Abstract A051: Regional lung cancer mortality disparity by their socioeconomic status in 246 municipalities in South Korea during 2008-2017
Authors: Byun Sungwon , Kim Sun-Young 
Published: September 2020

Abstract
Lung cancer is a main cause of cancer death worldwide. In particular, many studies reported geographical disparity of lung cancer mortality (LCM) related to socioeconomic status (SES). While lung cancer is also a leading cause of death in South Korea, few studies investigated geographical disparity attributable to SES. We aimed to explore the geographical distributions of LCM according to three SES indicators across 246 municipalities and their temporal patterns during 2008 to 2017 in South Korea. Our study will provide an insight into LCM disparity associated with SES gradients and guidance for policy-related activities. We obtained lung cancer age-standardized mortality rate (ASMR) in 246 municipalities for 2008-2017 from the Statistics Korea (KOSIS). We also used three SES factors for the same areas and period: income, education, and elderly population. Monthly income and education levels were obtained from the Community Health Survey (CHS): a nationwide, community-based, individual survey conducted annually since 2008 by the Korea Centers for Disease Control and Prevention. Elderly population (aged over 65) proportions were obtained from the KOSIS. We used averages of ASMR for three periods of 2008-2010, 2011-2013, and 2014-2017, while we used SES indicators from years 2009, 2012, and 2015, each representing the three periods. For CHS-collected SES factors, we computed the proportions of low-income earners with less than 2 million won monthly income and those with less than college education. Ranked municipalities by proportions of low income, education, and high elderly population were categorized into quintiles for each SES indicator. Then, we created boxplots based on SES quintiles and explored geographical disparity patterns by three periods. Temporal patterns in regional-disparity level were studied with line plots of absolute and relative ASMR differences. Absolute difference was the difference in the average ASMR in each SES quintile from that in 1st quantile. Relative difference was the absolute difference divided by the average ASMR in 1st quantile. Lung cancer ASMRs were generally higher in the municipalities with lower income and education level (median in 1st and 5th quantile in Period 2=25.8 and 23.9; 25.8 and 23.5, respectively). For elderly population, we did not find a clear pattern for the first two periods but turned to show an increase in period 3. Absolute and relative differences overall decreased for income and education level but with an exception in the difference in 3rd quintile which increased back in period 3. For elderly population, relative differences overall increased. Despite improved absolute and relative differences, we found municipality-level lung cancer ASMR being disproportionally distributed according to their income and education level throughout all periods. For effective health policies to reduce district-level LCD disparity, further studies that consider other regional characteristics for correlation analyses are needed.
Citation Format: Sungwon Byun, Sun-Young Kim. Regional lung cancer mortality disparity by their socioeconomic status in 246 municipalities in South Korea during 2008-2017 [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr A051.