Clinical and Translational Epidemiology Unit, Massachusetts General Hospital and Harvard Medical School, Boston.
Division of Gastroenterology, Massachusetts General Hospital, Boston.
JAMA Oncol. 2018 Jan 1;4(1):71-79. doi: 10.1001/jamaoncol.2017.3684.
Although high dietary fiber intake has been associated with a lower risk of colorectal cancer (CRC), it remains unknown whether fiber benefits CRC survivors.
To assess the association of postdiagnostic fiber intake with mortality.
DESIGN, SETTING, AND PARTICIPANTS: A total of 1575 health care professionals with stage I to III CRC were evaluated in 2 prospective cohorts, Nurses' Health Study and Health Professionals Follow-up Study. Colorectal cancer-specific and overall mortality were determined after adjusting for other potential predictors for cancer survival. The study was conducted from December 23, 2016, to August 23, 2017.
Consumption of total fiber and different sources of fiber and whole grains assessed by a validated food frequency questionnaire between 6 months and 4 years after CRC diagnosis.
Hazard ratios (HRs) and 95% CIs of CRC-specific and overall mortality after adjusting for other potential predictors for cancer survival.
Of the 1575 participants, 963 (61.1%) were women; mean (SD) age was 68.6 (8.9) years. During a median of 8 years of follow-up, 773 deaths were documented, including 174 from CRC. High intake of total fiber after diagnosis was associated with lower mortality. The multivariable HR per each 5-g increment in intake per day was 0.78 (95% CI, 0.65-0.93; P = .006) for CRC-specific mortality and 0.86 (95% CI, 0.79-0.93; P < .001) for all-cause mortality. Patients who increased their fiber intake after diagnosis from levels before diagnosis had a lower mortality, and each 5-g/d increase in intake was associated with 18% lower CRC-specific mortality (95% CI, 7%-28%; P = .002) and 14% lower all-cause mortality (95% CI, 8%-19%; P < .001). According to the source of fiber, cereal fiber was associated with lower CRC-specific mortality (HR per 5-g/d increment, 0.67; 95% CI, 0.50-0.90; P = .007) and all-cause mortality (HR, 0.78; 95% CI, 0.68-0.90; P < .001); vegetable fiber was associated with lower all-cause mortality (HR, 0.83; 95% CI, 0.72-0.96; P = .009) but not CRC-specific mortality (HR, 0.82; 95% CI, 0.60-1.13; P = .22); no association was found for fruit fiber. Whole grain intake was associated with lower CRC-specific mortality (HR per 20-g/d increment, 0.72; 95% CI, 0.59-0.88; P = .002), and this beneficial association was attenuated after adjusting for fiber intake (HR, 0.77; 95% CI, 0.62-0.96; P = .02).
Higher fiber intake after the diagnosis of nonmetastatic CRC is associated with lower CRC-specific and overall mortality. Increasing fiber consumption after diagnosis may confer additional benefits to patients with CRC.
尽管高膳食纤维摄入与结直肠癌（CRC）风险降低相关，但尚不清楚纤维是否对 CRC 幸存者有益。
评估诊断后纤维摄入量与死亡率的关联。
设计、地点和参与者：共有 1575 名 I 期至 III 期 CRC 医护人员在 2 项前瞻性队列研究中进行了评估，分别为护士健康研究和健康专业人员随访研究。在调整其他潜在癌症生存预测因素后，确定结直肠癌特异性和总体死亡率。研究于 2016 年 12 月 23 日至 2017 年 8 月 23 日进行。
诊断后通过验证的食物频率问卷评估总纤维和不同纤维来源及全谷物的摄入量，时间为 6 个月至 4 年。
调整其他潜在癌症生存预测因素后，CRC 特异性和总体死亡率的风险比（HR）和 95%置信区间。
在 1575 名参与者中，963 名（61.1%）为女性；平均（SD）年龄为 68.6（8.9）岁。在中位数为 8 年的随访期间，记录了 773 例死亡，其中 174 例死于 CRC。诊断后高纤维摄入与死亡率降低相关。每天每增加 5 克摄入量的多变量 HR 分别为 CRC 特异性死亡率 0.78（95%CI，0.65-0.93；P = .006）和全因死亡率 0.86（95%CI，0.79-0.93；P < .001）。与诊断前水平相比，诊断后增加纤维摄入量的患者死亡率较低，每增加 5 克/天的摄入量与 CRC 特异性死亡率降低 18%相关（95%CI，7%-28%；P = .002），全因死亡率降低 14%相关（95%CI，8%-19%；P < .001）。根据纤维来源，谷物纤维与较低的 CRC 特异性死亡率相关（每增加 5 克/天的 HR，0.67；95%CI，0.50-0.90；P = .007）和全因死亡率（HR，0.78；95%CI，0.68-0.90；P < .001）；蔬菜纤维与全因死亡率降低相关（HR，0.83；95%CI，0.72-0.96；P = .009）但与 CRC 特异性死亡率无关（HR，0.82；95%CI，0.60-1.13；P = .22）；水果纤维无相关性。全谷物摄入量与较低的 CRC 特异性死亡率相关（每增加 20 克/天的 HR，0.72；95%CI，0.59-0.88；P = .002），这种有益的关联在调整纤维摄入量后减弱（HR，0.77；95%CI，0.62-0.96；P = .02）。
非转移性 CRC 诊断后较高的纤维摄入量与较低的 CRC 特异性和总体死亡率相关。诊断后增加纤维摄入量可能会为 CRC 患者带来额外的益处。
