Factors associated with late-stage diagnosis and overall survival for lung cancer: An analysis of patients treated in a Brazilian hospital and a US-hospital from 2009 to 2019

Abstract

Background: Lung cancer is a major public health problem due to its high incidence and mortality rates worldwide. Histology, socioeconomic conditions, access, quality of healthcare, and regional aspects are associated with lung cancer stages at diagnosis and survival outcomes. This paper aims to examine and contrast the factors associated with late-stage diagnosis of lung cancer and overall survival rates in two different settings: a Brazilian hospital and a US hospital, spanning from 2009 to 2019.

Methods: This is a retrospective cohort study of the incidence of lung cancer cases at the institution's cancer registry from a Brazilian and a US-based cohort. Descriptive analyses are presented using either the mean and standard deviation or the median and interquartile interval. Frequency is used to present categorical variables. Factors associated with late-stage lung cancer diagnosis were identified through bivariate and multivariable forward stepwise logistic regression. One-year overall survival and its associated factors were identified by Kaplan-Meier curves and Cox's proportional hazards model.

Results: Between January 2009 and December 2019, a total of 5286 individuals were diagnosed with LC in the Brazilian cohort, and out of these cases, 85.6% were diagnosed with late-stage disease. The US-cohort consisted of 3594 individuals, of whom 60.3% were diagnosed with late-stage disease in lung cancer. The one-year overall survival was 8.6 months for the US cohort and 6.4 months for the Brazilian cohort. In both cohorts, late-stage diagnosis emerged as the most significant factor influencing overall survival. However, the factors associated with late-stage diagnosis differed between the US and Brazilian cohorts. In the Brazilian cohort, being male and belonging to black or brown ethnic groups, along with having a lower education level, were linked to late-stage diagnosis. On the other hand, in the US-based cohort, the factors related to late-stage diagnosis were being male, having been diagnosed before 2015, and possessing private insurance coverage.

Conclusion: Late-stage diagnosis was associated with the worst survival in both the US and Brazilian cohorts. This study provides valuable information on inequities and barriers to access for lung patients with cancer from upper-middle-income and high-income countries.

Keywords: Epidemiology; Lung neoplasms; Survival analysis.