Plasma MMP-2 and MMP-7 levels are elevated first month after surgery and may promote growth of residual metastases

BACKGROUND MMP-2 also known as gelatinase A and MMP-7 (matrilysin) are members of the zinc-dependent family of MMPs (Matrix metalloproteinase). MMP-2 and MMP-7 are remodeling enzymes that digest extracellular matrix; MMP-2 is extensively expressed during development and is upregulated at sites of tissue damage, inflammation, and in stromal cells of metastatic tumors. MMP-7 is expressed in the epithelial cells and in a variety of cancers including colon tumors. Plasma MMP-2 and MMP-7 levels were assessed before and after minimally invasive colorectal resection for cancer pathology. AIM To determine plasma MMP-2 and MMP-7 levels before and after minimally invasive colorectal resection for cancer pathology. METHODS Patients enrolled in a plasma bank for whom plasma was available were eligible. Plasma obtained from preoperative (Preop) and postoperative blood samples was used. Only colorectal cancer (CRC) patients who underwent elective minimally invasive cancer resection with preop, post-operative day (POD) 1, 3 and at least 1 late postop sample (POD 7-34) were included. Late samples were bundled into 7 d blocks (POD 7-13, 14-20, etc.) and treated as single time points. Plasma MMP-2 and MMP-7 levels were determined via enzyme-linked immunosorbent assay in duplicate. RESULTS Total 88 minimally invasive CRC resection CRC patients were studied (right colectomy, 37%; sigmoid, 24%; and LAR/AR 18%). Cancer stages were: 1, 31%; 2, 30%; 3, 34%; and 4, 5%. Mean Preop MMP-2 plasma level (ng/mL) was 179.3 ± 40.9 (n = 88). Elevated mean levels were noted on POD1 (214.3 ± 51.2, n = 87, P < 0.001), POD3 (258.0 ± 63.9, n = 80, P < 0.001), POD7-13 (229.9 ± 62.3, n = 65, P < 0.001), POD 14-20 (234.9 ± 47.5, n = 25, P < 0.001), POD 21-27 (237.0 ± 63.5, n = 17, P < 0.001,) and POD 28-34 (255.4 ± 59.7, n = 15, P < 0.001). Mean Preop MMP-7 level was 3.9 ± 1.9 (n = 88). No significant differences were noted on POD 1 or 3, however, significantly elevated levels were noted on POD 7-13 (5.7 ± 2.5, n = 65, P < 0.001), POD 14-20 (5.9 ± 2.5, n = 25, P < 0.001), POD 21-27 (6.1 ± 3.6, n = 17, P = 0.002) and on POD 28-34 (6.8 ± 3.3, n = 15 P < 0.001,) vs preop levels. CONCLUSION MMP-2 levels are elevated for 5 wk and MMP-7 levels elevated for weeks 2-6. The etiology of these changes in unclear, trauma and wound healing likely play a role. These changes may promote residual tumor growth and metastasis.