Background: Levels of serum and plasma metalloproteinases, especially type IV collagenases are important factors related to metastasis and invasion in various human cancer. The clinical significance of serum matrix metalloproteinase 2 (MMP-2, 72 kDa type IV collagenase) and plasma matrix metalloproteinase 9 (MMP-9, 92 kDa type IV collagenase) was evaluated as possible tumor markers in gastric cancer.
Materials and methods: The precursor form of MMP-2 (proMMP-2) in serum and the precursor form of MMP-9 (proMMP-9) in plasma were examined prior to surgery on 70 patients with gastric cancer, one-step sandwich immunoassay (EIA) was used and serum carcinoembryonic antigen (CEA) levels were also examined in the same patients. Normal sera and plasma samples obtained from healthy individuals without cancer were used as controls.
Results: ProMMP-2 levels in patients (mean +/- standard deviation) with gastric cancer (602 +/- 200 micrograms/l) were significantly higher than levels (542 +/- 80 micrograms/l) in sera from 70 healthy individuals (P < 0.02). Plasma proMMP-9 levels (119 +/- 232 micrograms/l) in patients with cancer were also significantly higher than those (37 +/- 13 micrograms/l) in plasma (P < 0.004). On the other hand, there was no significant correlation between CEA and proMMP-2 levels, and between CEA and proMMP-9 levels. Neither proMMP-2 levels nor proMMP-9 levels significantly related to clinicopathologic features.
Conclusions: Serum proMMP-2 levels and plasma proMMP-9 levels may serve as tumor markers, independent from known factors and CEA.