Distribución geográfica de los tipos más frecuentes de cáncer en la provincia de Huelva

Abstract

Cancer is one of the major health problems worldwide. The Huelva society is concerned about the possible existence of a large number of cases of this disease, especially in the capital and its surrounding towns. Studies on cancer incidence are the starting point to study possible correlations between environmental and social factors and the occurrence of disease within a specific geographical area. In Spain, the number of such studies is limited because the scarce data on cancer incidence from population-based cancer registries. In 2008, a population-based cancer registry was created in Huelva. The efforts of the government employees involved in the project have made the data available for the period 2007-2011 in a relatively short period of time. The aim of this work is to describe the patterns of the geographic distribution of the tumor incidence for the most frequent tumor locations in this province. Based on incidence data from Cancer Registry of the Province of Huelva, the municipal distribution of the standardized incidence reasons (SIR) for lung, prostate, bladder and colon-rectum cancer in men and breast and colon-rectum cancer in women has been computed for the years 2007-2011. As the reference cancer incidence, we used the incidence estimated by the World Health Organization for these cancers in Spain, allowing the comparison with other provinces in future studies using this same reference. Also, Bayesian spatial models were used to smooth the SIR, taken the adjacency between municipalities as neighborhood criterion and obtained relative risks with their confidence limits, and posterior probabilities for each relative risk being higher than one. All values obtained are shown by choropleth maps. The values of the relative risks referenced to the provincial incidence interpolated by kriging have been shown using isopleth maps on a continuous scale. The later was done so the boundaries of the municipalities do not mask a possible spatial pattern. The results show that the overall provincial cancer incidence for each tumor location studied is similar to the reported in other population-based cancer registries from Spain. As in the other population-based cancer registries, a relatively higher cancer incidence is observed in the capital of the province. Between the municipalities of the province, and for the types of cancer studied in men, except in the case of prostate cancer, well-defined distribution patterns are observed, but not coincident. In the types studied in women, breast and colorectal cancer, a quite matching pattern is observed. This work constitutes the starting point for future studies of geographic association needed to verify hypotheses about cancer risk factors in the tumor locations studied the province of Huelva.