Wang et al. 2022 — Heavy metal plasma concentrations in gastric cancer patients vs healthy controls (China)
A case-control study at a single hospital in Changzhi, China measured 18 heavy metals in blood plasma of 105 gastric cancer patients and 62 healthy controls by ICP-MS (Agilent 7800), finding significantly elevated Cr, Cu, Hg, Pb, Sb, Sn, Tl, and V in GC patients compared with controls. The authors also assessed MSI (microsatellite instability) status, HER2 gene amplification, and traditional serum biomarkers in subsets, finding that antimony (Sb) concentration was positively correlated with MSI status (r = 0.22, p < 0.05), and that Hg, Sn, and Tl were elevated in HER2-positive patients. As, Mn, Se, Sr, and Zn were significantly lower in GC patients than controls, suggesting complex metal homeostasis disruption associated with gastric cancer.
Key numbers
- n=105 GC patients + n=62 healthy controls; Changzhi, China, 2020
- ICP-MS analysis of plasma for 18 metals: V, Cr, Mn, Co, Ni, Cu, Zn, Ga, As, Se, Sr, Cd, Sn, Sb, Ba, Hg, Tl, Pb
- Metals significantly higher in GC vs controls (median, µg/L): Cr 2.47 vs 2.15; Pb 11.76 vs 7.42; Sb 0.01 vs 0 (p<0.05 for both)
- Metals significantly lower in GC vs controls (median, µg/L): As 0.82 vs 2.44; Mn 11.28 vs 13.55; Se 143.90 vs 193.60; Zn 5.68 vs 5.98
- Hg, Sn, Tl, V also significantly elevated in GC patients (near-zero medians but statistically significant by Wilcoxon)
- Sb positively correlated with MSI status: r = 0.22, p < 0.05 (in 97 patients with full data)
- Hg, Sn, Tl significantly higher in HER2-positive vs HER2-negative GC patients (p < 0.05 to p < 0.01)
- CA19-9 positively correlated with Hg (r = 0.51, p < 0.001); CA72-4 positively correlated with Cr (r = 0.71, p < 0.001) and Ni (r = 0.74, p < 0.001)
Methods (brief)
Cross-sectional case-control study. Plasma separated by centrifugation (3000 rpm/10 min) from 2 mL whole blood; stored at -20°C until analysis. ICP-MS (Agilent 7800) for 18 metals per manufacturer protocol. MSI detection by fluorescent multiplex PCR of 5 markers (BAT25, BAT26, D2S123, D5S346, D17S250); capillary electrophoresis on ABI 3730XL. HER2 FISH using Fast Probe FP-001 kit. Statistical analysis: Wilcoxon rank-sum test for continuous variables; Pearson correlation for metal-metal and metal-biomarker associations (SPSS 19.0, R studio v3.6.1). Limitations: single-center, single region of China; patients had not received prior chemotherapy or radiotherapy; biomarker subsets are not fully representative of all patients.
Implications
Certification: Documents heavy metal bioaccumulation in the context of gastric cancer, adding clinical evidence layer for Cr, Pb, Sb, Hg, Sn, Tl exposure effects. Confirms that dietary Pb and Cr exposure is measurable in plasma and elevated in patients with gastric pathology in a high-burden Chinese region. Courses: Useful case study linking heavy metal plasma levels to a specific cancer type; shows the mechanistic link (MSI disruption, HER2 pathway) through which heavy metals may promote carcinogenesis. App: Blood-plasma biomonitoring data supporting dietary exposure relevance of Pb, Cr, Sb as health-endpoint anchors. Microbiome: Cd, Pb, Hg co-exposure discussed in context of endocrine disruption and DNA repair inhibition; crosswalk relevant to gut-lead-axis.