A RECENT study has uncovered a potential connection between environmental metal exposure and an increased risk of digestive tract cancers, including those of the oesophagus, stomach, and colon. The research, based on data from the National Health and Nutrition Examination Survey (NHANES) 2011–2018, analysed blood metal levels in 13,467 U.S. adults, aged 20 and older.
The findings indicate that participants with oesophageal cancer (EC), gastric cancer (GC), and colorectal cancer (CRC) showed elevated blood concentrations of certain metals, including potassium (K), cadmium (Cd), and lead (Pb). Specifically, EC patients had higher potassium, cadmium, and lead levels than healthy controls. Gastric cancer patients showed an increased presence of lead, while colorectal cancer patients had elevated cadmium and lead levels.
Further analysis revealed strong associations between the blood metal levels and cancer risk. For oesophageal cancer, higher potassium, cadmium, and lead concentrations were all significantly linked to increased risk, with potassium showing the strongest correlation. In the case of gastric cancer, lead levels were a significant risk factor, while cadmium and lead were also linked to colorectal cancer risk.
A Random Forest model used in the study predicted cancer risk with 76% accuracy, highlighting cadmium and iron as the most influential factors. The research suggests that exposure to these metals, whether from the environment or other sources, could play a significant role in the development of digestive tract cancers.
This study underscores the importance of limiting environmental exposure to potentially harmful metals. By reducing contact with substances like cadmium and lead, public health strategies may help mitigate the risk of these common and often deadly cancers.
Helena Bradbury, EMJ
Reference
Shi C et al. Blood metal levels predict digestive tract cancer risk using machine learning in a U.S. cohort. Scientific Reports. 2025;15:1285.
