| Summary: | 碩士 === 國立臺灣大學 === 職業醫學與工業衛生研究所 === 99 === Several epidemiological studies reported the association between trace metals exposure and cancers. In Taiwan, a significant dose-response relationship between arsenic exposure and urothelial cell carcinoma was also demonstrated. Besides, animal studies showd tumor growth in animals exposed to arsenic, cadmium, lead and nickel. However, the roles of trace metals in the development of kidney cancer are unclear. The purpose of this study was to characterize the distribution of trace metals in urine and in renal cortex, pelvis, and ureter of the study subjects to further explore the relationship between trace metals and kidney cancer. In this study, 41 urothelial cell carcinoma (UCC) cases, 11 renal cell carcinoma (RCC) cases, and 8 controls were obtained from the Urological Department of the National Taiwan University Hospital. All UCC and RCC subjects were histologically diagnosed and classified according to the TNM classification system. Questionnaire was admintered to collect individual’s information, such as age, body height, weight, smoking history, occupation, alcohol drinking, dietary habit, herbal medicine uses, and familial disease history. Normal and tumor tissue samples of renal cortex, renal pelvis, and ureter were decomposed by using a microwave-assisted method in closed vessels. The inductively coupled plasma mass spectrometry was used to determine the contents of trace metals in normal and tumor renal tissue. Urine sample was first filtered through a 0.45-μm membrane prior to being analysed by ICP-MS. In this study no significant difference was found in urinary metal levels of kidney cancer cases among different stages. With respect to trace metals in renal tissues, the concentrations of cadmium in normal tissues were significantly higher than in tumor tissues of both renal cortex and pelvis, respectively, whereas the concentrations of arsenic and strontium in normal tissues were significantly higher than in tumor tissue only in renal cortex. For ureter, the concentrations of arsenic and cadmium in tumor tissue were significantly higher than in normal tissue, while those of manganese and copper in tumor tissue were also higher, though not statisticaly significantly, than in normal tissue. In summary, the concentrations of various trace metals in tumor and normal tissues differed in cortex, pelvis, or ureter, which might be caused by the fast proliferation of tumor cell or the over-expression of metallothionein in tumor cell. However, the real mechanism is still warrants further studies.
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