71795 - Income is associated with survival after diagnosis of metastatic colorectal cancer

Abstract Introduction Treatment for metastatic colorectal cancer (mCRC) has evolved rapidly over the last few decades. We hypothesised that this had led to increasing differences in survival based on patient income. The aim was to investigate whether income was associated with survival after mCRC and whether a potential association persisted over the years. Method All Swedish adult patients diagnosed with colorectal cancer in 2009-2021 and metastases including 2022 were included. The CRCBaSe linkage was used to identify patients and retrieve data. The association between income quartile at metastasis diagnosis and overall survival was investigated using Cox regression. Diagnosis year was investigated as an effect modifier. Models were adjusted for sex, age, education level, marital status, and birth country. Result There were 33,800 patients with mCRC included. Median survival was 13 months for patients in the lowest income quartile and 19 months for patients in the highest income quartile. Median survival improved during the study period from 14 months in 2007-2011 to 19 months in 2017-2022. The adjusted model showed that patients in the highest income quartile had a superior survival (HR Q4 vs Q1: 0.86, 95% confidence interval: 0.83-0.90). Diagnosis year only marginally modified the effect income had on survival. Discussion Income is an important factor affecting survival after mCRC. Survival improved significantly during the time period. However, diagnosis year neither strengthened nor weakened the association between income and survival.