Reference: JAMA Netw Open 2026 Jan 2;9(1):e2551553
Practice Point: True shared decision-making is possible only when patients have the most accurate understanding of information possible, even if access to that information does not ultimately influence the treatment plan.
EBM Pearl: A higher dropout rate in the intervention group without an intention-to-treat analysis can create a bias and overestimate the treatment effect.
Germline (inherited) genetic testing has become the standard for patients with breast cancer and is considered essential for educating patients on their risk of cancer recurrence or heritable transmission to their children. However, several studies indicate that patients still struggle to understand their future risk of cancer despite standard genetic counseling. To better understand and address this difficulty, researchers behind the Genetic Testing for All Breast Cancer Patients (GET FACTS) trial, published in JAMA Network Open, developed a new quantitative genetic counseling web-based tool that incorporates risk estimates into a visual clinical decision aid and presented risk data to patients in tables, graphs, and pictograms in addition to the standard discussion.
To put this new visual aid to the test, adults who were recently diagnosed with unilateral breast cancer received germline genetic testing and had their personal contralateral breast cancer risk calculated using previously developed statistical models. Next, patients were randomized to one of two genetic counseling conditions: (1) personalized quantitative genetic counseling with the visual aids or (2) standard genetic counseling. Both were centered on educating patients about their personal risk of contralateral breast cancer. Patients completed self-assessments of their contralateral breast cancer risk (primary outcome), and rates of contralateral prophylactic mastectomy were recorded (secondary outcome).
Prior to genetic counseling, patients’ self-assessed risk estimates were similarly inaccurate, with a clear tendency to overestimate risk. After genetic counseling, the visually aided genetic counseling group demonstrated a better understanding of their risk compared to the standard counseling group (p = 0.008). However, rates of contralateral prophylactic mastectomy were similar among the two groups (18.5% vs. 11.2%, not significant), suggesting that visually aided genetic counseling may not alter the patient treatment plan for patients with unilateral breast cancer.
Importantly, several caveats should be considered when interpreting the results of this study. First, there was a differential dropout rate, with more patients dropping out of the visually aided genetic counseling group. Moreover, rather than appropriately performing an intention-to-treat analysis to maintain prognostic equivalence and mitigate bias, the researchers performed a per-protocol analysis for the primary outcome, which systematically overestimates the effect of the intervention. Second, it is difficult to design a study with sufficient power to detect differences in any secondary outcome. Here, the difference for the secondary outcome, which was the rate of contralateral prophylactic mastectomy, was almost significant, but as we all know, almost doesn’t count. Without a power calculation using an appropriate effect size for this outcome, it is difficult to fully interpret this important result.
Overall, compared to standard genetic counseling, visually aided genetic counseling in patients with unilateral breast cancer appears to improve the patients’ understanding of their personal risk for developing contralateral breast cancer. However, it is unclear if that education influences the decision to undergo contralateral prophylactic mastectomy. Thus, when deciding whether to implement this type of genetic counseling, clinicians should balance the importance of patient education with the knowledge that it may not lead to changes in treatment, at least for this specific intervention in this specific patient population. That said, sometimes the biggest win in evidence-based medicine isn’t changing minds but rather making sure shared decisions are made with both parties having the same understanding of the best available information.
For more information, see the topic Hereditary Breast and Ovarian Cancer (HBOC) Syndromes in DynaMed.
DynaMed EBM Focus Editorial Team
This EBM Focus was written by Michael Butler, PhD, Medical Writer at DynaMed. Edited by Katharine DeGeorge, MD, MS, Executive Editor at DynaMed and Associate Professor of Family Medicine at the University of Virginia; Alan Ehrlich, MD, FAAFP, Executive Editor at DynaMed and Associate Professor in Family Medicine at the University of Massachusetts Medical School; McKenzie Ferguson, PharmD, BCPS, Senior Clinical Writer at DynaMed; Rich Lamkin, MPH, MPAS, PA-C, Senior Clinical Writer at DynaMed; by Claire Symanski, PhD, Medical Editor and Team Lead for ENT at DynaMed; Matthew Lavoie, BA, Senior Medical Copyeditor at DynaMed; Hannah Ekeh, MA, Senior Associate Editor II at DynaMed; and Jennifer Wallace, BA, Senior Associate Editor at DynaMed.