The Potential Clinical Significance of the Serum Iron and Ferritin Status in Lung Cancer Patients

Abstract

Background An increasing number of studies have shown that iron, one of the indispensable trace elements in the human body, is closely related to the occurrence and development of cancer. However, few studies have clearly demonstrated the role of the iron levels in lung cancer patients, or the potential effects of inflammation on iron levels. Methods The clinical data for lung cancer patients and non-lung cancer participants were retrospectively analyzed. The serum iron and ferritin levels were measured and compared using a rank-sum test. The correlation between the serum iron/ferritin and C-reactive protein (CRP) was analyzed by rank correlation. The cut-off values for continuous variables were obtained by the receiver operating characteristic curve (ROC) method. An analysis of potential prognostic factors in lung cancer patients was conducted by univariate and multivariate survival analyses. Results The serum iron levels in patients with extensive small-cell lung cancer (SCLC) were lower than those with limited-stage SCLC, and the levels of serum ferritin and CRP in those with extensive SCLC were higher than those with limited-stage SCLC. Similarly, the serum iron levels in patients with stage IV non-small cell lung cancer (NSCLC) were lower than those of patients with stage Ⅰ-Ⅲ disease, and the levels of serum ferritin and CRP in those with stage IV NSCLC were higher than those in stages Ⅰ-Ⅲ. The serum iron level was negatively correlated with the level of CRP, while the serum ferritin level was positively correlated with CRP. The stage of lung cancer, but not the serum iron/ ferritin level, was an independent prognostic factor in lung cancer patients. Conclusions The serum iron and ferritin levels are associated with the staging of lung cancer. The later stages of lung cancer are associated with a lower serum iron level, a higher serum ferritin level, and a higher CRP level. Inflammation may play an important role in regulating the serum iron and ferritin levels in lung cancer patients.