A substantial proportion of women have beliefs about their personal risk of breast cancer, and expectations about the performance of mammography that are abnormally high or unrealistic, according to a survey conducted at University of Michigan Health Systems in Ann Arbor, Michigan.
A survey was administered to women who came to an outpatient clinic for screening mammography. The participants were 397 women ranging from 40-83 years old. The responses to the survey questions showed that 16% thought that their personal risk of breast cancer was 50% or higher. These numbers compare to American Cancer Society reports that indicate that the chance of a woman having invasive breast cancer some time during her life is about 1 in 8.
The survey also found that 20.6% of the women agreed with the statement 'mammograms detect all breast cancers' and 11.4% were neutral about this statement. "Women have high expectations of mammography because patients in general (not specifically women), tend to have a view of all medical tests being yes or no, 'positive' or 'negative'; the general public as well as some health care professionals do not completely understand concepts of accuracy, sensitivity and specificity, false negatives, and false positives," said Marilyn Roubidoux, MD, co-investigator of the study. "People assume that if a mammogram can detect cancer the size of a pin, then it can detect all cancers bigger than a pin. The reality is much more complicated than that," she said.
Most of the women (94%) had had a prior mammogram; 14.1% had prior benign biopsy. Eighty-four percent of the respondents had one year of post high school education, 55% were college graduates, and 23% had graduate degrees.