Abstract PO1-03-08: Association of patient-reported triple-negative breast cancer (TNBC) knowledge with clinical trial participation

Background: Patients with TNBC are highly encouraged to participate in clinical trials given the lack of targeted treatment options for this breast cancer subtype. Yet little is known regarding barriers to trial participation in this population, including the impact of patients’ understanding about TNBC biology. We examined whether disease knowledge and other patient-level factors were associated with TNBC patients’ participation in trials. Methods: From a multicenter, prospective cohort study of patients enrolled from 2019-present with newly diagnosed TNBC (ER/PR ≤10% also eligible), we identified those with stage I-III tumors who completed at least one survey. Surveys assessed demographics, TNBC knowledge, risk perceptions, and participation in clinical trials. Patients were assigned to Cohort A if surgery was the first intervention and Cohort B if neoadjuvant therapy was given. Medical records were reviewed to verify the accuracy of tumor characteristics reported by patients. Data was summarized with descriptive statistics and logistic regression was used to identify factors associated with trial participation. Results: Of the 137 patients included, median age was 56 years (IQR 46-63), 104 (82%) were non-Hispanic White, 10 (8%) Black, 5 (4%) Hispanic. and 110 (86%) had at least some college education. Overall, 55 (41%) had stage I tumors, 65 (48%) stage II, and 14 (10%) stage III. Among 116 patients with available clinical trial participation data, 55 (47%) reported trial participation, 59 (51%) reported no trial participation, and 2 (2%) were unsure. The majority (36/55, 65%) of trial participants were in Cohort B. Among 129 patients with TNBC knowledge data, 82 (64%) and 73 (57%) correctly reported their tumor stage and grade, respectively. Most (104/129, 81%) knew TNBC was defined as ER/PR/HER2-negative, but only 16% (21/128) knew the ER/PR-negative cut off was ≤1%. Of 98 patients with risk perception data, 30 (31%) estimated their likelihood of recurrence within the next 5 years as 0%, 60 (61%) between 10-50%, and 8 (8%) between 60-100%. When asked if TNBC patients who remain cancer-free after 3 years will most likely not experience recurrence, 44 (45%) said “True,” 13 (13%) said “False,” and 40 (41%) were unsure. On univariate analysis, trial participation was less likely in Cohort A patients (OR 0.42, 95% CI 0.20 – 0.89, P=0.02) and more likely in stage II patients (vs. stage I, OR 2.43, 95% CI 1.09 – 5.39, P=0.03). On multivariable analysis, patients with at least some college education had higher odds of trial participation compared to patients with a college degree or higher (OR 3.21, 95% CI 1.11 – 9.28, P=0.03). No associations were found for other factors, including TNBC knowledge. Conclusions: About half of TNBC patients surveyed reported participating in clinical trials. Most of these patients were undergoing neoadjuvant therapy, likely reflective of greater study availability in this setting. While TNBC knowledge was not significantly associated with trial participation in this small sample, a considerable number of patients reported their tumor characteristics incorrectly and/or appeared to underestimate their recurrence risks. This highlights the need for enhanced informational support for TNBC patients during treatment decision-making. More research is needed to understand barriers to trial participation in this population to leverage patient engagement and accelerate progress towards more effective treatments for TNBC. Citation Format: Megan Tesch, Noah Graham, Sean Ryan, Melissa Hughes, Eileen Wrabel, Nadine Tung, Steve Lo, Thomas Fynan, Meredith Faggen, Natalie Sinclair, Maria Constantinou, Sarah Sinclair, Nabihah Tayob, Nancy Lin, Ann Partridge, Eric Winer, Sara Tolaney, Ana Garrido-Castro. Association of patient-reported triple-negative breast cancer (TNBC) knowledge with clinical trial participation [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-03-08.