Impact of socioeconomics on recurrences and survival in non-metastasized colorectal cancer.

Background: Survival differences between socioeconomic groups in colorectal cancer have been studied for patients diagnosed in the 90s and 00s, but research on recent patients using individual measures of socioeconomic position is limited.

Methods: CRCBaSe, a database of linked national registry data, was used to analyse stage I-III colorectal cancer patients diagnosed in Sweden between 2008 and 2021. The exposures of interest were income and education. Flexible parametric survival models were fitted and standardised survival probabilities and hazard ratios (HR) were calculated for cancer-specific survival, recurrence, and overall survival.

Results: Analysis of 59,995 patients showed better 5-year standardised cancer-specific survival in the least deprived income group, 77.8% (95%CI 76.9-78.6) vs. 73.2% (95%CI 72.6-73.9) in the most deprived income group, HR 0.93 (95%CI 0.87-0.99). Time to recurrence was not statistically different between socioeconomic groups. Overall survival was better in the least deprived income group, with a 5-year standardised overall survival of 70.0% (95%CI 69.1-70.8) vs. 63.5% (95%CI 62.9-64.1) in the most deprived income group, HR 0.82 (95%CI 0.79-0.86).

Conclusion: We found large disparities in cancer-specific and overall survival between the highest and most deprived income and education groups, despite improvements in care and the introduction of guidelines.