This analysis focused on associations between communication, encouragement and time since last colonoscopy among index cases with and without known HNPCC mutations and their FDRs. Family mutation status, communication about risk for HNPCC, encouragement to screen for CRC, and having family members who were involved in both communication and encouragement, were significantly associated with time since last colonoscopy. These findings represent one of the first comparisons of screening behavior between indeterminate and mutation-positive families. Although the study sample was relatively small, use of social network analysis and matching indeterminate and mutation-positive families facilitated the examination of the variables of interest.
There was no difference in time since last colonoscopy between respondents from mutation-positive vs. indeterminate families. This finding adds to the existing literature on screening 26
by evaluating reported health behaviors instead of screening intentions. For respondents from indeterminate families, heightened awareness of family history might facilitate screening participation 12
. The finding is consistent with a behavioral impact of appropriate genetic education and counseling on HNPCC screening 27, 28
. However, it is important to note that not all participants received genetic counseling, suggesting that communication about HNPCC and encouragement of CRC screening within at-risk families could be effective in promoting appropriate colonoscopy use. This contrasts with other findings that index cases with inconclusive genetic test results are less likely to have a colonoscopy in the year after receiving their genetic test results, compared to mutation-positive index cases 12
. The screening behaviors presented here represent the long-term behavioral impact of genetic education and counseling, with measurements obtained, on average, 6 years following disclosure of genetic test results. Indeterminate and inconclusive genetic test results have the potential to cause greater emotional distress than true-negative results 29, 30
. Some participants, particularly those in families with indeterminate genetic test results, may have taken longer to accept and act on screening recommendations. Additionally, differences in sample size and variable measurement could contribute to reported differences.
Respondents who received encouragement to screen for CRC from a larger proportion of family members had more recent colonoscopies. Among at-risk siblings, FDRs of CRC patients, and individuals at high risk for CRC, encouragement and recommendations to screen from family members and physicians are reported to improve screening 16-18
. Although participants were not asked specifically about health care providers during creation of the family network, 43% included a health care provider in their networks [data not shown]. Additionally, 3% of named encouragers were health care providers. Further examination of the role of health care providers in encouraging screening among individuals at high risk for CRC is warranted, including an exploration of the roles played by different health care providers (e.g., specialists, primary care providers). As genomics moves out of specialized clinics and into general practice, the role and influence of local health care providers on screening behaviors could increase 31
. In the general population, having a primary health care provider is associated with having a colonoscopy 32
. Under many health insurance plans, referrals from a primary health care provider are necessary in order to obtain screening exams such as colonoscopy. This may be of particular importance in families at risk for HNPCC, given the need for early CRC screening. Improved education regarding hereditary cancer syndromes among general practitioners would help mitigate limited knowledge 33, 34
, providing an important link between specialty care, general practice, and families. Future studies would benefit from including measures of encouragement to screen that focus on particular network members. This could help determine whether there is a differential effect of encouragement, depending on whether it is provided by a family member or a health care provider.
Respondents who communicated with a higher proportion of family members about risk for HNPCC had more recent colonoscopies. Individuals at high risk for CRC highlighted the motivating influence of family communication about CRC on completion of CRC screening 18
. Among FDRs of patients with sporadic CRC, discussion of CRC with social groups is associated with CRC screening 16
. Open family communication styles may facilitate the sharing of genetic risk information 35
; in turn, family members who learn of their own risk may be more inclined to participate in recommended screening. Having a larger proportion of family members involved in both communication and encouragement was also significantly associated with time since last colonoscopy, prompting speculation about family interactions. The current data were cross-sectional in nature, limiting our ability to ascertain the social mechanisms that promote CRC screening in at-risk families. Learning about the respondent’s risk for disease may prompt family to offer encouragement for screening. Alternatively, individuals who encourage CRC screening may be viewed as network members who would be willing to hear and talk about being at risk for cancer. Prospective, longitudinal studies would help disentangle these processes, providing necessary information for developing interventions that promote adherence to screening recommendations in at-risk families.
Although health care providers can directly influence patients’ actions, they should also recognize the potentially important influence of family members on cancer screening. Tapping into everyday family interactions, in contrast to large-scale public health education campaigns 36
, may be another way to educate individuals at risk for HNPCC about cancer screening and improve compliance with screening recommendations. The benefits of a family-based intervention lie in the continued support and encouragement that family members can offer to at-risk individuals; interactions among family members are generally more frequent than those with health care professionals. Additional study of how social relationships influence individual behaviors 36, 37
would aid in the development of interventions based on the informal social network. In this study, actions initiated by both the at-risk individual (communication) and social network members (encouragement) influenced the time since last colonoscopy. These findings might reflect the general communication pattern within the family and its potential effects on cancer screening 38
. Following replication and verification of these findings, another potential area of health care provider intervention may include encouraging family communication about disease risk and cancer screening, and providing support to individuals at risk for hereditary forms of cancer during these processes.
Several limitations of the current study should be considered when interpreting results. The sample size for the study was relatively small, with 46 respondents. This restricted the number of analyses conducted, and the inclusion of individual-level covariates (e.g., age, income, education). Additional differences between groups may not have been apparent, due to the small sample size. Because of this, respondents were matched and the number of analyses was limited. Larger-scale studies should be undertaken to better understand possible differences between mutation-positive and indeterminate families. Although respondent matching provided additional power for analysis, exact matches were not possible for all members of all families. Due to limitations of the family match process, individuals who tested negative for known family mutations were included in the analysis. Including only those who remain at high risk for HNPCC-associated cancers would provide an improved comparison for families with indeterminate genetic test results. Finally, broad response categories for the outcome variable limited the amount of detail gleaned from the data. This was done in order to allow comparison to data gathered in the parent study, however, measuring time since last colonoscopy in a more precise manner might have resulted in greater insight into participants’ screening behaviors.
Although many respondents in this study are meeting recommendations for colonoscopy screening, 26.1% of individuals from families with indeterminate test results, who remain at risk for HNPCC, are not, having had their most recent colonoscopy more than three years ago, or never having had one (). Additionally, 13% of individuals from mutation-positive families are not screening appropriately. Respondents have more recent colonoscopies when risk is discussed and screening is encouraged. While these findings have clear implications for clinical care of individuals at risk for HNPCC, replicated and expanded analysis of the association between family communication, family encouragement, and cancer screening would be valuable. Although the findings are limited by the relatively small sample size, use of a research-based population, and lack of ethnic diversity, these results suggest that health care providers should explore and encourage family communication about HNPCC risk to promote appropriate colonoscopy screening in individuals at risk for HNPCC.