The aim of this collaborative study was to understand the reasons for differences in survival in a new analysis of colorectal cancers diagnosed between 1988 and 1991.
2720 patients with adenocarcinoma of the large bowel from eleven European cancer registries were investigated.
They obtained information on stage at diagnosis, diagnostic determinants and surgical treatment, and analysed the data in relation to three-year observed survival, calculating relative risks of death. They adjusted for age, sex, site, stage, and determinants of stage.
Three-year observed survival rates ranged from 25% (Cracow) to 59% (Modena), and were low in the Thames area of England (38%). Survival rates between registries for 'resected' patients varied less than those for all patients. Relative risks of death in the 3 years after diagnosis ranged from 0.7 in Modena to 2.3 in Cracow when age, sex, and site were considered.
The wide differences across Europe in colorectal cancer survival depend to a large extent on differences in stage at diagnosis. There are wide variations in diagnostic and surgical practices.
Twofold range in the risk of death from colorectal cancer across Europe.
However, there was a twofold range in the risk of death from colorectal cancer, even after adjustment for surgery and disease stage.
The authors conclude that the large differences of survival seen in unresected patients reflects different therapeutic approaches to patients with little chance of being cured.
They call for earlier detection of colorectal cancer to improve effectiveness of treatment and survival.