Unit of Nutritional Epidemiology, Institute for Environmental Medicine, Karolinska Institutet, Box 210, 171 77 Stockholm, Sweden; Obstetrics and Gynecology Epidemiology Center, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA 02115, USA.
Unit of Nutritional Epidemiology, Institute for Environmental Medicine, Karolinska Institutet, Box 210, 171 77 Stockholm, Sweden.
Eur J Cancer. 2014 May;50(7):1223-31. doi: 10.1016/j.ejca.2014.02.013. Epub 2014 Mar 7.
The association between dietary vitamin C intake and breast cancer survival is inconsistent and few studies have specifically examined vitamin C supplement use among women with breast cancer. The purpose of this study was to summarise results from prospective studies on the association between vitamin C supplement use and dietary vitamin C intake and breast cancer-specific mortality and total mortality.
Studies were identified using the PubMed database through February 6, 2014 and by examining the references of retrieved articles. Prospective studies were included if they reported relative risks (RR) with 95% confidence intervals (95% CIs) for at least two categories or as a continuous exposure. Random-effects models were used to combine study-specific results.
The ten identified studies examined vitamin C supplement use (n=6) and dietary vitamin C intake (n=7) and included 17,696 breast cancer cases, 2791 total deaths, and 1558 breast cancer-specific deaths. The summary RR (95% CI) for post-diagnosis vitamin C supplement use was 0.81 (95% CI 0.72-0.91) for total mortality and 0.85 (95% CI 0.74-0.99) for breast cancer-specific mortality. The summary RR for a 100mg per day increase in dietary vitamin C intake was 0.73 (95% CI 0.59-0.89) for total mortality and 0.78 (95% CI 0.64-0.94) for breast cancer-specific mortality.
Results from this meta-analysis suggest that post-diagnosis vitamin C supplement use may be associated with a reduced risk of mortality. Dietary vitamin C intake was also statistically significantly associated with a reduced risk of total mortality and breast cancer-specific mortality.
维生素 C 摄入与乳腺癌生存之间的关联并不一致，且很少有研究专门研究乳腺癌患者的维生素 C 补充剂使用情况。本研究旨在总结前瞻性研究中关于维生素 C 补充剂使用与饮食中维生素 C 摄入与乳腺癌特异性死亡率和总死亡率之间关联的结果。
通过 2014 年 2 月 6 日的 PubMed 数据库和检索文章的参考文献确定研究。如果报告了至少两个类别的相对风险（RR）及其 95%置信区间（95%CI）或作为连续暴露，则纳入前瞻性研究。使用随机效应模型来合并研究特异性结果。
确定的十项研究检查了维生素 C 补充剂使用（n=6）和饮食中维生素 C 摄入（n=7），包括 17696 例乳腺癌病例、2791 例总死亡和 1558 例乳腺癌特异性死亡。诊断后维生素 C 补充剂使用的总死亡率的汇总 RR（95%CI）为 0.81（95%CI 0.72-0.91），乳腺癌特异性死亡率为 0.85（95%CI 0.74-0.99）。饮食中维生素 C 摄入量增加 100mg/天的总死亡率的汇总 RR 为 0.73（95%CI 0.59-0.89），乳腺癌特异性死亡率为 0.78（95%CI 0.64-0.94）。
这项荟萃分析的结果表明，诊断后维生素 C 补充剂的使用可能与降低死亡率风险相关。饮食中维生素 C 的摄入也与总死亡率和乳腺癌特异性死亡率降低显著相关。
