Diabetes Care：二甲双胍或不能改善糖尿病合并乳腺癌患者的生存

虽然既往研究显示糖尿病药物二甲双胍有抗癌效应，但来自女子学院医院的新的开创性的研究发现二甲双胍或不能改善某些乳腺癌患者的生存。这一研究发表于journal Diabetes Care杂志，研究发现当合并糖尿病的乳腺癌老年患者服用这一糖尿病一线治疗药物二甲双胍后，患者的生存并未得到改善。然而，文章作者同时警告说这一结论还需要进一步的研究证实。
“二甲双胍是一款常用于糖尿病患者控制血糖含量的药物，”研究的首席作者Iliana Lega博士说，他是女子学院医院研究所的研究员。“虽然现在的文献显示这款药物可预防癌症新发或乳腺癌死亡，但我们的研究发现二甲双胍并不能显著影响受试患者的生存率。”Lega博士在文中指出，科学研究发现二甲双胍可降低癌症发生率达百分30，且可减少非糖尿病乳腺癌患者的肿瘤生长。
为了检测这款药物的抗癌效应，文章作者检查了2361例女性患者，她们的年龄在66岁以上，均于1997年4月1日至2008年3月31日诊断为乳腺癌并接受二甲双胍的治疗。随访从诊断之日起至患者死亡或2010年3月20日。研究者发现二甲双胍的积累使用与患者全因死亡率或乳腺癌死亡率并无显著性统计学相关。“我们研究的独特之处在于，尽管很多文献可以证明二甲双胍的效应，但这些既往研究都没有检测患者服用这款药物的累积效应，特别是对于合并糖尿病的乳腺癌患者人群，”Lega博士说“尤其是当考虑到糖尿病患者可能于治疗期间更换药物的时候，这些就显得更加重要。”
文章作者强调，由于缺乏体重指数、乳腺癌分期相关数据以及乳腺癌特异性死亡的随访期短，因此不宜对上述发现作过分解读。必须对乳腺癌合并糖尿病更年轻患者人群进行进一步的研究。“二甲双胍对乳腺癌患者的效应是帮助我们找到合并或不合并糖尿病的癌症患者结局差异的关键，”她补充道，“这些发现将有助于医师获得更多的糖尿病合并患者的治疗方案。”
与二甲双胍相关的拓展阅读：

• Diabetes Care：糖尿病患者使用二甲双胍与患肺癌风险无关
• Diabetes Care：lixisenatide有效改善二甲双胍控制不佳的2型糖尿病人群的血糖
• Am J Psychiatry：二甲双胍可治疗抗精神病药物所致不良反应
• Nature：揭示二甲双胍降糖新机制
• Diabetes Care：二甲双胍能改善心血管高危的2型糖尿病患者心血管预后（SPREAD-DIMCAD研究
• JCEM：二甲双胍降低肥胖儿童BMI和血糖水平 更多信息请点击：有关二甲双胍更多资讯

Association Between Metformin Therapy and Mortality After Breast Cancer: A Population-Based Study.
Abstract
OBJECTIVEMetformin has been associated with a reduction in breast cancer risk and may improve survival after cancer through direct and indirect tumor-suppressing mechanisms. The purpose of this study was to evaluate the effect of metformin therapy on survival in women with breast cancer using methods that accounted for the duration of treatment with glucose-lowering therapies.RESEARCH DESIGN AND METHODSThis population-based study, using Ontario health care databases, recruited women aged 66 years or older diagnosed with diabetes and breast cancer between 1 April 1997 and 31 March 2008. Using Cox regression analyses, we explored the association between cumulative duration of past metformin use and all-cause and breast cancer-specific mortality. We modeled cumulative duration of past metformin use as a time-varying exposure.RESULTSOf 2,361 breast cancer patients identified, mean (± SD) age at cancer diagnosis was 77.4 ± 6.3 years, and mean follow-up was 4.5 ± 3.0 years. There were 1,101 deaths(46.6%), among which 386 (16.3%) were breast cancer-specific deaths. No significant association was found between cumulative duration of past metformin use and all-cause mortality (adjusted hazard ratio 0.97 [95% CI 0.92-1.02]) or breast cancer-specific mortality (0.91 [0.81-1.03]) per additional year of cumulative use.CONCLUSIONSOur findings failed to show an association between improved survival and increased cumulative metformin duration in older breast cancer patients who had recent-onset diabetes. Further research is needed to clarify this association, accounting for effects of cancer stage and BMI in younger populations or those with differing stages of diabetes as well as in nondiabetic populations.