Copyright © 2022 Elsevier Ltd. All rights reserved.BACKGROUND: Colorectal cancer is the third most frequent malignant disease worldwide. In Chile, colorectal cancer has been part of the Garantías Explícitas en Salud (Explicit Guarantees in Health Programme; also known as GES), which aims to ensure prompt access to affordable and quality health care, since 2014. Survival depends on the diagnosis of the disease in the earliest possible stage and on rapid access to adequate treatment. However, extreme inequality in social factors, such as education and income, has resulted in poor outcomes in cancer survival. The aim of this study was to obtain data on the epidemiology of colorectal cancer in Chile (in 2009-18) and on the effect of measurable factors on survival. METHODS: Publicly available data corresponding to the period of 2009-18 were obtained from registries of mortality and hospital discharges published by the Chilean Health Ministry and National Institute of Statistics, allowing for follow-up of individuals. Individual survival was studied by Kaplan-Meier curves. A Cox proportional-hazards model was used to estimate the effect of the measurable factors. FINDINGS: 103 239 hospital discharges of 41 615 patients with colorectal cancer were recorded in Chile in 2009-18. 24 217 (65·9%) patients died of the disease. By analysing empirical Kaplan-Meier survival rates, we observed a 5-year survival rate of 43·2% (95% CI 42·7-43·8), considering all patients in the treatment database, with no significant differences observed between men and women. A significant survival difference was observed between patients treated in public (5-year survival: 39·1% (38·5-39·7) and private (5-year survival: 63·4 % (61·9-64·9) health insurance systems (p<0·0001). We also observed differences within the public health insurance subgroups, showing poorer outcomes with decreased socioeconomic conditions (5-year survival rates ranging from 46·7% [45·2-48·3] in the wealthiest group to 30·9% [29·6-32·2] in the poorest group; p<0·0001). Higher survival rates were also seen in patients treated in Santiago, the capital, than in patients treated in other regions in the country. Survival rates did not improve since the implementation of GES (hazard ratio 0·99 [95% CI 0·94-1·05]; p=0·81). INTERPRETATION: We found an overall 5-year survival rate of 43·2% and a significant difference between health insurance status, with patients with private health insurance reaching survival curves similar to those observed in high-income countries. Barriers to health access, affected by a centralised distribution of resources, with higher availability of resources, such as specialty physicians and colonoscopy, in private hospitals, can be affecting factors. Although GES was created to ensure transversal access to diagnosis and treatment of colorectal cancer, no effect of the programme was found. It is yet to be determined whether results regarding colorectal cancer are not visible because 5 years are not enough to assess the effect of GES, or whether early diagnosis for colorectal cancer is the dominant factor, which can only be managed with screening programmes that are not included in GES. FUNDING: Complex Engineering Systems Institute (Centro Basal ANID/AFB18003) and Agencia Nacional de Investigación y Desarrollo/Programa de Becas/Doctorado Nacional 21200869.