Department of Epidemiology, University of Alabama at Birmingham, Birmingham, Alabama 35294-7331, USA.
Cancer. 2009 Dec 15;115(24):5798-806. doi: 10.1002/cncr.24598.
There is a survival disparity between African Americans and Caucasians who have colon cancer. The objectives of the current study were to quantify the impact of comorbidity and body mass index (BMI) on survival and to assess whether these 2 variables account for the decreased survival among African Americans.
Data from patients (n=496) who underwent surgery for a first primary colon cancer at the University of Alabama at Birmingham Hospital from 1981 to 2002 were analyzed. Hazard ratios (HRs) with 95% confidence intervals (CI) were obtained using Cox proportional hazards models for the association of race, comorbidity, BMI, and covariates with all-cause mortality. The confounding influence of comorbidity and BMI for the increased risk of death associated with African-American race was evaluated, and effect modification by disease stage for the association of comorbidity and BMI with mortality also was assessed.
African Americans experienced an increased risk of death compared with Caucasians (HR, 1.34; 95% CI, 1.06-1.68). The highest comorbidity burden was associated with an increased risk of all-cause mortality (HR, 1.63; 95% CI, 1.24-2.15). For BMI, being underweight increased the risk of death (HR, 1.54; 95% CI, 0.96-2.45); however, being overweight/obese was protective (HR, 0.77; 95% CI, 0.61-0.97). The effect of comorbidity was observed among those with early stage tumors, whereas the effect of BMI was confined to patients who had advanced tumors.
Although comorbidity and BMI had an impact on the survival of patients with colon cancer after surgery, these variables were not contributing factors to the decreased survival observed among African Americans.
非裔美国人和白种人患有结肠癌的存活率存在差异。本研究的目的是量化合并症和体重指数（BMI）对存活率的影响，并评估这两个变量是否导致非裔美国人存活率降低。
分析了 1981 年至 2002 年在阿拉巴马大学伯明翰分校医院接受首次原发性结肠癌手术的 496 名患者的数据。使用 Cox 比例风险模型获得种族、合并症、BMI 和协变量与全因死亡率之间关联的风险比（HR）和 95%置信区间（CI）。评估了合并症和 BMI 对与非裔美国人种族相关的死亡风险增加的混杂影响，并评估了疾病分期对合并症和 BMI 与死亡率之间关联的效应修饰作用。
与白种人相比，非裔美国人的死亡风险增加（HR，1.34；95%CI，1.06-1.68）。合并症负担最高与全因死亡率增加相关（HR，1.63；95%CI，1.24-2.15）。对于 BMI，体重不足会增加死亡风险（HR，1.54；95%CI，0.96-2.45）；然而，超重/肥胖是保护性的（HR，0.77；95%CI，0.61-0.97）。合并症的影响仅见于早期肿瘤患者，而 BMI 的影响仅限于晚期肿瘤患者。
尽管合并症和 BMI 对结肠癌患者手术后的生存有影响，但这些变量并不是导致非裔美国人存活率降低的因素。
