Global trends in incidence and mortality of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a rare malignancy with an extraordinarily skewed geographic distribution worldwide. Although decreasing trends in incidence and mortality of NPC have been sporadically reported in some high-risk areas, no comprehensive description of the global trends has ever been made. We accessed incidence (1970-2007) and mortality (1970-2013) data from multiple sources, with the main ones being the Cancer Incidence in Five Continents (CI5) series and the World Health Organization (WHO) cancer mortality database. During the entire period studied, age-standardized incidence rates (ASIRs) of NPC decreased significantly in southern and eastern Asia, north America and Nordic countries with average annual percent changes (AAPCs) of -0.9% to -5.4% in males and -1.1% to -4.1% in females. Declines in age-standardized mortality rates (ASMRs) are even more remarkable and extensive, with AAPCs varying from -0.9% and -0.8% to -3.7% and -6.5% in males and females, respectively. Decreasing trends in NPC incidence are probably due to tobacco control, changes in diets and economic development. Declines in mortality rates are the results of advancements in diagnostic and radiotherapy techniques, as well as decreased incidence rates.