Eighteen metals (A1, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Pb, Sb, Sr and Zn) were estimated in the scalp hair, plasma and tissues samples of cancer and benign patients and in hair and plasma of normal donors. Nitric acid-perchloric acid wet digestion procedure was used for the quantification of the selected metals using flame atomic absorption spectrophotometer. In the scalp hair of cancer patients, highest average levels were found for Ca (861.5 ug/g), followed by Na (671.8 ug/g), Zn (410.8 ug/g), Mg (347.5 ug/g), Fe (153.7 ug/g), Sr (129.4 ug/g) and K (115.9 ug/g), while in comparison, the dominant metals in the scalp hair of normal donors were Ca (567.5 ug/g ), Zn (177.3 ug/g), Mg (154.2 ug/g), Fe (110.3 ug/g) and Na (103.5 ug/g). However the concentrations of 14 metals in total (Ca, Cd, Co, Cr, Fe, K, Mg, Mn, Na, Ni, Pb, Sb, Sr and Zn) were notably higher in the hair of cancer patients as compared with normal donors. In the scalp hair of benign patients, dominant mean levels were revealed by Ca (1362 ug/g), Na (501.7 ug/g), Mg (483.4 ug/g), Zn (426.6 ug/g) followed by Sr (198.5 ug/g), K (130.5 ug/g) and Fe (123.5 ug/g). Most of the selected metals exhibited random distribution pattern in the scalp hair of male/female donors of three groups. Strong positive correlations were found between Mn-Pb (0.83), Cd-Cr (0.82), Cd-Li (0.57), Fe-Pb (0.56) and Fe-Mn (0.55) in the hair of cancer patients whereas Na-Cd, Li-Cr, Li-Co, Co-Cd, Li-Cd, Na-Co, Na-Li, Ca-Mg and Na-Cr exhibited strong relationships (r > 0.50) in the hair of normal donors. The correlation study also brings out marked differences in the co variation of selected trace metals in the scalp hair of benign patients compared with normal donors. Principal Component Analysis (PCA) of the data revealed 7 principal components (PCs), for cancer/benign patients and normal donors, but with significantly different loadings. Cluster Analysis (CA) was also used to support the PCA results which evidenced significantly different pattern of metal distribution in the hair of cancer and benign patients in comparison with normal donors.
In the plasma of cancer patients, mean concentrations of N a, K, Ca, Mg, Fe and Zn were 4131, 179.0, 43.37, 7.600, 4.399 and 3.860 ug/g, respectively, while the mean metal levels in the plasma of benign were for 4095, 187.5, 31.04, 8.737, 2.747, 2.582 ug/g, respectively, whereas the average metal levels in the plasma of normal donors were 3896, 151.0,76.36, 18.15,6.783 and 2.606 ug/g, in that order. Average concentrations of Cd, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Sr and Zn were noted to be significantly higher in the plasma of cancer patients compared with normal donors. The distribution of selected trace metal levels in the plasma of benign/cancer patients revealed significantly different pattern than normal donors. Very strong mutual correlations (r > 0.70) in the plasma of cancer patients were observed between Fe-Mn, Ca-Mn, Ca-Ni, Ca-Co, Cd-Pb, Co-Ni, Mn-Ni, Mn-Zn, Cr-Li, CaZn and Fe-Ni, whereas, Ca-Mn, Ca-Mg, Fe-Zn, Ca-Zn, Mg-Mn, Mg-Zn, Cd-Sb, Cd-Co, CdZn, Co-Sb and Sb-Zn exhibited strong relationships (r > 0.50) in the plasma of normal donors. Similarly, many strong correlations were also observed in the plasma of benign patents. PCA of the metal data extracted five PCs, both for cancer patients and controls and six PCs, for benign patients, with noticeably different loadings, duly supported by CA.
In the tissues of cancer patients, maximum average levels were found for Na (932.0 ug/g), K (537.8 ug/g) , Ca (212.2 ug/g), Mg (62.40 ug/g), Fe (36.90 ug/g) and Zn (17.85 ug/g) while, in the tissues of benign patients, higher average levels were shown by Na (902.2 ug/g), K (443.6 ug/g), Ca (180.9 ug/g), Mg (63.56 ug/g), Fe (23.3 ug/g), Zn (14.89 ug/g) and Al (10.03 ug/g). Strong correlations were observed between, Co-Mn, Cd-Mn, Fe-Mn, Cd-Co, Cd-Cr, Co-Fe, Mg-Pb, Cd-Fe, Ni-Pb, Mg-Ni and Ni-Sr in the tissues of cancer patients, whereas, in tissues of benign patients following metal pairs revealed strong relationships; Cd Mn, Cd-Co, Co-Mg, Co-Mn, Cu-Mn, Co-Ni, Mg Ni, Cd-Cu, Cd-Ni, Ca-Mg, Fe-Ni, Cu-Ni, Cd-Mg, Co-Cu, Cr- Na and Cd-Cr. PCA of the data revealed 6 PCs, for cancer and 5 PCs, for benign patients, with significantly different loadings. CA was in good agreement with the PCA results. The present study evidenced significantly different pattern of metal distribution in the tissues of cancer and benign patients.
The average metals levels in male and female donors of the three donors groups were also evaluated for each matrix and in addition, the general role of trace metals in the carcinogenesis was discussed. Average metals levels in the scalp hair, plasma and the tissues were compared for each group of donor and selected metals levels were also evaluated for different types of cancer and benign patients. Present metal levels in the scalp hair, plasma and tissues of different donor groups were also compared with the counterpart data published around different regions of the world. The study indicated appreciably different pattern of selected metal distribution and their mutual correlations in the hair, plasma and tissues of cancer/benign patients in comparison with the normal donors.