Serum Metabolomics for Early Detection of Lung Cancer Risk in High Radon Areas of Thailand: a Pilot Study

Abstract

Lung cancer (LC) is the leading cause of cancer-related death in Thailand, par ticularly in upper northern regions. After cigarette smoking, indoor radon is the main risk factor for LC. However, there is still no specific biomarkers for detecting LC caused by long-term indoor radon exposure. The study aimed to identify potential biomarkers for LC risk in high radon areas using a metabolomics approach. A passive radon-thoron discriminative monitor (RADUET) was used to assess indoor radon activity concentration in Mae Chaem district, Chiang Mai province from September 2022 to March 2023. The estimated indoor radon activity concentration ranged from 18.5−119 Bq/m³ with an average value of 40.8 ± 22.6 Bq/m³. Based on the indoor radon activity concentration measurements, serum samples from 15 LC patients and 30 matched healthy controls (low- and high-radon groups) were analyzed. Interestingly, a total of 139 differential metabolites were selected as promising biomarkers by the criteria of the variable importance in projection (VIP) ≥ 1 and a P value of ≤ 0.05. Consequently, the receiver operating characteristic curves indicate that 36 of these metabolites have the potential to serve as biomarkers of LC development caused by prolonged exposure to indoor radon. Among these, the fold change of 14 metabolites such as D-sphingosine, was considered significantly dif ferent in high radon groups compared to low radon groups. This study provides new insights into metabolic biomarkers for screening LC risk in areas with high residential radon exposure.