吸烟与原发性肝癌关系的巢式病例对照研究

目的 分析吸烟与上海市区中老年男性原发性肝癌的关系.方法 应用巢式病例对照研究方法,对一个18 244名男性队列随访11年,以队列中213例新发肝癌患者作为病例组,按照患者年龄、采样日期、同居住区等配对条件,从队列中随机抽取1094名健康人作为对照组.使用配对Logistic回归分析,调整可能的混杂因素,估计吸烟对肝癌发生的危险度和95%可信区间(CI).结果 调整肝炎、肝硬化、胆石症或其他胆囊病史及乙型肝炎病毒感染等可能的混杂因素后,男性吸烟者患肝痛的危险性是不吸烟者的1.91倍(95%CI为1.28～2.86),日随着每天吸烟量、吸烟年限和吸烟包年数的增加而增加.每天吸烟≥20支者、吸烟≥40年者和吸烟37包年者患肝癌的相对危险度分别为2.16(95%CI为1.37～3.40)、2.14(95%CI为1.18～3.87)和2.12(95%CI为1.21～3.74).吸烟开始年龄越小,危险性越大,吸烟开始年龄<20岁者患肝癌的危险性为2.57(95%CI为1.50～4.40).结论 吸烟是上海市区男性原发性肝癌的危险因素.

Cigarette smoking and primary liver cancer risk: a nested case-control study in Shanghai

Objective To evaluate the association between cigarette smoking and risk of primary liver cancer (PLC) among middle-aged and elderly men in urban Shanghai. Methods A nested case- control study was conducted based on a cohort of 18 244 men who were 45-64 years of age in 1986-1989 and had no history of cancer at recruitment in Shanghai. As of Dec 31, 2000, a total of 213 incident cases of PLC were identified. 1094 matched controls were randomly selected among the cohort subjects who were free of cancer and alive at the time of cancer diagnosis of the index case. The matching criteria were date of birth (within 2 years), date of biospsy specimen collection (within 1 month), and neighborhood of residence at recruitment. Conditional logistic regression models were used to estimate adjusted odds ratios (ORs) and their corresponding 95% confidence intervals (CIs). Results After controlling for potential confounders, cigarette smoking (ever vs. never) was associated with risk of PLC (OR=1.91; 95% CI:1.28-2.86). Risk of PLC increased with increasing number of cigarettes smoked per day, as well as duration of cigarette smoking,pack-years of cigarettes consumed over lifetime and earlier age started smoking. The ORs were 2.16 (95%CI=1.37～3.40), 2.14(95%CI=1.18～3.87), 2.12(95%CI=1.21～3.74) and 2.57 (95% CI=1.50～4.40) for men who smoked 20 cigarettes or more daily, smoked for 40 or more years, consumed more than 37 pack-years of cigarettes, and began smoking before 20 years of age, respectively. Conclusion This study confirms that cigarette smoking is an independent risk factor for primary liver cancer among males in Shanghai.