Baris D, Kwak L W, Rothman N, Wilson W, Manns A, Tarone R E, Hartge P
Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland 20892-7240, USA.
Cancer Epidemiol Biomarkers Prev. 2000 Feb;9(2):193-7.
Several small studies suggest a link between environmental exposure to organochlorine compounds and risk of non Hodgkin's lymphoma (NHL). Because NHL is uncommon, studies of the topic often use a population-based case-control design, in which cases generally are enrolled after treatment has begun. If chemotherapy affects blood levels of organochlorines, exposure will be misclassified and findings distorted. To determine whether chemotherapy alters serum levels of organochlorines in NHL cases, we compared serum samples before and after treatment in 22 cases diagnosed with NHL between March 1994 and August 1995 and enrolled in a clinical trial at the United States National Cancer Institute's Clinical Center. The time difference between pretreatment and posttreatment samples ranged from 15 to 27 months with an average of 20 months. Laboratory analyses were conducted in blinded pretreatment and posttreatment pairs of the subjects. Pretreatment and posttreatment organochlorine serum levels were compared using Pearson correlation coefficient (r) and paired t test. The pretreatment and posttreatment serum levels were highly correlated for 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and polychlorinated biphenyls (PCBs) PCB-138, PCB-153, PCB-156, and total PCBs (ranging from 0.78 to 0.93). Serum levels of all of these organochlorines significantly decreased between initiation and completion of chemotherapy, 25% for total PCB (P = 0.0044), 28% for DDE (P = 0.0014), 25% for PCB-138 (P = 0.0053), 27% for PCB-153 (P = 0.0031), and 29% for PCB-156 (P = 0.045). Neither weight change nor lipid change was correlated with changes in chemical levels. There was no association between the length of time between blood draws and changes in chemical levels. Our data raise the possibility that lymphoma treatment depresses serum organochlorine levels.
几项小型研究表明，环境中接触有机氯化合物与非霍奇金淋巴瘤（NHL）风险之间存在关联。由于NHL并不常见，该主题的研究通常采用基于人群的病例对照设计，其中病例一般在治疗开始后入组。如果化疗影响有机氯的血液水平，暴露情况将被错误分类，研究结果也会被扭曲。为了确定化疗是否会改变NHL病例中有机氯的血清水平，我们比较了1994年3月至1995年8月期间诊断为NHL并在美国国立癌症研究所临床中心参加一项临床试验的22例患者治疗前后的血清样本。治疗前和治疗后样本的时间间隔为15至27个月，平均为20个月。对受试者的治疗前和治疗后样本进行盲法实验室分析。使用Pearson相关系数（r）和配对t检验比较治疗前和治疗后有机氯血清水平。1,1-二氯-2,2-双（对氯苯基）乙烯（DDE）和多氯联苯（PCBs）PCB-138、PCB-153、PCB-156以及总多氯联苯的治疗前和治疗后血清水平高度相关（r值范围为0.78至0.93）。所有这些有机氯的血清水平在化疗开始至结束期间均显著下降，总多氯联苯下降25%（P = 0.0044），DDE下降28%（P = 0.0014），PCB-138下降25%（P = 0.0053），PCB-153下降27%（P = 0.0031），PCB-156下降29%（P = 0.045）。体重变化和脂质变化均与化学物质水平的变化无关。采血时间间隔与化学物质水平变化之间无关联。我们的数据增加了淋巴瘤治疗会降低血清有机氯水平的可能性。
