Fig. 3.

a Categorization in a short versus long treatment response group based on serum peptide profiling. Serum was collected postoperatively, before start of chemoradiation and peptides were profiled by MALDI-TOF-MS. Unsupervised cluster analysis was performed and samples were labeled by gender and good (PFS >16 months) versus poor treatment response (PFS <16 months). b–d Result of testing potential predictive classifiers to predict treatment response. Predictive classifiers were generated from the peptide profiles of 18 patients. Each classifier was tested in an independent patient set of 26 patients. Signatures generated by support vector machine (a), k-nearest neighbor (b) and random forrest (c) did not predict treatment response (b–d)