The “holy grail” in breath screening tests is the detection of lung cancer. In a multi-centric clinical study Herbig et al.* could identify biomarkers for lung cancer using PTR-MS. By combining only two markers, they reach a cross-validated AUROC value of > 83% for the detection of bronchial adeno-carcinoma.
*... Ref: Herbig J, 5th Int. Conf. on PTR-MS, IUP Conf. Series, pp. 31-33 (2011)
Kohl et al. performed a clinical study where they tested patients before and after renal transplantation. In this study they found a breath compound that correlates with blood creatinine concentration, a marker for kidney function.