Socioeconomic Inequalities in Colorectal Cancer Survival in Southern Spain: A Multilevel Population-Based Cohort Study

• Main Authors: Luque-Fernandez MA, Redondo-Sánchez D, Rodríguez-Barranco M, Chang-Chan YL, Salamanca-Fernández E, Núñez O, Fernandez-Navarro P, Pollán M, Sánchez MJ
• Format: Article
• Language: English
• Published: Dove Medical Press 2020-07-01
• Series: Clinical Epidemiology
• Subjects: socioeconomic inequalities; colorectal cancer; survival; population-based epidemiology; epidemiological methods; multilevel
• Online Access: https://www.dovepress.com/socioeconomic-inequalities-in-colorectal-cancer-survival-in-southern-s-peer-reviewed-article-CLEP

Miguel Angel Luque-Fernandez,1– 3 Daniel Redondo-Sánchez,1,2 Miguel Rodríguez-Barranco,1,2,4 Yoe-Ling Chang-Chan,1,4 Elena Salamanca-Fernández,1,2 Olivier Núñez,2,5 Pablo Fernandez-Navarro,2,5 Marina Pollán,2,5 María-José Sánchez1,2,4,6 1Instituto de Investigación Biosanitaria de Granada, Non-Communicable Disease and Cancer Epidemiology Group, ibs.GRANADA, University of Granada, Granada, Spain; 2Biomedical Network Research Centers of Epidemiology and Public Health (CIBERESP), Madrid, Spain; 3London School of Hygiene and Tropical Medicine, Non-Communicable Disease Epidemiology, London, UK; 4Andalusian School of Public Health, Granada, Spain; 5National Centre of Epidemiology, Health Institute Carlos III (CNE-ISCIII), Madrid, Spain; 6Department of Preventive Medicine and Public Health, University of Granada, Granada, SpainCorrespondence: Miguel Angel Luque-FernandezAndalusian School of Public Health, Cuesta Del Observatorio, 4, Granada 18080, SpainEmail [e-mail]: Colorectal cancer (CRC) is the most frequently diagnosed cancer in Spain. Socioeconomic inequalities in cancer survival are not documented in Spain. We aim to study the association of socioeconomic inequalities with overall mortality and survival among CRC patients in southern Spain.Methods: We conducted a multilevel population-based cohort study, including CRC cases for the period 2011– 2013. The study time-to-event outcome was death, and the primary exposure was CRC patients’ socioeconomic status assessed by the Spanish deprivation index at the census tract level. We used a mixed-effects flexible hazard model, including census tract as a random intercept, to derive overall survival estimates by deprivation.Results: Among 3589 CRC patients and 12,148 person-years at risk (pyr), 964 patients died before the end of the follow-up. Mortality by deprivation showed the highest mortality rate for the most deprived group (96.2 per 1000 pyr, 95% CI: 84.0– 110.2). After adjusting for sex, age, cancer stage, and the area of residence, the most deprived had a 60% higher excess mortality risk than the less deprived group (excess mortality risk ratio: 1.6, 95% CI: 1.1– 2.3).Conclusions: We found a consistent association between deprivation and CRC excess mortality and survival. The reasons behind these inequalities need further investigation in order to improve equality cancer outcomes in all social groups.Keywords: socioeconomic inequalities, colorectal cancer, survival, population-based epidemiology, epidemiological methods, multilevel