OBJECTIVE: In recent years many authors have reported an increase in thyroid cancer (TC) incidence in several countries. The cause of such phenomenon remains unclear. DESIGN: This study was designed to estimate the incidence of TC in Basilicata, the smallest region of Southern Italy with a population of 596,546 people, between 2001 and 2004. MAIN OUTCOME: A total of 302 cases of TC were identified. The annual incidence of TC changed over the years, from 10.0 per 100,000 people in 2001 to 15.7 per 100,000 people in 2004. The number of new TC cases per 100,000 people increased an average of 16% per yr. Median age at diagnosis was 49 yr. The most frequent histotype was papillary TC (PTC) (73.2%). In 20 (6.6%) patients with PTC, we identified at least one first-degree relative affected by differentiated TC. CONCLUSIONS: The present study shows a high incidence of sporadic and familial non-medullary TC in Basilicata. The reason for this finding may be related to several factors discussed in the paper. Further studies evaluating the trends in the incidence of TC in Basilicata in the future could provide some answers for the potential pathogenetic hypothesis.
OBJECTIVE: In recent years many authors have reported an increase in thyroid cancer (TC) incidence in several countries. The cause of such phenomenon remains unclear. DESIGN: This study was designed to estimate the incidence of TC in Basilicata, the smallest region of Southern Italy with a population of 596,546 people, between 2001 and 2004. MAIN OUTCOME: A total of 302 cases of TC were identified. The annual incidence of TC changed over the years, from 10.0 per 100,000 people in 2001 to 15.7 per 100,000 people in 2004. The number of new TC cases per 100,000 people increased an average of 16% per yr. Median age at diagnosis was 49 yr. The most frequent histotype was papillary TC (PTC) (73.2%). In 20 (6.6%) patients with PTC, we identified at least one first-degree relative affected by differentiated TC. CONCLUSIONS: The present study shows a high incidence of sporadic and familial non-medullary TC in Basilicata. The reason for this finding may be related to several factors discussed in the paper. Further studies evaluating the trends in the incidence of TC in Basilicata in the future could provide some answers for the potential pathogenetic hypothesis.