Risk perception and knowledge of breast and colon cancers in a diverse population.

Abstract

1563 Background: The accuracy of cancer risk perception has implications for preventive behaviors. Studies show that despite receiving personalized breast and colon cancer risk information, people continue to overestimate their numeric risks. It is still not fully understood why this occurs. Breast cancer, especially, is highly visible in the media so an individual may hear more about breast cancer, increasing general knowledge but potentially inflating risk perceptions. This study explores relationships between general knowledge and numeric risk perceptions for breast cancer (BC) and colon cancer (CC) among women. We hypothesize that general knowledge of BC will be high relative to CC, but risk perception for BC will be less accurate. Methods: Data was obtained from the first 369 (final N=490) patients recruited for the Kin Fact study from a Women’s Health Clinic. Kin Fact is a randomized controlled trial examining effects of an intervention to increase cancer risk communication in families. Women complete baseline surveys including knowledge and numeric risk perception measures for BC and CC. We use CA Gene software to calculate actual lifetime risk for BC and CC. Correlations, t-tests and linear regressions were used for the analysis. Results: Women averaged 33 years old, and 58% were African American. Average lifetime risk was 3% for CC and 11% for BC. Women overestimated their numeric risk for both BC and CC, but the mean overestimation for BC (24%) was significantly larger than for CC (19%) (p<0.001). Average scores for BC knowledge were also significantly higher than for CC (p<0.001). Compared to knowledge about CC, women who had greater knowledge of BC also were more inaccurate in terms of their perceived numeric risk (r= -0.131, p=0.016). This finding remained significant controlling for age, race and genetic literacy. Conclusions: Results endorse an apparently paradoxical effect that compared with CC, women with increased knowledge of BC have less accurate risk perception for BC. Inaccuracies in perceived risk can affect psychosocial well-being and adherence to screening and prevention recommendations. Findings reveal a need for increasing knowledge about cancer without adversely impacting the accuracy of risk perceptions.