Cancer in the Azores: initial results from a recently established population-based cancer registry

Abstract

INTRODUCTION: The Azores archipelago has long been the Portuguese region that presents the highest mortality rates for certain cancers. Lack of incidence data has prevented the evaluation of the actual burden of this disease in the Azorean population. METHODS: Malignant tumours (ICD-O 5th Digit /3) initially diagnosed between the January 1st 2000 and December 31st 2002 were retrieved from the database of the recently established population-based cancer registry. Crude, age-specific and age-standardized rates were calculated and confidence intervals were estimated using Poisson approximation. Relative risks of developing cancer in the Azores when compared to mainland Portugal have been represented by standardized ratios. Quality indicators, including Mortality:Incidence (M:I) ratios, were also assessed. RESULTS: Overall, the data shows a high incidence rate for some malignant diseases, specifically in men. Compared to those living in mainland Portugal, both Azorean men (RR 1.412; 99% CI 1.407-1.416) and women (1.127; 1.125-1.129) presented a significantly higher risk of developing cancer, all sites combined. When compared with other cancer registries, a less favourable cancer survival pattern is reported in the Azores, as emphasized by higher M:I ratios for several cancer sites. CONCLUSIONS: A preliminary analysis of the results suggests the presence of some major risk factors in the Azorean population, namely tobacco smoking in men. Higher M:I ratios would also point to survival disparities between the Azores archipelago and the continent, which should be further studied.