Table 3.

Correlations among phosphorylated extracellular signal-regulated kinase (pERK1/2) expression, clinical benefit, and changes in the receptor protein kinase expression

Correlation of change in pERK1/2 expression with	Pearson’s correlation coefficient	P-value
Clinical response (PR)	0.06	0.87
Clinical benefit (PR + SD)	−0.23	0.53
Change in C-KIT expression	0.56	0.09
Change in PDGFR-α expression	−0.12	0.74
Change in PDGFR-β expression	0.40	0.25

Changes in protein expression were categorized as follows: −1, decrease; 0, no change; +1, increase. For clinical response, partial response (PR) was coded as 1 and others as 0. For clinical benefit, PR or stable disease (SD) was coded as 1 and others as 0.