Supplementary Material for: Effects of Diet after Early Breast Cancer Treatment: A Systematic Review and Meta-Analysis of Clinical Trials

Purpose: Randomized clinical trials (RCT) are inconclusive regarding the role of dietary interventions in anthropometric measurements and survival in breast cancer patients. Our aim was to conduct a systematic review and meta-analysis to assess the effects of diet on these outcomes in women treated for early-stage breast cancer. Methods: Embase, MEDLINE, the Cochrane Database of Systematic Reviews, and the Cochrane Central Register of Controlled Trials were searched for RCT comparing dietary interventions (individualized dietary counseling, prescription of a specific diet, or others) with usual care in women that were treated for early breast cancer. Primary outcomes were overall survival (OS) and disease-free survival (DFS); secondary outcome was a change in body mass index (BMI). Results: We found 12 RCT eligible for analysis, 7 of which were included in the quantitative analysis. Two studies reported OS and DFS and 6 reported BMI data. The hazard ratio (HR) for OS and DFS was 0.91 (95% confidence interval [CI] 0.77–1.07, p = 0.25) and 0.92 (95% CI 0.79–1.08, p = 0.31) for the intervention and control groups, respectively. Intervention was associated with BMI reduction in subjects who received a specific diet instead of counseling or other types of intervention (–0.67; 95% CI –1.14 to –0.21). Conclusions: Despite increasing survival among breast cancer patients due to better oncological treatments, there is still a lack of prospective data regarding the effects of dietary interventions in this population. We found positive association between prescription of specific diets in terms of anthropometric measures; there were no differences in OS or DFS.目的：随机临床试验（Randomized Clinical Trial, RCT）在饮食干预对乳腺癌患者人体测量学指标与生存情况的作用方面尚无定论。本研究旨在开展系统评价与荟萃分析，以评估饮食干预对早期乳腺癌女性患者上述结局的影响。 方法：检索Embase、MEDLINE、Cochrane系统评价数据库（Cochrane Database of Systematic Reviews）及Cochrane对照试验中心注册库（Cochrane Central Register of Controlled Trials），筛选对比饮食干预（个体化饮食咨询、特定饮食处方或其他干预方式）与常规护理的早期乳腺癌女性患者相关随机临床试验。本研究的主要结局指标为总生存期（Overall Survival, OS）与无病生存期（Disease-Free Survival, DFS），次要结局指标为体质量指数（Body Mass Index, BMI）的变化。 结果：本研究共纳入12项符合分析标准的随机临床试验，其中7项纳入定量分析。2项研究报告了OS与DFS数据，6项研究提供了BMI相关数据。干预组与对照组的OS风险比（Hazard Ratio, HR）为0.91（95%置信区间[CI] 0.77~1.07，P=0.25），DFS风险比为0.92（95%置信区间[CI] 0.79~1.08，P=0.31）。相较于接受饮食咨询或其他类型干预的受试者，采用特定饮食处方的干预组受试者BMI出现显著降低（加权均数差为-0.67；95%置信区间-1.14~-0.21）。 结论：尽管肿瘤治疗手段的进步提升了乳腺癌患者的生存期，但该人群中饮食干预效应的前瞻性研究数据仍较为匮乏。本研究发现，特定饮食处方与人体测量学指标的改善呈正相关；但在总生存期与无病生存期方面未观察到组间显著差异。