Trends in net survival from colon cancer in six European Latin countries: results from the SUDCAN population-based study

Abstract

Colon cancer represents a major public health issue. The aim of the SUDCAN collaborative study was to compare the net survival from colon cancer between six European Latin countries (Belgium, France, Italy, Portugal, Spain, and Switzerland) and provide trends in net survival and dynamics of the excess mortality rates up to 5 years after diagnosis. The data were extracted from the EUROCARE-5 database. First, net survival was studied over the 2000-2004 period using the Pohar-Perme estimator. For trend analyses, the study period was specific to each country. Results were reported from 1992 to 2004 in France, Italy, Spain, and Switzerland and from 2000 to 2004 in Belgium and Portugal. These analyses were carried out using a flexible excess rate modeling strategy. There were few differences between countries in age-standardized net survivals (2000-2004). During the 2000-2004 period, the 5-year net survival ranged between 57 (Spain and Portugal) and 61% (Belgium and Switzerland). The age-standardized survival at 1 and 5 years after diagnosis increased between 1992 and 2004. This increase was observed at ages 60 and 70, but was less marked at 80. This increase was linked to a marked decrease in the excess mortality rate between 1992 and 2004 until 18 months after diagnosis. Beyond this period, the decrease in the excess mortality rates among countries was modest and nearly the same whatever the year of diagnosis. There were minor differences in survival after colon cancer between European Latin countries. A considerable improvement in the 5-year net survival was observed in all countries, but the gain was mainly limited to the first 18 months after diagnosis. Further improvements are expected through the implementation of mass screening programs.