Socioeconomic status and changing inequalities in colorectal cancer? A review of the associations with risk, treatment and outcome

Background: Upcoming mass screening for colorectal cancer (CRC) makes a review of recent literature on the association with socioeconomic status (SES) relevant, because of marked and contradictory associations with risk, treatment and outcome.

Methods: The Pubmed database using the MeSH terms 'Neoplasms' or 'Colorectal Neoplasms' and 'Socioeconomic Factors' for articles added between 1995 and 1st October 2009 led to 62 articles.

Results: Low SES groups exhibited a higher incidence compared with high SES groups in the US and Canada (range risk ratio (RR) 1.0-1.5), but mostly lower in Europe (RR 0.3-0.9). Treatment, survival and mortality all showed less favourable results for people with a lower socioeconomic status: Patients with a low SES received less often (neo)adjuvant therapy (RR ranging from 0.4 to 0.99), had worse survival rates (hazard ratio (HR) 1.3-1.8) and exhibited generally the highest mortality rates up to 1.6 for colon cancer in Europe and up to 3.1 for rectal cancer.

Conclusions: A quite consistent trend was observed favouring individuals with a high SES compared to those with a low SES that still remains in terms of treatment, survival and thus also mortality. We did not find evidence that the low/high SES gradients for treatment chosen and outcome are decreasing. To meet increasing inequalities in mortality from CRC in Europe for people with a low SES and to make mass screening successful, a high participation rate needs to be realised of low SES people in the soon starting screening program.