TRACE AND MAJOR ELEMENTS IN BLOOD SERUM OF MELANOMA PATIENTS BY PIXE

Abstract

Melanoma is a serious skin cancer that, if found and treated in its early stages can be cured before it gets invasive and develops metastasis. The incidence of this disease has steadily increased in white populations throughout the world in the last decades. Although the basis for this rise is incompletely understood, it is known that solar exposure and genetic factors are important precursors of melanoma. Nowadays, some studies are correlating some trace elements in blood and tissues with the disease. In this work, trace element concentrations in blood serum of patients with melanoma where measured by PIXE (Particle Induced X-ray Emission) to verify if there is a link between the concentrations of elements in the blood serum and melanoma. If the hypothesis is proven, elements in the blood serum could also be used as markers for melanoma. The samples were collected in the São Paulo Hospital and analyzed by PIXE after an internal standard addition. Concentrations of Chlorine (Cl), Potassium (K), Calcium (Ca), Copper (Cu), Zinc (Zn) and Bromine (Br) were measured in serum of 30 patients with melanoma and 116 control individuals. The elemental concentrations were calculated relative to an internal Gallium standard. The accuracy of the method was verified analyzing an IAEA A-13 Blood (International Atomic Energy Agency) and a QMEQAS08S-06 serum (National Institute of Public Health). The results of this work showed no significant difference between melanoma and control group (independent t-test and U-test, p = 0.05).