Giovannucci E, Stampfer M J, Colditz G A, Manson J E, Rosner B A, Longnecker M, Speizer F E, Willett W C
Channing Laboratory, Department of Medicine, Harvard Medical School, Boston, MA.
Am J Epidemiol. 1993 Mar 1;137(5):502-11. doi: 10.1093/oxfordjournals.aje.a116703.
Fat intake was examined in relation to risk of breast cancer using dietary questionnaires administered both before and after the diagnosis of breast cancer. Among the Nurses' Health Study cohort members who completed a food frequency questionnaire and were free of cancer in 1986, 398 were diagnosed with breast cancer during 2 years of follow-up. These cases and 798 age-matched controls (cohort members who also completed a dietary questionnaire in 1986 but did not develop breast cancer) were sent another food frequency questionnaire in 1989 inquiring about their diet in 1985. Three hundred cases and 602 controls responded to the second questionnaire. The age-adjusted analysis using the prospective (1986) questionnaire demonstrated no appreciable associations between breast cancer incidence and intakes of total fat (odds ratio (OR) between highest and lowest quintiles = 0.87; 95% confidence interval (CI) 0.54-1.40) and saturated fat (OR = 0.97; CI 0.64-1.46). The age-adjusted analysis using the retrospective (1989) questionnaire suggested positive associations between breast cancer incidence and intakes of total fat (OR = 1.43; 95% CI 0.90-2.27) and saturated fat (OR = 1.38; 95% CI 0.89-2.13). When nutrients were adjusted for total energy intake, the direction and magnitude of the differences between the prospective and retrospective analyses were similar to the analyses unadjusted for energy intake. These results suggest that case-control studies of diet and breast cancer may yield biased associations between fat intake and the risk of breast cancer.
通过在乳腺癌诊断前后均使用的饮食调查问卷，对脂肪摄入量与乳腺癌风险之间的关系进行了研究。在完成食物频率问卷且在1986年无癌症的护士健康研究队列成员中，有398人在2年随访期间被诊断出患有乳腺癌。这些病例以及798名年龄匹配的对照者（同样在1986年完成饮食调查问卷但未患乳腺癌的队列成员）在1989年收到了另一份食物频率问卷，询问他们1985年的饮食情况。300例病例和602名对照者回复了第二份问卷。使用前瞻性（1986年）问卷进行的年龄调整分析表明，乳腺癌发病率与总脂肪摄入量（最高和最低五分位数之间的比值比（OR）=0.87；95%置信区间（CI）0.54 - 1.40）和饱和脂肪摄入量（OR = 0.97；CI 0.64 - 1.46）之间无明显关联。使用回顾性（1989年）问卷进行的年龄调整分析表明，乳腺癌发病率与总脂肪摄入量（OR = 1.43；95% CI 0.90 - 2.27）和饱和脂肪摄入量（OR = 1.38；95% CI 0.89 - 2.13）之间存在正相关。当对营养素进行总能量摄入调整后，前瞻性和回顾性分析之间差异的方向和幅度与未进行能量摄入调整的分析相似。这些结果表明，饮食与乳腺癌的病例对照研究可能会在脂肪摄入量与乳腺癌风险之间产生有偏差的关联。
