Perceived risk of breast cancer among women at average and increased risk.

Background: The accuracy of a woman's perception of her risk of developing breast cancer has gained importance as more options for primary prevention have become available for those at increased risk. Conversely, women at average risk who perceive themselves as at increased risk may suffer from avoidable anxiety or unnecessary treatment. This study examined characteristics associated with perception of breast cancer risk among women at average and increased risk.

Methods: We included 1700 women 40-74 years old without a history of breast cancer. The outcome variable was a woman's perceived lifetime risk of developing breast cancer. The Gail model was used to categorize a woman's actual risk as average or high. Multivariate logistic regression models were used to model a woman's perception that her risk was (1) higher than average for those whose Gail score indicated average risk (<1.67% 5-year risk) and (2) accurate for those whose Gail score indicated increased risk (> or = 1.67% 5-year risk).

Results: Of women at average risk, 72%, but only 43% of those at high risk, accurately perceived their risk. Among women at average risk, those who were younger, had a family history of breast cancer, had no history of childbirth, or had more frequent exposure to lay media information about breast health were more likely than women without these characteristics to overestimate their future risk. Among women at increased risk, younger women and those with a family history of breast cancer were more likely than women without these characteristics to accurately perceive their increased risk. African American women were less likely than white women to accurately perceive their risk.

Conclusions: A majority of women at high risk of developing breast cancer underestimate their risk, and a substantial proportion of women at average risk perceive they are at increased risk.