Elemental and mutational analysis of lung tissue in lung adenocarcinoma patients

Background: This study aimed to observe the association between trace element concentrations in lung tissue from lung adenocarcinoma cancer (LADC) patients and mutations in the epidermal growth factor receptor (EGFR) and KRAS genes.

Methods: LADC patients who had undergone lung resection were included in this study. Furthermore, twenty patients without lung cancer were included in this study as the control group. Samples were separately collected from both tumor and peritumor tissues. The mutational status was assessed for EGFR mutations, ALK rearrangements and KRAS mutations. Based on these analyses, patients were grouped into three groups: EGFR mutation, KRAS mutation and wild-type groups. The concentrations of various trace elements in the lung tissues were measured by a particle-induced X-ray emission (PIXE) system, and the results were analyzed for statistical significance.

Results: A total of 110 LADC patients were included in this study. The median age was 70 years, and 60% of the participants were female. Moreover, 18% and 20% of patients were EGFR- and KRAS-positive, respectively. Thirty-two trace elements were measured, and 18 trace elements were detectable. The concentrations of Fe, Co, Ni, Cu, Zn and Br were significantly higher in the KRAS mutation and wild-type groups than in the control group regardless of whether the samples were from tumor or peritumor tissues. For these 6 trace elements, the concentrations were significantly higher in smokers than in non-smokers. Considering the effect of smoking, differences in the trace element concentrations between each mutational group remained.

Conclusions: Trace elements in the lung may play a role in development of LADC in both smokers and never-smokers. However, prospective studies with larger sample sizes are needed to support this hypothesis.