Bach Peter B, Schrag Deborah, Brawley Otis W, Galaznik Aaron, Yakren Sofia, Begg Colin B
Health Outcomes Research Group, Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
JAMA. 2002 Apr 24;287(16):2106-13. doi: 10.1001/jama.287.16.2106.
In recent years a theory that cancer biology is different in blacks and whites has gained prominence in reaction to epidemiologic observations that blacks have poorer survival than whites, even when diagnosed with cancer of similar severity. Yet, few studies have evaluated whether lower-quality treatment and shorter overall life expectancy due to a greater burden of other illnesses may explain the survival discrepancy.
To estimate the magnitude of overall and cancer-specific survival differences between blacks and whites who receive comparable treatment for similar-stage cancer.
We searched MEDLINE for English-language articles published from 1966 to January 2002 that reported on overall survival for black and white patients treated similarly for cancer.
The abstracts or titles for 891 citations were independently examined by 2 authors. The full text was retrieved if the abstract mentioned both black and white patients, made some comment regarding either similarity of treatment received or presented an analysis based on the treatment received, and commented on survival. Studies were included if they included data for at least 10 black and 10 white patients; specified the cohort ascertainment method and what measures were undertaken to minimize loss to follow-up; summarized survival of both blacks and whites using actuarial measures; presented outcomes within stage, adjusted for stage, or based on cohorts with balanced stage distributions; and specified that blacks and whites in the study received similar treatment. We identified 89 unique cohorts in 54 articles that met our inclusion criteria.
Overall survival rates and hazard ratios (HRs) for death for blacks relative to whites were calculated. These were subsequently adjusted for rates of death due to causes other than the cancer under study to determine cancer-specific survival and cancer-specific HRs.
Results represent 189 877 white and 32 004 black patients with 14 different cancers. Compared with whites, blacks had an overall excess risk of death (HR, 1.16; 95% confidence interval [CI], 1.12-1.20). After correction for deaths due to other causes, the cancer-specific HR was 1.07 (95% CI, 1.02-1.13). Of the 14 cancers, blacks were at a significantly higher risk of cancer-specific death only for cancer of the breast, uterus, or bladder.
Only modest cancer-specific survival differences are evident for blacks and whites treated comparably for similar-stage cancer. Therefore, differences in cancer biology between racial groups are unlikely to be responsible for a substantial portion of the survival discrepancy. Differences in treatment, stage at presentation, and mortality from other diseases should represent the primary targets of research and interventions designed to reduce disparities in cancer outcomes.
近年来，一种认为黑人与白人的癌症生物学存在差异的理论因流行病学观察结果而受到关注，该观察结果表明，即使被诊断为严重程度相似的癌症，黑人的生存率也低于白人。然而，很少有研究评估因其他疾病负担较重导致的治疗质量较低和总体预期寿命较短是否可以解释这种生存差异。
估计接受类似治疗的相似分期癌症患者中，黑人和白人在总体生存率和癌症特异性生存率方面的差异程度。
我们在MEDLINE数据库中检索了1966年至2002年1月发表的英文文章，这些文章报告了接受类似癌症治疗的黑人和白人患者的总体生存率。
两位作者独立审查了891篇文献的摘要或标题。如果摘要同时提及黑人和白人患者，对所接受治疗的相似性做出了一些评论，或者基于所接受的治疗进行了分析并对生存率进行了评论，则检索全文。如果研究包括至少10名黑人和10名白人患者的数据；明确了队列确定方法以及为尽量减少失访所采取的措施；使用精算方法总结了黑人和白人的生存率；按分期呈现结果、对分期进行调整或基于分期分布平衡的队列；并明确研究中的黑人和白人接受了类似治疗，则纳入该研究。我们在54篇文章中确定了89个符合我们纳入标准的独特队列。
计算了黑人相对于白人的总体生存率和死亡风险比（HR）。随后对这些数据进行调整，以排除所研究癌症以外的其他原因导致的死亡率，从而确定癌症特异性生存率和癌症特异性HR。
结果代表了189877名白人患者和32004名黑人患者，涉及14种不同的癌症。与白人相比，黑人的总体死亡风险更高（HR为1.16；95%置信区间[CI]为1.12 - 1.20）。在纠正其他原因导致的死亡后，癌症特异性HR为1.07（95%CI为1.02 - 1.13）。在这14种癌症中，仅乳腺癌、子宫癌或膀胱癌患者中，黑人的癌症特异性死亡风险显著更高。
对于接受类似治疗的相似分期癌症患者，黑人和白人之间仅存在适度的癌症特异性生存差异。因此，种族群体之间癌症生物学的差异不太可能是导致大部分生存差异的原因。治疗差异、就诊时的分期以及其他疾病导致的死亡率应成为旨在减少癌症治疗结果差异的研究和干预的主要目标。
