FIGURE 2.

MS analysis of protein change upon disease progression and recurrence. A, Plasma and serum samples of different cohorts of patient with melanoma analyzed for circulating proteins using MS proteomic profiling and Olink analysis. B, Volcano plot showing differential protein expression of serum analysis using MS, comparing protein expression between matched patients with stage III and stage IV disease (n = 64). Proteins higher expressed at stage III disease are displayed on the left, and proteins higher expressed at stage IV are displayed on the right. The protein fold change on a log₂ scale is shown on the x-axis, with the significance indicated by the −log₁₀ scale on the y-axis. The significance cutoff (P = 0.05) is indicated with the black dotted line, showing significant increased proteins for stage III in blue and for stage IV in purple. A two-tailed paired Student t test was used to determine statistical significance between stage III and stage IV samples. C, A Venn diagram for overlapping significant proteins of patients with stage IV melanoma and baseline samples of nonresponding stage III patients with recurrent disease. D, Volcano plot showing differential expression of plasma markers using MS, comparing protein expression of nonresponder patients of the OpACIN-neo study (n = 21) with or without a recurrence. Proteins higher expressed by patients without a recurrence are displayed on the left, and proteins higher expressed by patients with a recurrence are displayed right. The protein fold change on a log₂ scale is shown on the x-axis, with the significance indicated by the −log₁₀ scale on the y-axis. The significance cutoff (P value = 0.05) is indicated with the black dotted line, showing significant increased proteins for patients without a recurrence in green and for patients with a recurrence in red. A two-tailed unpaired Welch t test was used to determine statistical significance between samples of patients with and without a recurrence.