鼻咽癌治療後患者血液中氧化壓力、微量元素與重金屬之分析

An Analysis of Oxidative Stress, and the Concentration of Trace Elements and Heavy Metals in the Blood of Patients after Radiation Treatment for Nasopharyngeal Carcinoma

目的：本研究主要探討鼻咽癌患者體內氧化壓力、微量元素及重金屬之變化。方法：於2007年8月至2008年2月，收集罹患鼻咽癌接受治療後之患者，以及健康無系統性疾病者，經問診、問卷調查其營養狀態，同意採集血液之鼻咽癌患者及控制組各20人，檢測分析血液中之氧化壓力、微量元素及重金屬。其中氧化壓力以丙二醛（malondialdehyde，MDA)，麩胱甘肽過氧化酶（glutathione peroxidase，GP），麩胱甘肽還原酶（glutathione reductase，GR）及過氧化氫酶（catalase）為指標；微量元素方面測量鋅、銅、硒及鐵；重金屬則為鎘、鉛及汞。結果：本研究收集放射線治療後之鼻咽癌患者20人，平均年齡46.2歲（25~70歲），男性8人，女性12人。健康受試者為控制組20人，平均年齡36.9歲（26~60歲），男性13人，女性7人。在氧化壓力方面，鼻咽癌接受治療後之患者血液中MDA濃度較高；血液中的抗氧化酵素GP、GR及catalase濃度較低。微量元素方面，鼻咽癌接受治療後之患者血液中的鋅濃度較低；銅及銅／鋅比濃度較高。重金屬方面，接受治療的鼻咽癌患者血液中的鎘及汞之濃度較高。結論：本研究顯示，鼻咽癌接受放射線治療後之患者，血液中的氧化壓力較健康者高；微量元素中的鋅較低，且有較高的銅濃度及銅／鋅比；重金屬則有較高濃度的鎘及汞。

Purposes: The aim of this study was to investigate the differences in oxidative stress, trace elements, and heavy metals between patients who had received radiotherapy for nasopharyngeal carcinoma (NPC) and healthy controls. Methods: From August 2007 to February 2008, 20 patients, 8 men and 12 women, with a mean age of 46.2 years (range 25–70) who had received radiotherapy for NPC, and 20 healthy controls, 13 men and 7 women with a mean age of 36.9 years (range 26–60) completed a questionnaire addressing medical history and nutritional status and provided a fasting blood sample. We chose malondialdehyde (MDA), glutathione peroxidase (GP), glutathione reductase (GR), and catalase to represent oxidative stress. We measured trace elements including zinc, copper, selenium, and iron, and heavy metals including cadmium, lead, and mercury in the blood samples. Results: We observed more evidence of oxidative stress in patients who had been treated for NPC; the mean plasma MDA concentration was higher in the NPC group than in the control group. Anti-oxidative enzymes such as GP, GR, and catalase were decreased in the plasma of patients with NPC. Among the trace elements, plasma zinc levels were lower and plasma copper levels and plasma copper/zinc ratios were higher. Among the heavy metals, plasma cadmium and mercury levels were found to be higher in patients with NPC. Conclusions: Patients with NPC who received a complete course of radiation therapy had a greater burden of oxidative stress as well as higher levels of heavy metals including cadmium and mercury in their plasma. With regard to trace elements, they also had decreased plasma zinc levels and increased plasma copper levels and copper/zinc ratios in their blood.