标题：维生素C与乳癌患者的生存：一项meta分析

背景：关于膳食维生素C摄入和乳癌生存期之间的联系，目前仍存在争议，此外几乎没有关于乳癌患者补充维生素C的相关研究。本研究旨在综合前瞻性研究的结果，明确维生素C补充剂及膳食维生素C摄入，是否影响乳癌患者的乳癌特异性死亡率和总体死亡率。

方法：(简略)meta分析，计算相对风险(RR)和95%置信区间。

结果：最终共纳入10篇符合要求的研究，其中6篇与维生素C补充剂有关，有7篇探究了膳食维生素C摄入的影响。共计17,696例乳癌，2791例死亡(总体)，1558例乳癌特异性死亡。对于确诊后开始服用维生素C补充剂的乳癌患者，其总体死亡和乳癌特异性死亡的相对风险分别为0.81和0.85。若乳癌患者每日的膳食中增加100 mg的维生素C摄入，则其总体死亡和乳癌特异性死亡的相对风险分别为0.73和0.78。

结论：本meta分析的结果提示，如果乳癌患者在确诊后开始服用维生素C补充剂，则其死亡风险将下降。增加膳食中的维生素C摄入，与总体死亡和乳癌特异性死亡的风险下降之间存在统计学显著性关系。

Title

Vitamin C and survival among women with breast cancer: A Meta-analysis

Background

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.

Methods

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.

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 100 mg 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.

Conclusion

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.

选自2014年5月刊European Journal of Cancer