Trends in Guideline-Concordant Care for Inflammatory Breast Cancer.

Importance: Inflammatory breast cancer (IBC) is an aggressive variant for which trimodality treatment (ie, neoadjuvant systemic therapy [NST] followed by modified radical mastectomy without immediate reconstruction and postmastectomy radiotherapy [PMRT]) represents guideline-concordant care (GCC) and is associated with improved overall survival (OS). However, it is unclear whether there are disparities in trimodality treatment receipt among patients with IBC and how such disparities might affect OS. Objective: To assess trends in IBC trimodality treatment receipt in a contemporary cohort. Design, Setting, and Participants: A retrospective cohort study was conducted using data from the National Cancer Database. Women with nonmetastatic IBC treated from calendar years 2010 to 2018 were included. Data analysis was performed from April 1, 2023, to March 1, 2024. Exposures: Guideline-concordant care (ie, trimodality treatment administered in the correct sequence with time to NST initiation <60 days post diagnosis). Main Outcomes and Measures: The main outcomes were associations between patient-, disease-, treatment-, and facility-level factors and receipt of overall and modality-specific GCC and associations between these factors and adjusted OS. Results: Of 6945 patients identified (median age, 57 [IQR, 47-66] years; 2.4% Asian or Pacific Islander, 7.8% Hispanic, 17.1% non-Hispanic Black, and 71.5% non-Hispanic White), only 1740 (25.1%) received all forms of GCC: 91.3% (n = 5662) received NST initiation less than 60 days post diagnosis, 63.3% (n = 4395) received PMRT, and 51.3% (n = 3564) underwent guideline-concordant surgery (ie, modified radical mastectomy without immediate reconstruction with >6 lymph nodes removed). Receipt of GCC did not differ significantly by race and ethnicity, insurance status, or location. Asian (odds ratio [OR], 0.48; 95% CI, 0.27-0.84), Black (OR, 0.53; 95% CI, 0.41-0.68), and Hispanic (OR, 0.40; 95% CI, 0.29-0.55) patients were less likely to have NST initiation less than 60 days post diagnosis vs White patients (all P ≤ .001). Recipients of GCC had improved adjusted OS vs nonrecipients (hazard ratio [HR], 0.75; 95% CI, 0.68-0.84; P < .001). Black patients had significantly lower adjusted OS ,compared with White recipients (HR, 1.41; 95% CI, 1.26-1.58; P < .001). When GCC was received for triple-negative IBC, there was no racial and ethnic disparity in OS. Conclusions and Relevance: In this cohort study of women with nonmetastatic IBC, there were no disparities observed in GCC receipt, but only 25.1% of patients with IBC received all forms of GCC for which they were eligible. Among those who received GCC, there was no racial disparity in survival for triple-negative IBC, suggesting opportunities to improve equity through standardization of care.