Tabung Fred K, Steck Susan E, Ma Yunsheng, Liese Angela D, Zhang Jiajia, Caan Bette, Hou Lifang, Johnson Karen C, Mossavar-Rahmani Yasmin, Shivappa Nitin, Wactawski-Wende Jean, Ockene Judith K, Hebert James R
Cancer Prevention and Control Program, University of South Carolina, 915 Greene Street, Discovery I Building, Columbia, SC, 29208, USA.
Cancer Causes Control. 2015 Mar;26(3):399-408. doi: 10.1007/s10552-014-0515-y. Epub 2014 Dec 31.
Inflammation is a process central to carcinogenesis and in particular to colorectal cancer (CRC). Previously, we developed a dietary inflammatory index (DII) from extensive literature review to assess the inflammatory potential of diet. In the current study, we utilized this novel index in the Women's Health Initiative to prospectively evaluate its association with risk of CRC in postmenopausal women.
The DII was calculated from baseline food frequency questionnaires administered to 152,536 women aged 50-79 years without CRC at baseline between 1993 and 1998 and followed through 30 September 2010. Incident CRC cases were ascertained through a central physician adjudication process. Multiple covariate-adjusted Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95 % confidence intervals (95 % CI) for colorectal, colon (proximal/distal locations), and rectal cancer risk, by DII quintiles (Q).
During an average 11.3 years of follow-up, a total of 1,920 cases of CRC (1,559 colon and 361 rectal) were identified. Higher DII scores (representing a more pro-inflammatory diet) were associated with an increased incidence of CRC (HRQ5-Q1 1.22; 95 % CI 1.05, 1.43; p trend = 0.02) and colon cancer, specifically proximal colon cancer (HRQ5-Q1 1.35; 95 % CI 1.05, 1.67; p trend = 0.01) but not distal colon cancer (HRQ5-Q1 0.84; 95 % CI 0.61, 1.18; p trend = 0.63) or rectal cancer (HRQ5-Q1 1.20; 95 % CI 0.84, 1.72; p trend = 0.65).
Consumption of pro-inflammatory diets is associated with an increased risk of CRC, especially cancers located in the proximal colon. The absence of a significant association for distal colon cancer and rectal cancer may be due to the small number of incident cases for these sites. Interventions that may reduce the inflammatory potential of the diet are warranted to test our findings, thus providing more information for colon cancer prevention.
炎症是致癌过程尤其是结直肠癌（CRC）发生过程中的核心环节。此前，我们通过广泛的文献综述制定了饮食炎症指数（DII），以评估饮食的炎症潜能。在本研究中，我们在女性健康倡议（Women's Health Initiative）中运用这一全新指数，前瞻性地评估其与绝经后女性患CRC风险的关联。
DII由1993年至1998年期间对152,536名年龄在50 - 79岁、基线时无CRC的女性进行的基线食物频率问卷调查计算得出，并随访至2010年9月30日。通过中心医师判定流程确定新发CRC病例。采用多协变量调整的Cox比例风险回归模型，按DII五分位数（Q）估计结直肠癌、结肠癌（近端/远端部位）和直肠癌风险的风险比（HR）及95%置信区间（95%CI）。
在平均11.3年的随访期间，共识别出1920例CRC病例（1559例结肠癌和361例直肠癌）。较高的DII评分（代表更具促炎作用的饮食）与CRC发病率增加相关（HRQ5 - Q1 1.22；95%CI 1.05，1.43；p趋势 = 0.02），与结肠癌尤其是近端结肠癌相关（HRQ5 - Q1 1.35；95%CI 1.05，1.67；p趋势 = 0.01），但与远端结肠癌（HRQ5 - Q1 0.84；95%CI 0.61，1.18；p趋势 = 0.63）或直肠癌（HRQ5 - Q1 1.20；95%CI 0.84，1.72；p趋势 = 0.65）无关。
食用促炎饮食与CRC风险增加相关，尤其是近端结肠癌。远端结肠癌和直肠癌未显示出显著关联可能是由于这些部位的新发病例数较少。有必要进行可能降低饮食炎症潜能的干预措施，以验证我们的研究结果，从而为结肠癌预防提供更多信息。
