Brown B W, Brauner C, Minnotte M C
Department of Biomathematics, University of Texas M. D. Anderson Cancer Center, Houston 77030.
J Natl Cancer Inst. 1993 Jun 16;85(12):979-87. doi: 10.1093/jnci/85.12.979.
The cancer-specific death rate is a commonly used indicator in the assessment of progress against cancer. However, since the cause of death is often not substantiated and complete medical information is lacking, the validity of cancer-specific mortality rates is being questioned.
We investigated the validity of the cancer-specific death rate by examining noncancer deaths of cancer patients in a large patient population.
Data were obtained from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program on cancer patients diagnosed between 1973 and 1987, with follow-up complete through December 1987. The SEER database consists of 1.2 million records from nine population-based registries covering nine geographic regions of the United States. Rates of noncancer deaths in the U.S. population were obtained from the National Center for Health Statistics. Cancer mortality rates were subtracted from overall mortality rates to obtain noncancer death rates by sex and the 5-year age group for each calendar year. Excluded from the study were patients of races other than White and those diagnosed at age 85 years or more due to absence of noncancer death rate comparisons. Also excluded were cancer cases discovered at autopsy and in persons less than 20 years of age. The statistical analysis employed a log-linear model.
The ratio of patient-to-general-population noncancer death rates, as calculated by dividing the number of patient noncancer deaths per year by the number found in the matched U.S. population data and referred to as the noncancer relative hazard, is considered significant with values greater than 1 for those with all cancers combined and for the common solid tumors examined. Of the 12 leading causes of death other than cancer in the patient population, the most common causes were circulatory and respiratory failures. The noncancer relative risk of death decreased rapidly after diagnosis and also decreased with the patient's age at diagnosis. It increased slightly with the calendar year of diagnosis.
Because more noncancer deaths occurred shortly after diagnosis, it appears that this excess was caused by treatment of the cancer. Generally, cancer-specific death rates underestimate the mortality associated with a diagnosis of cancer. Therefore, because the degree of underestimation changes with time, an examination solely of cancer-caused mortality in assessing progress against the disease is incomplete.
癌症特异性死亡率是评估抗癌进展常用的指标。然而，由于死亡原因往往未经证实且缺乏完整的医疗信息，癌症特异性死亡率的有效性受到质疑。
我们通过检查大量患者群体中癌症患者的非癌症死亡情况来研究癌症特异性死亡率的有效性。
数据取自美国国家癌症研究所的监测、流行病学和最终结果（SEER）项目，涉及1973年至1987年期间确诊的癌症患者，随访至1987年12月结束。SEER数据库包含来自九个基于人群的登记处的120万条记录，覆盖美国九个地理区域。美国人群的非癌症死亡率数据来自美国国家卫生统计中心。从总体死亡率中减去癌症死亡率，以获得各历年按性别和5岁年龄组划分的非癌症死亡率。本研究排除了非白人种族的患者以及85岁及以上确诊的患者，因为缺乏非癌症死亡率比较数据。尸检发现的癌症病例以及20岁以下人群中的癌症病例也被排除。统计分析采用对数线性模型。
通过将每年患者非癌症死亡人数除以匹配的美国人群数据中的死亡人数计算得出的患者与总体人群非癌症死亡率之比，称为非癌症相对风险，对于所有癌症合并病例以及所检查的常见实体瘤病例，该值大于1时被认为具有显著性。在患者群体中，除癌症外的12种主要死亡原因中，最常见的是循环系统和呼吸衰竭。诊断后非癌症死亡相对风险迅速下降，并且也随着患者诊断时的年龄而降低。它随诊断年份略有增加。
由于更多的非癌症死亡发生在诊断后不久，似乎这种超额死亡是由癌症治疗引起的。一般来说，癌症特异性死亡率低估了与癌症诊断相关的死亡率。因此，由于低估程度随时间变化，仅检查癌症导致的死亡率来评估抗癌进展是不完整的。
