Is nasopharyngeal cancer really a “Cantonese cancer”?

Nasopharyngeal cancer(NPC) is endemic in Southern China,with Guandong province and Hong Kong reporting some of the highest incidences in the world.The journal Science has called it a "Cantonese cancer".We propose that in fact NPC is a cancer that originated in the Bai-Yue("proto-Tai-Kadai" or "proto-Austronesian" or "proto-Zhuang") peoples and was transmitted to the Han Chinese in southern China through intermarriage.However,the work by John Ho raised the profile of NPC,and because of the high incidence of NPC in Hong Kong and Guangzhou,NPC became known as a Cantonese cancer.We searched historical articles,articles cited in PubMed,Google,monographs,books and Internet articles relating to genetics of the peoples with high populations of NPC.The migration history of these various peoples was extensively researched,and where possible,their genetic fingerprint identified to corroborate with historical accounts.Genetic and anthropological evidence suggest there are a lot of similarities between the Bai-Yue and the aboriginal peoples of Borneo and Northeast India;between Inuit of Greenland,Austronesian Mayalo-Polynesians of Southeast Asia and Polynesians of Oceania,suggesting some common ancestry.Genetic studies also suggest the present Cantonese,Minnans and Hakkas are probably an admixture of northern Han and southern Bai-Yue.All these populations have a high incidence of NPC.Very early contact between southern Chinese and peoples of East Africa and Arabia can also account for the intermediate incidence of NPC in these regions.

Associations of lifestyle and diet with the risk of nasopharyngeal carcinoma in Singapore:a case–control study

Background: Nasopharyngeal carcinoma(NPC) is a commonly diagnosed cancer in Southeast Asia. Many studies have examined the risk factors for NPC, yet the roles of some risk factors remain inconclusive. The purpose of this study was to examine associations between modifiable lifestyle factors and the risk of NPC in the Singaporean population.Methods: We conducted a case–control study in Singapore with 300 patients and 310 controls who were recruited between 2008 and 2012. Each control was selected and individually matched to each patient based on sex, ethnicity, and age(±5 years). A total of 290 pairs of cases and controls were matched successfully. We examined lifestyle factors such as tobacco smoking, alcohol drinking, various salted and preserved food consumption, and weaning practices.Results: After adjusting for covariates, multivariate analysis showed that those participants who were current smokers and had ever smoked tobacco had a higher risk of NPC than participants who had never smoked, with odds ratios(ORs) of 4.50(95% confidence interval [CI] 2.58–7.86; P < 0.001) and 2.52(95% CI 1.54–4.12; P < 0.001), respectively. Those who consumed salted vegetables at least once a week also showed a significantly increased risk of NPC than those who never or rarely consumed salted vegetables, with an OR of 4.18(95% CI 1.69–10.38; P = 0.002).Conclusion: Smoking(currently and ever-smoked) and consuming salted vegetables once a week or more were lifestyle risk factors for NPC, and changes of these factors for the better may reduce the risk of NPC.

High incidence of nasopharyngeal cancer: similarity for 60% of mitochondrial DNA signatures between the Bidayuhs of Borneo and the Bai-yue of Southern China

Populations in Southern China (Bai-yue) and Borneo (Bidayuh) with high incidence of nasopharyngeal cancer (NPC) share similar mitochondrial DNA signatures, supporting the hypothesis that these two populations may share the same genetic predisposition for NPC, which may have first appeared in a common ancestral reference population before the sea levels rose after the last ice age.

新加坡的生活方式和饮食习惯与鼻咽癌风险的关系:一项病例对照研究

背景与目的鼻咽癌(nasopharyngeal carcinoma,NPC)是东南亚地区一种常见的癌症。许多研究已经对NPC的风险因素进行了研究,但一些风险因素的作用仍无定论。本研究旨在探讨新加坡人可改变的生活方式因素与NPC风险之间的关系。方法我们在新加坡进行了一项病例对照研究,在2008年至2012年期间招募了300例患者和310例对照。根据性别、种族和年龄(±5岁)对各例对照进行选择并分别与每一例患者匹配。共有290对病例和对照成功匹配。我们对多个生活方式因素,如吸烟、饮酒、各种腌制和罐头食品消费以及断奶习惯进行了研究。结果调整协变量后多因素分析显示,现行吸烟者和有既往吸烟史的参与者比从未吸烟的参与者患NPC的风险更高,优势比(odds ratios,ORs)分别为4.50 [95%置信区间(confidence interval,CI):2.58–7.86;P <0.001]和2.52(95%CI:1.54–4.12;P <0.001)。每周至少吃1次腌制蔬菜的人也比那些从不或很少食用腌制蔬菜的人表现出NPC风险显著增加,OR值为4.18(95%CI:1.69–10.38;P=0.002)。结论吸烟(现行和经常吸食)和每周1次或多次食用腌制蔬菜是NPC的生活方式风险因素,戒除这些不良因素可以降低NPC的风险。