Refusal of chemotherapy, surgery, and radiation in non-metastatic triple-negative breast cancer.

e12712 Background: Refusal of oncologist-recommended therapy is uncommon but clinically consequential. In triple-negative breast cancer (TNBC), understanding which patients decline treatments and the resulting survival impacts may inform oncologist discussions and interventions. Using real-world data, we examined factors associated with refusal of chemotherapy, surgery, and radiation among patients with stage I–III TNBC. Methods: Using the National Cancer Database, we identified women younger than 60 diagnosed with stage I–III TNBC from 2010–2019 who received or refused oncologist-recommended treatment. Multivariate logistic regression evaluated factors associated with treatment refusal. Multivariate Cox regression assessed three-year overall survival (OS). Analyses adjusted for stage, age, diagnosis year, comorbidity burden, insurance status, urban-rural residence, zip-code income quartile, and race/ethnicity. Results: The final cohort included 96,633 patients (39.1% stage I, 43.7% stage II, 17.2% stage III) with complete data for covariates. Refusal rates among treatment-recommended patients were 3.1% for chemotherapy, 0.3% for surgery, and 4.3% for radiation. Refusal of chemotherapy (adjusted hazard ratio [aHR] 2.18, 95% CI 1.96–2.43, p < 0.001), surgery (aHR 3.21, 95% CI 2.66–3.89, p < 0.001), and radiation (aHR 1.67, 95% CI 1.49–1.87, p < 0.001) were each associated with worse three-year OS. Higher comorbidity burden was associated with higher odds of refusal across all treatment modalities, whereas urban-rural residence, diagnosis year, and zip-code income quartile did not reach significance. For chemotherapy, refusal was less likely with increasing stage (stage III vs. stage I: adjusted odds ratio [aOR] 0.47, 95% CI 0.40–0.54, p < 0.001) and Hispanic ethnicity (aOR 0.71, 95% CI 0.57–0.87, p = 0.001). Older age (50–60 vs. < 40: aOR 2.03, 95% CI 1.73–2.39, p < 0.001), uninsured status (aOR 1.58, 95% CI 1.25–1.98, p < 0.001), and non-Hispanic Black (NHB) race (aOR 1.48, 95% CI 1.32–1.65, p < 0.001) were associated with higher odds of refusal. In contrast, odds of refusal of surgery increased with stage (stage III vs. stage I: aOR 6.00, 95% CI 4.14–8.91, p < 0.001), older age (40–50 vs. < 40: aOR 2.11, 95% CI 1.39–3.32, p < 0.001), uninsured status (aOR 3.49, 95% CI 2.19–5.37, p < 0.001), and NHB race (aOR 2.04, 95% CI 1.53–2.71, p < 0.001). Radiation refusal showed associations with uninsured status (aOR 1.90, 95% CI 1.52–2.34, p < 0.001), NHB race (aOR 1.24, 95% CI 1.11–1.40, p < 0.001), and stage II (vs. stage I: aOR 1.44, 95% CI 1.28–1.62, p < 0.001) but not stage III. Conclusions: In non-metastatic TNBC, refusal of recommended therapy was uncommon but strongly predicted by age, stage, and sociodemographic factors. These findings suggest that treatment refusal in TNBC is driven in part by patient- and system-level factors, highlighting a need for studies examining specific reasons for treatment refusal.