Prevalence of family history of colorectal cancer in the general population

AGA Clinical Practice Update on Risk Stratification for Colorectal Cancer Screening and Post-Polypectomy Surveillance: Expert Review

DESCRIPTION

Since the early 2000s, there has been a rapid decline in colorectal cancer (CRC) mortality, due in large part to screening and removal of precancerous polyps. Despite these improvements, CRC remains the second leading cause of cancer deaths in the United States, with approximately 53,000 deaths projected in 2023. The aim of this American Gastroenterological Association (AGA) Clinical Practice Update Expert Review was to describe how individuals should be risk-stratified for CRC screening and post-polypectomy surveillance and to highlight opportunities for future research to fill gaps in the existing literature.

METHODS

This Expert Review was commissioned and approved by the American Gastroenterological Association (AGA) Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the CPUC and external peer review through standard procedures of Gastroenterology. These Best Practice Advice statements were drawn from a review of the published literature and from expert opinion. Because systematic reviews were not performed, these Best Practice Advice statements do not carry formal ratings regarding the quality of evidence or strength of the presented considerations. Best Practice Advice Statements BEST PRACTICE ADVICE 1: All individuals with a first-degree relative (defined as a parent, sibling, or child) who was diagnosed with CRC, particularly before the age of 50 years, should be considered at increased risk for CRC. BEST PRACTICE ADVICE 2: All individuals without a personal history of CRC, inflammatory bowel disease, hereditary CRC syndromes, other CRC predisposing conditions, or a family history of CRC should be considered at average risk for CRC. BEST PRACTICE ADVICE 3: Individuals at average risk for CRC should initiate screening at age 45 years and individuals at increased risk for CRC due to having a first-degree relative with CRC should initiate screening 10 years before the age at diagnosis of the youngest affected relative or age 40 years, whichever is earlier. BEST PRACTICE ADVICE 4: Risk stratification for initiation of CRC screening should be based on an individual's age, a known or suspected predisposing hereditary CRC syndrome, and/or a family history of CRC. BEST PRACTICE ADVICE 5: The decision to continue CRC screening in individuals older than 75 years should be individualized, based on an assessment of risks, benefits, screening history, and comorbidities. BEST PRACTICE ADVICE 6: Screening options for individuals at average risk for CRC should include colonoscopy, fecal immunochemical test, flexible sigmoidoscopy plus fecal immunochemical test, multitarget stool DNA fecal immunochemical test, and computed tomography colonography, based on availability and individual preference. BEST PRACTICE ADVICE 7: Colonoscopy should be the screening strategy used for individuals at increased CRC risk. BEST PRACTICE ADVICE 8: The decision to continue post-polypectomy surveillance for individuals older than 75 years should be individualized, based on an assessment of risks, benefits, and comorbidities. BEST PRACTICE ADVICE 9: Risk-stratification tools for CRC screening and post-polypectomy surveillance that emerge from research should be examined for real-world effectiveness and cost-effectiveness in diverse populations (eg, by race, ethnicity, sex, and other sociodemographic factors associated with disparities in CRC outcomes) before widespread implementation.

Evidenced-Based Screening Strategies for a Positive Family History

The most commonly recognized high-risk group for colorectal cancer (CRC) is individuals with a positive family history. It is generally recognized that those with a first-degree relative (FDR) with CRC are at a 2-fold or higher risk of CRC or advanced neoplasia. FDRs of patients with advanced adenomas have a similarly increased risk. Accordingly, all major US guidelines recommend starting CRC screening by age 40 in these groups. Barriers to screening this group include patient lack of knowledge on family and polyp history, provider limitations in collecting family history, and insufficient application of guidelines.

Potential impact of family history-based screening guidelines on the detection of early-onset colorectal cancer

BACKGROUND

Initiating screening at an earlier age based on cancer family history is one of the primary recommended strategies for the prevention and detection of early-onset colorectal cancer (EOCRC), but data supporting the effectiveness of this approach are limited. The authors assessed the performance of family history-based guidelines for identifying individuals with EOCRC.

METHODS

The authors conducted a population-based, case-control study of individuals aged 40 to 49 years with (2473 individuals) and without (772 individuals) incident CRC in the Colon Cancer Family Registry from 1998 through 2007. They estimated the sensitivity and specificity of family history-based criteria jointly recommended by the American Cancer Society, the US Multi-Society Task Force on CRC, and the American College of Radiology in 2008 for early screening, and the age at which each participant could have been recommended screening initiation if these criteria had been applied.

RESULTS

Family history-based early screening criteria were met by approximately 25% of cases (614 of 2473 cases) and 10% of controls (74 of 772 controls), with a sensitivity of 25% and a specificity of 90% for identifying EOCRC cases aged 40 to 49 years. Among 614 individuals meeting early screening criteria, 98.4% could have been recommended screening initiation at an age younger than the observed age of diagnosis.

CONCLUSIONS

Of CRC cases aged 40 to 49 years, 1 in 4 met family history-based early screening criteria, and nearly all cases who met these criteria could have had CRC diagnosed earlier (or possibly even prevented) if earlier screening had been implemented as per family history-based guidelines. Additional strategies are needed to improve the detection and prevention of EOCRC for individuals not meeting family history criteria for early screening.

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.

Extent of Pedigree Required to Screen for and Diagnose Hereditary Nonpolyposis Colorectal Cancer: Comparison of Simplified and Extended Pedigrees

BACKGROUND

Obtaining an accurate pedigree is the first step in recognizing a patient with hereditary nonpolyposis colorectal cancer, or Lynch syndrome. However, lack of standardization of the degree of relationship included in the pedigrees generally limits obtaining a complete and/or accurate pedigree.

DESIGN

This study analyzed the extent of pedigree required to screen for colorectal cancer and to diagnose Lynch syndrome.

SETTINGS

The study was conducted at 2 tertiary care centers.

PATIENTS

A detailed family history was obtained from patients undergoing surgery for colorectal cancer from 2003 to 2016. A simplified pedigree that included only first-degree relatives was obtained and compared with the extended pedigree.

MAIN OUTCOME MEASURES

The eligibility of the 2 pedigrees was assessed for each proband. The proportion of patients who would be missed using a simplified rather than an extended pedigree was calculated based on the American Cancer Society guidelines for recommending screening for colorectal cancer, on the revised Bethesda guidelines and the revised suspected hereditary nonpolyposis colorectal cancer criteria for screening for hereditary colorectal cancer, and on the Amsterdam II criteria for diagnosis of Lynch syndrome.

RESULTS

The study examined 2015 families, including 41,826 individuals. Use of simplified and extended pedigrees was comparable in screening for colorectal cancer, with ratios of 183 of 185 (98.9%) for American Cancer Society guidelines, 295 of 295 (100%) for revised Bethesda guidelines, and 60 of 60 (100%) for revised suspected hereditary nonpolyposis colorectal cancer criteria. However, the use of simplified pedigrees missed a definitive diagnosis of Lynch syndrome in 6 of 10 patients fulfilling Amsterdam II criteria based on extended pedigrees. The mean ages at diagnosis of the 4 probands included and the 6 missed using simplified pedigrees differed significantly (60.8 vs 38.2 y).

LIMITATIONS

The study was limited by its recall bias, cross-sectional nature, lack of germline testing, and potential inapplicability to the general population.

CONCLUSIONS

A simplified pedigree is acceptable for selecting candidates to screen for hereditary colorectal cancer, whereas an extended pedigree is still required for a more precise diagnosis of Lynch syndrome, especially in younger patients. See Video Abstract at http://links.lww.com/DCR/B97. EXTENSIÓN DE PEDIGREE REQUERIDO EN LA DETECCIÓN Y DIAGNÓSTICO DE CÁNCER COLORRECTAL HEREDITARIO SIN POLIPOSIS: COMPARACIÓN DE LOS PEDIGREES SIMPLIFICADO Y EL EXTENDIDO: La obtención de un Pedigree exacto es el primer paso para reconocer un paciente con cáncer colorrectal hereditario sin poliposis o síndrome de Lynch. Sin embargo, la falta de estandarización del grado de relación incluido en los Pedigrees generalmente limita la obtención de un Pedigree completo y / o preciso.Este estudio analizó el grado de Pedigree requerido para detectar el cáncer colorrectal y diagnosticar el síndrome de Lynch.Se obtuvo una historia familiar detallada de pacientes sometidos a cirugía por cáncer colorrectal desde 2003 hasta 2016. Se obtuvo también un Pedigree simplificado que incluía solo familiares de primer grado y se comparó con el Pedigree extendido.La elegibilidad de los dos Pedigrees se evaluó para cada sujeto de prueba (proband). La proporción de pacientes que se perderían usando un Pedigree simplificado en lugar de extendido se calculó en base a las guías de la Sociedad Americana del Cáncer y sus recomendaciones en la detección de cáncer colorrectal, en las pautas revisadas de Bethesda y en los criterios revisados de cáncer colorrectal hereditario sin poliposis para la detección hereditaria de cáncer colorrectal y según las normas de Amsterdam II para el diagnóstico del síndrome de Lynch.El estudio examinó a 2.015 familias, incluidas 41.826 personas. El uso de Pedigree simplificado y extendido fue comparable en la detección del cáncer colorrectal, con proporciones de 183/185 (98,9%) comparadas con las recomendaciones de la American Cancer Society, 295/295 (100%) para las pautas revisadas de Bethesda y 60/60 (100%) para los criterios revisados de sospecha de cáncer colorrectal hereditario sin poliposis. Sin embargo, el uso de Pedigree simplificado omitió un diagnóstico definitivo del síndrome de Lynch en 6 de diez pacientes que cumplían las normas de Amsterdam II basados en Pedigrees extendidos. Las edades medias al diagnóstico de los cuatro sujetos de prueba incluidos y los seis perdidos usando el Pedigree simplificado diferían significativamente (60.8 vs. 38.2 años).Un Pedigre simplificado es aceptable en la selección de candidatos para la detección de cáncer colorrectal hereditario, mientras que aún se requiere un Pedigree extendido para un diagnóstico más preciso de síndrome de Lynch, especialmente en pacientes más jóvenes. Consulte Video Resumen en http://links.lww.com/DCR/B97. (Traducción-Dr. Edgar Xavier Delgadillo).

Frequency of a positive family history of colorectal cancer in general practice: a cross-sectional study

BACKGROUND

Evidence on the frequency of a positive family history of colorectal cancer (CRC) among individuals aged <55 years is lacking. General practice setting might be well suited for the identification of individuals in this above-average risk group.

OBJECTIVE

To determine the frequency of a reported positive family history of CRC among patients aged 40 to 54 years in a general practice setting.

METHODS

We conducted a cross-sectional study in 21 general practices in Germany. Patients aged 40 to 54 years were identified by means of the practice software and interviewed by health care assistants using a standardized four-item questionnaire. Outcome was occurrence of a positive family history of CRC, defined as at least one first-degree relative (FDR: parents, siblings, or children) with CRC. Further measurements were FDRs with CRC / colorectal polyps (adenomas) diagnosed before the age of 50 and occurrence of three or more relatives with colorectal, stomach, cervical, ovarian, urethel or renal pelvic cancer.

RESULTS

Out of 6723 participants, 7.2% (95% confidence interval [CI] 6.6% to 7.8%) reported at least one FDR with CRC and 1.2% (95% CI 0.9% to 1.5%) reported FDRs with CRC diagnosed before the age of 50. A further 2.6% (95% CI 2.3% to 3.0%) reported colorectal polyps in FDRs diagnosed before the age of 50 and 2.1% (95% CI 1.8% to 2.5%) reported three or more relatives with entities mentioned above.

CONCLUSION

One in 14 patients reported at least one FDR with CRC. General practice should be considered when defining requirements of risk-adapted CRC screening.

Understanding the contribution of family history to colorectal cancer risk and its clinical implications: A state-of-the-science review

Persons with a family history (FH) of colorectal cancer (CRC) or adenomas that are not due to known hereditary syndromes have an increased risk for CRC. An understanding of these risks, screening recommendations, and screening behaviors can inform strategies for reducing the CRC burden in these families. A comprehensive review of the literature published within the past 10 years has been performed to assess what is known about cancer risk, screening guidelines, adherence and barriers to screening, and effective interventions in persons with an FH of CRC and to identify FH tools used to identify these individuals and inform care. Existing data show that having 1 affected first-degree relative (FDR) increases the CRC risk 2-fold, and the risk increases with multiple affected FDRs and a younger age at diagnosis. There is variability in screening recommendations across consensus guidelines. Screening adherence is <50% and is lower in persons under the age of 50 years. A provider's recommendation, multiple affected relatives, and family encouragement facilitate screening; insufficient collection of FH, low knowledge of guidelines, and poor family communication are important barriers. Effective interventions incorporate strategies for overcoming barriers, but these have not been broadly tested in clinical settings. Four strategies for reducing CRC in persons with familial risk are suggested: 1) improving the collection and utilization of the FH of cancer, 2) establishing a consensus for screening guidelines by FH, 3) enhancing provider-patient knowledge of guidelines and communication about CRC risk, and 4) encouraging survivors to promote screening within their families and partnering with existing screening programs to expand their reach to high-risk groups. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2633-2645. © 2016 American Cancer Society.

Screening patterns in patients with a family history of colorectal cancer often do not adhere to national guidelines

BACKGROUND

Currently, there are no data on adherence to guidelines for colorectal cancer (CRC) screening in patients with a family history.

AIM

We conducted a retrospective study to assess if such patients were being appropriately screened according to American Gastroenterological Association (AGA) guidelines.

METHODS

Two independent reviewers performed a comprehensive medical record review of family and CRC screening history on 362 adults with a family history of CRC in a first-degree relative who had recently undergone screening colonoscopy. The endpoint was appropriate initiation of screening and endoscopist-recommended subsequent screening intervals, as compared to AGA guideline recommendations.

RESULTS

Of 362 subjects, only 146 (40.3 %) were screened appropriately; 213 (58.9 %) had late initiation of screening (i.e., screening was started ≥5 years later than the age recommended by guidelines) and three (0.8 %) had premature initiation (i.e., screening was started ≥1 year too early). Of cases involving delayed screening initiation, 126 were not under primary care at the time when screening was supposed to have started, while most of the remaining received either no or incorrect screening recommendations from their primary care provider. Of 270 subjects with no neoplasia found on initial screening, 112 (41.5 %) had endoscopist-recommended subsequent screening intervals that were ≥2 years shorter than that recommended by guidelines. Results were similar if American Society of Gastrointestinal Endoscopy or American College of Gastroenterology guidelines were used.

CONCLUSIONS

Patients with a family history often suffer from late initiation of screening and overly short endoscopist-recommended subsequent intervals for colonoscopy. Further education of patients and providers on screening recommendations may be helpful.

Increased risk of advanced neoplasms among asymptomatic siblings of patients with colorectal cancer

BACKGROUND & AIMS

Colorectal cancer (CRC) is the second-most common cancer in Hong Kong. Relatives of patients with CRC have an increased risk of colorectal neoplasm. We assessed the prevalence of advanced neoplasms among asymptomatic siblings of patients with CRC.

METHODS

Patients with CRC were identified from the Prince of Wales Hospital CRC Surgery Registry from 2001 to 2011. Colonoscopies were performed for 374 siblings of patients (age, 52.6 ± 7.4 y) and 374 age- and sex-matched siblings of healthy subjects who had normal colonoscopies and did not have a family history of CRC (controls, 52.7 ± 7.4 y). We identified individuals with advanced neoplasms (defined as cancers or adenomas of at least 10 mm in diameter, high-grade dysplasia, with villous or tubulovillous characteristics).

RESULTS

The prevalence of advanced neoplasms was 7.5% among siblings of patients and 2.9% among controls (matched odds ratio [mOR], 3.07; 95% confidence interval [CI], 1.5-6.3; P = .002). The prevalence of adenomas larger than 10 mm was higher among siblings of patients than in controls (5.9% vs 2.1%; mOR, 3.34; 95% CI, 1.45-7.66; P = .004), as was the presence of colorectal adenomas (31.0% vs 18.2%; mOR, 2.19; 95% CI, 1.52-3.17; P < .001). Six cancers were detected among siblings of patients; no cancers were detected in controls. The prevalence of advanced neoplasms among siblings of patients was higher when their index case was female (mOR, 4.95; 95% CI, 1.81-13.55) and had distally located CRC (mOR, 3.10; 95% CI, 1.34-7.14).

CONCLUSIONS

In Hong Kong, siblings of patients with CRC have a higher prevalence of advanced neoplasms, including CRC, than siblings of healthy individuals. Screening is indicated in this high-risk population. ClinicalTrials.gov number: NCT00164944.

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.

How much colonoscopy screening should be recommended to individuals with various degrees of family history of colorectal cancer?

BACKGROUND

Individuals with a family history of colorectal cancer (CRC) are at increased risk for CRC. Current screening recommendations for these individuals are based on expert opinion. The authors investigated optimal screening strategies for individuals with various degrees of family history of CRC based on a cost-effectiveness analysis.

METHODS

The MISCAN-Colon microsimulation model was used to estimate costs and effects of CRC screening strategies, varying by the age at which screening was started and stopped and by screening interval. The authors defined 4 risk groups, characterized by the number of affected first-degree relatives and their age at CRC diagnosis. For all risk groups, the optimal screening strategy had an incremental cost-effectiveness ratio of approximately $50,000 per life-year gained.

RESULTS

The optimal screening strategy for individuals with 1 first-degree relative diagnosed after age 50 years was 6 colonoscopies every 5 years starting at age 50 years, compared with 4 colonoscopies every 7 years starting at age 50 years for average risk individuals. The optimal strategy had 10 colonoscopies every 4 years for individuals with 1 first-degree relative diagnosed before age 50 years, 13 colonoscopies every 3 years for individuals with 2 or more first-degree relatives diagnosed after age 50 years, and 15 colonoscopies every 3 years for individuals with 2 or more first-degree relatives of whom at least 1 was diagnosed before age 50 years.

CONCLUSIONS

The optimal screening strategy varies considerably with the number of affected first-degree relatives and their age of diagnosis. Shorter screening intervals than the currently recommended 5 years may be appropriate for the highest risk individuals.

Increased risk of adenomas in individuals with a family history of colorectal cancer: results of a meta-analysis

OBJECTIVE

It is unclear to what extent the increased risk of colorectal cancer in individuals with a family history of colorectal cancer and no known genetic disorders is associated with a higher adenoma prevalence. Our aim is to estimate the relative difference in adenoma prevalence and its age-pattern in individuals with a family history of colorectal cancer compared to those without.

METHODS

We performed a literature search to identify colonoscopy studies reporting the adenoma prevalence by age. Using multilevel logistic regression, we examined how the adenoma prevalence by age differed between individuals with and without a family history of colorectal cancer. We excluded members of families with a known genetic disorder.

RESULTS

Thirteen colonoscopy studies were identified. The adenoma prevalence was significantly higher in individuals with a family history than in those without (OR 1.7, 95% CI 1.4-3.5). The adenoma prevalence increased with age (OR per year of age 1.06, 95% CI 1.05-1.07). The age trend did not differ significantly between the two groups.

CONCLUSION

Individuals with a family history of colorectal cancer have a considerably higher prevalence of adenomas compared to individuals without a family history. This is consistent with their increased risk of colorectal cancer.

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.

Germline MutY human homologue mutations and colorectal cancer: a multisite case-control study

BACKGROUND & AIMS

The MutY human homologue (MYH) gene is a member of the base-excision repair pathway involved in the repair of oxidative DNA damage. The objective of this study was to determine colorectal cancer (CRC) risk associated with mutations in the MYH gene.

METHODS

A total of 3811 CRC cases and 2802 controls collected from a multisite CRC registry were screened for 9 germline MYH mutations; subjects with any mutation underwent screening of the entire MYH gene. Logistic regression was used to estimate age- and sex-adjusted odds ratios (AOR). Clinicopathologic and epidemiologic data were reviewed to describe the phenotype associated with MYH mutation status and assess for potential confounding and effect modification.

RESULTS

Twenty-seven cases and 1 control subject carried homozygous or compound heterozygous MYH mutations (AOR, 18.1; 95% confidence interval, 2.5-132.7). CRC cases with homozygous/compound heterozygous mutations were younger at diagnosis (P=.01), had a higher proportion of right-sided (P=.01), synchronous cancers (P<.01), and personal history of adenomatous polyps (P=.003). Heterozygous MYH mutations were identified in 87 CRC cases and 43 controls; carriers were at increased risk of CRC (AOR, 1.48; 95% confidence interval, 1.02-2.16). There was a higher prevalence of low-frequency microsatellite instability (MSI) in tumors from heterozygous and homozygous/compound heterozygous MYH mutation carriers (P=.02); MSI status modified the CRC risk associated with heterozygous MYH mutations (P interaction<.001).

CONCLUSIONS

Homozygous/compound heterozygous MYH mutations account for less than 1% of CRC cases. Heterozygous carriers are at increased risk of CRC. Further studies are needed to understand the possible interaction between the base excision repair and low-frequency MSI pathways.

Q&A on diagnosis, screening and follow-up of colorectal neoplasia

The impressive and brisk evolution of medical science prevents many physicians from a thorough update on all the research fields. Colorectal cancer diagnosis, screening and follow-up is well known to require a multi-disciplinary approach, as it is faced by several specialties such as primary care physicians, gastroenterologists, non-gastroenterologist internists, radiologists and surgeons. To address this issue in a mutual perspective, we focused on the main points of the epidemiology, diagnosis, screening and follow-up of colorectal neoplasia by using a simple "Question & Answers" structure.

Screening patients with a family history of colorectal cancer

OBJECTIVES

To compare screening practices and beliefs in patients with and without a clinically important family history.

DESIGN

We mailed a brief questionnaire asking about family history and a second, longer survey asking about knowledge of and beliefs about colorectal cancer to all respondents with a family history and a random sample of respondents without a family history of colorectal cancer. We reviewed electronic medical records for screening examinations and recording of family history.

PARTICIPANTS

One thousand eight hundred seventy of 6,807 randomly selected patients ages 35-55 years who had been continuously enrolled in a large multispecialty group practice for at least 5 years.

MEASUREMENTS

Recognition of increased risk, screening practices, and beliefs-all according to strength of family history and patient's age.

RESULTS

Nineteen percent of respondents reported a family history of colorectal cancer. In 11%, this history was strong enough to warrant screening before age 50 years. However, only 39% (95% CI 36, 42) of respondents under the age of 50 years said they had been asked about family history and only 45% of those with a strong family history of colorectal cancer had been screened appropriately. Forty-six percent of patients with a strong family history did not know that they should be screened at a younger age than average risk people. Medical records mentioned family history of colorectal cancer in 59% of patients reporting a family history.

CONCLUSIONS

More efforts are needed to translate information about family history of colorectal cancer into the care of patients.

Colorectal cancer (CRC) screening using sigmoidoscopy followed by colonoscopy: a feasibility and efficacy study on a cancer institute based population

BACKGROUND

Advanced distal neoplasia found at sigmoidoscopy could be the marker for more proximal lesions.

PATIENTS AND METHODS

In the setting of a screening clinic, subjects underwent flexible sigmoidoscopy. If no significant lesion was found, sigmoidoscopy was planned after 5 years. If an advanced neoplasia was found, colonoscopy was performed just after the first sigmoidoscopy and at 1, 3 and 5 years. If a non-advanced neoplasia was found, sigmoidoscopy was performed at 1, 3 and 5 years and followed by colonoscopy if advanced lesion was found.

RESULTS

At first screening 1704/1912 (88%) subjects had a negative sigmoidoscopy, 104 (5.4%) had an advanced neoplasia, 96 (6%) had a non-advanced neoplasia and eight (0.4%) had invasive colorectal cancer (CRC). At follow-up examinations at 1, 3 and 5 years, among 170 subjects with advanced and non-advanced neoplasia, one developed invasive CRC and 47 (31.6%), advanced neoplasia. At 5 years, among 718 first negative sigmoidoscopies, 572 (80%) were confirmed negative and 97 (14%) had advanced neoplasia. Colorectal cancer status at 5 years could be checked for interval cancers in 97% of subjects and no CRC was diagnosed in subjects who did not attend sigmoidoscopy at 5 years. Comparison of the incidence of invasive CRC to the data of registries of the Netherlands and Luxembourg suggested that the incidence of CRC was decreased by 36%-46%. Seven of the nine CRCs were Duke's A and the two others were Duke's B and C.

CONCLUSIONS

Screening with sigmoidoscopy followed by colonoscopy in case of positive sigmoidoscopy leads to substantial decreases in the incidence of CRC. Most CRCs found are at an early, curable stage of their development.