families. However, the complicated nature of result interpretation and the emotional impact of the result necessitate that testing be carried out in conjunction with patient education and informed consent by a physician who has a keen appreciation for the inherent challenges. This article describes the genetic testing strategy in HNPCC and FAP.