Abstract PO-164: Neighborhood disparities in timeliness of treatment for early stage lung cancer patients
Authors: Obrochta Chelsea A. , Gibbons Joseph , Thompson Caroline A. 
Published: December 2020

Abstract
Disparities in receipt of appropriate and timely cancer treatment continue. While there has been ample research identifying disparities by unmodifiable factors such as race/ethnicity, modifiable mechanisms, such as a neighborhood’s social and built environment, that drive such disparities are poorly understood. Minority neighborhoods enduring the impact of residential segregation often have less access to resources to maintain health and little control over their environments. The objective of this study is to better understand the importance of neighborhood racial/ethnic composition on racial/ethnic disparities in timely treatment for early- stage non-small cell lung cancer (NSCLC) patients. We studied 22,903 stage I/II NSCLC (2006-2015) patients in the California Cancer Registry. Appropriate treatment was defined as receipt of guideline concordant therapy (GCT) according to the 2016 NCCN guidelines, and timeliness as initial treatment within 45 days and adjuvant therapy within 6 months. The exposure was neighborhood racial/ethnic concordance, defined by the racial/ethnic composition of a neighborhood being predominately concordant, mixed, or discordant from a patient’s race/ethnicity. Multivariable hierarchical regression models were used to estimate the effect of neighborhood racial/ethnic concordance on GCT and timely GCT, independently and jointly with patient race/ethnicity. Overall, 81.4% of patients received GCT; 57.7% of them in a timely manner. Non-Hispanic blacks (NHBs) (76.9%) had the lowest rate of GCT and Filipinos (49.7%) and NHBs (50.0%) had the lowest rate of timely GCT. Patients living in concordant neighborhoods had the highest rate of GCT (83.0%) and timely GCT (61.0%). Most patients lived in white (32.9%) and mixed white and Hispanic (34.4%) neighborhoods, and the percentage of patients living in concordant neighborhoods (33.7%) were the highest among non-Hispanic whites (NHWs; 41.0%) and Hispanics (28.7%). Compared to patients in concordant neighborhoods, patients in mixed (undertreatment: RR=1.09, 95% CI=1.02-1.17; treatment delay: RR=1.10, 95% CI=1.05-1.16) and discordant (undertreatment: RR=1.15, 95% CI=1.04-1.27; delay: RR=1.12, 95% CI=1.04-1.21) neighborhoods were at increased risk for undertreatment and delay. This association does not hold for all race/ethnicities.
However, compared to NHWs living in concordant neighborhoods, NHBs (undertreatment: RR=1.41, 95% CI=0.96-2.09) and Hispanics (undertreatment: RR=1.48, 95% CI=1.25-1.74; treatment delay: RR=1.26, 95% CI=1.10-1.44) living in concordant neighborhoods were also at increased risk. Early stage lung cancer has a high rate of survival when treated appropriately and in a timeline matter.
Neighborhoods are key determinants of health. Understanding the role that neighborhoods play in healthcare utilization can help craft individual- or policy-level interventions that may include additional health care resources and targeted health care interventions.
Citation Format: Chelsea A. Obrochta, Joseph Gibbons, Caroline A. Thompson. Neighborhood disparities in timeliness of treatment for early stage lung cancer patients [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-164.