Protein C Inhibitor Proteotypic Peptide Quantitation by LC-Free SISCAPA-MALDI Mass Spectrometry Predicts Recurrence of Prostate Cancer After Radiotherapy

摘要

MALDI-TOF is a viable approach for quantitation of peptide biomarkers when coupled with SISCAPA specific peptide enrichment (1) Target peptides from serum digests are analyzed in almost pure form Quantitative results can be replicated on (1) Research and clinical MALDI-TOFs (2) Different vendor's MALDI-TOF's (3) Classical ESI-TQMS vs MALDI-TOF (4) Different occasions a year apart Applicability of clinical MALDI-TOFs now used for microbial identification is particularly significant enabling SISCAPA assay use in routine clinical laboratories The specific PCI peptide measured shows significant potential for predicting recurrence of prostate cancer in patients treated with radiotherapy/hormone therapy A much larger cohort (～1000 patients) will be required to unequivocally validate the PCI analyte for clinical use.