Serum matrix metalloproteinase-7: a potential biomarker in patients with Lynch Syndrome

The expression of tissue and serum matrix metalloproteinase-7 (MMP-7) was shown to be elevated both in colon cancer and dysplastic lesions. We aimed to evaluate, for the first time, its role as a diagnostic marker in Lynch syndrome (LS) carriers, a hereditary syndrome with predisposition to colon cancer.

This was a case control study. Baseline serum MMP-7 levels were determined by ELISA in 40 colon cancer patients, 62 LS-carriers and 60 healthy controls. Retrieved data from medical files included demographics, background diseases, clinical data regarding tumor characteristics and genetic data. We assessed the association of serum MMP-7 levels with different variables in the study cohort using linear regression model adjusted for potential confounders.

In crude analysis, serum MMP-7 levels were significantly higher in colon cancer group compared to LS-carriers and controls [median (IQR) 4.1 ng/ml (2.7-6.0), 2.3 ng/ml (1.7-3.1), 2.5 ng/ml (1.5-3.7), respectively; p value - p < 0.001) while there was no difference between the two last groups (p value = 0.583). However, after adjusting for age and gender, LS-carriers' patients had 18% higher concentrations of serum MMP-7 compared to healthy controls (p value = 0.037), while colon cancer patients had 50% higher serum MMP-7 level in comparison to healthy controls (p value < 0.001). Additionally, age was positively associated with higher serum MMP-7 levels across all study groups (r = 0.67, p value < 0.001). In contrast, no correlation was observed between serum MMP-7 and either tumor staging and gene mutation.

Age-adjusted serum MMP-7 levels in asymptomatic LS carriers are higher than its levels in healthy population. While in colon cancer, MMP-7 higher level probably reflects the tumor burden and may have a prognostic effect, its significance and clinical applicability as a biomarker for tumorigenesis in LS is less clear and should be elucidated.