A Discriminant Analysis of Trace Elements in Scalp Hair of Healthy Controls and Stage-IIIB Non-small Cell Lung Cancer (NSCLC) Patients

Abstract

Our work aimed at extending the search for the trace elements (TE) abnormalities in patients with lung cancer and in healthy controls who smoke, and also for evidence of a possible association between lung cancer and TE. The analysis of the hair from patients with Stage-IIIB non-small cell lung cancer (group 1) and healthy controls (group 2) were analyzed using the inductively coupled plasma mass spectrometry technique in order to obtain information on the correlation between the lung cancer patients and healthy controls. Sixty-seven one-hair samples in group 1 were individually collected before chemoradiotherapy. For comparison, 74 hair samples were collected from group 2. In group 1, the trace elements present at the highest levels were measured to be Ca, Zn, Sn, Na and Mg, respectively, and they were quantified as 68.2, 53.2, 33.9, 23.3, and 28.9 μg.kg⁻¹, respectively. In group 2, the trace elements present at the highest levels were Zn, Mg, Ca, Fe, and Se, respectively, and they were quantified as 109.7, 31.9, 30.8, 25.0, and 20.1 μg.kg⁻¹. In group 1, the highest levels of Ca, Sn, and Na were 2.03, 1.06, and 1.01 times higher, respectively, compared with group 2. In group 2, Zn, Mg, Fe, and Se were 2, 1.01, 2.7, and 1.6 times higher, respectively, compared with group 1. When the levels of trace elements were compared between groups 1 and 2 using Student’s t test, the levels of Ag, Au, Be, Bi, Ca, Cd, Ce, Co, Cr, Cu, Fe, Ga, Hg, K, Ni, Rb, Rh, Sb, Sc, Ti, V, and Zn were found to be statistically different (p < 0.05). According to Pearson’s correlation, the most powerful correlation was found for Cr–As (r = 0.858) couple in group 1 (r = 0.745) and for Mn-Cr couple in group 2. The factors obtained according to converted matrix were observed to be as follows: for group 1, first factor, ten variables (Cd, Li, Cs, Ag, Rb, Pd, Ga, Zn, Al, and K); second factor, seven variables (Cr, As, Sn, Co, Ca, Rh, and Fe) and third factor, four variables (Mn, Au, Cu, and Hg). Within the first factor that best describes the overall change, the most important variables are Cd and Li, respectively the first and the second factors. Group 2 contained the following: first factors, six variables, Cr, Mn, Al, Ba, Rb, and Pb; second factor, eight variables, Co, As, Sn, Cd, Hg, Cs, Ca, and Ce; third factor, five variables Na, Ga, Be, B, and Sr; and fourth factor, two variables K and Ag. First, second, third, and fourth factors explain the 36% of the overall change. Within the first factor that best described the overall change, the most important variables were Cr and Mn. In this analysis, we observed that the group 2 trace elements accumulated were heavy metals and that the control group showed both heavy metals and macroelements required for the body. The average trace elements levels in the two groups were evaluated. In addition, the general role of trace elements in the lung carcinogenic processes was discussed. The study revealed that the carcinogenic processes are significantly affecting the trace elements and the trace elements distribution in the hair of lung cancer patients compared with the healthy controls. It was revealed that there was a relation between lung cancer and trace elements, especially heavy metals. Our findings suggest that the heavy metals accumulated in the body may pose a high risk for lung cancer development.