Evaluation of nonviral risk factors for nasopharyngeal carcinoma in a high‐risk population of Southern China

Abstract

To understand the role of environmental and genetic influences on nasopharyngeal carcinoma (NPC) in populations at high risk of NPC, we have performed a case-control study in Guangxi Province of Southern China in 2004-2005. NPC cases (n=1049) were compared to 785 NPC-free matched controls who were seropositive for IgA antibodies (IgA) to Epstein-Barr virus (EBV) capsid antigen (VCA)—a predictive marker for NPC in Chinese populations. A questionnaire was used to capture exposure and NPC family history data. Risk factors associated with NPC in a multivariant analysis model were the following: 1) a first, second or third degree relative with NPC [Attributable risk (AR)= 6%, Odds ratio (OR) = 3.1, 95%CI = 2.0-4.9, p < 0.001]; 2) consumption of salted fish 3 or more than 3 times per month (AR=3%, OR = 1.9, 95%CI = 1.1-3.5, p = 0.035); 3) exposure to domestic wood cooking fires for more than 10 years (AR=69%, OR = 5.8, 95%CI = 2.5-13.6, p < 0.001); and 4) exposure to occupational solvents for 10 or less years (AR=4%, OR = 2.6, 95%CI = 1.4-4.8, p = 0.002). Consumption of preserved meats or a history of tobacco smoking were not associated with NPC (P>0.05). We also assessed the contribution of EBV/IgA/VCA antibody serostatus to NPC risk—32.2% of NPC can be explained by IgA+ status. However, family history and environmental risk factors cumulatively explained only 2.7% of NPC development in NPC high risk population. These findings should have important public health implications for NPC risk reduction in endemic regions.

Cannabis, tobacco and domestic fumes intake are associated with nasopharyngeal carcinoma in North Africa

“…These results, further supported by a multivariate analysis, suggest that domestic fumes exposure during childhood is a risk factor for NPC in North Africa. They corroborate the positive associations reported in endemic populations of Asia (Shanmugaratnam et al, 1978;Zheng et al, 1994;Guo et al, 2009).…”

“…Although the association with UCNT was not significant, a trend of increased risk of UCNT with increased dose of cigarette intake per day was apparent, leaving the question unresolved. Case -control studies from endemic areas (mainly from Asia), where the vast majority of NPCs are UCNTs, have produced conflicting results (Chen et al, 1990;Ning et al, 1990;Yu et al, 1990;Cheng et al, 1999;Armstrong et al, 2000;Yuan et al, 2000;Zou et al, 2000;Friborg et al, 2007;Guo et al, 2009). Our findings point to the importance of separating UCNT and non-UCNT in analyses.…”

The Incidence and Prognosis of Nasopharyngeal Carcinoma Patients With Family History

“…The incidence rate of familial NPC patients was 9.9%-14.6% in Southern China, including Guangdong and Guangxi province [9,10,23,24]. Another study from Taiwan revealed that 11.0% NPC patients had family history [11].…”

“…EBV infection may influence the early stages of tumorigenesis in NPC [4][5][6][7]. The potential environmental etiologic factors include high consumption of salt-preserved fish and other foods, cigarette smoking, alcohol, occupational exposures, air pollution and wood fire, etc [8][9][10][11][12][13][14].…”

Beating 'Guangdong cancer': a review and update on nasopharyngeal cancer

“…6 N-nitrosamine found in the preserved salted fish is believed to be the carcinogen concerned. 25 Other factors such as the use of Chinese medicinal herbs and high consumption of fermented food were also suggested, but the associations were often inconsistent among studies. 24 …”