The Relation Between Projected Breast Cancer Risk, Perceived Cancer Risk, and Mammography Use: Results from the National Health Interview Survey

Breast cancer is a significant cause of morbidity and mortality in the United States, with approximately 217,000 women expected to be diagnosed in 2004.1 Despite recent controversy about the effectiveness of mammography, most organizations endorse regular mammography screening as a means of decreasing breast cancer mortality.2–6 Unfortunately, some studies suggest that only about two thirds of women who get a mammogram return for regular testing.7, 8 As repeat mammography at regular intervals is required for optimal mortality reduction,9 many of these women may not be receiving the benefit of screening. Some have suggested that mammography utilization could be increased by tailoring screening recommendations to each woman's individualized risk of breast cancer.10 In women with a prior history of breast cancer, mammograms have a higher case finding rate and mammography-detected tumors are more likely to be earlier stage.11–14 As a result, current guidelines state that women with increased breast-cancer risk should begin consider initiating screening at an earlier age and return at regular intervals.2, 15–18 What type of risk information should be integrated into clinical decision making? Until recently, most guidelines and studies have relied exclusively on family history as the marker of breast cancer risk.19, 20 Indeed, women with a family history are more likely to receive mammograms than women without a family history, but as many as a third of women ≥50 years of age with a family history have been found to have not had a mammogram in the past year.19, 20 A broader concept of breast cancer risk can help to tailor risk stratification to individual patients far more accurately. Besides family history, other important risk factors for breast cancer include a history of prior breast abnormalities or hormone replacement therapy use, obesity, physical inactivity, age, ethnicity, and age at primary menarche, first live birth, and menopause.10, 21, 22 Comprehensive breast cancer risk assessment tools, such as the widely used model developed by Gail et al.21 incorporate multiple patient characteristics into a validated algorithm for informing the woman of her projected breast cancer risk. Women's perceptions of breast cancer risk are not always consistent with their “objective” breast cancer risk estimates.23–25 These discrepancies are important because some data have suggested that perceived risk may be a stronger predictor of mammography use than quantitative estimates of projected risk.23, 26 Conversely, it is important not to overemphasize risk; some work has suggested that too much trepidation over one's risk may hinder screening.23, 27–29 Because women who misinterpret their risk may be less likely to make informed decisions about mammography use, it is important to understand factors that influence cancer risk perceptions and whether these perceptions impact mammography use at the population level. The objective of this study was to examine the interconnecting relationships between projected breast cancer risk, perceived cancer risk, and routine mammography use.30 We assessed predictors of routine mammography use using data from the 2000 National Health Interview Survey (NHIS) to address the following research questions (Fig. 1): First, what is the association between projected breast cancer risk and routine mammography use? Second, is perceived cancer risk independently associated with routine mammography use? Third, what factors are associated with perceived cancer risk in the general population, as well as among a subgroup of women with increased projected cancer risk? FIGURE 1 Study schema and research questions.