The main purpose of this study was to evaluate the association between the incidence of larynx cancer and socioeconomic factors in the province of Girona, Spain, from a spatial point of view.
To this end, we analyzed the incidence of larynx cancer throughout the 1994-2004 period reported in the Girona Cancer Registry (Registro de Cáncer de Girona). At a census level, we had data on the total number of larynx cancer cases and socioeconomic information, such as the deprivation index.
The standardized incidence ratio (SIR) was calculated based on the incidence rates in men living in each census section of the province of Girona, Spain, assuming a Poisson distribution. The relative risk was calculated by applying the Besag-York-Mollié model. The deprivation index was included in the model categorized into quartiles.
The most relevant findings of our study were that the risk of larynx cancer was lower in the census sections associated with a lower deprivation rate quartile and increased in those with higher quartiles. The risk of larynx cancer in the highest quartile was 1.91 times higher than that in the lowest one. This association was significant when the entire province was considered.
Based on these results, we concluded that the deprivation index explained only part of the geographical variability of the incidence of this condition per census section. Other unobserved risk factors with a spatial structure, such as air pollution, could also contribute to explain this phenomenon.