Differences in the management and survival of metastatic colorectal cancer in Europe. A population-based study.

Background: The management regarding metastatic colorectal cancer throughout Europe is not well known.

Aims: To draw a European comparison of the management and prognosis of metastatic colorectal cancers.

Methods: Factors associated with chemotherapy administration were identified through logistic regressions. Net survival was estimated and crude probabilities of death related to cancer and other causes using a flexible cumulative hazard model.

Results: Among the 13 227 patients with colorectal cancer diagnosed between 2010 and 2013 in cancer registries from 10 European countries, 3140 were metastatic. 62% of metastatic patients received chemotherapy. Compared to Spain, the related adjusted odds ratios ranged from 0.7 to 4.0 (P<0.001) according to country. The 3-year net survival by country ranged between 16% and 37%. The survival gap between countries diminished from 21% to 10% when adjusting for chemotherapy, age and sex. Geographical differences in the crude probability of death related to cancer were large for patients <70 or ≥80 years at diagnosis.

Conclusion: Heterogeneity in the application of European guidelines partly explain these differences. General health between populations, accessibility to a reference centre, or provision of health care could also be involved. Further population-based studies are warranted to disentangle between these possible explanations.