McCollum A David, Catalano Paul J, Haller Daniel G, Mayer Robert J, Macdonald John S, Benson Al B, Fuchs Charles S
A. D. McCollum, R. J. Mayer, C. S. Fuchs, Dana-Farber Cancer Institute, Boston, MA, USA.
J Natl Cancer Inst. 2002 Aug 7;94(15):1160-7. doi: 10.1093/jnci/94.15.1160.
Previous studies have demonstrated that African-Americans with colon cancer have worse overall and stage-specific survival rates than Caucasians. Such differences could reflect variation in access to health care, in tumor biology, or in treatment efficacy. Little is known about potential differences in chemotherapy-related toxicities between African-Americans and Caucasians. In this study, we examined survival and toxic effects among African-American and Caucasian patients enrolled in a large, randomized phase III trial of adjuvant chemotherapy for resected colon cancer.
We analyzed data on 3380 patients (344 African-Americans and 3036 Caucasians) enrolled in a randomized trial of adjuvant 5-fluorouracil-based chemotherapy in patients with stage II (high risk) and stage III colon cancer to evaluate differences in outcomes and toxicity. We compared disease-free survival (DFS) and overall survival (OS) between African-Americans and Caucasians by the Kaplan-Meier method, computed Cox proportional hazards by multivariable analysis, and compared treatment-related toxicity rates by Fisher's exact test. All statistical tests were two-sided.
We found no differences in DFS or OS between African-American and Caucasian patients. Five-year DFS was 57% (95% confidence interval [CI] = 52% to 62%) for African-Americans and 58% (95% CI = 56% to 60%) for Caucasians (P =.15), and 5-year OS was 65% (95% CI = 60% to 70%) for African-Americans and 66% (95% CI = 64% to 68%) for Caucasians (P =.38). On multivariable analysis, no statistically significant difference in disease recurrence or death was detected between the racial/ethnic groups (hazard ratios for African-Americans versus Caucasians: disease recurrence = 1.1, 95% CI = 0.9 to 1.3; death = 1.1, 95% CI = 0.9 to 1.3). Treatment-related toxicity differed between the African-American and Caucasian patients, with African-Americans experiencing statistically significantly lower rates of diarrhea (P<.001), nausea (P<.001), vomiting (P =.01), stomatitis (P<.001), and overall toxicity (P =.005).
In this study of patients with similar access to health care resources and treatment with adjuvant chemotherapy, we found similar 5-year DFS and OS in African-Americans and Caucasians with stage II and III colon cancer. The two groups derived similar benefits from adjuvant chemotherapy. Moreover, African-Americans appeared to experience less treatment-related toxicity.
既往研究表明，患有结肠癌的非裔美国人总体生存率和特定分期生存率均低于白种人。这种差异可能反映在医疗保健可及性、肿瘤生物学或治疗效果方面的差异。对于非裔美国人和白种人在化疗相关毒性方面的潜在差异知之甚少。在本研究中，我们调查了参与一项大型随机III期辅助化疗治疗结肠癌试验的非裔美国人和白种人患者的生存情况和毒性反应。
我们分析了3380例患者（344例非裔美国人，3036例白种人）的数据，这些患者参与了一项针对II期（高危）和III期结肠癌患者的基于5-氟尿嘧啶的辅助化疗随机试验，以评估结局和毒性方面的差异。我们采用Kaplan-Meier方法比较非裔美国人和白种人的无病生存期（DFS）和总生存期（OS），通过多变量分析计算Cox比例风险，并用Fisher精确检验比较治疗相关毒性发生率。所有统计检验均为双侧检验。
我们发现非裔美国人和白种人患者在DFS或OS方面无差异。非裔美国人的5年DFS为57%（95%置信区间[CI]=52%至62%），白种人为58%（95%CI=56%至60%）（P=0.15）；非裔美国人的5年OS为65%（95%CI=60%至70%），白种人为66%（95%CI=64%至68%）（P=0.38）。在多变量分析中，种族/族裔组之间在疾病复发或死亡方面未检测到统计学显著差异（非裔美国人与白种人的风险比：疾病复发=1.1，95%CI=0.9至1.3；死亡=1.1，95%CI=0.9至1.3）。非裔美国人和白种人患者在治疗相关毒性方面存在差异，非裔美国人腹泻（P<0.001）、恶心（P<0.001）、呕吐（P=0.01）、口腔炎（P<0.001）和总体毒性（P=0.005）的发生率在统计学上显著较低。
在这项针对医疗保健资源可及性相似且接受辅助化疗的患者的研究中，我们发现II期和III期结肠癌的非裔美国人和白种人5年DFS和OS相似。两组从辅助化疗中获得的益处相似。此外，非裔美国人似乎经历的治疗相关毒性较少。
