Association of Breast Cancer Knowledge With Receipt of Guideline-Recommended Breast Cancer Treatment

Purpose Knowledge about one's breast cancer characteristics is poor, but whether this knowledge affects treatment is uncertain. Among women with breast cancer, we examined whether tumor knowledge was associated with adjuvant treatment receipt. Methods We surveyed a population-based sample of women in Northern California with stage 0 to III breast cancer diagnosed during 2010 to 2011 (participation rate, 68.5%). Interviews were conducted between 4 months and 3 years after diagnosis. Among 414 respondents with stage I to III disease, we examined receipt of guideline-recommended chemotherapy, radiation, and hormonal therapy by reporting correct information about one's tumor, including stage, estrogen receptor, human epidermal growth factor receptor 2 (HER2), and grade (using registry data for confirmation). We performed multivariate logistic regression to assess the probability of receiving each treatment in relevant patient groups, adjusting for patient and tumor characteristics, and examined the impact of reporting correct tumor information on treatment receipt. Results Among relevant treatment-eligible groups, 81% received chemotherapy, 91% received radiation, and 83% received hormonal therapy. In adjusted analyses, having correct (v incorrect) information for stage and HER2 were associated with chemotherapy receipt (odds ratio [OR], 4.45; 95% CI, 1.50 to 12.50 for stage; OR, 2.70; 95% CI, 1.02 to 7.18 for HER2). Correctly reporting estrogen receptor status was associated with hormonal therapy receipt (OR, 3.91; 95% CI, 1.73 to 8.86), and correctly reporting stage was associated with radiation receipt (OR, 2.76; 95% CI, 1.03 to 7.40). Conclusion Knowledge about one's tumor characteristics was strongly associated with receipt of recommended therapies. Interventions to improve patients' knowledge and understanding of their cancers should be tested as a strategy for improving receipt of care.