Sessions

The development and progression of neoplastic diseases may involve alterations in the homeostasis of essential and toxic elements. Multielement analysis may therefore provide a complementary approach in oncological research. While an increasing number of studies in human oncology have investigated the relationship between elemental profiles and neoplastic diseases, considerably less information is available in veterinary medicine.

This study aimed to perform multielement analysis of biological samples from dogs with neoplastic diseases and to investigate potential alterations in elemental homeostasis. We compared element concentrations in paired whole-blood and plasma samples and evaluated differences in elemental profiles among groups defined by clinical status.

We analysed paired whole-blood and EDTA-plasma samples from 86 sampling events. Concentrations of 19 elements—Mg, Al, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Mo, Cd, Sb, I, and Pb—were determined by inductively coupled plasma mass spectrometry (ICP-MS). We verified method performance using certified reference materials for whole blood and serum. After excluding repeated sampling events and cases with incomplete sample or clinical data, we evaluated data from 72 individual animals. We classified the animals into active neoplastic disease (31), treated/remission (20), non-neoplastic with clinical signs (9), and healthy control (12) groups.

We assessed relationships between whole-blood and plasma concentrations using Pearson and Spearman correlation analyses and evaluated differences between compartments using the Wilcoxon test. We compared clinical groups using the Kruskal–Wallis test.

We observed strong relationships between concentrations measured in whole blood and plasma for several elements; Pearson correlation coefficients exceeded 0.75 for six elements (I, As, Mo, Sr, Cu, and Se). However, concentrations differed considerably between the two compartments for several elements: iron, zinc, and magnesium concentrations were significantly higher in whole blood, whereas calcium concentrations were significantly higher in plasma (p<0.001). In dogs with active neoplastic disease, median whole-blood iron was lower (488.0 vs. 513.5 ppm), whereas median whole-blood zinc (4.56 vs. 3.70 ppm), plasma calcium (90.0 vs. 83.5 ppm), and plasma selenium (360 vs. 279 µg/L) were higher than in healthy controls.

Our results demonstrate the suitability of ICP-MS for multielement analysis of whole blood and plasma; however, the two sample types cannot generally be considered interchangeable because elements are distributed differently between the compartments. The concentration differences observed among the clinical groups suggest that elemental profiles may provide information related to neoplastic disease and its clinical status. These findings support further investigation of multielement profiles in veterinary oncology.