Department of Epidemiology, University of Alabama at Birmingham, Birmingham; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham; Department of Epidemiology, University of Kentucky, Lexington.
Department of Epidemiology, University of Alabama at Birmingham, Birmingham; Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham; Department of Surgery, Washington University School of Medicine, St. Louis, MO.
Ann Epidemiol. 2018 Jan;28(1):33-40.e2. doi: 10.1016/j.annepidem.2017.11.003. Epub 2017 Nov 23.
Racial disparities exist in the prevalence of cancer-related risk factors and incidence of cancer. The objective of this study is to determine if cancer-related risk factors mediate the association between race and cancer incidence.
We performed prospective analysis of data from the National Institutes of Health-American Association of Retired Persons Diet and Health Study, years 1995 through 2011. We compared differences in baseline characteristics between black and white participants using χ tests and Wilcoxon tests, as appropriate. We determined risk of any cancer and the most common cancer types (i.e., breast, prostate, and colorectal) using Cox Proportional hazards models, adjusted for age, sex, marital status, education, health status, region, and adherence to guidelines on cancer-related risk factors (i.e., body mass index [BMI], smoking status, physical activity, nutrition, and alcohol consumption). We examined the mediation effect of cancer-related risk factors on the association between race and cancer incidence.
Among 425,152 participants, 16,110 (3.79%) were black, and 409,042 (96.21%) were white. The white participants were more likely to be aged 65 years and older (35.33% vs. 25.93%), male (60.88% vs. 42.67%), married (70.37% vs. 48.26%), reside in Western US (30.14% vs. 23.88%), be physically active (46.72% vs. 41.94%), and have higher adherence scores (3.14 vs. 3.04). Blacks had reduced risk of breast cancer (adjusted hazard ratio [HR]: 0.82, 95% confidence intervals [CI]: 0.74-0.90) but higher risk of prostate (adjusted HR: 1.86, 95% CI: 1.75-1.98) and colorectal cancer (adjusted HR: 1.17, 95% CI: 1.05-1.31) compared with whites. Nutrition mediated the association between race and breast cancer (6.35% mediated, P < .01), whereas BMI mediated the association between race and colorectal cancer (7.99% mediated, P < .01).
Blacks were at reduced risk of breast cancer but increased risks for prostate and colorectal cancer incidence. Nutrition and BMI exerted small but significant mediating effects on the racial disparity in risk of breast and colorectal cancers, respectively.
癌症相关风险因素的流行率和癌症发病率在种族间存在差异。本研究的目的是确定癌症相关风险因素是否在种族与癌症发病率之间的关联中起中介作用。
我们对美国国立卫生研究院-美国退休人员协会饮食与健康研究（1995 年至 2011 年）的数据进行了前瞻性分析。我们使用 χ2 检验和 Wilcoxon 检验比较了黑人和白人参与者之间的基线特征差异，具体情况视需要而定。我们使用 Cox 比例风险模型确定了任何癌症和最常见癌症类型（即乳腺癌、前列腺癌和结直肠癌）的发病风险，调整了年龄、性别、婚姻状况、教育程度、健康状况、地区以及对癌症相关风险因素（即体重指数[BMI]、吸烟状况、身体活动、营养和饮酒）指南的依从性。我们研究了癌症相关风险因素对种族与癌症发病率之间关联的中介作用。
在 425152 名参与者中，16110 名（3.79%）为黑人，409042 名（96.21%）为白人。白人参与者更可能年龄在 65 岁及以上（35.33% vs. 25.93%）、男性（60.88% vs. 42.67%）、已婚（70.37% vs. 48.26%）、居住在美国西部（30.14% vs. 23.88%）、身体活跃（46.72% vs. 41.94%）和具有更高的依从性评分（3.14 分 vs. 3.04 分）。黑人患乳腺癌的风险较低（调整后的危险比[HR]：0.82，95%置信区间[CI]：0.74-0.90），但患前列腺癌（调整后的 HR：1.86，95% CI：1.75-1.98）和结直肠癌（调整后的 HR：1.17，95% CI：1.05-1.31）的风险较高。与白人相比。营养在种族与乳腺癌之间的关联中起中介作用（6.35%中介，P<0.01），而 BMI 在种族与结直肠癌之间的关联中起中介作用（7.99%中介，P<0.01）。
黑人患乳腺癌的风险较低，但患前列腺癌和结直肠癌的风险增加。营养和 BMI 对乳腺癌和结直肠癌风险的种族差异分别产生了较小但有统计学意义的中介作用。
