International journal of cancer. Journal international du cancer
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Multicenter Study
The cure for colon cancer: results from the EUROCARE study.
The interpretation of time trends and geographical differences of population-based survival rates is generally not easy, due to the difficulty in disentangling the effects of observational biases, diagnostic and therapeutic procedures and their interactions. Whereas descriptive analysis of relative survival is generally based on survival levels estimated at fixed time since diagnosis, interpretation issues can take advantage from the analysis of the shape of the considered relative survival. Parametric survival models allowing the estimation of the fraction of cured patients are applied here to analyze and discuss the differences in colon cancer relative survival between European countries, according to age and period of diagnosis. ⋯ The opposite effect was shown by survival time of fatal cases, i.e., 1.71, 1.75 and 0.77 years for the same age classes, respectively. Proportion of cured cases and mean survival time of fatal cases tended to be positively correlated with each other across countries. Our results are consistent with the hypothesis that a real improvement in colon cancer survival took place in Europe during the years 1978-1985 and also suggest that the well-known decrease of relative survival with age at diagnosis could be mostly due to a decreasing efficacy of early diagnosis for patients under 60 years old and to less effective therapies for older patients.