- Email: [email protected]
Trace Elements Distribution in Renal Cell Carcinoma Depending on Stage of Disease
European Urology
European Urology 42 (2002) 475±480
Trace Elements Distribution in Renal Cell Carcinoma Depending on Stage of Disease Zygmunt Dobrowolskia,*, Tomasz Drewniaka, Wojciech Kwiatekb, Piotr Jakubikb a
Department of Urology, Collegium Medicum Jagiellonian University, 18 Grzegorzecka, 31-531 Krakow, Poland Institute of Nuclear Physics, Krakow, Poland
b
Accepted 27 August 2002
Abstract Objectives: The aim of this study was to identify those trace elements which can be used to distinguish between normal and malignant tissue in renal cell cancer (RCC) kidney and to assess changes in trace elements concentration in tissue with progressing malignant disease. Methods: In case control study, 36 cases of RCC were analyzed by Synchrotron Radiation Induced X-ray Emission (SRIXE) in order to establish the concentration of 19 elements. Patients with RCC were examined to obtain staging of disease after radical nephrectomy, which was performed in each case. Results were compared with 15 control kidney cortex tissue obtained during autopsy in which cause of death was trauma. Results: The most relevant decrease was detected in Cd content: from 81 39.2 ppm in normal control samples to 16.6 22.2 ppm concentration in RCC. We found that the concentrations of Ti, Pb and Rb were also lower in RCC tissue. On the other hand, the RCC tissue was rich in iron and zirconium. With the progress of malignant disease, assessed by TNM (UICC 1997) scale, lower concentration of S and higher concentration of Ca in both RCC and neoplastic kidney cortex can be seen. The same tendency is observed in Zn and Se concentrations. Cadmium shows raising concentration with progress of RCC only in cortex of neoplastic kidney. In all cases it was shown that the relatively high tissue concentration of iron in both investigated tissues is decreasing with the progress of disease. The zirconium has shown raising tissue concentration in advanced disease. Conclusion: Trace elements concentration is different in malignant tissue and surrounding macroscopically unchanged kidney cortex. Progress of the disease is connected with changes in trace elements concentration. This may re¯ect different biology of compared tissue with potential practical implication. # 2002 Published by Elsevier Science B.V. Keywords: Renal cell carcinoma (RCC); Trace elements; Carcinogenesis 1. Introduction Metals are an important and emerging class of carcinogen [3]. Many metals are potent carcinogen in laboratory animals [13]. A few are potent carcinogen and several are suspected human carcinogen [4]. Metals are ubiquitous in both natural environment and work place. Beyond this, metals are typically persistent within the natural and man-made environment with growing concentration in biosphere [11]. Often metallic carcinogens are highly tissue speci®c and are often related to high *
Corresponding author. Tel. 48-12-424-7950; Fax: 48-12-422-9244. E-mail address: [email protected] (Z. Dobrowolski).
concentration at the target organ. It is thought that nonessential metals, including the carcinogenic metals, often follow the metabolic pathway of similar essential metals and frequently disrupts their metabolisms and function [16]. It is growing awareness of renal cell cancer (RCC). In United States of America, death rates from RCC have increased during the last 30 years by 35% in men, and by 20% in women [2]. There is considerable variation of both incidence and mortality in different countries. The highest rates of both have been found in developed country [4,11]. Information of trace elements as risk factor for RCC is limited, but suggesting that cadmium could play a major role in the development of RCC [1,17]. The aim of this study was
0302-2838/02/$ ± see front matter # 2002 Published by Elsevier Science B.V. PII: S 0 3 0 2 - 2 8 3 8 ( 0 2 ) 0 0 4 0 0 - 1
476
Z. Dobrowolski et al. / European Urology 42 (2002) 475±480
to identify those trace elements which can be used to distinguish between normal and malignant tissue in RCC kidney and to assess changes in trace elements tissue concentration with progressing malignant disease. Trace elements were divided to group according to carcinogenicity evaluations made by the International Agency for Research on Cancer [3]. 2. Materials and methods We examined 36 patients with RCC and 15 controls from selected autopsies. All the patients underwent radical nephrectomy. The vessel bed of removed RCC kidney was infused with 5% glucose for 10 min to obtain blood free tissue samples. Tissue samples of renal tumor and kidney cortex from the part, which was not involved in neoplastic process, were obtained during surgery. Tissue samples of the RCC were taken from the peripheral zone of tumor (below the pseudocapsule). The kidney samples were taken cortically, because RCC originated from proximal tubuli cells. Slide was always obtained from every sample for routine histology assessment. These procedure allow us the comparison of cell reach, well blood perfused and necrotic free tissue samples. Part of the mass was ®xed in 10% buffered formalin for routine histology assessment. The tissue samples for trace elements assessment were stored in liquid nitrogen. Two independent pathologists reviewed pathological assessments. RCC patients were classi®ed according to TNM scale [7]. Controls (kidney cortex tissue) were obtained from selected autopsies in which cause of death was trauma. 2.1. Clinical data The average age of study group was 60.3 years with standard deviation 9.2 and 37.8 years with standard deviation 10.1 in control group. All patients were living in city and were comparably exposed to the industrial hazards of heavy metals in their living and working environment. The dimensions of tumors varied from 2 to 14 cm with median dimension of 6.8 cm. Staging and presence of distant metastasis according to UICC 1997 are shown in Table 1. The non-parametric statistical analysis was used (KruskalWallis, Friedman and McNemar statistical test). 2.2. Target preparation and measurements Tissue samples were dried, mortar and prepared as pellet of 10 mm in diameter and 1 mm thick for Synchrotron Radiation Induced X-ray Emission (SRIXE) bulk analysis. The elemental analyses by means of SRIXE allow us to determine trace element concentrations with high accuracy and also to use the same samples for several measurements. The SRIXE method is designed for elemental composition analysis. In this Table 1 Tumor, metastasis and grading assessment among group of patients with RCC T in TNM scale
No. of patients
Distant metastasis
No. of patients
T2 T3a T3b T4
9 11 7 9
M0 M1
26 10
method characteristic X-ray emission is measured, but the X-rays are induced by synchrotron radiation. All spectra were detected with a Si (Li) detector of 140 eV energy resolution for 180 s. Since the beam size was 100 mm2 each sample was irradiated with ``white'' photon beam at least three different points to check its homogeneity [15]. As a standard reference material for trace element analysis the IAEA standard (H-8 horse kidney) was used. The standard samples were prepared in the same way for analysis as the kidney samples [10]. Of course, due to high accuracy, there was a high risk of pollution, consequently great attention was needed during the preparation of tissues, the cleansing of supplies. All reagents were chemically pure and metal free [8]. All tissue trace elements concentration measurements presented in this paper were performed by Dr. Wojciech Kwiatek in Brookhaven National Laboratory, Long Island, Upton, New York, USA.
3. Results 3.1. Results of X-ray ¯uorescence analysis Quantitative determination was performed on 90 elements. The values were expressed in parts per million (ppm) referring to the lyophilized weight. From above data, a decrease in metal carcinogenÐCd and Zn and Se concentrationÐknown as carcinoma prevention trace elements, in RCC was evident. The most relevant decrease was detected in Cd content: from 81 39.2 ppm in normal control samples to 16.6 22.2 ppm concentration in RCC. We found that concentrations of Ti, Pb and Rb were also lower in RCC tissue. Ti and Rb are not involved in known metabolic process. On the other hand the RCC tissue was rich in iron and zirconium. The relative comparison of tissue from RCC changed kidney-tumor tissue and unchanged cortex, bring interesting results. We can observe higher concentration of iron and low concentration of Cu malignant tissue. All other trace elements have signi®cant lower concentration in RCC. Mean pro®le of elements in RCC tissue (RCC) compared to healthy kidney cortex (control) and mean pro®le of elements in cortex of neoplastic kidney compared to healthy kidney cortex are shown in Figs. 1 and 2 and Table 2. With the progress of malignant disease, described by T and M (according to TNM scaleÐUICC 1997), lower concentration of S and higher concentration of Ca in both RCC and neoplastic kidney cortex can be seen. The same growing concentration is observed in Zn and Se. Cadmium (carcinogen) only shows higher concentration with progress of RCC, especially in kidney cortex. In all cases was shown that relative high tissue concentration of iron in both investigated tissues is decreasing with the disease progress. In the group of metals with unknown role in carcinogenesis, the zirconium has shown raising tissue concentration in advanced disease.
477
Fig. 2. Mean pro®le of elements in cortex of neoplastic kidney compared to healthy kidney cortex (control).
Z. Dobrowolski et al. / European Urology 42 (2002) 475±480
Fig. 1. Mean pro®le of elements in RCC tissue (RCC) compared to healthy kidney cortex (control).
478
Z. Dobrowolski et al. / European Urology 42 (2002) 475±480
Table 2 Comparison of trace elements concentration in RCC and cortex of malignant kidney with control group (healthy kidney cortex) Trace elements
Groups
No. of patients
RCC vs. healthy kidney cortex
Cortex of neoplastic kidney vs. healthy kidney cortex
Arithmetic average
Arithmetic average
Statistical assessment
Statistical assessment
S
Study Control
36 15
520.5 371.1
NS
632.8 371.1
*
Cl
Study Control
36 15
255.1 457.3
***
385.4 457.3
NS
K
Study Control
36 15
3591.9 5736.4
***
3865.6 5736.4
***
Ca
Study Control
36 15
828.1 861.5
NS
722.4 861.5
NS
Ti
Study Control
36 15
3.6 7.1
**
7.6 7.1
NS
V
Study Control
36 15
0.9 0.5
NS
3.4 0.5
***
Cr
Study Control
36 15
0.9 0.47
NS
2.4 0.47
***
Mn
Study Control
36 15
2.3 3.9
***
3.4 3.9
NS
Fe
Study Control
36 15
446.7 221.9
220.1 221.9
NS
Ni
Study Control
36 15
0.7 0.5
NS
1.8 0.5
Cu
Study Control
36 15
12.9 11.5
NS
24.5 11.5
NS
Zn
Study Control
36 15
73.1 184.8
***
205.4 184.8
NS
Pb
Study Control
36 15
1.0 1.5
*
2.1 1.5
NS
Se
Study Control
36 15
2.7 6.1
***
5.3 6.1
NS
Br
Study Control
36 15
29.5 47.6
***
39.2 47.6
NS
Rb
Study Control
36 15
17.7 24.3
***
25.5 24.3
NS
Sr
Study Control
36 15
8.1 1.7
***
10.6 1.7
***
Zr
Study Control
36 15
24.9 2.8
***
54.3 2.8
***
Cd
Study Control
36 15
16.5 81.7
***
211.0 81.7
***
**
*
NS: not signi®cant statistical difference. * p 0:05. ** p 0:01. *** p 0:001.
Comparison of changes in concentration of trace elements in RCC tissue depending on the tumor stage and presence of distant metastasis are shown in Figs. 3 and 4.
To rule out that trace elements concentration may change with age, the entire data were correlated with age of the patients. In Tau-Kendall analyses, we do not found any correlation (Table 2).
Z. Dobrowolski et al. / European Urology 42 (2002) 475±480
Fig. 3. Concentration of elements depending on the tumor stage.
Fig. 4. Concentration of elements depending on presence of distant metastasis.
479
480
Z. Dobrowolski et al. / European Urology 42 (2002) 475±480
4. Discussion Several authors performed trace elements analysis by EDXRF, PIXE or ASS to test each technique for routine analysis of biological samples [15]. SRIXE is suf®cient also to measure elements concentration at parts per million with S.D. <10%. SRIXE provides rapidly multielemental information, in single measurements, without destroying the sample. High concentration of Fe and signi®cantly lower concentration of metal carcinogen (Cd), potential for human carcinogen and elements with preventing function against cancer (Se and Zn) has been observed also by Fassina et al. [5]. Lower concentration of cadmium in RCC tissue has been con®rmed by several authors [1,6,12]. It was concluded that serum iron level might be used as a useful tumor marker in staging and follow-up of RCC [19]. Other data suggest that indirectly ferritin may be also useful serum marker for monitoring patients with RCC, when source of ferritin is tumor itself [9,14]. Several authors reported iron induced renal carcinogenesis model in animals [13,18]. Our data con®rmed higher concentration of Fe in RCC tissue which acts as natural stimulus for ferritin production in neoplastic kidney, especially in organ con®ned disease. In unchanged cortex of neoplastic kidney, we observe higher concentrations than in RCC of Cd [1,6,12], Ni and Cr which belong to group of carcinogen for humans and Pb, Ti and V which are carcinogen in animals model [3]. A possible explanation could be
that tumor growth excluded the neoplastic tissue from glomerular ®ltrate and metal intake becomes impossible in the mass. Our ®ndings show that Zn and Se are strongly decreased in the neoplastic mass, while Fe is increased in RCC with strong correlation in statistic analyses. Changes in Zn and Se concentrations in malignant disease are known from research on other cancers [3]. We have also seen raising concentrations of Zn and Se with progress of malignant disease. Same observation was made by Hardell et al. [6]. Our data con®rmed changes in trace elements concentration depending on stage of disease. These data are not suf®cient per se to draw conclusions and we believe that it will be of interest to further investigation. Several issues remain to be investigated: whether we can ®nd metal carcinogen concentration in kidney cortex when chance of carcinogenesis is signi®cantly higher and to monitor body elements stores and risk of cancer with indirect methods (blood or urine concentration of metals), whether we can change iron metabolisms in malignant tissue as new supporting methods in RCC treatment. Acknowledgements The authors wish to thank Dr. Sasa Bajt and Patt Nuessle for their help in data taking at the X26A beam line of the National Synchrotron Light Source at Brookhaven National Laboratory, Long Island.
References [1] Ala Opas M, Tahvonen R. Concentrations of cadmium and lead in renal cell cancer. J Trace Elem Med Biol 1995;9(3):176±80. [2] American Cancer Society: Cancer facts and ®gures. Atlanta (GA): American Cancer Society, 1993. [3] Boffetta P. Carcinogenicity of trace elements with reference to evaluations made by the International Agency for Research on Cancer. Scand J Work Environ Health 1993;19:67±70. [4] Delahunt B, Bethwaite Nacey JN. Occupational risk for renal cell carcinoma. Br J Urol 1997;75:578±82. [5] Fassina AS, Calliari I, Sangiorgio A, Rossato M, et al. Quantitative analysis of trace elements in human clear cell carcinoma of the kidney by energy-dispersive X-ray ¯uorescence. Eur Urol 1990;18(2):140±4. [6] Hardell L, Wing AM, Ljungberg B, Dreifaldt AC, et al. Levels of cadmium, zinc and copper in renal cell carcinoma and normal kidney. Eur J Cancer Prev 1994;3(1):45±8. [7] HusiatynÂski W. TNM classi®cation 1997. Przegl Urol 2000;2:50. [8] Iyengar GV, Sansoni B. Sample preparation of biological materials for Trace element analysis. IAEA Technical Report 197. Vienna: IAEA, 1980, p. 73. [9] Kirkali Z, Esen AA, Kirkali G, Guner G. Ferritin: a tumor marker expressed by renal cell carcinoma. Eur Urol 1995;28(2):131±4. [10] Kwiatek WM. Bio-medical application of synchrotron radiation X-ray ¯uorescence. Acta Phisica Polonica 1994;86:695±703.
[11] Mandel JS, McLaughlin JK, Schlehofer B, Mellemgaard A. International renal-cell cancer study IV. Occupat Int J Cancer 1995;61(5):601±5. [12] Muller I, Helmers E, Barchet R, Schweinsberg F. Cadmium concentration in the renal cortex of kidney tumor patients and controls. J Trace Elem Electrolytes Health Dis 1994;8(3/4):173±6. [13] Nogueira E, Cardesa A, Mohr U. Experimental models of kidney tumors. J Cancer Res Clin Oncol 1993;119(4):190±8. [14] Partin AW, Criley SR, Steiner MS, Hsieh K, et al. Serum ferritin as a clinical marker for renal cell carcinoma: in¯uence of tumor volume. Urology 1995;45(2):211±7. [15] Rindby A. Microbeam technique for energy dispersive X-ray ¯uorescence. X-ray Spectrom 1989;18:109. [16] Rose J, editor. Trace Elements in Health, Butterworth Co. Ltd., London, 1983. [17] Staessen A, Lauwerys W, Robert R. Renal function and historical environmental cadmium pollution from zinc smelters. Lancet 1994; 343(8912):1523±7. [18] Toyokuni S, Mori T, Dizdaroglu M. DNA base modi®cation in renal chromatin of wistar rats treated with a renal carcinogen, ferric nitriltriacetate. Int J Cancer 1994;57:123±8. [19] Yu CC, Chen KK, Chen MT, Huang JK, et al. Serum iron as a tumor marker in renal cell carcinoma.. Eur Urol 1991;19(1):54±8.
European Urology 42 (2002) 475±480
Trace Elements Distribution in Renal Cell Carcinoma Depending on Stage of Disease Zygmunt Dobrowolskia,*, Tomasz Drewniaka, Wojciech Kwiatekb, Piotr Jakubikb a
Department of Urology, Collegium Medicum Jagiellonian University, 18 Grzegorzecka, 31-531 Krakow, Poland Institute of Nuclear Physics, Krakow, Poland
b
Accepted 27 August 2002
Abstract Objectives: The aim of this study was to identify those trace elements which can be used to distinguish between normal and malignant tissue in renal cell cancer (RCC) kidney and to assess changes in trace elements concentration in tissue with progressing malignant disease. Methods: In case control study, 36 cases of RCC were analyzed by Synchrotron Radiation Induced X-ray Emission (SRIXE) in order to establish the concentration of 19 elements. Patients with RCC were examined to obtain staging of disease after radical nephrectomy, which was performed in each case. Results were compared with 15 control kidney cortex tissue obtained during autopsy in which cause of death was trauma. Results: The most relevant decrease was detected in Cd content: from 81 39.2 ppm in normal control samples to 16.6 22.2 ppm concentration in RCC. We found that the concentrations of Ti, Pb and Rb were also lower in RCC tissue. On the other hand, the RCC tissue was rich in iron and zirconium. With the progress of malignant disease, assessed by TNM (UICC 1997) scale, lower concentration of S and higher concentration of Ca in both RCC and neoplastic kidney cortex can be seen. The same tendency is observed in Zn and Se concentrations. Cadmium shows raising concentration with progress of RCC only in cortex of neoplastic kidney. In all cases it was shown that the relatively high tissue concentration of iron in both investigated tissues is decreasing with the progress of disease. The zirconium has shown raising tissue concentration in advanced disease. Conclusion: Trace elements concentration is different in malignant tissue and surrounding macroscopically unchanged kidney cortex. Progress of the disease is connected with changes in trace elements concentration. This may re¯ect different biology of compared tissue with potential practical implication. # 2002 Published by Elsevier Science B.V. Keywords: Renal cell carcinoma (RCC); Trace elements; Carcinogenesis 1. Introduction Metals are an important and emerging class of carcinogen [3]. Many metals are potent carcinogen in laboratory animals [13]. A few are potent carcinogen and several are suspected human carcinogen [4]. Metals are ubiquitous in both natural environment and work place. Beyond this, metals are typically persistent within the natural and man-made environment with growing concentration in biosphere [11]. Often metallic carcinogens are highly tissue speci®c and are often related to high *
Corresponding author. Tel. 48-12-424-7950; Fax: 48-12-422-9244. E-mail address: [email protected] (Z. Dobrowolski).
concentration at the target organ. It is thought that nonessential metals, including the carcinogenic metals, often follow the metabolic pathway of similar essential metals and frequently disrupts their metabolisms and function [16]. It is growing awareness of renal cell cancer (RCC). In United States of America, death rates from RCC have increased during the last 30 years by 35% in men, and by 20% in women [2]. There is considerable variation of both incidence and mortality in different countries. The highest rates of both have been found in developed country [4,11]. Information of trace elements as risk factor for RCC is limited, but suggesting that cadmium could play a major role in the development of RCC [1,17]. The aim of this study was
0302-2838/02/$ ± see front matter # 2002 Published by Elsevier Science B.V. PII: S 0 3 0 2 - 2 8 3 8 ( 0 2 ) 0 0 4 0 0 - 1
476
Z. Dobrowolski et al. / European Urology 42 (2002) 475±480
to identify those trace elements which can be used to distinguish between normal and malignant tissue in RCC kidney and to assess changes in trace elements tissue concentration with progressing malignant disease. Trace elements were divided to group according to carcinogenicity evaluations made by the International Agency for Research on Cancer [3]. 2. Materials and methods We examined 36 patients with RCC and 15 controls from selected autopsies. All the patients underwent radical nephrectomy. The vessel bed of removed RCC kidney was infused with 5% glucose for 10 min to obtain blood free tissue samples. Tissue samples of renal tumor and kidney cortex from the part, which was not involved in neoplastic process, were obtained during surgery. Tissue samples of the RCC were taken from the peripheral zone of tumor (below the pseudocapsule). The kidney samples were taken cortically, because RCC originated from proximal tubuli cells. Slide was always obtained from every sample for routine histology assessment. These procedure allow us the comparison of cell reach, well blood perfused and necrotic free tissue samples. Part of the mass was ®xed in 10% buffered formalin for routine histology assessment. The tissue samples for trace elements assessment were stored in liquid nitrogen. Two independent pathologists reviewed pathological assessments. RCC patients were classi®ed according to TNM scale [7]. Controls (kidney cortex tissue) were obtained from selected autopsies in which cause of death was trauma. 2.1. Clinical data The average age of study group was 60.3 years with standard deviation 9.2 and 37.8 years with standard deviation 10.1 in control group. All patients were living in city and were comparably exposed to the industrial hazards of heavy metals in their living and working environment. The dimensions of tumors varied from 2 to 14 cm with median dimension of 6.8 cm. Staging and presence of distant metastasis according to UICC 1997 are shown in Table 1. The non-parametric statistical analysis was used (KruskalWallis, Friedman and McNemar statistical test). 2.2. Target preparation and measurements Tissue samples were dried, mortar and prepared as pellet of 10 mm in diameter and 1 mm thick for Synchrotron Radiation Induced X-ray Emission (SRIXE) bulk analysis. The elemental analyses by means of SRIXE allow us to determine trace element concentrations with high accuracy and also to use the same samples for several measurements. The SRIXE method is designed for elemental composition analysis. In this Table 1 Tumor, metastasis and grading assessment among group of patients with RCC T in TNM scale
No. of patients
Distant metastasis
No. of patients
T2 T3a T3b T4
9 11 7 9
M0 M1
26 10
method characteristic X-ray emission is measured, but the X-rays are induced by synchrotron radiation. All spectra were detected with a Si (Li) detector of 140 eV energy resolution for 180 s. Since the beam size was 100 mm2 each sample was irradiated with ``white'' photon beam at least three different points to check its homogeneity [15]. As a standard reference material for trace element analysis the IAEA standard (H-8 horse kidney) was used. The standard samples were prepared in the same way for analysis as the kidney samples [10]. Of course, due to high accuracy, there was a high risk of pollution, consequently great attention was needed during the preparation of tissues, the cleansing of supplies. All reagents were chemically pure and metal free [8]. All tissue trace elements concentration measurements presented in this paper were performed by Dr. Wojciech Kwiatek in Brookhaven National Laboratory, Long Island, Upton, New York, USA.
3. Results 3.1. Results of X-ray ¯uorescence analysis Quantitative determination was performed on 90 elements. The values were expressed in parts per million (ppm) referring to the lyophilized weight. From above data, a decrease in metal carcinogenÐCd and Zn and Se concentrationÐknown as carcinoma prevention trace elements, in RCC was evident. The most relevant decrease was detected in Cd content: from 81 39.2 ppm in normal control samples to 16.6 22.2 ppm concentration in RCC. We found that concentrations of Ti, Pb and Rb were also lower in RCC tissue. Ti and Rb are not involved in known metabolic process. On the other hand the RCC tissue was rich in iron and zirconium. The relative comparison of tissue from RCC changed kidney-tumor tissue and unchanged cortex, bring interesting results. We can observe higher concentration of iron and low concentration of Cu malignant tissue. All other trace elements have signi®cant lower concentration in RCC. Mean pro®le of elements in RCC tissue (RCC) compared to healthy kidney cortex (control) and mean pro®le of elements in cortex of neoplastic kidney compared to healthy kidney cortex are shown in Figs. 1 and 2 and Table 2. With the progress of malignant disease, described by T and M (according to TNM scaleÐUICC 1997), lower concentration of S and higher concentration of Ca in both RCC and neoplastic kidney cortex can be seen. The same growing concentration is observed in Zn and Se. Cadmium (carcinogen) only shows higher concentration with progress of RCC, especially in kidney cortex. In all cases was shown that relative high tissue concentration of iron in both investigated tissues is decreasing with the disease progress. In the group of metals with unknown role in carcinogenesis, the zirconium has shown raising tissue concentration in advanced disease.
477
Fig. 2. Mean pro®le of elements in cortex of neoplastic kidney compared to healthy kidney cortex (control).
Z. Dobrowolski et al. / European Urology 42 (2002) 475±480
Fig. 1. Mean pro®le of elements in RCC tissue (RCC) compared to healthy kidney cortex (control).
478
Z. Dobrowolski et al. / European Urology 42 (2002) 475±480
Table 2 Comparison of trace elements concentration in RCC and cortex of malignant kidney with control group (healthy kidney cortex) Trace elements
Groups
No. of patients
RCC vs. healthy kidney cortex
Cortex of neoplastic kidney vs. healthy kidney cortex
Arithmetic average
Arithmetic average
Statistical assessment
Statistical assessment
S
Study Control
36 15
520.5 371.1
NS
632.8 371.1
*
Cl
Study Control
36 15
255.1 457.3
***
385.4 457.3
NS
K
Study Control
36 15
3591.9 5736.4
***
3865.6 5736.4
***
Ca
Study Control
36 15
828.1 861.5
NS
722.4 861.5
NS
Ti
Study Control
36 15
3.6 7.1
**
7.6 7.1
NS
V
Study Control
36 15
0.9 0.5
NS
3.4 0.5
***
Cr
Study Control
36 15
0.9 0.47
NS
2.4 0.47
***
Mn
Study Control
36 15
2.3 3.9
***
3.4 3.9
NS
Fe
Study Control
36 15
446.7 221.9
220.1 221.9
NS
Ni
Study Control
36 15
0.7 0.5
NS
1.8 0.5
Cu
Study Control
36 15
12.9 11.5
NS
24.5 11.5
NS
Zn
Study Control
36 15
73.1 184.8
***
205.4 184.8
NS
Pb
Study Control
36 15
1.0 1.5
*
2.1 1.5
NS
Se
Study Control
36 15
2.7 6.1
***
5.3 6.1
NS
Br
Study Control
36 15
29.5 47.6
***
39.2 47.6
NS
Rb
Study Control
36 15
17.7 24.3
***
25.5 24.3
NS
Sr
Study Control
36 15
8.1 1.7
***
10.6 1.7
***
Zr
Study Control
36 15
24.9 2.8
***
54.3 2.8
***
Cd
Study Control
36 15
16.5 81.7
***
211.0 81.7
***
**
*
NS: not signi®cant statistical difference. * p 0:05. ** p 0:01. *** p 0:001.
Comparison of changes in concentration of trace elements in RCC tissue depending on the tumor stage and presence of distant metastasis are shown in Figs. 3 and 4.
To rule out that trace elements concentration may change with age, the entire data were correlated with age of the patients. In Tau-Kendall analyses, we do not found any correlation (Table 2).
Z. Dobrowolski et al. / European Urology 42 (2002) 475±480
Fig. 3. Concentration of elements depending on the tumor stage.
Fig. 4. Concentration of elements depending on presence of distant metastasis.
479
480
Z. Dobrowolski et al. / European Urology 42 (2002) 475±480
4. Discussion Several authors performed trace elements analysis by EDXRF, PIXE or ASS to test each technique for routine analysis of biological samples [15]. SRIXE is suf®cient also to measure elements concentration at parts per million with S.D. <10%. SRIXE provides rapidly multielemental information, in single measurements, without destroying the sample. High concentration of Fe and signi®cantly lower concentration of metal carcinogen (Cd), potential for human carcinogen and elements with preventing function against cancer (Se and Zn) has been observed also by Fassina et al. [5]. Lower concentration of cadmium in RCC tissue has been con®rmed by several authors [1,6,12]. It was concluded that serum iron level might be used as a useful tumor marker in staging and follow-up of RCC [19]. Other data suggest that indirectly ferritin may be also useful serum marker for monitoring patients with RCC, when source of ferritin is tumor itself [9,14]. Several authors reported iron induced renal carcinogenesis model in animals [13,18]. Our data con®rmed higher concentration of Fe in RCC tissue which acts as natural stimulus for ferritin production in neoplastic kidney, especially in organ con®ned disease. In unchanged cortex of neoplastic kidney, we observe higher concentrations than in RCC of Cd [1,6,12], Ni and Cr which belong to group of carcinogen for humans and Pb, Ti and V which are carcinogen in animals model [3]. A possible explanation could be
that tumor growth excluded the neoplastic tissue from glomerular ®ltrate and metal intake becomes impossible in the mass. Our ®ndings show that Zn and Se are strongly decreased in the neoplastic mass, while Fe is increased in RCC with strong correlation in statistic analyses. Changes in Zn and Se concentrations in malignant disease are known from research on other cancers [3]. We have also seen raising concentrations of Zn and Se with progress of malignant disease. Same observation was made by Hardell et al. [6]. Our data con®rmed changes in trace elements concentration depending on stage of disease. These data are not suf®cient per se to draw conclusions and we believe that it will be of interest to further investigation. Several issues remain to be investigated: whether we can ®nd metal carcinogen concentration in kidney cortex when chance of carcinogenesis is signi®cantly higher and to monitor body elements stores and risk of cancer with indirect methods (blood or urine concentration of metals), whether we can change iron metabolisms in malignant tissue as new supporting methods in RCC treatment. Acknowledgements The authors wish to thank Dr. Sasa Bajt and Patt Nuessle for their help in data taking at the X26A beam line of the National Synchrotron Light Source at Brookhaven National Laboratory, Long Island.
References [1] Ala Opas M, Tahvonen R. Concentrations of cadmium and lead in renal cell cancer. J Trace Elem Med Biol 1995;9(3):176±80. [2] American Cancer Society: Cancer facts and ®gures. Atlanta (GA): American Cancer Society, 1993. [3] Boffetta P. Carcinogenicity of trace elements with reference to evaluations made by the International Agency for Research on Cancer. Scand J Work Environ Health 1993;19:67±70. [4] Delahunt B, Bethwaite Nacey JN. Occupational risk for renal cell carcinoma. Br J Urol 1997;75:578±82. [5] Fassina AS, Calliari I, Sangiorgio A, Rossato M, et al. Quantitative analysis of trace elements in human clear cell carcinoma of the kidney by energy-dispersive X-ray ¯uorescence. Eur Urol 1990;18(2):140±4. [6] Hardell L, Wing AM, Ljungberg B, Dreifaldt AC, et al. Levels of cadmium, zinc and copper in renal cell carcinoma and normal kidney. Eur J Cancer Prev 1994;3(1):45±8. [7] HusiatynÂski W. TNM classi®cation 1997. Przegl Urol 2000;2:50. [8] Iyengar GV, Sansoni B. Sample preparation of biological materials for Trace element analysis. IAEA Technical Report 197. Vienna: IAEA, 1980, p. 73. [9] Kirkali Z, Esen AA, Kirkali G, Guner G. Ferritin: a tumor marker expressed by renal cell carcinoma. Eur Urol 1995;28(2):131±4. [10] Kwiatek WM. Bio-medical application of synchrotron radiation X-ray ¯uorescence. Acta Phisica Polonica 1994;86:695±703.
[11] Mandel JS, McLaughlin JK, Schlehofer B, Mellemgaard A. International renal-cell cancer study IV. Occupat Int J Cancer 1995;61(5):601±5. [12] Muller I, Helmers E, Barchet R, Schweinsberg F. Cadmium concentration in the renal cortex of kidney tumor patients and controls. J Trace Elem Electrolytes Health Dis 1994;8(3/4):173±6. [13] Nogueira E, Cardesa A, Mohr U. Experimental models of kidney tumors. J Cancer Res Clin Oncol 1993;119(4):190±8. [14] Partin AW, Criley SR, Steiner MS, Hsieh K, et al. Serum ferritin as a clinical marker for renal cell carcinoma: in¯uence of tumor volume. Urology 1995;45(2):211±7. [15] Rindby A. Microbeam technique for energy dispersive X-ray ¯uorescence. X-ray Spectrom 1989;18:109. [16] Rose J, editor. Trace Elements in Health, Butterworth Co. Ltd., London, 1983. [17] Staessen A, Lauwerys W, Robert R. Renal function and historical environmental cadmium pollution from zinc smelters. Lancet 1994; 343(8912):1523±7. [18] Toyokuni S, Mori T, Dizdaroglu M. DNA base modi®cation in renal chromatin of wistar rats treated with a renal carcinogen, ferric nitriltriacetate. Int J Cancer 1994;57:123±8. [19] Yu CC, Chen KK, Chen MT, Huang JK, et al. Serum iron as a tumor marker in renal cell carcinoma.. Eur Urol 1991;19(1):54±8.