Tseng Chin-Hsiao
Department of Internal Medicine, National Taiwan University College of Medicine, Taipei, Taiwan.
Division of Endocrinology and Metabolism, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
Oncotarget. 2017 Jun 20;8(25):41132-41142. doi: 10.18632/oncotarget.17066.
This study evaluated whether metformin might reduce lung cancer risk. The reimbursement database of the Taiwan's National Health Insurance was used. A sample of 15414 never users and 280159 ever users of metformin (original sample) and a 1:1 matched-pairs of ever and never users (n=15414 in each group, matched sample) were recruited from patients with newly diagnosed type 2 diabetes mellitus during 1999-2005. They were followed until December 31, 2011. Cox regression incorporated with the inverse probability of treatment weighting using propensity score was used to estimate hazard ratios. Results showed that the respective incidence of lung cancer in ever and never users was 173.36 and 292.65 per 100000 person-years in the original sample; and was 211.71 and 292.65, respectively, in the matched sample. The overall hazard ratios (95% confidence intervals) of 0.586 (0.509-0.674) in the original sample and 0.717 (0.584-0.881) in the matched sample suggested a significantly lower risk among metformin users. Hazard ratios comparing the first (<22.60 months), second (22.60-46.67 months) and third (>46.67 months) tertile of cumulative duration of metformin use to never users was 1.163 (1.005-1.348), 0.612 (0.526-0.711) and 0.176 (0.148-0.210), respectively, in the original sample; and was 1.465 (1.131-1.897), 0.758 (0.566-1.016) and 0.228 (1.460-0.357) in the respective tertile of the matched sample. Sensitivity analyses after excluding patients with certain risk factors of cancer and subgroup analyses supported a favorable effect of metformin. In conclusion,metformin use may reduce lung cancer risk in patients with type 2 diabetes mellitus.
本研究评估了二甲双胍是否可降低肺癌风险。研究使用了台湾全民健康保险的报销数据库。从1999年至2005年新诊断的2型糖尿病患者中招募了15414名从未使用过二甲双胍的患者和280159名曾经使用过二甲双胍的患者作为原始样本，并按1:1配对曾经使用和从未使用二甲双胍的患者（每组n = 15414，配对样本）。对他们进行随访直至2011年12月31日。采用Cox回归结合使用倾向评分的治疗权重逆概率来估计风险比。结果显示，在原始样本中，曾经使用和从未使用二甲双胍的患者肺癌发病率分别为每100000人年173.36例和292.65例；在配对样本中，分别为211.71例和292.65例。原始样本中总体风险比（95%置信区间）为0.586（0.509 - 0.674），配对样本中为0.717（0.584 - 0.881），表明二甲双胍使用者的风险显著较低。在原始样本中，将二甲双胍使用累积时长的第一个三分位数（<22.60个月）、第二个三分位数（22.60 - 46.67个月）和第三个三分位数（>46.67个月）与从未使用者比较的风险比分别为1.163（1.005 - 1.348）、0.612（0.526 - 0.711）和0.176（0.148 - 0.210）；在配对样本的相应三分位数中分别为1.465（1.131 - 1.897）、0.758（0.566 - 1.016）和0.228（1.460 - 0.357）。在排除具有某些癌症风险因素的患者后进行的敏感性分析和亚组分析均支持二甲双胍的有益作用。总之，使用二甲双胍可能降低2型糖尿病患者的肺癌风险。
