Nasopharyngeal Carcinoma Incidence in North Tunisia: Negative Trends in Adults but not Adolescents, 1994-2006

Abstract

Nasopharyngeal carcinoma (NPC) is the second most common neoplasm of head and neck in Tunisia. The distribution is bimodal with a first period occurrence between 15 and 20 years old and a second peak at around 50 years of age. Undifferentiated carcinoma of nasopharynx type III (UCNT) is the predominant histological type (93.4%). Data of cancer registry of North Tunisia confirmed that it is an intermediate risk area for NPC with overall ASRs of 3.6 and 1.6/100,000 respectively in males and females. This study aimed to present the evolution of incidence rate of nasopharyngeal carcinoma over a period of 12 years (1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006). Data of cancer registry of North Tunisia (NTCR), covering half of the Tunisian population, were used to determine evolution of NPC incidence, calculated by 5 year periods. The estimated annual percentage change (EAPC) was used as an estimate of the trend. To best summarize the behavior or the data trend across years, we used a join-point regression program. Between 1994 and 2006, we observed negative annual average change of standardized incidence in men and women (-3.3%and -2.7%) also for the standardized incidences which showed a rather important decline (26.4% in males and 22.3% in females). The truncated age standardized incidence rate of NPC in adults aged of 30 years old and more (N= 1209) decreased by -0.4% per year from 1994 to 2006 over time in north Tunisia dropping from 6.09 to 4.14 person-years. However, the rate was relatively stable during this period among youths aged 0-29 years (N= 233) in both sexes. NPC demonstrated a favorable evolution from 1994-2006 probably due to a improvement in socioeconomic conditions.

Global trends in nasopharyngeal cancer mortality since 1970 and predictions for 2020: Focus on low-risk areas

“…EBV, in interaction with salted fish and preserved food consumption, which are high in nitrous compounds and volatile nitrosamines, induces carcinogenic development for NKC, the predominant histology in endemic areas . In several high risk areas, a noticeable decline in NPC incidence has been reported . Our study showed a significant decreasing NPC mortality in Hong Kong.…”

“…There were about 85,000 incident cases and over 50,000 deaths from nasopharyngeal carcinoma (NPC) worldwide in 2012 . The global distribution of incidence and mortality showed a unique disparity, with extremely high rates (over 20–30/100,000 men and 10/100,000 women) in some regions of Southern China, Hong Kong, Taiwan, Singapore, other areas of Southeast Asia, selected Chinese migrants (mostly to North America), and in North Africa . In non‐endemic areas including most western countries, Latin America and Japan, NPC is a rare malignancy with incidence rates lower than 1/100,000 …”

Declining Incidence of Nasopharyngeal Carcinoma in Brunei Darussalam: a Three Decade Study (1986-2014)

“…In the younger age group, the rates were stable. (Wided et al, 2015) Importantly, along with the declining incidence of NPC, the mortality rate has also declined. (Huang et al, 2012) The declining rates observed in our studies, consistent with what have been generally reported elsewhere are accounted for by several important factors.…”

“…These findings are consistent with have been reported in other countries. (Wided et al, 2015) In Singapore, undifferentiated NPC accounts for 85.1% of all nasopharyngeal cancers. (Singapore Cancer Registry 2007) Of the three tumor types, undifferentiated NPC has been strongly linked to EBV infection (Raab-Traub.…”

Clinical Outcome and Prognostic Factors for Nasopharyngeal Carcinoma: A Single Institution Study in Iran

“…The geographical distribution of NPC incidence is rather distinct and well-defined all over the world (2). Although it rarely occurs in most areas of the world, NPC is among the most common cancers in Southeast Asia and China (3,4).…”