Department of Biology, Formation and Research Unit of Sciences and Technology, University Claude Bernard Lyon 1, Lyon, France.
Eur J Cancer Prev. 2011 May;20(3):157-65. doi: 10.1097/CEJ.0b013e3283447497.
Many in-vitro and animal studies have provided evidence that tea has many possible anticarcinogenic mechanisms, but epidemiological evidence for the effect of tea consumption on the primary liver cancer risk remains controversial and, to date, there have been no quantitative meta-analyses reported regarding this topic. The aim of this meta-analysis is to evaluate the association between tea consumption and the risk of primary liver cancer from case-control and cohort studies. Epidemiological studies of tea consumption in relation to primary liver cancer were identified by searching MEDLINE, EMBASE, Chinese Bio-medicine Database, and Chinese Wanfang Database, from January 1979 to December 2009. The language of publication was restricted to English and Chinese. Heterogeneity and publication bias were evaluated and the pooled relative risks (RRs) were calculated using a fixed-effect model. A random-effect model was used when statistically significant heterogeneity existed. All data analyses were carried out using R software and the package 'meta'. A total of 13 epidemiological studies consisting of six case-control and seven prospective cohort studies were included. An inverse association with a borderline significance [RR = 0.77; 95% confidence interval (CI) = 0.57-1.03] was found between tea consumption and primary liver cancer. The studies with higher quality showed a similar finding with pooled RR of 0.79 (95% CI = 0.61-1.01). Both men (RR = 0.86; 95% CI = 0.77-0.95) and women (RR = 0.54; 95% CI = 0.37-0.79) showed the preventive effects of tea intake on the development of primary liver cancer. Eight studies conducted on green tea consumption suggested that it was associated with a moderate reduction in risk for primary liver cancer (RR = 0.79; 95% CI = 0.68-0.93). No publication bias was found either from funnel plot visualization or the Egger-weighted regression (P value = 0.34) and the Begg rank correlation (P value = 0.12) methods. These results provide more evidence for a protective effect of tea consumption against the development of primary liver cancer. More well-conducted and large-scale epidemiological studies are needed.
许多体外和动物研究已经提供了证据表明茶具有许多可能的抗癌机制，但关于饮茶对原发性肝癌风险的影响的流行病学证据仍然存在争议，迄今为止，尚未有关于这一主题的定量荟萃分析报告。本荟萃分析的目的是评估病例对照和队列研究中茶消费与原发性肝癌风险之间的关系。通过搜索 MEDLINE、EMBASE、中国生物医学数据库和中国万方数据库，从 1979 年 1 月至 2009 年 12 月，确定了与原发性肝癌相关的茶消费的流行病学研究。出版语言限于英语和中文。评估了异质性和发表偏倚，并使用固定效应模型计算了合并相对风险（RR）。当存在统计学显著异质性时，使用随机效应模型。所有数据分析均使用 R 软件和' meta '包进行。共纳入 13 项流行病学研究，包括 6 项病例对照研究和 7 项前瞻性队列研究。发现茶消费与原发性肝癌之间存在边缘显著的负相关[RR = 0.77；95%置信区间（CI）= 0.57-1.03]。质量较高的研究得出了类似的发现，合并 RR 为 0.79（95%CI=0.61-1.01）。男性（RR=0.86；95%CI=0.77-0.95）和女性（RR=0.54；95%CI=0.37-0.79）均显示出茶摄入对原发性肝癌发展的预防作用。八项关于绿茶消费的研究表明，绿茶消费与原发性肝癌风险的适度降低有关（RR=0.79；95%CI=0.68-0.93）。漏斗图可视化或 Egger 加权回归（P 值=0.34）和 Begg 等级相关（P 值=0.12）方法均未发现发表偏倚。这些结果为茶消费对原发性肝癌发展的保护作用提供了更多证据。需要进行更多精心设计和大规模的流行病学研究。
