Long-term Cancer Survival Trends by Updated Summary Stage
Menée à partir des données 1975-2018 des registres américains des cancers, cette étude analyse l'évolution de la survie relative des patients (25 localisations) selon le stade de la maladie au diagnostic
Background: Stage is the most important prognostic factor for understanding cancer survival trends. Summary stage (SS) classifies cancer based on the extent of spread: In situ, Localized, Regional, or Distant. Continual updating of staging systems poses challenges to stage comparisons over time. We use a consistent SS classification and present survival trends for 25 cancer sites using the joinpoint survival model (JPSurv). Methods: We developed a modified SS variable, Long-Term Site-Specific Summary Stage, based on as consistent a definition as possible and applied it to a maximum number of diagnosis years, 1975–2019. We estimated trends by stage by applying JPSurv to relative survival data for 25 cancer sites in SEER-8, 1975–2018, followed through December 31, 2019. To help interpret survival trends, we report incidence and mortality trends using the joinpoint model. Results: Five-year relative survival improved for nearly all sites and stages. Large improvements were observed for localized pancreatic cancer (4.25 percentage points annually, 2007–2012 (95% confidence interval (CI) = 3.40–5.10)), distant skin melanoma (2.15 percentage points annually, 2008–2018 (1.73–2.57)), and localized esophagus cancer (1.18 percentage points annually, 1975–2018 (1.11–1.26)). Conclusions: This is the first analysis of survival trends by SS for multiple cancer sites. The largest survival increases were seen for cancers with a traditionally poor prognosis and no organized screening, which likely reflects clinical management advances. Impact: Our study will be particularly useful for understanding the population-level impact of new treatments and identifying emerging trends in health disparities research.