Epidemiology of Thyroid Cancer in an Area of Epidemic Thyroid Goiter

The aim of this study was to analyze and describe the epidemiological characteristics and trends of thyroid cancer in the province of Sassari (Sardinia, Italy), an area with epidemic thyroid goiter, in the period 1992–2010. Data were obtained from the local tumor registry which makes part of a wider registry web, coordinated today by the Italian Association for Tumor Registries. An increasing trend in the incidence of thyroid cancer in the province of Sassari was evidenced. This trend seems to follow the general worldwide trend and does not seem to be related to the high incidence of thyroid goiter in the area. The frequencies of the different histological subtypes were similar to those reported in numerous national and international reports. Women are affected earlier than men and, therefore, suffer greater professional, economic, and social impacts. Overall mortality is low and a relative 5-year survival is excellent, especially in comparison to other malignancies. 1. Introduction Thyroid cancer accounts for approximately 2% of all cancers diagnosed worldwide and 95% of all endocrine cancers [1]. Recent reports describe a continuous increase in thyroid cancer incidence worldwide. In certain geographical areas, this increase exceeds 100% (and is as high as 250% in some cases) [2]. By contrast, small declines in incidence were registered in a few areas [2]. It has been suggested that this generally steady trend of increasing thyroid cancer incidence may be only apparent, and that it depends on higher detection rates of small tumors due to the technological advances in morphological and functional imaging techniques over the last few decades [3]. Thyroid goiter is a pathological condition with epidemic dimensions in some areas because of several geographical, nutritional, and genetic factors. It has been linked to a higher risk of thyroid cancer, especially the follicular histotype [4]. The aim of this population-based study was to analyze and describe the epidemiological characteristics and trends of thyroid cancer in the province of Sassari (Sardinia, Italy), an area with epidemic thyroid goiter, in the period 1992–2010. 2. Materials and Methods The epidemiological data presented in this paper were obtained from the “Registry of the Tumors of the province of Sassari.” This registry was created in 1992 by the local health agency for the epidemiological surveillance of tumors in the province. In 1999, it became part of a wider web of tumor registries, coordinated today by the Italian Association for Tumor Registries (Associazione Italiana Registri Tumori