Mattson M E, Winn D M
Division of Cancer Prevention and Control, National Cancer Institute, Bethesda, MD 20892.
NCI Monogr. 1989(8):13-6.
Smokeless tobacco (chewing tobacco and snuff) contains known carcinogens shown to increase the risk for oral cancer. The effect of snuff has been more fully documented than other forms of smokeless tobacco, although the carcinogenic potential of all such products is acknowledged. Risk increases with increasing length of exposure, with risks greatest for anatomic sites where the product has been held in contact the longest time. In some studies, other organs, such as the esophagus, larynx, and stomach, have been shown to be at increased risk for cancer from the use of smokeless tobacco, although at present the data are insufficient to substantiate fully a causal association. Numerous reports have shown an association between snuff use and leukoplakia, with less evidence at present linking chewing tobacco use with leukoplakia. The documented early onset of the smokeless tobacco habit and reports of increases in certain oral cancers among young men raise serious concerns of an impending oral cancer epidemic in this population. In addition, synergistic interactions with other oral cancer risk factors, e.g., smoking and alcohol, and a high rate for second primaries observed for these cancers add to the concern. Unless the tide of its use is stemmed, long-term use can be expected to produce an increase in oral cancers, and perhaps cancers of other sites, as youthful users mature and accumulate exposure to this carcinogenic agent.
无烟烟草（嚼烟和鼻烟）含有已知的致癌物质，已证实会增加患口腔癌的风险。尽管所有此类产品的致癌潜力已得到认可，但鼻烟的影响比其他形式的无烟烟草有更充分的记录。风险随着接触时间的延长而增加，产品接触时间最长的解剖部位风险最大。在一些研究中，其他器官，如食管、喉和胃，已显示因使用无烟烟草而患癌风险增加，尽管目前的数据不足以充分证实因果关系。许多报告显示使用鼻烟与白斑病有关，目前较少有证据表明嚼烟使用与白斑病有关。无烟烟草习惯的早期形成记录以及年轻男性中某些口腔癌增加的报告引发了对该人群即将出现口腔癌流行的严重担忧。此外，与其他口腔癌风险因素（如吸烟和饮酒）的协同相互作用以及这些癌症观察到的第二原发癌高发生率增加了人们的担忧。除非其使用趋势得到遏制，随着年轻使用者成熟并累积接触这种致癌物质，长期使用预计会导致口腔癌增加，甚至可能导致其他部位的癌症增加。
