Spitz M R, Hsu T C, Wu X, Fueger J J, Amos C I, Roth J A
Department of Epidemiology, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
Cancer Epidemiol Biomarkers Prev. 1995 Mar;4(2):99-103.
Cigarette smoking is the major determinant of lung cancer. However, only a fraction of smokers develops lung cancer; genetically determined susceptibility factors seem to play an important role also. Previous case-control studies have shown that in vitro bleomycin-induced mutagen sensitivity is an independent risk factor for head-and-neck cancers, and preliminary data suggest a similar association with lung cancer. However, these studies were almost exclusively performed on Caucasian populations. To test whether ethnic differences in cancer risk are due to differences in mutagen sensitivity, we are using the in vitro mutagen sensitivity assay to conduct a case-control study of mutagen sensitivity and lung cancer risk in low-risk (Mexican-American) and high-risk (African-American) groups. Here we report the results of our ongoing study of 209 African-Americans (90 cases and 119 controls) in the Houston-Galveston area. Mexican-American data will be reported separately as case accrual increases. Predictably, all measures of cigarette smoking status (including intensity, duration, tar content, depth of inhalation, and type of cigarette) were significant predictors of risk. In addition, 55.3% of the cases were mutagen sensitive (defined as > or = 1 break/cell), compared with 24.6% of the controls, with an age-, sex-, and smoking-adjusted odds ratio (OR) of 3.7 (95% confidence limits = 1.4, 9.4). Of interest, higher risks were noted for former smokers (OR = 5.4) compared with current smokers (OR = 3.1) and especially for younger former smokers (< 55 years). By histologic-specific analysis, mutagen sensitivity was significantly associated with risk for adenocarcinoma (OR = 4.8) and squamous cell carcinoma (OR = 8.5).(ABSTRACT TRUNCATED AT 250 WORDS)
吸烟是肺癌的主要决定因素。然而，只有一小部分吸烟者会患肺癌；基因决定的易感性因素似乎也起着重要作用。先前的病例对照研究表明，体外博来霉素诱导的诱变敏感性是头颈癌的独立危险因素，初步数据表明其与肺癌也有类似关联。然而，这些研究几乎都只在白种人群中进行。为了检验癌症风险的种族差异是否源于诱变敏感性的差异，我们正在使用体外诱变敏感性测定法，对低风险（墨西哥裔美国人）和高风险（非裔美国人）群体进行诱变敏感性与肺癌风险的病例对照研究。在此，我们报告正在进行的对休斯顿 - 加尔维斯顿地区209名非裔美国人（90例病例和119名对照）的研究结果。随着病例积累的增加，墨西哥裔美国人的数据将另行报告。不出所料，吸烟状况的所有指标（包括强度、持续时间、焦油含量、吸入深度和香烟类型）都是风险的显著预测因素。此外，55.3%的病例对诱变敏感（定义为≥1个断裂/细胞），而对照中这一比例为24.6%，年龄、性别和吸烟调整后的优势比（OR）为3.7（95%置信区间 = 1.4, 9.4）。有趣的是，与现吸烟者（OR = 3.1）相比， former吸烟者的风险更高（OR = 5.4），尤其是年龄较轻的former吸烟者（<55岁）。通过组织学特异性分析，诱变敏感性与腺癌风险（OR = 4.8）和鳞状细胞癌风险（OR = 8.5）显著相关。（摘要截短于250字） （注：文中former吸烟者未明确翻译出具体意思，需结合上下文确定准确含义）
