Family history assessment to detect increased risk for colorectal cancer: conceptual considerations and a preliminary economic analysis

Perceived susceptibility to developing cancer and screening for colorectal and prostate cancer: A longitudinal analysis of Alberta's Tomorrow Project

INTRODUCTION

To assess the association between perceived susceptibility of developing cancer and being screened via sigmoidoscopy/colonoscopy and prostate-specific antigen, respectively.

METHODS

Participants aged 35-69, who resided in Alberta, Canada, were enrolled into the study between 2000 and 2008. We used general linear mixed models, adjusted for age, marital status, work status, education, family history and place of residence, to explore the association.

RESULTS

Perceived susceptibility of developing cancer was associated with both screening tests at baseline and a maximum of 14-year follow-up: (i) colorectal cancer screening - adjusted odds ratios were 1.97 (95% CI = 1.52-2.55) per one-unit increase in participants' personal belief in susceptibility to cancer, and 1.03 (95% CI = 1.00-1.04) per one-percent increase in participants' estimate of their own chance of developing cancer; (ii) prostate cancer screening - adjusted odds ratios were 1.36 times greater (95% CI = 1.07-1.72), and 1.02 times higher (95% CI = 1.01-1.03), for each respective perceived susceptibility measure.

CONCLUSION

Health promotion can focus on targeting and heightening personal perceived susceptibility of developing cancer in jurisdictions with low screening rates for colorectal or prostate cancer.

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.

Tumor-induced DNA methylation in the white blood cells of patients with colorectal cancer

The secretions of cancer cells alter epigenetic regulation in cancer stromal cells. The present study investigated the methylation changes in white blood cells (WBCs) caused by the secretions of colorectal cancer (CRC) cells. Changes in the DNA methylation of peripheral blood mononuclear cells (PBMCs) from normal individuals co-cultured with CRC cells were estimated using a methylation microarray. These changes were then compared against the DNA methylation changes and mRNA levels observed in the WBCs of patients with CRC. Procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (PLOD1) and matrix metalloproteinase 9 (MMP9) were selected to assess the DNA methylation of the WBCs from CRC patients using real-time methylation-specific PCR. The majority of the genes analyzed presented high levels of mRNA in the WBCs of the patients with CRC and DNA methylation in the co-cultured PBMCs. Intragenic methylation revealed the strongest association (P=8.52×10^-21). For validation, MMP9 and PLOD1 were selected and used to test WBCs from 32 patients with CRC and 57 normal controls. The intragenic MMP9 methylation was commonly found (P<0.0001) with high sensitivity (90.63%) and high specificity (96.49%), and a positive predictive value of 93.33% and a negative predictive value of 93.22%. PLOD1 methylation was revealed to have lower sensitivity (30.00%) but higher specificity (97.92%). In addition to circulating WBCs, MMP9 protein expression was observed in infiltrating WBCs and the metastatic lymph nodes of patients with CRC. In conclusion, CRC cells secrete factors that induce genome wide DNA methylation changes in the WBCs of patients with CRC. These changes, including intragenic MMP9 methylation in WBCs, are promising CRC biomarkers to be tested in future CRC screening studies.

Barriers in identification and referral to genetic counseling for familial cancer risk: the perspective of genetic service providers

The purpose of this study was to obtain genetic counselors' perspectives about the identification of appropriate patients and barriers to referral of high-risk patients for cancer genetic counseling services. Genetic service providers from eight integrated health systems were surveyed. Data analysis included descriptive statistics. Twenty-eight of 40 potential participants responded (70%). Referrals for familial cancer risk assessment overwhelmingly came from providers (89%); only 10% were self-referrals. Use of guidelines to assist providers with referral was reported by 46% of the respondents. Genetic service providers perceived patient barriers to seeking genetic counseling after referral included: risk evaluation viewed as a non-priority (72%), concerns about impact on insurability (52%), distance to appointments (48%), lack of insurance (44%), lack of patient/provider knowledge about the value of genetic counseling (36%), discouragement by family members (28%), and fear (20%). The best approaches suggested by respondents to increase appropriate referrals were attending meetings and giving presentations to oncologists, surgeons, primary care and gynecologists. The genetic service providers reported several barriers to the referral and use of genetic counseling. This finding is consistent with current literature from the providers' perspective. Our survey adds the genetic service providers' perspective and identifies areas of opportunity for further research and intervention as few of the perceived barriers are being addressed through current educational efforts.

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.

The cost-effectiveness of genetic testing strategies for Lynch syndrome among newly diagnosed patients with colorectal cancer

PURPOSE

To estimate the cost-effectiveness of genetic testing strategies to identify Lynch syndrome among newly diagnosed patients with colorectal cancer and to offer targeted testing to relatives of patients with Lynch syndrome.

METHODS

We calculated incremental costs per life-year saved for universal testing relative to no testing and age-targeted testing for strategies that use preliminary genetic tests (immunohistochemistry or microsatellite instability) of tumors followed by sequencing of mismatch repair genes. We also calculated incremental cost-effectiveness ratios for pairs of testing strategies.

RESULTS

Strategies to test for Lynch syndrome in newly diagnosed colorectal tumors using preliminary tests before gene sequencing have incremental cost-effectiveness ratios of <or=$45,000 per life-year saved compared with no testing and <or=$75,000 per life-year saved compared with testing restricted to patients younger than 50 years. The lowest cost testing strategies, using immunohistochemistry as a preliminary test, cost <or=$25,000 per life-year saved relative to no testing and <or=$40,000 per life-year saved relative to testing only patients younger than 50 years. Other testing strategies have incremental cost-effectiveness ratios >or=$700,000 per life-year saved relative to the lowest cost strategies. Increasing the number of relatives tested would improve cost-effectiveness.

CONCLUSION

Laboratory-based strategies using preliminary tests seem cost-effective from the US health care system perspective. Universal testing detects nearly twice as many cases of Lynch syndrome as targeting younger patients and has an incremental cost-effectiveness ratio comparable with other preventive services. This finding provides support for a recent US recommendation to offer testing for Lynch syndrome to all newly diagnosed patients with colorectal cancer.

Characteristics of health information gatherers, disseminators, and blockers within families at risk of hereditary cancer: implications for family health communication interventions

OBJECTIVES

Given the importance of the dissemination of accurate family history to assess disease risk, we characterized the gatherers, disseminators, and blockers of health information within families at high genetic risk of cancer.

METHODS

A total of 5466 personal network members of 183 female participants of the Breast Imaging Study from 124 families with known mutations in the BRCA1/2 genes (associated with high risk of breast, ovarian, and other types of cancer) were identified by using the Colored Eco-Genetic Relationship Map (CEGRM). Hierarchical nonlinear models were fitted to characterize information gatherers, disseminators, and blockers.

RESULTS

Gatherers of information were more often female (P<.001), parents (P<.001), and emotional support providers (P<.001). Disseminators were more likely female first- and second-degree relatives (both P<.001), family members in the older or same generation as the participant (P<.001), those with a cancer history (P<.001), and providers of emotional (P<.001) or tangible support (P<.001). Blockers tended to be spouses or partners (P<.001) and male, first-degree relatives (P<.001).

CONCLUSIONS

Our results provide insight into which family members may, within a family-based intervention, effectively gather family risk information, disseminate information, and encourage discussions regarding shared family risk.

Will knowledge of gene-based colorectal cancer disease risk influence quality of life and screening behavior? Findings from a population-based study

BACKGROUND

Several gene variants conveying a modestly increased risk for disease have been described for colorectal cancer. Patient acceptance of gene variant testing in clinical practice is not known. We evaluated the potential impact of hypothetical colorectal-cancer-associated gene variant testing on quality of life, health habits and cancer screening behavior.

METHODS

First-degree relatives of colorectal cancer patients and controls from the Seattle Colorectal Cancer Familial Registry were invited to participate in a web-based survey regarding testing for gene variants associated with colorectal cancer risk.

RESULTS

310 relatives and 170 controls completed the questionnaire. Quality of life for the hypothetical carrier state was modestly and nonsignificantly lower than current health after adjustment for sociodemographic and health factors. In the positive test scenario, 30% of respondents expressed willingness to change their diet, 25% to increase exercise, and 43% to start colorectal cancer screening. The proportions willing to modify these habits did not differ between groups.

CONCLUSIONS

Testing for gene variants associated with colorectal cancer risk may not influence quality of life, but may impact health habits and screening adherence. Changing behaviors as a result of testing may help to reduce cancer incidence and mortality, particularly among those at higher risk for colorectal cancer.

Interviews with primary care physicians regarding taking and interpreting the cancer family history

BACKGROUND

The cancer family history can be used to stratify risk and guide management regarding screening and prevention of cancer.

OBJECTIVE

The current study was designed to gain understanding of specific barriers to obtaining and using the cancer family history for the primary care physician.

METHODS

Interviews were conducted with structured samples of specialists in family medicine, general internal medicine and gynaecology in three settings in two north-eastern states. A medical anthropologist conducted interviews based on a topical outline; transcripts were systematically analyzed by a research team to identify major themes expressed by participants.

RESULTS

Among 40 urban, suburban and rural physicians interviewed, 40% were women and medical school graduation years ranged from 1963 to 2000. These physicians regarded cancer family history as important, but process and content were not standardized. Major barriers to more focused use of this information included limitations of patients' family history knowledge; time needed to clarify and interpret this information and the lack of clear and accessible guidelines to assist in collection, interpretation and management decisions for average, moderate and higher risk patients. Language and cultural barriers made it more difficult to collect family histories in some populations.

CONCLUSIONS

Barriers to effective application of cancer family history information included limitations of patients' family history information; lack of methods to systematically and efficiently focus on the most useful information and lack of accessible guidance for risk stratification and management. Results suggest a need for support addressing these concerns to better utilize several readily available cancer risk management opportunities.

Feasibility of screening for Lynch syndrome among patients with colorectal cancer

PURPOSE

Identifying individuals with Lynch syndrome (LS) is highly beneficial. However, it is unclear whether microsatellite instability (MSI) or immunohistochemistry (IHC) should be used as the screening test and whether screening should target all patients with colorectal cancer (CRC) or those in high-risk subgroups.

PATIENTS AND METHODS

MSI testing and IHC for the four mismatch repair proteins was performed on 500 tumors from unselected patients with CRC. If either MSI or IHC was abnormal, complete mutation analysis for the mismatch repair genes was performed.

RESULTS

Among the 500 patients, 18 patients (3.6%) had LS. All 18 patients detected with LS (100%) had MSI-high tumors; 17 (94%) of 18 patients with LS were correctly predicted by IHC. Of the 18 probands, only eight patients (44%) were diagnosed at age younger than 50 years, and only 13 patients (72%) met the revised Bethesda guidelines. When these results were added to data on 1,066 previously studied patients, the entire study cohort (N = 1,566) showed an overall prevalence of 44 of 1,566 patients (2.8%; 95% CI, 2.1% to 3.8%) for LS. For each proband, on average, three additional family members carried MMR mutations.

CONCLUSION

One of every 35 patients with CRC has LS, and each has at least three relatives with LS; all of whom can benefit from increased cancer surveillance. For screening, IHC is almost equally sensitive as MSI, but IHC is more readily available and helps to direct gene testing. Limiting tumor analysis to patients who fulfill Bethesda criteria would fail to identify 28% (or one in four) cases of LS.

Data reduction for prediction: a case study on robust coding of age and family history for the risk of having a genetic mutation

Data reduction is often desired in the development of a prediction model, for example for effects of age and family history in the identification of subjects having a genetic mutation. We aimed to evaluate a strategy for model simplification by robust coding of related predictors. We considered 898 patients suspected of having Lynch syndrome, which is caused primarily by mutations in the mismatch repair genes, MLH1 or MSH2. The presence of colorectal cancer (CRC) and endometrial cancer in patients and their relatives was related to mutation prevalence with logistic regression analysis. The performances of simplified and more complex models were quantified with a concordance statistic (c), which was corrected for optimism by cross-validation and bootstrapping. External validation was performed in 1016 patients. The first challenge was the coding of age at diagnosis of CRC, where we forced effects to be identical in patients, in 1st degree and in 2nd degree relatives, by taking the sum of the ages at diagnosis. As a further simplification, CRC diagnosis in 2nd degree relatives was weighted half that of 1st degree relatives. These data reduction approaches were also followed for endometrial cancer. The simplified model used 7 instead of 17 degrees of freedom (df) for a more complex model incorporating individual predictor effects. The optimism-corrected c was higher (0.79 instead of 0.77), but the external c was similar (0.78 for the simplified and more complex models). A stepwise selected model performed slightly worse (external c=0.77). In conclusion, a prediction model could be developed with relatively few df that captured effects of age at diagnosis across patients and relatives per type of cancer in the family. Such robust coding may especially be relevant for modeling in relatively small data sets.

Family history and colorectal cancer survival in women

PURPOSE

Family history of colorectal cancer may be a phenotype for numerous genetic mutations which increase colorectal cancer risk and may affect survival after diagnosis. We examined the relationship between self-reported first-degree family history of colorectal cancer and survival.

METHODS

We identified female Wisconsin residents ages 20-74 with a new diagnosis of invasive colorectal cancer from two population-based case-control studies; 1,469 women were interviewed. Follow-up averaged 7.9 years. We performed multivariable Cox proportional hazards regressions to calculate adjusted hazard rate ratios [HR] and corresponding 95% confidence intervals [95% CI] for risk of death by family history.

RESULTS

Of 1,391 cases with available first-degree family history, 481 were deceased, 268 due to colorectal cancer. In multivariable analyses, cases with any family history (N=262) had a statistically non-significant lower risk of death (HR 0.86, 95% CI 0.62, 1.20) compared to no family history (N=1,129). Cases with two or more affected family members (N=46) showed significantly lower risk of death when compared to women with no family history (HR 0.34, 95% CI 0.13, 0.92).

CONCLUSIONS

Although individuals with a colorectal cancer family history are diagnosed with the disease more often than the general population, these data suggest that survival from colorectal cancer may not be worse.

Family history of cancer in Brazil: is it being used?

In developing countries, low budgets make the issue of integrating genetics into clinical practice a challenge, a situation in which the use of family history (FH) becomes important for patient care, as it is a low cost strategy and a risk assessment tool. The purpose of this study was to review medical records of patients with colorectal cancer (CRC) seen in a public University Hospital and evaluate how often FH of cancer is registered. Initially we searched a database for patients who were seen in our hospital between 2002 and 2004 with the diagnosis of CRC. We found 415 patients, 104 of whom were excluded. A total of 311 charts were reviewed and classified into 3 groups. Group A: no FH documented; group B: FH was documented, but FH of cancer was not collected; and group C: FH of cancer was documented. We also investigated what type of information was recorded, in order to verify if important elements were assessed. Ninety-eight charts (31.5%) were classified in group A, 20 (6.5%) in group B, and 193 (62%) in group C. In addition, we observed that important information regarding affected relatives was not collected in most of the charts. In conclusion, we found that although FH of cancer was recorded in 62% of charts of patients with CRC, information that could be relevant for risk assessment and management of at-risk families was missing. Our findings expose an important problem in health education that could reflect negatively in the quality of medical assistance to individuals at risk for familial cancer.

Effects of colon cancer risk counseling for first-degree relatives

BACKGROUND

Individuals with a first-degree relative who has had colorectal cancer are at increased risk for colorectal cancer and thus can benefit from early detection. Tailored risk counseling may increase adherence to screening guidelines in these persons. The present study evaluated a culturally sensitive Colon Cancer Risk Counseling (CCRC) intervention for relatives of colorectal cancer patients.

METHODS

A randomized trial evaluated personalized CCRC sessions with print materials and follow-up phone calls compared with a comparable General Health Counseling (GHC) intervention. One hundred and seventy-six siblings and children of colorectal cancer patients, living in Hawaii, were assessed at baseline and 4 and 12 months after intervention. Physician verification of colorectal cancer screening reports supplemented survey data.

RESULTS

The CCRC intervention had a significant treatment effect at 4 months (13% greater increase than for GHC) that plateaued to a trend at 12 months. For those who were nonadherent at baseline, the CCRC led to a 17% net increase in screening adherence. Participants rated the CCRC intervention better than GHC for the amount and usefulness of new information.

CONCLUSIONS

Using a study design that compared risk counseling to an attention-matched and tailored control condition provided a rigorous test of CCRC that emphasized the relevance of family experience with colorectal cancer. The combination face-to-face, phone, and small media risk counseling intervention for people with a family history of colorectal cancer should be considered for adoption in health care and public health settings.

Valuing personalized medicine: willingness to pay for genetic testing for colorectal cancer risk

Objectives: Personalized medicine using genetic information is increasing in cancer screening and treatment; however, little is known about perceived value of genetic testing for cancer risk in a general population. The objectives of this report are: to identify a general population’s willingness to pay for genetic testing that provids colorectal cancer risk information; examine whether screening intentions (likelihood of testing and test choice) change based on risk; and identify providers’ beliefs about patients’ perceived value. Methods: A survey of US general (n = 1087) and physician (n = 100) populations using the willingness-to-pay method was carried out. Physicians responded from the perspective of a typical patient. χ2 tests, t-tests and ordered logistic regression were used to examine factors associated with willingness to pay and intentions to be screened. Results: General population respondents’ average willingness to pay for a genetic test for colorectal cancer risk was US$150. Higher willingness to pay was significantly associated with being male, having higher income and education, having private health insurance and reporting a greater likelihood of getting colorectal cancer screening when due. Physicians’ beliefs about patients were different than general population responses: physicians believed patients would be willing to pay more (US$212; p < 0.001), fewer believed patients would not pay (1 vs 17%; p<0.001), and if a genetic test indicated higher than average risk, physicians believed patients would be more likely to get screened (65 vs 46%; p < 0.001) and would choose alternative screening tests (62 vs 22%; p < 0.001). Conclusion: Respondents valued genetic tests to inform screening decisions and indicated that tests may influence screening choices. Additional studies are needed to examine the implications of physicians’ beliefs about patients’ choices for screening.