Serum IGFBP3, IGF-I, and MMP7 changes in advanced colorectal cancer (ACRC) patients (pts) treated with anti-EGFR therapy: A GEMCAD study
e15109 Background: Insulin-like growth factor-I (IGF-I) is a potent mitotic and anti-apoptotic peptide, whereas IGF binding protein-3 (IGFBP3) seems to have pro-apoptotic effects. Matrix metalloproteinase-7 (MMP7), an enzyme with in vitro ability to degrade IGFBP3, has been shown to be a prognostic factor in ACRC. Methods: This is a prospective single cohort traslational study. Pts undergoing second/third line with irinotecan plus anti-EGFR therapy were eligible as cases. Patients with ACRC not undergoing therapy were eligible as controls. IGFBP3 and MMP7 were measured in serum with immunoassays at baseline and at 48h after treatment start. KRAS mutation status in codons 12/13 was determined by sequencing in 53 pts. The primary endpoint is to define the IGFBP3 and MMP7 variation under anti-EGFR therapy. IGFBP3 was used as a continuous variable and MMP7 was used to create two groups by its third quartile. Results: Eighty-five cases and 25 controls were recruited. No significant changes at 48h in IGF-I and IGFBP3 were found, but a significant decrease in MMP7 from 10.8 (95%IC 8.3–13.3) to 8.4 ng/ml (95%IC 6–10.9) was observed in cases (p<0.001) in contrast with controls, where no changes were found. Splitting the sample by the third quartile of MMP7 interesting changes in IGFBP3 variations were found. In the group with low levels of MMP7, IGFBP3 increases from 1,859 to 1,959 ng/ml (p=0.043) 48h after treatment initiation; on the contrary, in the group with high levels of MMP7, IGFBP3 decreases from 1,811 to 1,757 ng/ml (p=0.741). We found no association with IGFBP3 and neither response rate, time to progression nor overall survival. This latter analysis was also done only in pts with wild-type KRAS, without any change in the results. Conclusions: In pts with ACRC treated with anti-EGFR therapy, serum levels of IGFBP3 variations depend on basal MMP7 levels. IGFBP3 failed to be a predictive/prognostic factor in our sample although the limited number of KRAS pts analyzed can influence our results. [Table: see text] No significant financial relationships to disclose.