Research Article | Open Access
Bogusław Czerny, Krzysztof Krupka, Marcin Ożarowski, Agnieszka Seremak-Mrozikiewicz, "Screening of Trace Elements in Hair of the Female Population with Different Types of Cancers in Wielkopolska Region of Poland", The Scientific World Journal, vol. 2014, Article ID 953181, 15 pages, 2014. https://doi.org/10.1155/2014/953181
Screening of Trace Elements in Hair of the Female Population with Different Types of Cancers in Wielkopolska Region of Poland
Background. Cancer constitutes a major health problem worldwide. Thus, search for reliable and practical markers of the disease process remains the key issue of the diagnostic process. Objectives. The study aims at linking the trace element status of an organism, assessed by hair analysis, with the occurrence of cancer diseases. Material and Methods. Hair samples were collected from 299 patients with cancer diseases confirmed by a histopathological test and from 100 controls. Cancer patients were divided into three groups, depending on cancer type: hormone-dependent cancer, cancer of the alimentary tract, and cancer with high glycolytic activity. Mineral element analysis of hair was performed using an atomic emission spectrophotometer with inductively coupled plasma (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS). Results. Statistically significantly lower concentrations of selenium, zinc, copper, germanium and boron, iron, and magnesium were observed in the three groups of cancer patients. Disturbance in the axis glucose-insulin and changes in concentrations of heavy metals and toxic elements were also noted. Conclusions. It seems safe to conclude that our results confirmed usefulness of hair element analysis in screening tests for the assessment of the biomarker of various cancer diseases in a female population.
According to the World Health Organization (WHO) , cancer is and will become an increasingly important factor in the global burden of disease in the decades to come. The number of new cases reported annually is expected to rise from 10 million in 2000 to 15 million in 2020. Thus, early detection may allow for early diagnosis in the symptomatic and screening in asymptomatic, but at risk, populations. Moreover, screening of seemingly healthy individuals can disclose cancer in early or precursor stages, when treatment is most effective. Therefore, there is a need for further search of appropriate screening methods and cancer markers.
In recent years, the analysis of trace elements in human tissues has attracted the attention of numerous researchers and its application continues to expand due to the role of these elements in the biochemical and physiological processes . Determination of trace elements in human hair is important in biological, medical, environmental, and forensic disciplines as it represents an interesting biological matrix for various studies [3, 4]. Lately, hair has become a fundamental biological specimen, alternative to the usual blood and urine samples, as well as biopsy material, in clinical toxicology and chemistry [5–7]. Human hair has been shown to be attractive as diagnostic material due to simplicity of sampling. Moreover, hair constitutes a neutral and stable tissue material and may provide valuable information about accumulation of trace elements that are considerably more concentrated in hair than in other biological materials [8, 9]. Thus, hair analysis may provide an indirect screening test for physiological excess as well as deficiency of elements in the body. It is vital to note, as was summarized by Rȩbacz-Maron et al. , that the content of chemical elements in hair is determined, among others, by diet, sex, age, race, individual demand of each organism, socioeconomic conditions, the content of chemical elements in drinking water, geographical location, and environmental pollution. The main advantage of this method is that it enables monitoring the changes in trace element status in the body over a long period of time, much longer than in case of blood samples. Nowadays, clinical research indicates that levels of certain trace elements in hair (particularly potentially toxic elements) are highly correlated with pathological disorders . A growing amount of data supports the theory that biochemical analysis of trace elements in hair may be useful in identifying the possible risk of cancer development or progression as simple biomarkers without the need for an invasive biopsy. Silva et al.  demonstrated that investigation of trace elements in cancer tissues may be regarded as tumor biomarkers and prognostic factors in breast cancer. Other authors showed also that alterations in trace elements in plasma and cancer tissues were observed in patients with, for example, colorectal cancer [11, 12], malignant breast tissues , malignant prostate , cancerous endometrial and ovarian tissues , and head and neck cancers . Also, several studies have focused on the relationship between scalp hair trace element levels and cancer in patients from various geographical locations, that is, Turkey (Anatolia) , India (Malwa region, Punjab) , Pakistan (Rawalpindi district; Jamshoro) [6, 18–21], Iran (Tehran) , Italy (Modena region) , and China (Guangdong Provence) [24, 25] but not Poland. The role of trace elements in the development or inhibition of cancer remains to be fully elucidated. Moreover, that field has not been extensively studied in cancer patients in Poland. The main objective of our study was to assess the concentrations of trace elements in hair of cancer patients hospitalized in clinical hospitals (Pomeranian Medical University in Szczecin) by atomic emission spectrometer with inductively coupled plasma (ICP-OES) and inductively coupled plasma mass spectrometry (ICP-MS) by NZOZ Biomol-Med Sp. z o.o. (Łódź, Poland).
2. Material and Methods
2.1. Patient Groups
A total of 399 Polish women were included in the study, both for the cancer and control groups. Individuals using supplementation with trace elements and vitamins during the last three months preceding the study were excluded. All patients had been histopathologically tested for the disease and were randomly selected from the clinical hospitals at the Pomeranian Medical University (Szczecin, Poland). Cancer patients (aged 35–60 years) were divided into three groups. Group 1 (H) was comprised of 98 females with hormone-dependent cancers, such as breast and ovarian carcinomas. Group 2 (HG) consisted of 101 patients with cancers characterized by high glycolytic activity system, such as Hodgkin’s lymphoma, leukemia, non-Hodgkin lymphoma, melanoma, and brain tumor. Group 3 (D) was composed of 100 women suffering from digestive tract cancers. Healthy volunteers (, aged 25–40 years) were recruited as controls (C). The study was approved by the local ethics committee (Pomeranian Medical University).
2.2. Sample Collection, Preparation, and Analysis of Hair Element Composition
The 3-4 cm hair samples were obtained from the head, according to widely accepted standards, that is, hair without perming or coloring, cut from the back of the head (from a few places), close to the skin. The weight of a hair sample ranged between 300 and 400 g. The samples were washed in solutions of nonionic detergents and then dried to constant mass.
An accurately weighed portion (0.3 g) of the hair sample was placed in flasks with 25 mL capacity. 5 mL of a freshly prepared mixture of concentrated 65% HNO3-H2O2 (2 : 1, v/v) was added to each flask and heated at 80°C for 10 min in accordance with the method described above . Final solutions were made up to 10 mL with 2 mol/L HNO3. The samples were mineralized in a closed system in an ETOS microwave station (Mileston). Triplicate scalp hair samples of each cancer patient and healthy participants were treated as described above. The analysis of the hair element composition was made with an atomic emission spectrometer with inductively coupled plasma (ICP-OES), Optima 5300 DV (Perkin Elmer 2300 D), and inductively coupled plasma mass spectrometry (ICP-MS; Perkin Elmer DRC II). The source materials for comparison were reference materials compliant with the standard. The apparatus was calibrated using standard solutions. The calibration curve was drawn automatically by the computer coupled with the apparatus.
Analytical figures such as calibration curve for each trace elements, the linear correlation coefficient for calibration curves (r), coefficient of variance (SD2), detection limits, certified reference material, and sample volume used in this study were summarized in Table 1.
All reagents were purchased from Sigma-Aldrich (Poland) and Merck (Poland). The content of 23 nutritional elements, that is, arsenic (As), Barium (Ba), boron (B), cadmium (Cd), calcium (Ca), cobalt (Co), copper (Cu), chromium (Cr), germanium (Ge), iodine (I), iron (Fe), lithium (Li), magnesium (Mg), manganese (Mn), molybdenum (Mo), nickel (Ni), potassium (K), selenium (Se), silicon (Si), sodium (Na), strontium (Sr), sulfur (S), tin (Sn), vanadium (V), and zinc (Zn), and of 6 toxic elements, aluminum (Al), lead (Pb), and mercury (Hg) was determined in the collected samples. The results were assumed to be the so-called “element status.”
2.3. Statistical Analysis
Statistical analysis of the results was performed using the software package Statistica 7.1. All values were expressed as means ± SEM and results were expressed as micrograms per gram. The statistical comparison of the results was carried out using the Kruskal-Wallis test (nonparametric several independent samples test) to evaluate differences between the three cancer groups and healthy controls and also by the Mann-Whitney test U, setting as the limit of significance.
Mean concentrations with standard deviations (± SEM) for each analyzed chemical element in hair of cancer patients and healthy participants are presented in Table 2. The results indicate that concentrations of essential trace and toxic elements in the biological samples of cancer patients were altered.
|H, HG, and D, respectively, are hormone dependent cancers, cancers with high glycolytic activity, and alimentary tract cancers; values expressed as mean ± SEM.|
Statistical difference versus control, , respectively.
Statistical difference versus D group, , respectively.
Statistical difference versus HG group, , respectively.
Statistical difference versus H group,