Environ Sci Pollut Res DOI 10.1007/s11356-014-3970-9

RESEARCH ARTICLE

Analysis of serum levels of 15 trace elements in breast cancer patients in Shandong, China Xiao Ding & Meng Jiang & Haiyan Jing & Wei Sheng & Xingwen Wang & Junqing Han & Luhua Wang

Received: 5 August 2014 / Accepted: 8 December 2014 # Springer-Verlag Berlin Heidelberg 2014

Abstract Experimental and epidemiological studies suggest that serum levels of trace elements may be associated with breast cancer risk. We compared serum levels of 15 trace elements between breast cancer patients and normal controls from Shandong, China, for the first time to assess whether serum levels of trace elements were associated with breast cancer risk. Eighty-eight breast cancer patients and 84 healthy controls were enrolled in the study. A Spectraspan V direct current plasma atomic emission spectrometer was used to determine the serum levels of 15 trace elements including Zn, Mn, Al, Cd, Fe, Mg, Ca, Pb, Cu, Se, Ni, Ti, Co, Li, and Cr. Breast cancer patients had significantly higher serum levels of Cd (p=0.000), Mg (p=0.001), Cu (p=0.000), Co (p=0.006), and Li (p=0.003) and borderline higher Cr (p=0.052), while significantly lower Mn (p=0.000), Al (p=0.000), Fe (p= 0.000), and Ti (p=0.000) compared to their matched controls. However, there were no significant differences in serum levels of Zn (p=0.824), Ca (p=0.711), Pb (p=0.274), Se (p=0.236), Responsible editor: Philippe Garrigues Xiao Ding and Meng Jiang contributed equally to the work. X. Ding : W. Sheng : X. Wang : J. Han (*) Cancer Center, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China e-mail: [email protected] M. Jiang Department of Neurosurgery, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China H. Jing Department of Pathology, Provincial Hospital Affiliated to Shandong University, Jinan 250021, China L. Wang (*) Department of Radiation Oncology, Cancer Hospital and Cancer Institute, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China e-mail: [email protected]

and Ni (p=0.185) between the two groups. Our study showed a possible association between serum levels of trace elements and breast cancer risk in eastern China, though it warrants further investigations to confirm the association. If confirmed, modulation of trace elements may help reduce breast cancer risk. Keywords Breast cancer . Trace elements . Serum . Risk . Cd . Mg . Cu . Co

Introduction Breast cancer, the most common malignant disease in women, is multi-etiological and multi-factorial. Well-established risk factors do not explain a substantial proportion of breast cancer cases. Genetic studies have been useful in identifying hereditary risk factors. However, for cases without established risk factors, it remains a challenge to identify individuals at risk. There has been continued interest in investigating trace elements as potential environmental risk factors (Almquist et al. 2007; Gaur et al. 2013) since levels of exposure to them are potentially modifiable and benefit may gain from preventive interventions. Changed serum levels of trace elements have been observed in breast cancer patients in different countries and areas (Gupta et al. 1991; Martin et al. 2010; Wu et al. 2006; Zowczak et al. 2001). However, their role is not fully understood, and the data is limited worldwide and is lacking in China. The efficacy of trace elements is related to a “U”-shaped curve in terms of health benefit. Trace elements play an important role in various biological processes by activating or inhibiting enzymatic reactions by competing with other elements and proteins for binding sites and by affecting permeability of cell membranes. However, abnormality of trace elements could severely impair hosts’ resistance against carcinogenic stress and induce carcinogenicity.

Environ Sci Pollut Res

Shandong is a region of eastern China, where breast cancer incidence has risen. We compared serum levels of 15 trace elements including Zn, Mn, Al, Cd, Fe, Mg, Ca, Pb, Cu, Se, Ni, Ti, Co, Li, and Cr between breast cancer patients and normal controls from Shandong to determine whether serum levels of trace elements were correlated with breast cancer risk.

Al, 0.0048 μg/ml for Cd, 0.0106 μg/ml for Fe, 0.0320 μg/ml for Mg, 0.0160 μg/ml for Ca, 0.0193 μg/ml for Pb, 0.0033 μg/ml for Cu, 0.0540 μg/ml for Se, 0.0032 μg/ml for Ni, 0.0027 μg/ml for Ti, 0.0090 μg/ml for Co, 0.0029 μg/ml for Li, and 0.0046 μg/ml for Cr. Statistical analysis

Materials and methods Subjects Eighty-eight female patients, with histopathological diagnosis of breast cancer, aged 26–62 years were selected from the Provincial Hospital Affiliated to Shandong University, Jinan, China. The exclusion criteria included diagnosis of any malignancy other than primary breast cancer. Eighty-four agematched healthy women who attended routine health examination in the same hospital were selected from the same area with no history of any tumor or breast disease. The study was approved by Ethics Committee of Provincial Hospital Affiliated to Shandong University. All subjects gave consent for inclusion in the study. These subjects were from the population residing in Shandong and were representative of the population. A questionnaire was administered to obtain a comprehensive interview of lifestyle habits, medical history, and use of medications. Established risk factors of breast cancer were available from the questionnaire. Body mass index was calculated as weight/height squared (kg/m2). We selected healthy controls who were matched to the patients for age, residence, and other established risk factors of breast cancer. Determination of trace elements Blood samples after a 12-h overnight fasting were collected from an antecubital vein from patients before any treatment and from controls. Serum was obtained by centrifuging subjects’ blood samples and stored at −20 °C until analyzed. A Beckman Spectraspan V direct current plasma atomic emission spectrometer was used to determine serum levels of Zn, Mn, Al, Cd, Fe, Mg, Ca, Pb, Cu, Se, Ni, Ti, Co, Li, and Cr according to the manufacturer’s instructions. The analytical toxicologist was totally blind to the medical history and final diagnosis of the subjects. Serum samples of 0.5 ml each were diluted with deionized water in the proportion of 1:2. Quality controls were checked. All the equipments were cleaned using 10 mL of nitric acid and deionized water to prevent contamination. Calibration curves were established (r>0.999). The relative standard deviation was

Analysis of serum levels of 15 trace elements in breast cancer patients in Shandong, China.

Experimental and epidemiological studies suggest that serum levels of trace elements may be associated with breast cancer risk. We compared serum leve...
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