Associations between perceived cancer risk and established risk factors in a national community sample

Introduction: Perceptions of personal cancer risk may not accurately reflect individual’s exposure to established risk factors. The purpose of this study was to assess associations between perceived cancer risk and selected established risk factors, using a large nationally representative sample. Methods: We used data from the 2000 National Health Interview Survey (NHIS) to perform a cross-sectional analysis of 30,223 adults without a cancer diagnosis. Multinominal logistic regression analyses were used to assess factors associated with medium and high perceived cancer risk. Results: The effects of age, family history, and smoking status on perceived risk were linear and more pronounced on those with high perceived risk. High perceived risk was associated with every day smoking (relative risk ratio [RRR]=4.27, 95% confidence intervals [CI]=3.65–5.01), alcohol consumption (e.g. RRR=1.26, 95% CI=1.01–1.56 for current drinker), number of relatives with cancer (e.g. RRR=20.64, 95% CI=16.37–26 for those with both parents positive), low income (RRR=1.25, 95% CI=1.08–1.45), and female (RRR=1.39, 95%CI=1.23–1.57). Obesity (RRR=1.32, 95% CI=1.1–1.6), but not overweight, was identified as an independent determinant. High perceived risk was inversely related to age (e.g. RRR=0.19, 95%CI=0.16–0.24 for adults 60 and older). Ethnic minorities were less likely to perceive cancer risk. Physical inactivity was not associated with high perceived risk. Conclusions: Among established risk factors, family history appears to be most reflected in the single measure of perceived cancer risk. The relationship between perceived cancer risk and exposure to established risk factors differs in important ways from what public campaigns have communicated with the public. Prevention messages should highlight that cancer risk increases with age and certain modifiable risk factors, including overweight and physical inactivity. The relationship between cancer risk perceptions and ethnicity merits further exploration.