Vaughan T L, Shapiro J A, Burt R D, Swanson G M, Berwick M, Lynch C F, Lyon J L
Program in Epidemiology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98104, USA.
Cancer Epidemiol Biomarkers Prev. 1996 Aug;5(8):587-93.
Nasopharyngeal cancer (NPC) is a major public health problem in parts of Southeast Asia and North Africa, but is rare among whites and blacks. Although infection with the EBV and genetic susceptibility appear to play large roles in high-incidence populations, migrant studies suggest that environmental factors may also be important. Aside from the high risks associated with ingestion of salted fish, surprisingly few other risk factors have been established from studies in endemic areas. We studied a low-incidence population to determine whether tobacco use, alcohol consumption, and certain medical conditions and treatments are related to NPC and to examine variations in risk by histology. We reasoned that new relationships might be best identified in the absence of strong causal pathways, such as intake of preserved foods and genetic susceptibility. A population-based case-control study was conducted from 1987 to 1993 at five cancer registries in the United States: western Washington, metropolitan Detroit, Connecticut, Iowa, and Utah. Controls were identified by random digit dialing and frequency matched to the gender and age distribution of cases at each registry. Telephone interviews were completed by 231 cases and 246 controls. We observed a strong dose-response relationship between cigarette smoking and risk of differentiated squamous cell carcinoma (test for trend, P < .001). The highest risk [odds ratio (OR), 6.5; 95% confidence interval (CI), 2.0-21.3] occurred among current smokers with a history of more than 60 pack-years. In contrast, there was no evidence that undifferentiated or nonkeratinizing carcinomas were associated with cigarette smoking. Similarly, a significant increase in risk was observed for the heaviest alcohol consumers (21 or more drinks/week) only for differentiated squamous cell carcinomas (OR, 2.9; 95% CI, 1.2-6.9). The associations with cigarettes and alcohol appeared to be stronger among persons 50 years or older. There was a suggestion that diagnosis with infectious mononucleosis (a marker of late infection with EBV) is linked with decreased NPC risk (OR, 0.4; 95% CI, 0.1-1.1). This report indicates that over two-thirds of differentiated squamous cell NPC cases arising in older persons in the United States can be accounted for by cigarettes and alcohol, but leaves unexplained cases arising in the young and carcinomas of undifferentiated or nonkeratinizing histology. Future studies of NPC need to take into account histology and age in evaluating these and other environmental and genetic risk factors.
鼻咽癌（NPC）是东南亚和北非部分地区的一个主要公共卫生问题，但在白人和黑人中较为罕见。尽管感染EB病毒和遗传易感性在高发病率人群中似乎起很大作用，但移民研究表明环境因素可能也很重要。除了与食用咸鱼相关的高风险外，令人惊讶的是，在流行地区的研究中确定的其他风险因素很少。我们研究了一个低发病率人群，以确定吸烟、饮酒以及某些医疗状况和治疗是否与鼻咽癌有关，并按组织学检查风险的差异。我们推断，在没有诸如摄入腌制食品和遗传易感性等强烈因果途径的情况下，可能最容易确定新的关系。1987年至1993年在美国的五个癌症登记处进行了一项基于人群的病例对照研究：华盛顿州西部、底特律大都市、康涅狄格州、爱荷华州和犹他州。通过随机数字拨号确定对照，并按性别和年龄分布与每个登记处的病例进行频率匹配。231例病例和246例对照完成了电话访谈。我们观察到吸烟与分化型鳞状细胞癌风险之间存在强烈的剂量反应关系（趋势检验，P < .001）。风险最高的[比值比（OR），6.5；95%置信区间（CI），2.0 - 21.3]出现在有超过60包年吸烟史的当前吸烟者中。相比之下，没有证据表明未分化或非角化癌与吸烟有关。同样，仅在分化型鳞状细胞癌中，重度饮酒者（每周饮酒21杯或更多）的风险显著增加（OR，2.9；95% CI，1.2 - 6.9）。吸烟和饮酒的关联在50岁及以上人群中似乎更强。有迹象表明，传染性单核细胞增多症（EB病毒晚期感染的标志物）的诊断与鼻咽癌风险降低有关（OR，0.4；95% CI，0.1 - 1.1）。本报告表明，在美国老年人中出现的超过三分之二的分化型鳞状细胞鼻咽癌病例可归因于吸烟和饮酒，但无法解释年轻人中出现的病例以及未分化或非角化组织学的癌症。未来对鼻咽癌的研究在评估这些及其他环境和遗传风险因素时需要考虑组织学和年龄。
