Purpose: The main purpose of this study was to determine if comprehension of the cancer risk information presented in a hypothetical report for BRCA1/2 gene analyses was influenced by the format in which the information was presented. A secondary objective was to determine physician characteristics that might influence comprehension of the report.
Methods: A survey was conducted in which a case vignette describing a young woman at high risk for carrying a BRCA mutation was presented. Survey participants, all primary care practitioners, were asked to interpret a laboratory report that provided the patient's BRCA1/2 test result and accompanying data about the cumulative risk and incidence rates of breast cancer for BRCA1/2 mutation carriers and the general population. These data were presented in the report in either a tabular or a graphic format. The main outcome was measured by the responses to four questions that addressed the probabilistic cancer risk information. Physician predictor variables included medical specialty, practice setting, years in practice, continuing medical education in genetics, and knowledge of cumulative risk.
Results: Knowledge of cumulative risk was the only physician variable that influenced comprehension of the cancer risk information (OR = 31.9; P < 0.001). After adjusting for this variable, the graphic format tended to perform better than the tabular format in conveying breast cancer risk information (OR = 3.1; P = 0.102).
Conclusions: Many physicians may be unprepared to interpret genetic risk information, due to lack of understanding of basic epidemiologic terms used to express the risk of disease.