no PR. In the patient group classified as no PR, median PFS was 125 days vs. 231 days in the group classified as PR. Median overall survival of patients predicted to have no PR was shorter, but not significantly, at 231 days vs. 613 days for patients predicted to have a PR. Classification analysis was performed using support vec tor selleck chemicals llc machine with different combinations of features. The LOOCV accuracy was again poor when using all 682 pep tides, at about 67%. When the five differential pre treat ment peptides were used, the LOOCV accuracy was 89% at 100% sensitivity and 83% specificity. The average accu racy over 10 runs was 74% using random feature selection for five peptides. The LOOCV prediction accuracy was reduced to 85%, at 100% sensitivity and 78% specificity, when we used also the five peptides that changed differ ently in intensity level over the three time points.

Peptide Inhibitors,Modulators,Libraries Inhibitors,Modulators,Libraries pattern discriminating NSCLC patients from cancer free controls Finally, in an exploratory additional analysis, we com pared the serum peptide spectra of 13 cancer free control subjects and the pre treatment serum spectra of the 27 NSCLC patients included in this study. We performed a principal component analysis Inhibitors,Modulators,Libraries analysis of the 40 profiles using all 682 peptides, Inhibitors,Modulators,Libraries see Figure 5A. While there is over lap between the two groups in the three dimensional plot, the healthy profiles are clustered at the bottom right region. Furthermore, we observed no indication of outliers in the dataset. Next we performed a supervised analysis to identify peptides that were significantly differ ential in intensity between the two groups.

For this pur pose, the Mann Whitney U test was carried out on each of the 682 peptides using all profiles. Inhibitors,Modulators,Libraries The peptides were selected based on the criteria outlined in Methods, result ing in 47 peptides. A heat map of the intensities of the 47 peptides is shown in Figure 5B. Figure 5C shows the spectra overlay of the top 8 most discrimi nating peaks, all of which have a p value 0. 0001. Note that for example the peak at mz 1777. 966 has a higher intensity in NSCLC patients compared cancer free controls and the peak at mz 1039. 6249 has a lower intensity in NSCLC patients. We carried out classification analysis using support vector machine. A grid search for parameters was employed to find the best model accord ing to LOOCV.

Using all 682 peptides, an LOOCV accu racy of 93% was achieved. selleck chem Y-27632 When the 47 peptides selected by the Mann Whitney U test were used, the LOOCV accu racy was 98% with 100% sensitivity and 96% specificity. To substantiate the result, we compared it to a random selection of peptides. Using the same model selection mechanism for support vector machine with 47 different peptides randomly selected the average accuracy over 10 runs was 90%. In this secondary analysis, control subjects were unmatched for age and gender. We therefore also consid ered peptides that express differently in the two gender groups.