Extracellular Matrix (Ecm) Protein Fragments In Serum And Outcomes In Two Metastatic Breast Cancer Cohorts.

1085Background: Extracellular matrix (ECM) is the non-cellular component of all tissues. Increased ECM formation and matrix metallo-protease (MMP) mediated ECM degradation are parts of tumorgenesis. The altered ECM remodeling generates specific ECM fragments that are released into the circulation. We evaluated the association of specific ECM/collagen fragments measured in serum with outcomes in two independent metastatic breast cancer (MBC) cohorts. Methods: C1M (MMP-degraded type I collagen), C3M (MMP-degraded type III collagen), C4M (MMP-degraded type IV collagen), and PRO-C3 (pro-peptide reflecting truetype III collagen formation) were measured by ELISA in pre-treatment serum from a phase III randomized clinical trial of 2nd-line hormone therapy (HR+, n= 153), and a 1st-line trastuzumab-treated cohort (HER2+, n=64). In both cohorts, all sites of metastases were included. The collagen-fragments were evaluated on continuous and categorical (75th percentile cut-off) bases by univariate Cox-regression anal...