Nangia and Shapiro both agree that tamoxifen and raloxifene, which have been around the longest, are the preferred chemoprevention agents compared with exemestane and anastrozole. Shapiro said that because of this, he believes that properly educating the patient on the side effects and explaining the evidence can help overcome their reluctance to pursue chemoprevention therapy. For example, a study of 158 high-risk women found that, when these women were asked to rate their concern about the side effects of tamoxifen on a scale of 1 to 5, with a higher score indicating greater concern, the average score given was 4.28. FDA-approved SERMs for chemoprevention are tamoxifen and raloxifene, and approved AIs are exemestane and anastrozole.Д®vidence suggests that while the patient decision-making process is complex, the concern about side effects is a major factor. The low uptake is despite the overwhelming evidence that use of 5 years of treatment with selective estrogen receptor modulators (SERMs) and aromatase inhibitors (AIs) is effective at preventing breast cancer. Andrew McKay, MD, of Health Sciences Centre University of Manitoba Winnipeg in Canada, and co-authors noted that their own prospective study of high-risk patients (average 5-year Gail risk of 3% and 61% with atypia) found an overall rate of uptake of 15%.

The rate of uptake tends to differ between women who are high risk for developing breast cancer, defined as a risk level above a prespecified threshold determined by a risk model, and those with benign lesions. The proportion of women who decline to have chemoprevention can vary widely - in part depending on the physician's familiarity with the medications, with reports of the percentage of patients who do chose chemoprevention ranging from 5% to 42%.

Comprehensive meta analysis version 3