Do participants in major, practice-changing breast cancer trials reflect the breast cancer patient population?

Results 33 breast cancer specialists ranked 39 trials in order of importance with the 12 most selected included in this study. Of 4811 women in the Tayside dataset, the number meeting eligibility criteria for the 12 trials ranged from 822 (17%) to 3419 (71%). Reasons for exclusion included age and comorbidity. Many women received a treatment evaluated in a trial but would themselves not have been eligible for the trial. For example, of 572 patients prescribed anastrazole and tamoxifen, only 281 were eligible for the trial evaluating that combination. Work to explicitly compare treatment decisions in clinical practice to trial eligibility criteria is ongoing.