Association between heavy metal concentrations and chemotherapy-related acute adverse events in the patients with nasopharyngeal carcinoma: A prospective, longitudinal, observational study.

Abstract

e18045 Background: Chronic exposure to heavy metals may cause chronic burden on liver, kidney, bone marrow and other organs. To determine whether the accumulation of heavy metals prior to treatment was related to the occurrence of acute adverse events in patients with nasopharyngeal carcinoma (NPC) receiving platinum-based chemotherapy, we conducted a single-center, prospective, longitudinal study. Methods: The heavy metal concentrations of pretreatment whole blood samples and the pretreatment and posttreatment morning urine samples for 140 NPC patients were measured, which were classified into low and high levels based on the 75% quartile. The highest grades of acute adverse events for every cycle of platinum-based chemotherapy were recorded according to the Common Terminology Criteria for Adverse Events (version 4.03). Wilcoxon rank-sum test was used to compare the difference in the distribution of acute adverse events between two levels. To illustrate the potential relationship of metal between in blood and urine, the spearman’s correlation coefficient of metal concentration in blood and urine adjusted by creatinine was calculated. The kendal's correlation coefficients were calculated to characterize the correlation between heavy metal levels and acute adverse events. Finally, the study developed multivariable adjusted logistic regression models to calculate odds ratios (OR) and 95% CIs of the association between various heavy metals and risk of chemotherapy-related acute adverse events, respectively. Results: The study enrolled 140 patients with stage II (n=2, 1.4%), III (n=76, 54.3%), and IVa (n=62, 44.3%) NPC. A total of 13 heavy metals of both blood and urine samples were measured, with Cd, Pb, Hg, As, Pt, Mg, Ca, Cr, Co, Ni, Cu, Zn, and Se included. The concentrations of the same metals in blood and urine (including Cd, Pb, Hg, As, Pt, Co and Se) had a moderate correlation (0.2 < correlation coefficient < 0.7). High level patients were prone to experiencing acute adverse events ( p<0.05). In multivariable adjusted logistic regression, patients with impaired liver function had higher BCd (Cd in blood) level (OR, 3.65; 95% CI, 1.38–9.64; p=0.009). Patients with thrombocytopenia had higher UCr (Cr in urine) level (OR, 5.63; 95% CI, 1.60–19.87; p=0.007). And UPb (OR, 3.16; 95% CI, 1.26–7.92; p=0. 014) and UZn (OR, 2.69; 95% CI, 1.10–6.59; p=0. 030) were found significantly higher in patients with abnormal blood glucose. Conclusions: NPC patients with chronic accumulation of BCd had tendency to have impaired liver function when receiving platinum-based chemotherapy. Similar correlations were also observed in the thrombocytopenia with UCr, and the abnormal blood glucose with UPb and UZn.