Abstract 35P
Background
Research indicates cancer patients in impoverished areas have lower survival rates. A recent Korean study investigated the impact of area-level deprivation on survival rates, revealing 5-year rates ranging from 88.21% to 92.66%. This study aimed to explore the association between deprivation and survival at a small area level.
Methods
This study utilized breast cancer data from the Busan Regional Cancer Registry covering the period from 2003 to 2020, encompassing a dataset of 23,582 patients linked with national mortality data to ascertain dates and causes of death. The primary outcome focused on breast cancer mortality from diagnosis until death or study conclusion on December 31, 2022. Individual-level variables included age, cancer stage, and year of diagnosis; the regional level incorporated the Deprivation Index (DI). Multi-level survival analysis with frailty was employed to assess the impact of individual and area-level factors on survival rates.
Results
A notable proportion of patients fell within the 40-49 age range (32.9%, n = 7,752), with the majority diagnosed at the local stage (58.6%, n = 13,890). The incidence of breast cancer diagnoses displayed an upward trend from 2003 to 2020 (p < 0.001). Younger or older patients, as well as those experiencing higher deprivation levels, exhibited diminished median survival probabilities (p < 0.001). In the multi-level survival model, each incremental unit of the area-level deprivation index corresponded to median survival rate reductions of 0.6%, 0.7%, 1.0%, and 0.6%, respectively. Applying Model 2 and utilizing empirical Bayesian estimation for regional estimates revealed lower survival rates in 2003-2005 compared to 2007, with subsequent overall rate enhancements. The graphical comparison of area deprivation index (x-axis) and survival probability (y-axis) indicated a steeper slope for 3-year and 5-year survival rates relative to the 1-year rate across all disease stages.
Conclusions
Small-area deprivation adversely impacts breast cancer patient survival, with a more pronounced effect as deprivation levels worsen.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Pusan national university hospital.
Disclosure
All authors have declared no conflicts of interest.