Recording, Interpreting, and Updating the Family History of Cancer Implications for Cancer Prevention

EVIDENCE-BASED GUIDELINES RECOMMEND THAT PERsons at elevated risk of cancer begin cancer screening at a younger age than the general population and consider more sensitive screening tests. A family history of cancer contains powerful information for cancer risk stratification. Because most common cancers are diagnosed in older age, the prevalence of a family history of cancer increases throughout adulthood. However, agespecific data based on detailed family history have only recently become available. In this issue of JAMA, Ziogas and coinvestigators from the Cancer Genetics Network (CGN) report prospective and retrospective data from a populationbased registry to illustrate the extent to which family history relevant for cancer prevention increases with age. What are the implications for preventive care? Family history is an integral part of medical history and decision making yet has not, until recently, been standardized or widely recorded in structured fashion. Thus, little high-quality evidence is available to confirm the health benefits of generally screening family history in primary care. However, precise family history of an array of cancers is the basis for state-of-the-art cancer risk assessment. An Agency for Healthcare Research and Quality (AHRQ) expert panel concluded that systematic family history collection tools, some self-administered, are likely to improve on usual practice in primary care. The panel recommended recording a patient’s family history of several cancers at the initial visit (including ethnicity, lineage, and age at diagnosis of each affected relative). Relevant family history also may include the family member’s tumor pathology and genotype. Family history may be more consistently discussed with new patients than with established patients. To optimize the use of clinical time and resources, it is important to know when (at what ages and how often) to update the family history of common cancers. Knowing this, health information systems can be designed to accomplish this task. Furthermore, estimating the age-specific prevalence of increased familial risk is important for planning risk-appropriate cancer prevention services. The study by Ziogas et al presents longitudinal data from the population-based CGN registry that show changes in self-reported family history of cancer through adult life, increasing most steeply before age 50 years for breast and colorectal cancer and before age 60 years for prostate cancer. The authors found a 5% chance that an individual’s colorectal cancer screening recommendation would change between the ages of 30 and 50 years based on new family history and a 4% chance that women would be newly identified candidates for breast magnetic resonance imaging. The CGN study found age-specific prevalences of “clinically relevant” family histories of colon, breast, and prostate cancer that are similar to cross-sectional population-based data obtained from the California Health Interview Survey, lending confidence that these estimates could reasonably be extrapolated to the general population. The CGN investigators recommend updating family history of cancer every 5 to 10 years between ages 30 and 60 years. In current practice, updates likely occur either when patients present to clinicians with concerns about cancer (especially a relative or friend with a recent diagnosis), or for preventive care. Although primary care clinicians generally order cancer screening, it is easy to think of circumstances when updating the family history of cancer would be relevant for surgeons, gastroenterologists, urologists, radiologists, oncologists, gynecologists, and other clinicians. Having all clinicians and patients participate in reviewing and recording family history will become more feasible as electronic health records (EHRs) compile information from all who care for a patient, and as EHRs and personal health records eventually include structured family medical history data.