Neighborhood-Level Disadvantage and Delayed Adjuvant Therapy in Head and Neck Cancer.

Importance:For patients with head and neck squamous cell carcinoma (HNSCC), initiation of postoperative radiation therapy (PORT) within 6 weeks of surgery is recommended by the National Comprehensive Cancer Network Guidelines and the Commission on Cancer. Although individual-level measures of socioeconomic status are associated with receipt of timely, guideline-adherent PORT, the role of neighborhood-level disadvantage has not been examined. Objective:To characterize the association of neighborhood-level disadvantage with delays in receiving PORT. Design, Setting, and Participants:This retrospective cohort study included 681 adult patients with HNSCC undergoing curative-intent surgery and PORT from 2018 to 2020 at 4 US academic medical centers. The data were analyzed between June 21, 2023, and March 5, 2024. Main Outcome Measures and Measures:The primary outcome was delay in initiating guideline-adherent PORT (ie, >6 weeks after surgery). Time-to-PORT (TTP) was a secondary outcome. Census block-level Area Deprivation Index (ADI) scores were calculated and reported as national percentiles (0-100); higher scores indicate greater deprivation. The association of ADI scores with PORT delay was assessed using multivariable logistic regression adjusted for demographic, clinical, and institutional characteristics. PORT initiation across ADI score population quartiles was evaluated with cumulative incidence plots and Cox models. Results:Among 681 patients with HNSCC undergoing surgery and PORT (mean [SD] age, 61.5 [11.2] years; 487 [71.5%] men, 194 [29.5%] women) the PORT delay rate was 60.8% (414/681) and median (IQR) TTP was 46 (40-56) days. The median (IQR) ADI score was 62.0 (44.0-83.0). Each 25-point increase in ADI score was associated with a corresponding 32% increase in the adjusted odds ratio (aOR) of PORT delay (aOR, 1.32; 95% CI, 1.07-1.63) on multivariable regression adjusted for institution, age, race and ethnicity, insurance, comorbidity, cancer subsite, stage, postoperative complications, care fragmentation, travel distance, and rurality. Increasing ADI score population quartiles were associated with increasing TTP (hazard ratio of PORT initiation, 0.71; 95% CI, 0.53-0.96; 0.59; 95% CI, 0.44-0.77; and 0.54; 95% CI, 0.41-0.72; for ADI quartiles 2, 3, and 4 vs ADI quartile 1, respectively). Conclusions and Relevance:Increasing neighborhood-level disadvantage was independently associated with a greater likelihood of PORT delay and longer TTP in a dose-dependent manner. These findings indicate a critical need for the development of multilevel strategies to improve the equitable delivery of timely, guideline-adherent PORT.