Management of colorectal cancer explains differences in 1-year relative survival between France and England for patients diagnosed 1997-2004.

BACKGROUND: Few international population-based studies have provided information on potential determinants of international disparities in cancer survival. This population-based study was undertaken to identify the principal differences in disease characteristics and management that accounted for previously observed poorer survival in English compared with French patients with colorectal cancer. METHODS: The study population comprised all cases of colorectal cancer diagnosed between 1997 and 2004 in the areas covered by three population-based cancer registries in France and one in England (N=40 613). To investigate the influence of clinical and treatment variables on survival, we applied multivariable excess hazard modelling based on generalised linear models with Poisson error. RESULTS: Poorer survival for English patients was primarily due to a larger proportion dying within the first year after diagnosis. After controlling for inter-country differences in the use of chemotherapy and surgical resection with curative intent, country of residence was no-longer associated with 1-year survival for advanced colon cancer patients (excess hazard ratio (EHR)=0.99 (0.92-1.01), P=0.095)). Longer term (2-5 years) excess hazards of death for colon and rectal cancer patients did not differ between France and England. CONCLUSION: This study suggests that difference in management close to diagnosis of colon and rectum cancer is related to differences in survival observed between France and England. All efforts (collection and standardisation of additional variables such as co-morbidity) to investigate the reasons for these disparities in management between these two countries, and more generally across Europe, should be encouraged.