Regulating Serum Concentrations to Discriminate Specific Volatile Organic Compounds (VOCs) in Serum Produced by Lung Cancer Cells by Headspace Solid-Phase Microextraction Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS)

Volatile organic compounds (VOCs) from lung cancer cells represent promising biomarkers for noninvasive early diagnosis. However, the variability of VOCs due to environmental and nutritional influences poses a challenge, highlighting the need to identify stable, cancer-specific markers for reliable clinical translation. Addressing the clinically relevant factor of serum concentration, this work reveals its significant impact on VOC profiles in cultured cells. The human lung cancer cell line A549 and the normal bronchial epithelial cell line BEAS-2B were cultured in Dulbecco’s Modified Eagle Medium (DMEM) supplemented with either 10% or 2.5% fetal bovine serum (FBS). VOCs released by the cells were determined using headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with the untargeted analysis. The results showed that 12 and 6 differential VOCs associated with A549 were identified in high-serum (10%) and low-serum (2.5%), respectively. Among these, four VOCs—3-methyl-1-butanol, 2-methyl-1-butanol, ethyl 2-methylbutyrate, and 2-tridecanone—were consistently detected as differential metabolites across both serum concentrations, with the latter two showing greater metabolic stability. This work is the first to elucidate the impact of serum concentration on VOCs from cultured cells and to identify differential VOCs with metabolic stability that are associated with cancer progression. These findings provide new insights for selecting highly stable and specific VOC biomarkers and may contribute to enhancing the translational potential of VOC-based clinical screening strategies.